View MAX34440_5067709.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-5527; Rev 0; 9/10
PMBus 6-Channel Power-Supply Manager
General Description
The MAX34440 is a complex system monitor that can manage up to six power supplies. The power-supply manager monitors the power-supply output voltage and constantly checks for user-programmable overvoltage and undervoltage thresholds. It can also margin the power-supply output voltage up or down to a userprogrammable level. The margining is performed in a closed-loop arrangement whereby the device automatically adjusts a pulse-width-modulated (PWM) output and then measures the resultant output voltage. The powersupply manager can also sequence the supplies in any order at both power-up and power-down. With the addition of an external current-sense amplifier, the device can also monitor currents.
Features
S 6 Channels of Power-Supply Management Voltage Measurement/Monitoring Differential 12-Bit 1% Accurate ADC Min/Max Threshold Excursion Detection Supports Current Monitoring with External Current-Sense Amplifier Automatic Closed-Loop Margining Programmable Up and Down Sequencing Power-Good Output S Supports Up to Eight Temperature Sensors Two Remote Diode Temperature Sensors Five Local Temperature Sensors One Internal Temperature Sensor Fault Detection on All Temp Sensors S PMBusTM-Compliant Command Interface S I2C/SMBusTM-Compatible Serial Bus with Bus Timeout Function S On-Board Nonvolatile Fault Logging and Default Configuration Setting S No External Clocking Required S +3.3V Supply Voltage
MAX34440
Applications
Network Switches/Routers Base Stations Servers Smart Grid Network Systems Industrial Controls
Ordering Information
PART MAX34440ETL+ MAX34440ETL+T TEMP RANGE -40NC to +85NC -40NC to +85NC PIN-PACKAGE 40 TQFN-EP* 40 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad.
PMBus is a trademark of SMIF, Inc. SMBus is a trademark of Intel Corp.
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, go to: www.maxim-ic.com/errata.
_______________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
PMBus 6-Channel Power-Supply Manager MAX34440
TABLE OF CONTENTS
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 I2C/SMBus Interface Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 I2C/SMBus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Multiple Device Connection Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Address Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SMBus/PMBus Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SMBus/PMBus Communication Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Group Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Group Command Write Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ALERT and Alert Response Address (ARA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Alert Response Address (ARA) Byte Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends or Reads Too Few Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends or Reads Too Few Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends Too Many Bytes or Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Reads Too Many Bytes or Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Sends Improperly Set Read Bit in the Slave Address Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Unsupported Command Code Received . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Invalid Data Received . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Host Reads from a Write-Only Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Host Writes to a Read-Only Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 SMBus Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PMBus Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PMBus Protocol Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Interpreting Received DIRECT Format Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Sending a DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Fault Management and Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 System Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Temperature Sensor Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2
PMBus 6-Channel Power-Supply Manager MAX34440
TABLE OF CONTENTS (continued)
PMBus Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 PAGE (00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 OPERATION (01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 ON_OFF_CONFIG (02h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 CLEAR_FAULTS (03h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 WRITE_PROTECT (10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 STORE_DEFAULT_ALL (11h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 RESTORE_DEFAULT_ALL (12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 CAPABILITY (19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 VOUT_MODE (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 VOUT_MARGIN_HIGH (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 VOUT_MARGIN_LOW (26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 VOUT_SCALE_MONITOR (2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 IOUT_CAL_GAIN (38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 VOUT_OV_FAULT_LIMIT (40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 VOUT_OV_WARN_LIMIT (42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 VOUT_UV_WARN_LIMIT (43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 VOUT_UV_FAULT_LIMIT (44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 IOUT_OC_WARN_LIMIT (46h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 IOUT_OC_FAULT_LIMIT (4Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 OT_FAULT_LIMIT (4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 OT_WARN_LIMIT (51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 POWER_GOOD_ON (5Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 POWER_GOOD_OFF (5Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 TON_DELAY (60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 TON_MAX_FAULT_LIMIT (62h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 TOFF_DELAY (64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 STATUS_BYTE (78h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 STATUS_WORD (79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 STATUS_VOUT (7Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 STATUS_CML (7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 STATUS_MFR_SPECIFIC (80h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 READ_VOUT (8Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 READ_IOUT (8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 READ_TEMPERATURE_1 (8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 PMBUS_REVISION (98h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_ID (99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3
PMBus 6-Channel Power-Supply Manager MAX34440
TABLE OF CONTENTS (continued)
MFR_MODEL (9Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_REVISION (9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_LOCATION (9Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_DATE (9Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_SERIAL (9Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 MFR_MODE (D1h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 MFR_VOUT_PEAK (D4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 MFR_IOUT_PEAK (D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 MFR_TEMPERATURE_PEAK (D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 MFR_VOUT_MIN (D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 MFR_FAULT_RESPONSE (D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 MFR_FAULT_RETRY (DAh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 MFR_NV_FAULT_LOG (DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 MFR_TIME_COUNT (DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 MFR_MARGIN_CONFIG (E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 MFR_TEMP_SENSOR_CONFIG (F0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Applications Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Power-Supply Decoupling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Open-Drain Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Typical Operating Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Package Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4
PMBus 6-Channel Power-Supply Manager MAX34440
LIST OF FIGURES
Figure 1. Power-Supply Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Figure 2. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
LIST OF TABLES
Table 1. PMBus Command Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Table 2. PMBus/SMBus Serial-Port Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 3. PMBus Command Code Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Table 4. Coefficients for DIRECT Format Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Table 5. Device Parametric Monitoring States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Table 6. DS75LV Address Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Table 7. Page Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 8. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Table 9. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Table 10. ON_OFF_CONFIG (02h) Command Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 11. WRITE_PROTECT Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 12. CAPABILITY Command Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Table 13. VOUT_SCALE_MONITOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 14. IOUT_OC_FAULT_LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Table 15. TON_MAX_FAULT_LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Table 16. STATUS_BYTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Table 17. STATUS_WORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Table 18. STATUS_VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Table 19. STATUS_CML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Table 20. STATUS_MFR_SPECIFIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Table 21. MFR_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Table 22. MFR_FAULT_RESPONSE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Table 23. MFR_FAULT_RESPONSE Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Table 24. MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Table 25. MFR_MARGIN_CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Table 26. MFR_TEMP_SENSOR_CONFIG. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5
PMBus 6-Channel Power-Supply Manager MAX34440
ABSOLUTE MAXIMUM RATINGS
VDD to VSS ...........................................................-0.3V to +5.5V RS- to VSS ............................................................-0.3V to +0.3V All Other Pins Except REG18 and REG25 Relative to VSS ........................ -0.3V to (VDD + 0.3V)* Continuous Power Dissipation (TA = +70NC) 40-Pin TQFN (derate 35.7mW/NC above +70NC) .........................2857.1mW *Subject to not exceeding +5.5V.
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Operating Temperature Range .......................... -40NC to +85NC Storage Temperature Range............................ -55NC to +125NC Lead Temperature (soldering, 10s) ................................+260NC Soldering Temperature (reflow) ......................................+260NC
RECOMMENDED OPERATING CONDITIONS
(TA = -40NC to +85NC.) PARAMETER VDD Operating Voltage Range Input Logic 1 Input Logic 0 Input Logic-High: SCL, SDA, MSCL, MSDA Input Logic-Low: SCL, SDA, MSCL, MSDA SYMBOL VDD VIH VIL VI2C_IH VI2C_IL 2.7V P VDD P 3.6V (Note 1) 2.7V P VDD P 3.6V (Note 1) (Note 1) CONDITIONS MIN 2.7 0.7 x VDD -0.3 2.1 -0.3 TYP MAX 5.5 VDD + 0.3 0.3 x VDD VDD + 0.3 +0.8 UNITS V V V V V
DC ELECTRICAL CHARACTERISTICS
(VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER Supply Current Brownout Voltage Brownout Hysteresis Internal System Clock System Clock Error (Note 3) Output Logic-Low Output Logic-High PWM, PSEN Pullup Current ADC Internal Reference ADC Voltage Measurement Error ADC Internal Reference Temperature Drift 6 VERR -1 -0.5 SYMBOL ICPU IPROGRAM VBO VBOH fMOSC fERR:MOSC VOL1 VOH1 IPU +25NC P TA P +85NC -40NC P TA P +25NC IOL = 4mA (Note 1) IOH = -2mA (Note 1) VPIN = VSS, VDD = 3.3V -3 -6.5 VDD 0.5 38 55 1.225 +1 +0.5 107 Monitors VDD (Note 1) Monitors VDD (Note 1) 2.40 (Note 2) CONDITIONS MIN TYP 2.5 8 2.46 30 4.0 +2 +1.6 0.4 2.55 MAX UNITS mA V mV MHz % V V FA V % %
PMBus 6-Channel Power-Supply Manager
DC ELECTRICAL CHARACTERISTICS (continued)
(VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER ADC Internal Reference Initial Accuracy (+25NC) ADC Full-Scale Input Voltage ADC Measurement Resolution ADC Bit Resolution RS+ Input Resistance ADC Integral Nonlinearity ADC Differential Nonlinearity ADC Offset Internal Temperature Measurement Error Store Default All Time Nonvolatile Log Write Time Nonvolatile Log Delete Time Flash Endurance Data Retention Voltage Sample Rate Current Sample Rate Temperature Sample Rate Device Startup Time PWM Frequency PWM Resolution Measurement from POR until monitoring begins Power supply Power supply NFLASH TA = +50NC TA = +50NC 20,000 100 5 200 1000 12 62.5 6 RIN INL DNL VOFFSET TA = -40NC to +85NC -3 37 12 200 Q2 +3 VFS VLSB 12 15 Q4 Q1 SYMBOL CONDITIONS MIN -1 1.213 1.225 300 TYP MAX +1 1.237 UNITS mV V FV Bits MI LSB LSB LSB NC ms ms ms Write Cycles Years ms ms ms ms kHz Bits
MAX34440
7
PMBus 6-Channel Power-Supply Manager MAX34440
I2C/SMBus INTERFACE ELECTRICAL SPECIFICATIONS
(VDD = 2.7V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 3.3V, TA = +25NC, unless otherwise noted.) PARAMETER SCL Clock Frequency Bus Free Time Between STOP and START Conditions Hold Time (Repeated) START Condition Low Period of SCL High Period of SCL Data Hold Time Data Setup Time START Setup Time SDA and SCL Rise Time SDA and SCL Fall Time STOP Setup Time Clock Low Timeout SYMBOL fSCL tBUF tHD:STA tLOW tHIGH tHD:DAT tSU:DAT tSU:STA tR tF tSU:STO tTO 4.0 25 35 Receive Transmit CONDITIONS MIN 10 4.7 4.0 4.7 4.0 0 300 100 4.7 300 300 TYP MAX 100 UNITS kHz Fs Fs Fs Fs ns ns Fs ns ns Fs ms
Note 1: All voltages are referenced to ground (VSS). Currents entering the IC are specified as positive, and currents exiting the IC are negative. Note 2: This does not include pin input/output currents. Note 3: Guaranteed by design.
I2C/SMBus Timing
SDA tBUF tLOW SCL tHIGH tHD:DAT STOP START tSU:DAT REPEATED START tF tHD:STA tSP
tHD:STA
tR
tSU:STA
tSU:STO
NOTE: TIMING IS REFERENCED TO VIL(MAX) AND VIH(MIN).
