View LTC1706EMS-81_690212.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

LTC1706-81 5-Bit Desktop VID Voltage Programmer
FEATURES
s
DESCRIPTIO
s
s
s s s
Programs Regulator Output Voltage Range from 1.3V to 2.05V in 50mV Steps and from 2.1V to 3.5V in 100mV Steps (VRM 8.4) Programs a Wide Range of Linear Technology DC/DC Converters with a 0.8V Reference Fully Compliant with the Intel Pentium(R) Processor Desktop VID Specification 0.25% Accurate Output Voltage Built-In 40k Pull-Up Resistors on VID Inputs Available in MSOP-10 Package
The LTC(R)1706-81 is a precision, digitally programmed, resistive ladder which adjusts the output of any 0.8V referenced regulator. Depending on the state of the five VID inputs, an output voltage between 1.3V and 3.5V is programmed in 50mV and 100mV increments. The LTC1706-81 is designed specifically to program an entire family of Linear Technology DC/DC converters in full compliance with the Intel Desktop (VRM 8.4) VID specification. The LTC1706-81 programs the following Linear Technology DC/DC converter products: LTC1622, LTC1628, LTC1629, LTC1702, LTC1735, LTC1735-1, LTC1772 and LTC1929. (Consult factory for future compatible DC/DC converter products.)
, LTC and LT are registered trademarks of Linear Technology Corporation. Pentium is a registered trademark of Intel Corporation. AMD Athlon is a trademark of Advanced Micro Devices, Inc.
APPLICATIO S
s s s s
Intel Pentium II and III Processor Power Supply AMD AthlonTM Processor Power Supply Workstations and Servers Large Memory Array Supply
TYPICAL APPLICATION
5-Bit VID-Controlled High Current 4-Phase Application (Simplified Block Diagram)
VIN 4.5V TO 22V VIN LTC1629 VID0 VID1 FROM P VCC SENSE TG1 SW1 INTVCC VDIFFOUT SGND FB GND EAIN TG2 SW2 BG2 VIN 4.5V TO 22V VIN LTC1629 TG1 SW1 BG1 PGND SGND EAIN TG2 SW2 BG2
1706-81 TA01
L1
RSENSE1
BG1 PGND VIN
VID2 LTC1706-81 VID3 VID4
L2
RSENSE2
L3
RSENSE3
VIN
L4
RSENSE4
U
+
VOUT 1.3V TO 3.5V UP TO 70A COUT
U
U
1
LTC1706-81
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PACKAGE/ORDER INFORMATION
TOP VIEW VID0 VID1 VID2 VID3 VCC 1 2 3 4 5 10 9 8 7 6 FB GND NC VID4 SENSE
(Voltages Referred to GND Pin) Input Supply Voltage (VCC) ..........................- 0.3V to 7V VID Input Pins .............................................- 0.3V to 7V SENSE Pin ...................................................- 0.3V to 7V FB Pin ..........................................................- 0.3V to 7V Operating Temperature Range (Note 2) .. - 40C to 85C Junction Temperature ........................................... 110C Storage Temperature Range ................. - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
ORDER PART NUMBER LTC1706EMS-81 MS10 PART MARKING LTLR
MS10 PACKAGE 10-LEAD PLASTIC MSOP TJMAX = 110C, JA = 120C/ W
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
The q denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25C. 2.7V VCC 5.5V, VID0 = VID1 = VID2 = VID3 = VID4 = NC unless otherwise specified.
SYMBOL VCC IVCC RFB-SENSE VOUT Error % RPULLUP VIDTH IVID-LEAK VPULLUP PARAMETER CONDITIONS Operating Supply Voltage Range Supply Current (Note 3) Resistance Between SENSE and FB Output Voltage Accuracy Programmed from 1.3V to 2.05V (VID4 = 0) Programmed from 2.1V to 3.5V (VID4 = 1) VID Input Pull-Up Resistance VDIODE = 0.6V (Note 4) VID Input Voltage Threshold VIL (2.7V VCC 5.5V) VIH (2.7V VCC 5.5V) VID Input Leakage Current VCC < VID < 7V (Note 4) VID Pull-Up Voltage VCC = 3.3V VCC = 5V MIN 2.7
q q q
TYP 0.1 20
12 - 0.25 - 0.35
MAX 5.5 5 28 + 0.25 + 0.25 0.4
40 1.6 0.01 2.8 4.5 1
UNITS V A k % % k V V A V V
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1706-81 is guaranteed to meet performance specifications from 0C to 70C. Specifications over the - 40C to 85C operating temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3: With all five VID inputs floating, the VCC supply current is simply the device leakage current. However, the VCC supply current will rise and be approximately equal to the number of grounded VID input pins times (VCC - 0.6V)/40k. (See the VID Input Characteristics section for more details.) Note 4: Each built-in pull-up resistor attached to the VID inputs also has a series diode connected to VCC to allow input voltages higher than the VCC supply without damage or clamping. (See Operation section for further details.)