8
PMBus 6-Channel Power-Supply Manager
Typical Operating Characteristics
(TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
MAX34440 toc01
MAX34440
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX34440 toc02
2.6 2.5 2.4 IDD (mA)
2.6 2.5 2.4 IDD (mA) 2.3
2.3
VDD = 3.3V
2.2 2.1 2.0 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
TA = +25C
2.2 2.1 2.0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 VDD (V)
WEAK PULLUP VOLTAGE vs. TIME AT POR (UNLOADED PINS, VDD = 3.3V)
MAX34440 toc03
IDD vs. TIME DURING A NONVOLATILE LOG WRITE (TA = +25C, VDD = 3.3V)
MAX34440 toc04
0V 0V 1V/div
C1 = PSEN0 C3 = PWM0
1mA/div
C2 = VDD
0V 1ms/div
0A 2ms/div
FILTERED MARGINING VOLTAGE vs. TIME DURING MARGIN UP
MAX34440 toc05
200mV/div
0V
100ms/div
9
PMBus 6-Channel Power-Supply Manager MAX34440
Pin Configuration
PSEN0 PSEN1 PSEN2 PSEN3 REG25 PWM1 VSS 20 PWM3 19 PSEN4 18 PWM4 17 PSEN5
MAX34440
TOP VIEW
SDA 31 SCL 32 A0/MUXSEL 33 FAULT 34 CONTROL 35 VSS 36 A1/PG 37 ALERT 38 RS-5 39 RS+5 40
30 29 28 27 26 25 24 23 22 21
REG18
PWM0
PWM2
16 PWM5 15 MSCL 14 MSDA
+
EP
13 RST 12 RS-2 11 RS+2
1 RS-4
2 VSS
3 RS+4
4 RS-3
5 RS+3
6 RS+0
7 RS-0
8 RS+1
9 VDD
10 RS-1
TQFN (6mm x 6mm x 0.75mm)
Pin Description
PIN 1 2, 21, 36 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 NAME RS-4 VSS RS+4 RS-3 RS+3 RS+0 RS-0 RS+1 VDD RS-1 RS+2 RS-2 RST MSDA MSCL PWM5 PSEN5 Digital-Supply Return Node (Ground) Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-4 Ground Reference for ADC3 Voltage Measurement Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-3 Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-0 Ground Reference for ADC0 Voltage Measurement Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-1 Supply Voltage. Bypass VDD to VSS with a 0.1FF capacitor. Ground Reference for ADC1 Voltage Measurement Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-2 Ground Reference for ADC2 Voltage Measurement Reset Active-Low Input Master I2C Data Input/Output. Open-drain output. Master I2C Clock Output. Open-drain output. PWM Margin Output #5. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. Power-Supply Enable Output #5. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. FUNCTION Ground Reference for ADC4 Voltage Measurement
10
PMBus 6-Channel Power-Supply Manager
Pin Description (continued)
PIN 18 19 20 22 23 24 25 26 27 28 29 30 31 32 NAME PWM4 PSEN4 PWM3 REG18 PSEN3 PWM2 PSEN2 PWM1 PSEN1 PWM0 REG25 PSEN0 SDA SCL FUNCTION PWM Margin Output #4. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. Power-Supply Enable Output #4. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. PWM Margin Output #3. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. Regulator for Low-Voltage Digital Circuitry. Bypass REG18 to VSS with 1FF and 10nF capacitors. Do not connect other circuitry to this pin. Power-Supply Enable Output #3. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. PWM Margin Output #2. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. Power-Supply Enable Output #2. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. PWM Margin Output #1. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. Power-Supply Enable Output #1. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. PWM Margin Output #0. High impedance when the margining is disabled. A 100% duty cycle implies this pin is continuously high. Regulator for Analog Circuitry. Bypass REG25 to VSS with 1FF and 10nF capacitors. Do not connect other circuitry to this pin. Power-Supply Enable Output #0. Programmable through MFR_MODE for either active high or active low and either open drain or CMOS push-pull. I2C/SMBus-Compatible Input/Output I2C/SMBus-Compatible Clock Input
MAX34440
33
SMBus Address 0 Input/Multiplexer Control Output. This dual-function pin is sampled on device power-up to determine the SMBus address; connect a 100kI resistor from this pin to either VSS or A0/MUXSEL VDD to set the address. After device power-up, this pin becomes an output that acts as voltage/ current selector for an external analog multiplexer. MUXSEL is low for voltage measurements and high for current measurements. Active-Low, Open-Drain Fault Input/Output. This pin is asserted when one or more of the power supplies in a global group are shut down due to a fault condition. Also, this pin is monitored and, when it is asserted, all power supplies in a global group are shut down. This pin is used to provide hardware control for power supplies in a global group across multiple devices. This output is unconditionally deasserted when RST is asserted or the device is power cycled. This pin has a 50Fs deglitch filter. Device Enable. Option through ON_OFF_CONFIG for active-low or active-high power-supply control. This pin has a 50Fs deglitch filter. SMBus Address 1 Input/Power-Good Output. This dual-function pin is sampled on device power-up to determine the SMBus address; connect a 100kI resistor from this pin to either VSS or VDD to set the address. After device power-up, this pin becomes an output that transitions high when all the enabled power supplies are above their associated POWER_GOOD_ON thresholds. Active-Low, Open-Drain Alert Output
34
FAULT
35
CONTROL
37
A1/PG
38
ALERT
11
PMBus 6-Channel Power-Supply Manager MAX34440
Pin Description (continued)
PIN 39 40 -- NAME RS-5 RS+5 EP FUNCTION Ground Reference for ADC5 Voltage Measurement Power-Supply ADC Voltage-Sense Input, Measurement Relative to RS-5 Exposed Pad (Bottom Side of Package). Connect EP to VSS.
Note: All pins except VDD, VSS, REG18, REG25, ADC, and the EP are high impedance with a 50A pullup during device power-up and reset. After device reset, the weak pullup is removed, and the pin is configured as input or output.
Block Diagram
VDD VSS REG25 VSS REG18 VSS
POWER CONTROL 2.5V VREG 1.8V VREG
PULSEWIDTH MODULATOR
PWM0 PWM1 PWM2 PWM3 PWM4 PWM5 PSEN0
4MHz OSCILLATOR MSDA MSCL SDA SCL RST ALERT FAULT CONTROL A0/MUXSEL A1/PG SMBus MASTER INTERFACE SMBus SLAVE INTERFACE 16-BIT MAXQ RISC CORE
POWERSUPPLY OUTPUT ENABLES
PSEN1 PSEN2 PSEN3 PSEN4 PSEN5
ADC SYSTEM CONTROL SIGNALS
MAX34440
RAM
FLASH
TEMP SENSOR
RS+0 RS-0 RS+1 RS-1 RS+2 RS-2 RS+3 RS-3 RS+4 RS-4 RS+5 RS-5
12
MUX
PMBus 6-Channel Power-Supply Manager
Multiple Device Connection Diagram
MAX34440
+3.3V
ALERT HOST INTERFACE CLOCK DATA CONTROL RST SDA SCL RST ALERT FAULT CONTROL A1/PG A0/MUXSEL +3.3V
MAX34440 #0
SDA SCL RST ALERT FAULT CONTROL A1/PG A0/MUXSEL
MAX34440 #1
ADDITIONAL DEVICES
13
PMBus 6-Channel Power-Supply Manager MAX34440
Detailed Description
The MAX34440 is a highly integrated system monitor based upon a 16-bit MAXQM microcontroller with factory-programmed functionality to monitor up to six power supplies. The device provides power-supply closed-loop control, and local/remote thermal-sensing facilities. The power-supply manager monitors the power-supply output voltage and constantly checks for user-programmable overvoltage and undervoltage thresholds. It also can margin the power-supply output voltage up or down by a user-programmable level. The margining is performed in a closed-loop arrangement, whereby the device automatically adjusts a pulse-width-modulated (PWM) output and then measures the resultant output voltage. The power-supply manager can also sequence the supplies in any order at both power-up and powerdown. With the addition of an external current-sense amplifier, the device can also monitor currents. Thermal monitoring can be accomplished using up to eight temperature sensors, including an on-chip thermal sensor, four DS75LV digital thermometers, and a MAX6695 dual remote/local thermal temperature sensor. Communication with the DS75LV and MAX6695 temperature sensors is conducted through a dedicated I2C/ SMBus interface. The device provides ALERT and FAULT output signals. Host communications are conducted through a PMBuscompatible communications port. Address input connections are also provided to allow up to four MAX34440 devices to reside on the system's I/O bus.
Table 1. PMBus Command Codes
CODE 00h 01h 02h 03h 10h 11h 12h 19h 20h 25h 26h 2Ah 38h 40h 42h 43h 44h 46h 4Ah 4Fh 51h 5Eh 5Fh PAGE OPERATION ON_OFF_CONFIG CLEAR_FAULTS WRITE_PROTECT STORE_DEFAULT_ALL RESTORE_DEFAULT_ALL CAPABILITY VOUT_MODE VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_SCALE_MONITOR IOUT_CAL_GAIN VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT IOUT_OC_WARN_LIMIT IOUT_OC_FAULT_LIMIT OT_FAULT_LIMIT OT_WARN_LIMIT POWER_GOOD_ON POWER_GOOD_OFF COMMAND NAME TYPE R/W Byte R/W Byte R/W Byte Send Byte R/W Byte Send Byte Send Byte Read Byte Read Byte R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word PAGE 0-5 R/W R/W R/W W R/W W W R R R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W -- -- R/W R/W PAGE 6-13 (NOTE 1) R/W -- R/W W R/W W W R R -- -- -- -- -- -- -- -- -- -- R/W R/W -- -- R/W W R/W W R/W W W R R -- -- -- -- -- -- -- -- -- -- -- -- -- -- PAGE 255 NO. OF BYTES 1 1 1 0 1 0 0 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 FLASH STORED (NOTE 2) N N Y N N N N N FIXED Y Y Y Y Y Y Y Y Y Y Y Y Y Y DEFAULT VALUE (NOTE 2) 00h 00h 1Ah -- 00h -- -- 00h/10h 40h 0000h 0000h 7FFFh 0000h 7FFFh 7FFFh 0000h 0000h 7FFFh 0000h 7FFFh 7FFFh 0000h 0000h
MAXQ is a registered trademark of Maxim Integrated Products, Inc. 14
PMBus 6-Channel Power-Supply Manager
Table 1. PMBus Command Codes (continued)
CODE 60h 62h 64h 78h 79h 7Ah 7Eh 80h 8Bh 8Ch 8Dh 98h 99h 9Ah 9Bh 9Ch 9Dh 9Eh D1h D4h D5h D6h D7h D9h DAh DCh DDh E0h F0h COMMAND NAME TON_DELAY TON_MAX_FAULT_LIMIT TOFF_DELAY STATUS_BYTE STATUS_WORD STATUS_VOUT STATUS_CML STATUS_MFR_SPECIFIC READ_VOUT READ_IOUT READ_TEMPERATURE_1 PMBUS_REVISION MFR_ID MFR_MODEL MFR_REVISION MFR_LOCATION MFR_DATE MFR_SERIAL MFR_MODE MFR_VOUT_PEAK MFR_IOUT_PEAK MFR_TEMPERATURE_PEAK MFR_VOUT_MIN MFR_FAULT_RESPONSE MFR_FAULT_RETRY MFR_NV_FAULT_LOG MFR_TIME_COUNT MFR_MARGIN_CONFIG MFR_TEMP_SENSOR_CONFIG TYPE R/W Word R/W Word R/W Word Read Byte Read Word Read Byte Read Byte Read Byte Read Word Read Word Read Word Read Byte Read Byte Read Byte Read Word Block R/W Block R/W Block R/W R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word Block Read Block Read R/W Word R/W Word PAGE 0-5 R/W R/W R/W R R R R R R R -- R R R R R/W R/W R/W R/W R/W R/W -- R/W R/W R/W R R R/W -- PAGE 6-13 (NOTE 1) -- -- -- R R -- R R -- -- R R R R R R/W R/W R/W R/W -- -- R/W -- -- R/W R R -- R/W -- -- -- R R -- R -- -- -- -- R R R R R/W R/W R/W R/W -- -- -- -- -- R/W R R -- -- PAGE 255 NO. OF BYTES 2 2 2 1 2 1 1 1 2 2 2 1 1 1 2 8 8 8 2 2 2 2 2 2 2 255 4 2 2 FLASH STORED (NOTE 2) Y Y Y N N N N N N N N FIXED FIXED FIXED FIXED Y Y Y Y N N N N Y Y Y N Y Y DEFAULT VALUE (NOTE 2) 0000h 0000h 0000h 00h 0000h 00h 00h 00h 0000h 0000h 0000h 11h 4Dh 51h 3030h (Note 3) (Note 3) (Note 3) 0000h 0000h 0000h 8000h 7FFFh 0000h 0000h (Note 4) (Note 5) 0000h 0000h
MAX34440
Note 1: Common commands are shaded. Access through any page results in the same device response. Note 2: In the Flash Stored column, an "N" indicates that this parameter is not stored in flash memory when the STORE_ DEFAULT_ALL command is executed and the value shown in the Default Value column is automatically loaded upon power-on reset or when the RST pin is asserted. A "Y" in the Flash Stored column indicates that the currently loaded value in this parameter is stored in flash memory when the STORE_DEFAULT_ALL command is executed and is automatically loaded upon power-on reset or when the RST pin is asserted and the value shown in the Default Value column is the value when shipped from the factory. "FIXED" in the Flash Stored column means this value is fixed at the factory and cannot be changed. Note 3: The factory-set default value for this 8-byte block is 3130313031303130h. Note 4: The factory-set default value for the complete block of the MFR_NV_FAULT_LOG is FFh. Note 5: The power-on reset value for this 4-byte block is 00000000h.
15
PMBus 6-Channel Power-Supply Manager MAX34440
Table 2. PMBus/SMBus Serial-Port Address
A1 100kI to VSS 100kI to VDD A0 100kI to VSS 100kI to VDD 100kI to VSS 100kI to VDD 7-BIT SLAVE ADDRESS 1101 010 (D4h) 1101 011 (D6h) 1101 100 (D8h) 1101 101 (DAh)
On device power-up, the device samples the A0 and A1 pins to determine the PMBus/SMBus serial-port address.
Address Select
The device implements the PMBus command structure using the SMBus format. The structure of the data flow between the host and the slave is shown below for several different types of transactions. Data is sent most significant bit (MSB) first. SMBus/PMBus Communication Examples
SMBus/PMBus Operation
READ WORD FORMAT
1 S 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 1 Sr 7 SLAVE ADDRESS 1 R 1 A 8 DATA BYTE LOW 1 A 8 DATA BYTE HIGH 1 NA 1 P
READ BYTE FORMAT
1 S 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 1 Sr 7 SLAVE ADDRESS 1 R 1 A 8 DATA BYTE 1 NA 1 P
WRITE WORD FORMAT
1 S 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 8 DATA BYTE LOW 1 A 8 DATA BYTE HIGH 1 A 1 P
WRITE BYTE FORMAT
1 S 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 8 DATA BYTE 1 A 1 P
SEND BYTE FORMAT
1 S 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 1 P
KEY: S = START Sr = REPEATED START P = STOP W = WRITE BIT (0) R = READ BIT (1) A = ACKNOWLEDGE (0) NA = NOT ACKNOWLEDGE (1) SHADED BLOCK = SLAVE TRANSACTION
16
PMBus 6-Channel Power-Supply Manager
The device supports the group command. With the group command, a host can write different data to multiple devices on the same serial bus with one long
Group Command
continuous data stream. All the devices addressed during this transaction wait for the host to issue a STOP before beginning to respond to the command. Group Command Write Format
MAX34440
SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE 1
1 S 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 8 DATA BYTE LOW 1 A 8 DATA BYTE HIGH 1 A UUU
SLAVE ADDRESS, COMMAND BYTE, AND DATA BYTE FOR DEVICE 2
1 Sr 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 8 DATA BYTE 1 A UUU
KEY: S = START Sr = REPEATED START P = STOP W = WRITE BIT (0) A = ACKNOWLEDGE (0) SHADED BLOCK = SLAVE TRANSACTION
SLAVE ADDRESS AND SEND BYTE FOR DEVICE 3
1 Sr 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A UUU
UUU
SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE N
1 Sr 7 SLAVE ADDRESS 1 W 1 A 8 COMMAND CODE 1 A 8 DATA BYTE LOW 1 A 8 DATA BYTE HIGH 1 A 1 P
The device responds to receiving its fixed slave address by asserting an acknowledge (ACK) on the bus. The device does not respond to a general call address; it only responds when it receives its fixed slave address. The only exception to this operation is if the ALERT output is enabled (ALERT bit = 1 in MFR_MODE) and ALERT has been asserted. When this condition occurs, the device only recognizes the alert response address (0001 100, 18h). See the ALERT and Alert Response Address (ARA) section for more details. If the ALERT output is enabled (ALERT bit = 1 in MFR_MODE), when a fault occurs the device asserts the ALERT signal and then waits for the host to send the alert
Addressing
response address (ARA) as shown in the Alert Response Address (ARA) Byte Format section. While waiting for the ARA, the device does not respond to its fixed slave address. When the ARA is received and the device is asserting ALERT, the device ACKs it and then attempts to place its fixed slave address on the bus by arbitrating the bus, since another device could also try to respond to the ARA. The rules of arbitration state that the lowest address device wins. If the device wins the arbitration, it deasserts ALERT and begins to respond to its fixed slave address. If the device loses arbitration, it keeps ALERT asserted and waits for the host to once again send the ARA.
ALERT and Alert Response Address (ARA)
17
PMBus 6-Channel Power-Supply Manager MAX34440
Alert Response Address (ARA) Byte Format
1 S 7 ARA 0001100 1 R 1 A 8 DEVICE SLAVE ADDRESS WITH LSB = 0 1 NA 1 P
If for any reason the host does not complete writing a full byte or reading a full byte from the device before a START or STOP is received, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). For each supported command, the device expects a fixed number of bytes to be written or read from the device. If for any reason fewer than the expected number of bytes is written to or read from the device, the device completely ignores the command and takes no action. For each supported command, the device expects a fixed number of bytes to be written to the device. If for any reason more than the expected number of bytes or bits is written to the device, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). For each supported command, the device expects a fixed number of bytes to be read from the device. If for any reason more than the expected number of bytes or bits is read from the device, the device does the following: 1) Sends all ones (FFh) as long as the host keeps acknowledging. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled).
18
Host Sends or Reads Too Few Bits
If the device receives the R/W bit in the slave address set to one immediately preceding the command code, the device does the following (note this does not apply to ARA): 1) ACKs the address byte. 2) Sends all ones (FFh) as long as the host keeps acknowledging. 3) Sets the CML bit in STATUS_BYTE. 4) Sets the CML bit in STATUS_WORD. 5) Sets the DATA_FAULT bit in STATUS_CML. 6) Notifies the host through ALERT assertion (if enabled). If the host sends the device a command code that it does not support, or if the host sends a command code that is not supported by the current PAGE setting, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the COMM_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). The device checks the PAGE, OPERATION, and WRITE_PROTECT command codes for valid data. If the host writes a data value that is invalid, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the DATA_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled).
Host Sends Improperly Set Read Bit in the Slave Address Byte
Host Sends or Reads Too Few Bytes
Unsupported Command Code Received
Host Sends Too Many Bytes or Bits
Invalid Data Received
Host Reads Too Many Bytes or Bits
PMBus 6-Channel Power-Supply Manager
When a read request is issued to a write-only command (CLEAR_FAULTS, STORE_DEFAULT_ALL, RESTORE_DEFAULT_ALL), the device does the following: 1) ACKs the address byte. 2) Ignores the command. 3) Sends all ones (FFh) as long as the host keeps acknowledging. 4) Sets the CML bit in STATUS_BYTE. 5) Sets the CML bit in STATUS_WORD. 6) Sets the DATA_FAULT bit in STATUS_CML. 7) Notifies the host through ALERT assertion (if enabled). When a write request is issued to a read-only command, the device does the following: 1) Ignores the command. 2) Sets the CML bit in STATUS_BYTE. 3) Sets the CML bit in STATUS_WORD. 4) Sets the COMM_FAULT bit in STATUS_CML. 5) Notifies the host through ALERT assertion (if enabled). If during an active SMBus communication sequence the SCL signal is held low for greater than the timeout duration (tTO), the device terminates the sequence and resets the serial bus. It takes no other action. No status bits are set. From a software perspective, the device appears as a PMBus device capable of executing a subset of PMBus commands. A PMBus 1.1-compliant device uses the SMBus version 1.1 for transport protocol and responds to the SMBus slave address. In this data sheet, the term SMBus is used to refer to the electrical characteristics of the PMBus communication using the SMBus physical layer. The term PMBus is used to refer to the PMBus command protocol. The device employs a number of standard SMBus protocols to program output voltage and warning/faults thresholds, read monitored data, and provide access to all manufacturer-specific commands. The device supports the group command. The group command is used to send commands to more than one PMBus device. It is not required that all the devices receive the same command. However, no more than one command can be sent to any one device in one group command packet. The group command must not be used with commands that require receiving devices
Host Reads from a Write-Only Command
to respond with data, such as the STATUS_BYTE command. When the device receives a command through this protocol, it immediately begins execution of the received command after detecting the STOP condition. The device supports the PAGE command and uses it to select which individual channel to access. When a data word is transmitted, the lower order byte is sent first and the higher order byte is sent last. Within any byte, the most significant bit (MSB) is sent first and the least significant bit (LSB) is sent last. The device supports a subset of the commands defined in the PMBusTM Power System Management Protocol Specification Part II - Command Language, Revision 1.1. For detailed specifications and the complete list of PMBus commands, refer to Part II of the PMBus specification available at www.PMBus.org. The supported PMBus commands and the corresponding device behavior are described in this document. All data values are represented in DIRECT format, unless otherwise stated. Whenever the PMBus specification refers to the PMBus device, it is referring to the MAX34440 operating in conjunction with a power supply. While the command can call for turning on or turning off the PMBus device, the MAX34440 always remains on to continue communicating with the PMBus master, and the MAX34440 transfers the command to the power supply accordingly. Voltage data for commanding or reading the output voltage or related parameters (such as the overvoltage threshold) is presented in DIRECT format. DIRECT format data is a 2-byte, two's complement binary value. DIRECT format data can be used with any command that sends or reads a parametric value. The DIRECT format uses an equation and defined coefficients to calculate the desired values. Table 3 shows the coefficients used by the device.
MAX34440
PMBus Protocol Support
Host Writes to a Read-Only Command
SMBus Timeout
Data Format
PMBus Operation
The host system uses the following equation to convert the value received from the PMBus device--in this case, the MAX34440--into a reading of volts, degrees Celsius, or other units as appropriate: X = (1/m) x (Y x 10-R - b) where X is the calculated, real world value in the appropriate units (V, NC, etc.); m is the slope coefficient; Y is the 2-byte, two's complement integer received from the PMBus device; b is the offset; and R is the exponent.
19
Interpreting Received DIRECT Format Values
PMBus 6-Channel Power-Supply Manager MAX34440
Table 3. PMBus Command Code Coefficients
PARAMETER COMMANDS VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT POWER_GOOD_ON POWER_GOOD_OFF READ_VOUT MFR_VOUT_PEAK MFR_VOUT_MIN VOUT_SCALE_MONITOR IOUT_OC_WARN_LIMIT IOUT_OC_FAULT_LIMIT READ_IOUT MFR_IOUT_PEAK IOUT_CAL_GAIN OT_FAULT_LIMIT OT_WARN_LIMIT READ_TEMPERATURE_1 MFR_TEMPERATURE_PEAK TON_DELAY TON_MAX_FAULT_LIMIT TOFF_DELAY MFR_FAULT_RETRY UNITS RESOLUTION MAX m b R
Voltage
mV
1
32,767
1
0
0
Voltage Scaling Current Current Scaling Temperature
-- mA mI NC
1/32,767 1 0.1 0.01
1 32,767 3276.7 327.67
32,767 1 1 1
0 0 0 0
0 0 1 2
Timing
ms
1
32,767
1
0
0
To send a value, the host must use the below equation to solve for Y: Y = (mX + b) x 10R
Sending a DIRECT Format Value
If a host wants to set the device to change the powersupply output voltage to 3.465V (or 3465mV), the corresponding VOUT_MARGIN_HIGH value is: Y = (1 x 3465 + 0) x 100 = 3465 (decimal) = 0D89h (hex) Conversely, if the host received a value of 0D89h on a READ_VOUT command, this is equivalent to: X = (1/1) x (0D89h x 10-(-0) - 0) = 3465mV = 3.465V Power supplies and power converters generally have no way of knowing how their outputs are connected to ground. Within the power supply, all output voltages are most commonly treated as positive. Accordingly, all output voltages and output voltage-related parameters of PMBus devices are commanded and reported as positive values. It is up to the system to know that a particular output is negative if that is of interest to the system. All output-voltage-related commands use 2 data bytes.
where Y is the 2-byte, two's complement integer to be sent to the unit; m is the slope coefficient; X is the real world value, in units such as volts, to be converted for transmission; b is the offset; and R is the exponent. The following example demonstrates how the host can send and retrieve values from the device. Table 4 shows the coefficients used in the following parameters.
Table 4. Coefficients for DIRECT Format Value
COMMAND CODE 25h 8Bh COMMAND NAME VOUT_MARGIN_HIGH READ_VOUT m 1 1 b 0 0 R 0 0
20
PMBus 6-Channel Power-Supply Manager
For reporting faults/warnings to the host on a real-time basis, the device asserts the open-drain ALERT pin (if enabled in MFR_MODE) and sets the appropriate bit in the various status registers. On recognition of the ALERT assertion, the host or system manager is expected to poll the I2C bus to determine the device asserting ALERT. The host sends the SMBus ARA (0001 100). The device ACKs the SMBus ARA, transmits its slave address, and deasserts ALERT. The system controller then communicates with PMBus commands to retrieve the fault/warning status information from the device. See the individual command sections for more details. Faults and warnings that are latched in the status registers are cleared when any one of the following conditions occurs: * ACLEAR_FAULTScommandisreceived. * TheRST pin is toggled. * Biaspowertothedeviceisremovedandthenreapplied. One or more latched-off power supplies is only restarted when one of the following occurs: * The output is commanded through the CONTROL pin, the OPERATION command, or the combined action of the CONTROL pin and OPERATION command to turn off and then turn back on. * TheRST pin is toggled. * Biaspowertothedeviceisremovedandthenreapplied. A power supply is not allowed to turn on if any faults the supply responds to are detected. Only after the faults
Fault Management and Reporting
clear is the power supply allowed to turn on. When global supplies are being sequenced on, a fault on any of the supplies keeps all supplies from being turned on. A system-wide power-up (OPERATION command is received to turn the supplies on when PAGE is 255 or the CONTROL pin is toggled to turn on the supplies) allows all enabled power supplies to power-up. If any faults are detected once the supplies start to turn on, the response of MFR_FAULT_RESPONSE is performed. The device responds to fault conditions according to the manufacturer fault response command (MFR_FAULT_RESPONSE). This command byte determines how the device should respond to each particular fault. Table 5 illustrates the required conditions and fault actions for specific parameters. The device uses an internal watchdog timer that is internally reset every 5ms. In the event that the device is locked up and this watchdog reset does not occur after 500ms, the device automatically resets. After the reset occurs, the device reloads all configuration values that were stored to flash and begins normal operation. After the reset, the device also does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the WATCHDOG bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE).
MAX34440
System Watchdog Timer
Table 5. Device Parametric Monitoring States
PARAMETER Overvoltage * * * * * REQUIRED CONDITIONS FOR ACTIVE MONITORING Power Supply Enabled (TON_MAX_FAULT_LIMIT 0000h) Power Supply Enabled (TON_MAX_FAULT_LIMIT 0000h) PSEN Output is Active Channel's VOUT Must Have Exceeded VOUT_UV_FAULT During Channel Power-Up Power Supply Enabled (TON_MAX_FAULT_LIMIT 0000h) Current Monitoring Enabled (IOUT_OC_FAULT_LIMIT 0000h) ACTION DURING A FAULT Continue Monitoring Stop Monitoring While the Power Supply is Off
Undervoltage
Overcurrent Power-Up Time Overtemperature
Continue Monitoring Monitor Only During Power-On Continue Monitoring
Power Supply Enabled (TON_MAX_FAULT_LIMIT 0000h) Temp Sensor Enabled (ENABLE in MFR_TEMP_SENSOR_CONFIG = 1)
21
PMBus 6-Channel Power-Supply Manager MAX34440
The device can monitor up to eight different temperature sensors, seven external sensors plus its own internal temperature sensor. The external temperature sensors are all connected in parallel to the master I2C port (MSDA and MSCL pins). The device can support up to four DS75LV devices plus one MAX6695 device. Each of the enabled temperature sensors is measured once a second. The internal temperature sensor is averaged four times to reduce the affect of noise. Each time the device attempts to read a temperature sensor it checks for faults. For the remote diode, a fault is defined as either an open or short across the diode. For the internal temperature sensor, a fault is defined as reading greater than +130NC or less than -60NC. For the I2C temperature sensors, a fault is defined as a communication access failure. Temperature sensor faults are reported by setting the temperature reading to 7FFFh. A temperature sensor fault results in the setting of the TEMPERATURE
Temperature Sensor Operation
bit in STATUS_BYTE and STATUS_WORD and ALERT is asserted (if enabled in MFR_MODE). No bits are set in STATUS_MFR_SPECIFIC. Reading disabled temperature sensors returns a fixed value of 0000h. The device can control up to four DS75LV digital temperature sensors. The A0, A1, and A2 pins on the DS75LV should be configured as shown in Table 6. The thermostat function on the DS75LV is not used and thus the O.S. output should be left open circuit. The device can control one MAX6695, which consists of one local temperature sensor and two remote diode temperature sensors. Each of the temperature sensors can be reinitialized by disabling and re-enabling the sensor through MFR_TEMP_SENSOR_CONFIG. The valid range for the MAX6695 temperature sensor is -40C to +125C. The page assignment is shown in Table 6. The ALERT, OT1, and OT2 pins on the MAX6695 are not used and should be left open circuit.
Table 6. DS75LV Address Pin Configurations
PAGE 6 7 8 9 10 11 12 13 MAX34440 I2C TEMP SENSOR MAX34440 Internal DS75LV (Address 0) DS75LV (Address 1) DS75LV (Address 2) DS75LV (Address 3) MAX6695 (Local Sensor) MAX6695 (Remote Diode 1) MAX6695 (Remote Diode 2) DS75LV ADDRESS PIN CONFIGURATION A2 -- 0 0 0 0 -- -- -- A1 -- 0 0 1 1 -- -- -- A0 -- 0 1 0 1 -- -- --
22
PMBus 6-Channel Power-Supply Manager
PMBus Commands
A summary of the PMBus commands supported by the device are described in the following sections. The device can control up to six power supplies and up to eight temperature sensors using one PMBus (I2C) address. Send the PAGE command with data 0 to 13 to select which power supply or which temperature sensor is affected by all the PMBus commands shown in Table 1. Not all commands are supported within each page. If an unsupported command is received, the CML status bit is set. Some commands are common, meaning that any selected page has the same effect on and the same response from the device.
MAX34440
PAGE (00h)
Table 7. Page Commands
PAGE (DEC) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 to 254 255 Power Supply Connected to ADC 0 Power Supply Connected to ADC 1 Power Supply Connected to ADC 2 Power Supply Connected to ADC 3 Power Supply Connected to ADC 4 Power Supply Connected to ADC 5 Internal Temperature Sensor External DS75LV Temperature Sensor with Address 0 External DS75LV Temperature Sensor with Address 1 External DS75LV Temperature Sensor with Address 2 External DS75LV Temperature Sensor with Address 3 External MAX6695 Local Temperature Sensor External MAX6695 Remote Diode 1 Temperature Sensor External MAX6695 Remote Diode 2 Temperature Sensor Reserved Applies to All Pages ASSOCIATED CONTROL
23
PMBus 6-Channel Power-Supply Manager MAX34440
The OPERATION command is used to turn the power supply on and off in conjunction with the CONTROL input pin. The OPERATION command is also used to cause the power supply to set the output voltage to the upper or lower margin voltages. The power supply stays in the commanded operating mode until a subsequent OPERATION command or until a change in the state of the CONTROL pin (if enabled) instructs the power supply to change to another state. The valid OPERATION command byte values are shown in Tables 8 and 9. The OPERATION command controls how the device responds when commanded to change the output. When the command byte is 00h, the device immediately turns the power supply off and ignores any programmed turn-off delay. When the command byte is set to 40h, the device powers down according to the programmed turn-off delay. In Tables 8 and 9, "act on any fault" means that if any warning or fault on the selected power supply is detected when the output is margined, the device treats this as a warning or fault and responds as programmed. "Ignore all faults" means that overvoltage, overcurrent, and undervoltage warnings and faults on the selected power supply are ignored and not reported. Any command value not shown in Tables 8 and 9 is an invalid command. If the device receives a data byte that is not listed in Tables 8 and 9, then it treats this as invalid data, declares a data fault (set CML bit and assert ALERT), and responds as described in the Fault Management and Reporting section. USER NOTE: All power supplies tagged as GLOBAL supplies (see MFR_FAULT_RESPONSE) should be turned on and off at the same time.
OPERATION (01h)
Table 8. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 1)
COMMAND BYTE 00h 40h 80h 94h 98h A4h A8h POWER SUPPLY ON OR OFF Immediate Off (No Sequencing) Soft Off (with Sequencing) On On On On On MARGIN STATE N/A N/A Margin Off Margin Low (Ignore All Faults) Margin Low (Act On Any Fault) Margin High (Ignore All Faults) Margin High (Act On Any Fault)
Note: The VOUT of all enabled channels must exceed POWER_GOOD_ON for margining to begin.
Table 9. OPERATION Command Byte (When Bit 3 of ON_OFF_CONFIG = 0)
COMMAND BYTE 00h 40h 80h 94h 98h A4h A8h POWER SUPPLY ON OR OFF Command Has No Effect Command Has No Effect Command Has No Effect Command Has No Effect Command Has No Effect Command Has No Effect Command Has No Effect MARGIN STATE N/A N/A Margin Off Margin Low (Ignore All Faults) Margin Low (Act On Any Fault) Margin High (Ignore All Faults) Margin High (Act On Any Fault)
Note: The device only takes action if the supply is enabled. The VOUT of all enabled channels must exceed POWER_GOOD_ON for margining to begin.
24
PMBus 6-Channel Power-Supply Manager
The ON_OFF_CONFIG command configures the combination of CONTROL input and PMBus OPERATION commands needed to turn the power supply on and off. This indicates how the power supply is commanded when power is applied. Table 10 describes the ON_OFF_CONFIG message content. The host should not modify ON_OFF_CONFIG while the power supplies are active.
ON_OFF_CONFIG (02h)
MAX34440
Table 10. ON_OFF_CONFIG (02h) Command Byte
BIT 7:5 Reserved Turn on supplies when bias is present or use the CONTROL pin and/or OPERATION command OPERATION Command Enable CONTROL Pin Enable CONTROL Pin Polarity CONTROL Pin Turn-Off Action PURPOSE BIT VALUE N/A 0 1 0 1 0 1 0 1 0 1 Always returns 000. Turn on the supplies (with sequencing, if so configured) as soon as bias is supplied to the device regardless of the CONTROL pin. Operate the supplies as instructed by the CONTROL pin and/or the OPERATION command. Ignore the on/off portion of the OPERATION command. OPERATION command enabled and required for action. Ignore the CONTROL pin. CONTROL pin enabled and required for action. Active low (drive low to turn on the power supplies). Active high (drive high to turn on the power supplies). Use the programmed turn-off delay (soft off). Turn off the power supplies immediately. MEANING
4
3 2 1 0
The CLEAR_FAULTS command is used to clear any fault or warning bits in the status registers that have been set. This command clears all bits simultaneously. The CLEAR_FAULTS command does not cause a power supply that has latched off for a fault condition to restart. The status of PSEN under fault conditions is not affected by this command and changes only if commanded through the OPERATION command or CONTROL pin. If a fault is still present after the CLEAR_FAULTS command is executed, the fault status bit is set again and the host is also notified by asserting ALERT (if enabled in MFR_MODE). This command is write-only. There is no data byte for this command. The WRITE_PROTECT command is used to provide protection against accidental changes to the device operating memory. All supported commands can have their parameters read, regardless of the WRITE_PROTECT settings. The WRITE_PROTECT message content is described in Table 11.
CLEAR_FAULTS (03h)
WRITE_PROTECT (10h)
Table 11. WRITE_PROTECT Command Byte
COMMAND BYTE 80h 40h 20h 00h MEANING Disable all writes except the WRITE_PROTECT command. Disable all writes except the WRITE_PROTECT, OPERATION, and PAGE commands. Disable all writes except the WRITE_PROTECT, OPERATION, PAGE, and ON_OFF_CONFIG commands. Enable writes for all commands (default).
Note: No fault or error is generated if the host attempts to write to a protected area.
25
PMBus 6-Channel Power-Supply Manager MAX34440
The STORE_DEFAULT_ALL command instructs the device to transfer the device configuration information to the internal flash memory array. Not all information is stored. Only configuration data is stored, not any status, or operational data. If an error occurs during the transfer, ALERT asserts if enabled and the CML bit in STATUS_BYTE and STATUS_WORD is set to 1. No bits are set in STATUS_CML. It is NOT recommended to use the STORE_DEFAULT_ALL command while the device is operating power supplies. The device is unresponsive to PMBus commands and does not monitor power supplies while transferring the configuration. This command is write-only. There is no data byte for this command. USER NOTE: VDD must be above 2.9V for the device to perform the STORE_DEFAULT_ALL command. The RESTORE_DEFAULT_ALL command transfers the default configuration information from the internal flash memory array to the user memory registers in the device. The RESTORE_DEFAULT_ALL command should only be executed when the device is not operating the power supplies. Upon a device reset, this command is automatically executed by the device without PMBus action required. This command is write-only. There is no data byte for this command. The CAPABILITY command is used to determine some key capabilities of the device. The CAPABILITY command is read-only. The message content is described in the Table 12.
STORE_DEFAULT_ALL (11h)
RESTORE_DEFAULT_ALL (12h)
CAPABILITY (19h)
Table 12. CAPABILITY Command Byte
BIT 7 6:5 4 3:0 DESCRIPTION Packet-Error Checking PMBus Speed ALERT Reserved 0 = PEC not supported. 00 = Maximum supported bus speed is 100kHz. 1 = Device supports an ALERT output (if ALERT is enabled in MFR_MODE). 0 = Device does not support ALERT output (ALERT is disabled in MFR_MODE). Always returns 0000. MEANING
The VOUT_MODE command is used to report the data format of the device. The device uses the DIRECT format for all the voltage-related commands. The value returned is 40h, indicating DIRECT data format. This command is read-only. If a host attempts to write this command, the CML status bit is asserted. See Table 3 for the m, b, and R values for the various commands.
VOUT_MODE (20h)
The VOUT_MARGIN_HIGH command loads the device with the voltage to which the power-supply output is to be changed when the OPERATION command is set to margin high. If the power supply is already operating at margin high, changing VOUT_MARGIN_HIGH has no effect on the output voltage. The device only adjusts the power supply to the new VOUT_MARGIN_HIGH voltage after receiving a new margin high OPERATION command. The 2 data bytes are in DIRECT format. If the device cannot successfully close-loop margin the power supply, the device keeps attempting to margin the supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE).
VOUT_MARGIN_HIGH (25h)
26
PMBus 6-Channel Power-Supply Manager
The VOUT_MARGIN_LOW command loads the device with the voltage to which the power-supply output is to be changed when the OPERATION command is set to margin low. If the power supply is already operating at margin low, changing VOUT_MARGIN_LOW has no effect on the output voltage. The device only adjusts the power supply to the new VOUT_MARGIN_LOW voltage after receiving a new margin low OPERATION command. The 2 data bytes are in DIRECT format. If the device cannot successfully close-loop margin the power supply, the device keeps attempting to margin the supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). VOUT_SCALE_MONITOR is used in applications where the measured power-supply voltage is not equal to the voltage at the ADC input. For example, if the ADC input expects a 1.0V input for a 12V output, VOUT_SCALE_MONITOR = 1.0V/12V = 0.0833. In applications where the power-supply output voltage is greater than the device input range, the output voltage of the power supply is sensed through a resistive voltage-divider. The resistive voltage-divider reduces or scales the output voltage. The PMBus commands specify the actual power-supply output voltages and not the input voltage to the ADC. To allow the device to map between the power-supply voltage (such as 12V) and the voltage at the ADC input, the VOUT_SCALE_MONITOR command is used. The 2 data bytes are in DIRECT format. This value is dimensionless. For example, if the required scaling factor is 0.0833, then VOUT_SCALE_MONITOR should be set to 0AABh (2731/32,767 = 0.0833).
VOUT_MARGIN_LOW (26h)
MAX34440
VOUT_SCALE_MONITOR (2Ah)
Table 13. VOUT_SCALE_MONITOR
NOMINAL VOLTAGE LEVEL MONITORED (V) 1.2 1.5 1.8 2.5 3.3 5 12 NOMINAL ADC INPUT VOLTAGE LEVEL (V) (SEE NOTE) 1.0 1.0 1.0 1.0 1.0 1.0 1.0 RESISTIVE VOLTAGEDIVIDER RATIO 0.833 0.667 0.555 0.4 0.303 0.2 0.0833 VOUT_SCALE_MONITOR VALUE (HEX) 6AAAh 5555h 470Ah 3333h 26C8h 1999h 0AABh
Note: On the device, the full-scale ADC voltage is 1.225V. A scaling factor where a 1.0V ADC input represents a nominal 100% voltage level is recommended.
The IOUT_CAL_GAIN command is used to set the ratio of the voltage at the ADC input to the sensed current. The units of the IOUT_CAL_GAIN factor are 0.1mI. The 2 data bytes are in DIRECT format. For example, if a 10mI sense resistor is used with a 50V/V current-sense amplifier, the IOUT_CAL_GAIN should be set to 500mI or 1388h. USER NOTE: On the device, the full-scale ADC voltage is 1.225V. The value of the sense resistor and currentsense amplifier gain must be scaled appropriately.
IOUT_CAL_GAIN (38h)
27
PMBus 6-Channel Power-Supply Manager MAX34440
The VOUT_OV_FAULT_LIMIT command sets the value of the output voltage that causes an output overvoltage fault. The 2 data bytes are in DIRECT format. In response to the VOUT_OV_FAULT_LIMIT being exceeded, the device does the following: 1) Sets the VOUT_OV bit in STATUS_BYTE. 2) Sets the VOUT_OV and VOUT bits in STATUS_WORD. 3) Sets the VOUT_OV_FAULT bit in STATUS_VOUT. 4) Responds as specified in the MFR_FAULT_RESPONSE. 5) Notifies the host through ALERT assertion (if enabled in MFR_MODE). The VOUT_OV_WARN_LIMIT command sets the value of the output voltage that causes an output-voltage high warning. This value is typically less than the output overvoltage threshold in VOUT_OV_FAULT_LIMIT. The 2 data bytes are in DIRECT format. In response to the VOUT_OV_WARN_LIMIT being exceeded, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the VOUT_OV_WARN bit in STATUS_VOUT. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). The VOUT_UV_WARN_LIMIT command sets the value of the output voltage that causes an output-voltage low warning. This value is typically greater than the output undervoltage fault threshold in VOUT_UV_FAULT_LIMIT. This warning is masked until the output voltage reaches the programmed VOUT_UV_FAULT for the first time and also during turn-off when the power supply is disabled. The 2 data bytes are in DIRECT format. In response to violation of the VOUT_UV_ WARN_LIMIT, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the VOUT_UV_WARN bit in STATUS_VOUT. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). The VOUT_UV_FAULT_LIMIT command sets the value of the output voltage that causes an output undervoltage fault. This fault is masked until the output voltage reaches the programmed VOUT_UV_FAULT for the first time and also during turn-off when the power supply is disabled. The VOUT_UV_FAULT_LIMIT threshold is also used to determine if TON_MAX_FAULT_LIMIT is exceeded. The 2 data bytes are in DIRECT format. In response to violation of the VOUT_ UV_FAULT_LIMIT, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the VOUT_UV_FAULT bit in STATUS_VOUT. 4) Responds as specified in MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE).
VOUT_OV_FAULT_LIMIT (40h)
VOUT_OV_WARN_LIMIT (42h)
VOUT_UV_WARN_LIMIT (43h)
VOUT_UV_FAULT_LIMIT (44h)
28
PMBus 6-Channel Power-Supply Manager
The IOUT_OC_WARN_LIMIT command sets the value of the current that causes an overcurrent warning. This value is typically less than the overcurrent fault threshold in IOUT_OC_FAULT_LIMIT. The 2 data bytes are in DIRECT format. In response to violation of the IOUT_OC_WARN_LIMIT, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE, IOUT, and MFR bits in STATUS_WORD. 3) Sets the OC_WARN bit in STATUS_MFR_SPECIFIC. 4) Notifies the host using ALERT assertion (if enabled in MFR_MODE). The IOUT_OC_FAULT_LIMIT command sets the value of the current that causes an overcurrent fault. The factory default value for IOUT_OC_FAULT_LIMIT is 0000h. This value disables the device from measuring current. Any nonzero positive value written to IOUT_OC_FAULT_LIMIT causes the device to enable current measurement. The 2 data bytes are in DIRECT format. In response to violation of the IOUT_OC_FAULT_LIMIT, the device does the following: 1) Sets the IOUT_OC bit in STATUS_BYTE. 2) Sets the IOUT, IOUT_OC, and MFR bits in STATUS_WORD. 3) Sets the OC_FAULT bit in STATUS_MFR_SPECIFIC. 4) Responds as specified in the MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE).
IOUT_OC_WARN_LIMIT (46h)
MAX34440
IOUT_OC_FAULT_LIMIT (4Ah)
Table 14. IOUT_OC_FAULT_LIMIT
IOUT_OC_FAULT_LIMIT VALUE 8000h to FFFFh 0000h 0001h to 7FFFh DEVICE RESPONSE (ON THE ASSOCIATED PAGE) Negative values are invalid. Current measurement disabled. Current measurement enabled.
The OT_FAULT_LIMIT command sets the temperature, in degrees Celsius, of the selected temperature sensor at which an overtemperature fault is detected. The 2 data bytes are in DIRECT format. In response to the OT_FAULT_LIMIT being exceeded, the device does the following: 1) Sets the TEMPERATURE bit in STATUS_BYTE. 2) Sets the TEMPERATURE and MFR bits in STATUS_WORD. 3) Sets the OT_FAULT bit in STATUS_MFR_SPECIFIC. 4) Responds as specified in MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE).
OT_FAULT_LIMIT (4Fh)
29
PMBus 6-Channel Power-Supply Manager MAX34440
The OT_WARN_LIMIT command sets the temperature, in degrees Celsius, of the selected temperature sensor at which an overtemperature warning is detected. The 2 data bytes are in DIRECT format. In response to the OT_WARN_LIMIT being exceeded, the device does the following: 1) Sets the TEMPERATURE bit in STATUS_BYTE. 2) Sets the TEMPERATURE and MFR bits in STATUS_WORD. 3) Sets the OT_WARN bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). The POWER_GOOD_ON command sets the value of the output voltage that causes the PG output to assert. All enabled power supplies must be above their associated POWER_GOOD_ON thresholds before the PG output is asserted. All the enabled power supplies must also be above POWER_GOOD_ON for power-supply margining to begin. The POWER_GOOD_ON level is normally set higher than the POWER_GOOD_OFF level and VOUT_UV_FAULT_LIMIT. The 2 data bytes are in DIRECT format.
OT_WARN_LIMIT (51h)
POWER_GOOD_ON (5Eh)
OPERATION COMMAND CODE OR CONTROL PIN
TON_DELAY
TOFF_DELAY
PSEN PIN (ACTIVE HIGH OR LOW/ OPEN DRAIN OR PUSH-PULL) TON_MAX_FAULT_LIMIT POWER_GOOD_ON VOUT_UV_FAULT_LIMIT ADC INPUT POWER_GOOD_OFF
POWER_GOOD# BIT IN STATUS_MFR_SPECIFIC
Figure 1. Power-Supply Sequencing
30
PMBus 6-Channel Power-Supply Manager
The POWER_GOOD_OFF command sets the value of the output voltage that causes the PG output to deassert after it has been asserted. Any enabled power supply that falls below the associated POWER_GOOD_OFF threshold causes the PG output to be deasserted. The POWER_GOOD_OFF level is normally set lower than the POWER_GOOD_ON level. The 2 data bytes are in DIRECT format. When the VOUT level of a power supply falls from greater than POWER_GOOD_ON to less than POWER_GOOD_OFF, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE, POWER_GOOD#, and STATUS_MFR_SPECIFIC bits in STATUS_WORD. 3) Sets the POWER_GOOD# bit in STATUS_MFR_SPECIFIC. TON_DELAY sets the time, in milliseconds, from when a START condition is received (a valid OPERATION command or through the CONTROL pin when enabled) until the PSEN output is asserted. The undervoltage fault and warning are masked off during TON_DELAY. The 2 data bytes are in DIRECT format.
POWER_GOOD_OFF (5Fh)
MAX34440
TON_DELAY (60h)
The TON_MAX_FAULT_LIMIT sets an upper time limit, in milliseconds, from when the TON_DELAY and the PSEN output are asserted until the output voltage crosses the VOUT_UV_FAULT_LIMIT threshold. The 2 data bytes are in DIRECT format. If the value is 0, the power supply is not sequenced by the device and the associated PSEN output remains deasserted; voltage and current monitoring is disabled. In response to the TON_MAX_FAULT_LIMIT being exceeded, the device does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD. 3) Sets the TON_MAX_FAULT bit in STATUS_VOUT. 4) Responds as specified in the MFR_FAULT_RESPONSE. 5) Notifies the host using ALERT assertion (if enabled in MFR_MODE).
TON_MAX_FAULT_LIMIT (62h)
Table 15. TON_MAX_FAULT_LIMIT
TON_MAX_FAULT_LIMIT VALUE 8000h to FFFFh 0000h 0001h to 7FFFh DEVICE RESPONSE (FOR THE ASSOCIATED PAGE) Negative values are invalid. Channel off (PSEN remains deasserted with no monitoring). Channel on and sequencing enabled.
Note: TON_MAX_FAULT_LIMIT should be set higher than 5ms.
The TOFF_DELAY sets the time, in milliseconds, from when a STOP condition is received (a soft-off OPERATION command or through the CONTROL pin when enabled) until the PSEN output is deasserted. When commanded to turn off immediately (either through the OPERATION command or the CONTROL pin), the TOFF_DELAY value is ignored. The 2 data bytes are in DIRECT format.
TOFF_DELAY (64h)
31
PMBus 6-Channel Power-Supply Manager MAX34440
The STATUS_BYTE command returns 1 byte of information with a summary of the most critical faults. A value of 1 indicates that a fault or warning event has occurred and a 0 indicates otherwise. Bits for unsupported features are reported as 0. The STATUS_BYTE cannot be restored by the RESTORE_DEFAULT_ALL command. The STATUS_BYTE message content is described in Table 16. This command is read-only.
STATUS_BYTE (78h)
Table 16. STATUS_BYTE
BIT 7:6 5 4 3 2 1 0 BIT NAME 0 VOUT_OV IOUT_OC 0 TEMPERATURE CML These bits always return a 0. An overvoltage fault has occurred. An overcurrent fault has occurred. This bit always returns a 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. MEANING
NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred.
The STATUS_WORD command returns 2 bytes of information with a summary of the reason for a fault. The low byte of the STATUS_WORD is the same data as the STATUS_BYTE. Table 17 describes the STATUS_WORD message content.
STATUS_WORD (79h)
Table 17. STATUS_WORD
BIT 15 14 13 12 11 10:6 5 4 3 2 1 0 BIT NAME VOUT IOUT 0 MFR POWER_GOOD# 0 VOUT_OV IOUT_OC 0 TEMPERATURE CML MEANING An output voltage fault or warning or TON_MAX_FAULT has occurred. An overcurrent fault or warning has occurred. This bit always returns a 0. A bit in STATUS_MFR_SPECIFIC has been set. A power-supply voltage has fallen from POWER_GOOD_ON to less than POWER_GOOD_OFF. These bits always return a 0. An overvoltage fault has occurred. An overcurrent fault has occurred. This bit always returns a 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred.
NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred.
32
PMBus 6-Channel Power-Supply Manager
The STATUS_VOUT command returns 1 byte of information with contents as described in Table 18.
STATUS_VOUT (7Ah)
MAX34440
Table 18. STATUS_VOUT
BIT 7 6 5 4 3 2 1:0 BIT NAME VOUT_OV_FAULT VOUT_OV_WARN VOUT_UV_WARN VOUT_UV_FAULT 0 TON_MAX_FAULT 0 VOUT overvoltage fault. VOUT overvoltage warning. VOUT undervoltage warning. VOUT undervoltage fault. This bit always returns a 0. TON maximum fault. These bits always return a 0. MEANING
The STATUS_CML command returns 1 byte of information with contents as described in Table 19.
STATUS_CML (7Eh)
Table 19. STATUS_CML
BIT 7 6 5:1 0 BIT NAME COMM_FAULT DATA_FAULT 0 FAULT_LOG_FULL MEANING An invalid or unsupported command has been received. An invalid or unsupported data has been received. These bits always return a 0. MFR_NV_FAULT_LOG is full and needs to be cleared.
The STATUS_MFR_SPECIFIC command returns 1 byte of information with a summary of the reason for a fault. The STATUS_MFR_SPECIFIC message content is described in Table 20.
STATUS_MFR_SPECIFIC (80h)
Table 20. STATUS_MFR_SPECIFIC
BIT 7 6 5 4 3 2 1 0 BIT NAME OFF OT_WARN OT_FAULT WATCHDOG MARGIN_FAULT POWER_GOOD# OC_FAULT OC_WARN MEANING This bit is set if the power supply is off (due to either a fault or sequencing delay; this bit is not set if the power supply is disabled). Overtemperature warning. Overtemperature fault. A watchdog reset has occurred. This bit is set if the device cannot properly close-loop margin the power supply. Power-supply voltage has fallen from POWER_GOOD_ON to less than POWER_GOOD_OFF. IOUT overcurrent fault. IOUT overcurrent warning.
Note: The settings of the OFF and POWER_GOOD# bits do not assert the ALERT signal.
33
PMBus 6-Channel Power-Supply Manager MAX34440
The READ_VOUT command returns the actual measured (not commanded) output voltage. READ_VOUT is measured and updated every 5ms. The 2 data bytes are in DIRECT format. The READ_IOUT command returns the latest measured current value. READ_IOUT is measured and updated every 200ms. The 2 data bytes are in DIRECT format. The READ_TEMPERATURE_1 command returns the temperature returned from the temperature sensor. READ_TEMPERATURE_1 returns 7FFFh if the sensor is faulty and 0000h if the sensor is disabled. READ_TEMPERATURE_1 is measured and updated once a second. The 2 data bytes are in DIRECT format. The PMBUS_REVISION command returns the revision of the PMBus specification to which the device is compliant. The command has 1 data byte. Bits [7:4] indicate the revision of PMBus specification Part I to which the device is compliant. Bits [3:0] indicate the revision of PMBus specification Part II to which the device is compliant. This command is read-only. The PMBUS_REVISION value returned is always 11h, which indicates that it is compliant with Part I Rev 1.1 and Part II Rev 1.1. The MFR_ID command returns the text (ISO/IEC 8859-1) character of the manufacturer's (Maxim) identification. The default MFR_ID value is 4Dh (M). This command is read-only. The MFR_MODEL command returns the text (ISO/IEC 8859-1) character of the device model number. The default MFR_MODEL value is 51h (Q). This command is read-only. The MFR_REVISION command returns two text (ISO/IEC 8859-1) characters that contain the device revision numbers for hardware (upper byte) and firmware (lower byte). The default MFR_REVISION value is 3030h (00). This command is read-only.
READ_VOUT (8Bh)
READ_IOUT (8Ch)
READ_TEMPERATURE_1 (8Dh)
PMBUS_REVISION (98h)
MFR_ID (99h)
MFR_MODEL (9Ah)
MFR_REVISION (9Bh)
The MFR_LOCATION command loads the device with text (ISO/IEC 8859-1) characters that identify the facility that manufactures the power supply. The maximum number of characters is 8. This data is written to internal flash using the STORE_DEFAULT_ALL command. The factory default text string value is 10101010. The MFR_DATE command loads the device with text (ISO/IEC 8859-1) characters that identify the date of manufacture of the power supply. The maximum number of characters is 8. This data is written to internal flash using the STORE_DEFAULT_ALL command. The factory default text string value is 10101010. The MFR_SERIAL command loads the device with text (ISO/IEC 8859-1) characters that uniquely identify the device. The maximum number of characters is 8. This data is written to internal flash using the STORE_DEFAULT_ALL command. The factory default text string value is 10101010.
MFR_LOCATION (9Ch)
MFR_DATE (9Dh)
MFR_SERIAL (9Eh)
34
PMBus 6-Channel Power-Supply Manager
The MFR_MODE command is used to configure the device to support manufacturer specific commands. The MFR_ MODE command is described in Table 21.
MFR_MODE (D1h)
MAX34440
Table 21. MFR_MODE
BIT 15 BIT NAME MEANING Setting this bit to 1 forces the device to log data into the nonvolatile fault log. Once set, the device clears this bit when the action is completed. The host must set again for subsequent FORCE_NV_FAULT_LOG action. If an error occurs during this action, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. Setting this bit to 1 forces the device to clear the nonvolatile fault log by writing FFh to all byte locations. Once set, the device clears this bit when the action is completed. The host CLEAR_NV_FAULT_LOG must set again for subsequent action. If an error occurs during this action, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. ALERT 0 SOFT_RESET 0 = ALERT disabled (device does not respond to ARA). 1 = ALERT enabled (device responds to ARA and ARA must be used). This bit always returns a 0. This bit must be set, then cleared and set again within 8ms for a soft reset to occur. PGTIME1 10:9 PGTIME[1:0] 0 0 1 1 8 7 0 PSEN_PP_OD This bit always returns a 0. Applies to all PSEN outputs. 0 = PSEN push-pull output. 1 = PSEN open-drain output. Applies to all PSEN outputs. 0 = PSEN active low. 1 = PSEN active high. These bits always return a 0. PGTIME0 0 1 0 1 TIME FROM POWER GOOD DETERMINED UNTIL PG OUTPUT IS ASSERTED (ms) Immediately 100 500 1000
14
13 12 11
6 5:0
PSEN_HI_LO 0
Note: VDD must be above 2.9V for the device to clear or log data into MFR_NV_FAULT_LOG. MFR_MODE should not be changed while power supplies are being sequenced.
35
PMBus 6-Channel Power-Supply Manager MAX34440
The MFR_VOUT_PEAK command returns the maximum actual measured output voltage. To reset this value to 0, write to this command with a data value of 0. Any values written to this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. The MFR_IOUT_PEAK command returns the maximum measured current. To reset this value to 0, write to this command with a data value of 0. Any values written to this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. The MFR_TEMPERATURE_PEAK command returns the maximum measured temperature. To reset this value to its lowest value, write to this command with a data value of 8000h. Any other values written by this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format.
MFR_VOUT_PEAK (D4h)
MFR_IOUT_PEAK (D5h)
MFR_TEMPERATURE_PEAK (D6h)
The MFR_VOUT_MIN command returns the minimum actual measured output voltage. To reset this value, write to this command with a data value of 7FFFh. Any values written to this command are used as a comparison for future minimum updates. The 2 data bytes are in DIRECT format. The MFR_FAULT_RESPONSE command specifies the response to each fault condition supported by the device. In response to a fault, the device always reports the fault in the appropriate status register and asserts the ALERT output (if enabled in MFR_MODE). A CML fault cannot cause any device action other than setting the status bit and asserting the ALERT output. The MFR_FAULT_RESPONSE command is described in Table 22.
MFR_VOUT_MIN (D7h)
MFR_FAULT_RESPONSE (D9h)
Table 22. MFR_FAULT_RESPONSE
BIT 15 14 BIT NAME NV_LOG GLOBAL MEANING 0 = Do not log the fault into MFR_NV_FAULT_LOG. 1 = Log the fault into MFR_NV_FAULT_LOG. 0 = Affect only the selected page power supply. 1 = Affect all supplies with GLOBAL = 1. 0 = Fault on first voltage sample excursion occurrence. 1 = Requires two consecutive voltage sample excursions before a fault is declared and action is taken. These bits always return a 0. See Table 23 (see Notes 1 and 2).
13 12:10 9:8 7:6 5:4 3:2 1:0
UV_OV_FILTER 0 OT_FAULT_LIMIT_RESPONSE[1:0]
IOUT_OC_FAULT_LIMIT_RESPONSE[1:0] See Table 23. TON_MAX_FAULT_LIMIT_RESPONSE[1:0] See Table 23. VOUT_UV_FAULT_LIMIT_RESPONSE[1:0] See Table 23. VOUT_OV_FAULT_LIMIT_RESPONSE[1:0] See Table 23.
Note 1: All enabled temperature sensor faults are logically ORed together. Note 2: Temperature faults affect all enabled power supplies. Supplies that are designated as global all respond in the same manner. This response is the worst-case response of the global channels for the given fault. Supplies that are not global respond to a temperature fault based upon the programmed response for the particular supply. Note 3: The fault response for a power-supply fault is determined by MFR_FAULT_RESPONSE for the faulting channel. If this channel is part of a global group, this fault response is performed for all the global channels.
36
PMBus 6-Channel Power-Supply Manager
Table 23. MFR_FAULT_RESPONSE Codes
RESPONSE SETTING [1:0] 11 * * * * * * 10 * FAULT RESPONSE Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. Continue power-supply operation. Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. If GLOBAL = 1, assert the FAULT output until faults on all GLOBAL supplies clear and MFR_FAULT_RETRY expires. Shut down the power supply by deasserting the PSEN output. Wait for the time configured in MFR_FAULT_RETRY and restart the supply. If GLOBAL = 1, all enabled power supplies with GLOBAL = 1 are shut down in sequence as configured with TOFF_DELAY, or they are all shut down immediately as configured by bit 0 in ON_OFF_CONFIG. Wait for the time configured in MFR_FAULT_RETRY and restart supplies in sequence as configured with TON_DELAY. Set the corresponding fault bit in the appropriate status register. Log fault into MFR_NV_FAULT_LOG if NV_LOG = 1. If GLOBAL = 1, assert the FAULT output until power supplies are restarted by the user. Latch-off the power supply by deasserting the PSEN output. If GLOBAL = 1, all enabled power supplies with GLOBAL = 1 are either shut down in sequence as configured with TOFF_DELAY, or they are all shut down immediately as configured by bit 0 in ON_OFF_CONFIG. Set the corresponding fault bit in the appropriate status register. Continue power-supply operation.
MAX34440
01
* * * *
00
* *
Note: ALERT is asserted if enabled when a new status bit is set. A status bit is latched the first time a particular fault or warning occurs.
The MFR_FAULT_RETRY command sets the delay time between a power supply being shut down by a fault response and the power supply restarting. This command sets the retry time delay in multiples of 1ms. This command value is used for all fault responses that require delay retry. If global supplies are being sequenced off, the retry delay time does not begin until the last global channel is turned off. The 2 data bytes are in DIRECT format. When MFR_FAULT_RETRY = 0000h, the device restarts the power supply at the next available time period. Each time the MFR_NV_FAULT_LOG command is executed, the device returns a block of 255 bytes containing one of the 15 nonvolatile fault logs. The MFR_NV_FAULT_LOG command must be executed 15 times to dump the complete nonvolatile fault log. If the returned fault log is all FFs, this indicates that this fault log has not been written by the device. As the device is operating, it is reading the latest operating conditions for voltage, current, and temperature, and it is updating the status registers. All this information is stored in on-board RAM. When a fault is detected (if so enabled in MFR_FAULT_RESPONSE), the device automatically logs this information to one of the 15 nonvolatile fault logs. After 15 faults have been written, bit 0 of STATUS_CML is set and the host must clear the fault log by setting the CLEAR_NV_FAULT_LOG bit in MFR_MODE before any additional faults are logged. All the latest status information is logged as well as eight readings of voltage from the last 800ms in 100ms increments and four readings of current from the last 800ms of operation. If a power supply is not enabled to measure either current or voltage or if a temperature sensor is disabled, the associated fault log position returns 0000h. There is a FAULT_LOG_COUNT (16-bit counter) at the beginning of each fault log that indicates which fault log is the latest. This counter rolls over should more than 65,535 faults be logged. This counter is not cleared when the CLEAR_NV_FAULT_LOG bit in MFR_MODE is toggled. The 255 bytes returned by the MFR_NV_FAULT_LOG command are described in Table 24.
37
MFR_FAULT_RETRY (DAh)
MFR_NV_FAULT_LOG (DCh)
PMBus 6-Channel Power-Supply Manager MAX34440
EACH FAULT IS WRITTEN INTO THE NEXT FAULT LOG FLASH FAULT LOG INDEX 0 (255 BYTES) RAM FAULT LOG INDEX 1 (255 BYTES) STATUS VOLTAGE CURRENT TEMPERATURE MFR_NV_FAULT_LOG FAULT LOG INDEX 2 (255 BYTES) EACH COMMAND READ ACCESSES THE NEXT FAULT LOG
FAULT OCCURENCE
FAULT LOG INDEX 14 (255 BYTES)
Figure 2. MFR_NV_FAULT_LOG
If an error occurs while the device is attempting to write or clear the NV_FAULT_LOG, the device sets the CML bit in STATUS_BYTE and STATUS_WORD; no bits are set in STATUS_CML. ALERT is asserted (if enabled in MFR_MODE). See Figure 2. USER NOTE: VDD must be above 2.9V for the device to clear or log data into MFR_NV_FAULT_LOG.
Table 24. MFR_NV_FAULT_LOG
BYTE 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 38 PARAMETER 00h/FAULT_LOG_INDEX FAULT_LOG_COUNT MFR_TIME_COUNT (LSW) MFR_TIME_COUNT (MSW) STATUS_BYTE/STATUS_CML STATUS_WORD STATUS_VOUT Pages 0/1 STATUS_VOUT Pages 2/3 STATUS_VOUT Pages 4/5 STATUS_MFR_SPECIFIC Pages 0/1 STATUS_MFR_SPECIFIC Pages 2/3 STATUS_MFR_SPECIFIC Pages 4/5 STATUS_MFR_SPECIFIC Pages 6/7 STATUS_MFR_SPECIFIC Pages 8/9 STATUS_MFR_SPECIFIC Pages 10/11 STATUS_MFR_SPECIFIC Pages 12/13 MFR_VOUT_PEAK Page 0 MFR_VOUT_PEAK Page 1 MFR_VOUT_PEAK Page 2 MFR_VOUT_PEAK Page 3 MFR_VOUT_PEAK Page 4 BYTE 128 130 132 134 136 138 140 142 144 146 148 150 152 154 156 158 160 162 164 166 168 READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT READ_VOUT PARAMETER Index = 3, Page 2 Index = 3, Page 3 Index = 3, Page 4 Index = 3, Page 5 Index = 4, Page 0 Index = 4, Page 1 Index = 4, Page 2 Index = 4, Page 3 Index = 4, Page 4 Index = 4, Page 5 Index = 5, Page 0 Index = 5, Page 1 Index = 5, Page 2 Index = 5, Page 3 Index = 5, Page 4 Index = 5, Page 5 Index = 6, Page 0 Index = 6, Page 1 Index = 6, Page 2 Index = 6, Page 3 Index = 6, Page 4
PMBus 6-Channel Power-Supply Manager
Table 24. MFR_NV_FAULT_LOG (continued)
BYTE 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110 112 114 116 118 120 122 124 126 PARAMETER MFR_VOUT_PEAK Page 5 MFR_IOUT_PEAK Page 0 MFR_IOUT_PEAK Page 1 MFR_IOUT_PEAK Page 2 MFR_IOUT_PEAK Page 3 MFR_IOUT_PEAK Page 4 MFR_IOUT_PEAK Page 5 MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_TEMPERATURE_PEAK Page MFR_VOUT_MIN Page 0 MFR_VOUT_MIN Page 1 MFR_VOUT_MIN Page 2 MFR_VOUT_MIN Page 3 MFR_VOUT_MIN Page 4 MFR_VOUT_MIN Page 5 RESERVED (0000h) VOLTAGE_INDEX/00h READ_VOUT Index = 0, Page 0 READ_VOUT Index = 0, Page 1 READ_VOUT Index = 0, Page 2 READ_VOUT Index = 0, Page 3 READ_VOUT Index = 0, Page 4 READ_VOUT Index = 0, Page 5 READ_VOUT Index = 1, Page 0 READ_VOUT Index = 1, Page 1 READ_VOUT Index = 1, Page 2 READ_VOUT Index = 1, Page 3 READ_VOUT Index = 1, Page 4 READ_VOUT Index = 1, Page 5 READ_VOUT Index = 2, Page 0 READ_VOUT Index = 2, Page 1 READ_VOUT Index = 2, Page 2 READ_VOUT Index = 2, Page 3 READ_VOUT Index = 2, Page 4 READ_VOUT Index = 2, Page 5 READ_VOUT Index = 3, Page 0 READ_VOUT Index = 3, Page 1 BYTE 170 172 174 176 178 180 182 184 186 188 190 192 194 196 198 200 202 204 206 208 210 212 214 216 218 220 222 224 226 228 230 232 234 236 238 240 242 244 246 248 250 252 254 PARAMETER READ_VOUT Index = 6, Page 5 READ_VOUT Index = 7, Page 0 READ_VOUT Index = 7, Page 1 READ_VOUT Index = 7, Page 2 READ_VOUT Index = 7, Page 3 READ_VOUT Index = 7, Page 4 READ_VOUT Index = 7, Page 5 RESERVED (0000h) CURRENT_INDEX/00h READ_IOUT Index = 0, Page 0 READ_IOUT Index = 0, Page 1 READ_IOUT Index = 0, Page 2 READ_IOUT Index = 0, Page 3 READ_IOUT Index = 0, Page 4 READ_IOUT Index = 0, Page 5 READ_IOUT Index = 1, Page 0 READ_IOUT Index = 1, Page 1 READ_IOUT Index = 1, Page 2 READ_IOUT Index = 1, Page 3 READ_IOUT Index = 1, Page 4 READ_IOUT Index = 1, Page 5 READ_IOUT Index = 2, Page 0 READ_IOUT Index = 2, Page 1 READ_IOUT Index = 2, Page 2 READ_IOUT Index = 2, Page 3 READ_IOUT Index = 2, Page 4 READ_IOUT Index = 2, Page 5 READ_IOUT Index = 3, Page 0 READ_IOUT Index = 3, Page 1 READ_IOUT Index = 3, Page 2 READ_IOUT Index = 3, Page 3 READ_IOUT Index = 3, Page 4 READ_IOUT Index = 3, Page 5 RESERVED (0000h) READ_TEMPERATURE_1 Page 6 READ_TEMPERATURE_1 Page 7 READ_TEMPERATURE_1 Page 8 READ_TEMPERATURE_1 Page 9 READ_TEMPERATURE_1 Page 10 READ_TEMPERATURE_1 Page 11 READ_TEMPERATURE_1 Page 12 READ_TEMPERATURE_1 Page 13 LOG_VALID (see note)
MAX34440
6 7 8 9 10 11 12 13
Note: LOG_VALID is set to DDh if the fault log contains valid data.
39
PMBus 6-Channel Power-Supply Manager MAX34440
The MFR_TIME_COUNT command returns the number of seconds the device has been operating since the last time power was applied to the device, RST was toggled, or a soft reset occurred. The counter is a 32-bit value and cannot be reset by the user.
MFR_TIME_COUNT (DDh)
The MFR_MARGIN_CONFIG command configures the digital PWM outputs to margin the power supplies. The MFR_MARGIN_CONFIG command is described in Table 25. Power-supply margining is implemented using the PWM outputs. The PWM frequency is 62.5kHz. The device close-loop controls the duty cycle to margin the power supply. The device provides 6 bits of duty-cycle resolution. The device margins the power supplies when OPERATION is set to one of the margin states. Margining of the supplies does not begin until all enabled power supplies have exceeded their programmed POWER_GOOD_ON levels. When this happens, the PWM output is enabled and the seed value from MFR_MARGIN_CONFIG is loaded as the initial PWM duty cycle. The device then averages eight samples of VOUT for a total time of 40ms. If the measured VOUT and the target (set by either VOUT_MARGIN_HIGH or VOUT_MARGIN_LOW) differ by more than 1%, the PWM duty cycle is adjusted by one step. The direction of the duty cycle adjustment is determined by the SLOPE bit in MFR_MARGIN_CONFIG. All changes to the PWM are made after averaging eight samples of VOUT over a 40ms period. The device is unable to successfully margin a power supply to the programmed target when the PWM duty cycle reaches 0% or 100% and the target voltage has not been achieved. If this occurs, the device continues attempting to margin the power supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE). Also, the averaged VOUT after the PWM has initially been enabled with the seed value is compared to the target value. If the programmed seed value causes VOUT to exceed the target, a MARGIN_FAULT is declared. For example, if the target is VOUT_MARGIN_LOW and VOUT is less than VOUT_MARGIN_LOW after seeding, MARGIN_FAULT is set. In response to this fault, the device continues margining the power supply and does the following: 1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE. 2) Sets the NONE OF THE ABOVE and MFR bits in STATUS_WORD. 3) Sets the MARGIN_FAULT bit in STATUS_MFR_SPECIFIC. 4) Notifies the host through ALERT assertion (if enabled in MFR_MODE).
MFR_MARGIN_CONFIG (E0h)
Table 25. MFR_MARGIN_CONFIG
BIT 15 14:6 5:0 BIT NAME SLOPE 0 SEED MEANING PWM duty cycle to resulting voltage relationship. 0 = Negative slope (increasing duty cycle results in a lower voltage). 1 = Positive slope (increasing duty cycle results in a higher voltage). These bits always return a 0. This 6-bit value is used as the initial PWM duty cycle (i.e., seed value) when the device begins to margin a power supply either up or down.
40
PMBus 6-Channel Power-Supply Manager
The MFR_TEMP_SENSOR_CONFIG command is used to configure the temperature sensors. Table 26 describes the MFR_TEMP_SENSOR_CONFIG command.
MFR_TEMP_SENSOR_CONFIG (F0h)
MAX34440
Table 26. MFR_TEMP_SENSOR_CONFIG
BIT 15 14:0 BIT NAME ENABLE 0 MEANING Clearing and setting this bit reinitializes the temperature sensor. 0 = Temperature sensor disabled. 1 = Temperature sensor enabled. These bits always return a 0.
Applications Information
To achieve the best results when using the device, decouple the VDD power supply with a 0.1FF capacitor. Use a high-quality, ceramic, surface-mount capacitor if possible. Surface-mount components minimize lead inductance, which improves performance, and ceramic capacitors tend to have adequate high-frequency response for decoupling applications. Decouple the REG25 and REG18 regulator outputs using 1FF and 10nF capacitors (one each per output). Do not connect other circuitry to either of these pins.
Power-Supply Decoupling
MSDA, MSCL, SCL, SDA, FAULT, and ALERT are opendrain pins and require external pullup resistors connected to VDD to realize high logic levels. PSEN0 to PSEN5 can be user-configured as either CMOS push-pull or open-drain outputs. When configured as open-drain, external pullup resistors connected to VDD are required to realize high logic levels (see the MFR_MODE settings).
Open-Drain Pins
41
PMBus 6-Channel Power-Supply Manager MAX34440
Typical Operating Circuit
INPUT VOLTAGE IN POWER SUPPLY TRIM EN LOAD OUT
MAX6695 TWO REMOTE AND ONE LOCAL
MAX9938 CURRENT-SENSE AMPLIFIER
SPDT MUX
6 CHANNELS MSDA
DS75LV I2C TEMP SENSOR
+3.3V
MSCL
PSEN0 PWM0 RS-0 RS+0 PSEN1 PWM1 RS-1 RS+1
OPTIONAL SUPPORT FOR CURRENT MONITORING
FROM MUXSEL
VDD VSS SDA SCL HOST INTERFACE
MAX34440
RST ALERT FAULT A0/MUXSEL A1/PG
PSEN2 PWM2 RS-2 RS+2 PSEN3 PWM3 RS-3 RS+3 PSEN4 PWM4 RS-4 RS+4
REG25
PSEN5 PWM5 RS-5 RS+5
REG18
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE 40 TQFN-EP PACKAGE CODE T4066+2 OUTLINE NO. 21-0141 LAND PATTERN NO. 90-0053
42
PMBus 6-Channel Power-Supply Manager
Revision History
REVISION NUMBER 0 REVISION DATE 9/10 Initial release DESCRIPTION PAGES CHANGED --
MAX34440
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
(c)
43
2010 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.

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