2
U
W
U
U
WW
W
LTC1706-81 TYPICAL PERFORMANCE CHARACTERISTICS
Typical Error % vs Output Voltage
0.25 TA = 25C 0.25
ERROR (%)
ERROR (%)
0 VID4 = 0
-0.25 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 OUTPUT VOLTAGE (V)
1706-81 G01
RFB1 vs Temperature
30 120 100 80 60 40 20 0 -50
20
RFB1 (k)
10
VID PULL-UP CURRENT (A)
0 50 TEMPERATURE (C)
Supply Current vs Temperature
2.0 ALL VID INPUTS OPEN 4
SUPPLY CURRENT (A) SUPPLY CURRENT (A)
1.5
1.0 VCC = 5V 0.5 VCC = 3.3V
0 -50
0 50 TEMPERATURE (C)
UW
Typical Error % vs Temperature
0
VOUT = 1.3V
VOUT = 1.7V
VOUT = 2V
VID4 = 1 -0.25 -50 VOUT = 3.5V 0 50 TEMPERATURE (C) 100
1706-81 G02
IVID-PULLUP vs Temperature
VCC = 5V VID4 = 0V VID0 = VID1 = VID2 = VID3 = OPEN
100
1706-81 G03
0 -50
0 50 TEMPERATURE (C)
100
1706-81 G04
Supply Current vs Supply Voltage
5 ALL VID INPUTS OPEN TA = 25C
3
2
VCC = 2.7V
1
0 100
1706-81 G05
0
2 4 6 SUPPLY VOLTAGE (V)
8
1706-81 G06
3
LTC1706-81
PIN FUNCTIONS
VID0 (Pin 1): LSB Programming Input. Low = GND, High = VCC or Float. Grounding VID0 adds 50mV (VID4 = LOW) or 100mV (VID4 = HIGH) to the output sense voltage. VID1 (Pin 2): 3rd MSB Programming Input. Low = GND, High = VCC or Float. Grounding VID1 adds 100mV (VID4 = LOW) or 200mV (VID4 = HIGH) to the output sense voltage. VID2 (Pin 3): 2nd MSB Programming Input. Low = GND, High = VCC or Float. Grounding VID2 adds 200mV (VID4 = LOW) or 400mV (VID4 = HIGH) to the output sense voltage. VID3 (Pin 4): MSB Programming Input. Low = GND, High = VCC or Float. Grounding VID3 adds 400mV (VID4 = LOW) or 800mV (VID4 = HIGH) to the output sense voltage. VCC (Pin 5): Power Supply Voltage. Range from 2.7V to 5.5V. SENSE (Pin 6): Regulator Output Voltage. Connect directly to regulator output sense node or, when used with the LTC1629 and LTC1929 to VDIFFOUT. VID4 (Pin 7): High-Low Output Range Programming Input. VID4 = Low puts the output voltage in the lower range of 1.3V to 2.05V in 50mV steps. VID4 = HIGH puts the output voltage in the upper range of 2.1V to 3.5V in 100mV steps. NC (Pin 8): No Connect. GND (Pin 9): Ground. Connect to regulator signal ground. FB (Pin 10): Feedback Input. Connect to the 0.8V feedback pin of a compatible regulator or the EAIN pin of the LTC1629 and LTC1929.
PIN 1 2 3 4 5 6 7 8 9 10
NAME VID0 VID1 VID2 VID3 VCC SENSE VID4 NC GND FB
4
U
U
U
DESCRIPTION LSB Programmable Input 3rd MSB Programmable Input 2nd MSB Programmable Input 1st MSB Programmable Input Power Supply Regulator Output Voltage Output Range Programmable Input Ground 0.8V Feedback Input
MIN 0 0 0 0 2.7 1.3 0
NOMINAL (V) TYP MAX VCC VCC VCC VCC 5.5 3.5 VCC 0
ABSOLUTE MAX (V) MIN MAX - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 7 7 7 7 7 7 7 7 7
0
0.8
1.5
- 0.3
LTC1706-81
BLOCK DIAGRA
VCC
VID0 1 VCC VCC 5
VID1 2 VCC SWITCH CONTROL LOGIC 40k VID2 3
VCC
VID3 4
OPERATIO
The LTC1706-81 is a precision resistive divider designed specifically for use with an entire family of Linear Technology Corporation DC/DC switching regulators with 0.8V internal reference and feedback voltage. The LTC1706-81 produces an output voltage ranging from 1.3V to 2.05V in 50mV steps and from 2.1V to 3.5V in 100mV steps by closing the loop between the output voltage sense and the feedback input of the regulator with the appropriate resistive divider network. The "top" feedback resistor, RFB1, connected between SENSE and FB, is typically 20k and is not modified by the state of the VID program inputs. The "bottom" feedback resistor, RFB2, however, is modified by the five VID inputs and is precisely ratioed to RFB1.
W
40k 40k RFB1 10 FB RFB2 9 GND 6 SENSE
1706-81 BD
VCC
40k VID4 7
40k
U
VID Programming A list of programmed inputs and their corresponding output voltages is shown in Table 1. Programming is accomplished by applying the proper voltage (or float condition) on the five digital VID inputs. VID4 is the range bit that puts the output voltage in either the 1.3V to 2.05V range or the 2.1V to 3.5V range. In either range, VID3 is the most significant bit (MSB) and VID0 is the least significant bit (LSB). In the lower range (VID4 = 0), when the four VID inputs are low or grounded, the regulator output voltage is set to 2.05V. Each increasing binary count is equivalent to a decrease of 50mV in the output voltage. Therefore, to obtain a 1.3V output, the four VID inputs should be floating, or high.
5
LTC1706-81
OPERATIO
CODE 10000 10001 10010 10011 10100 10101 10110 10111 11000 11001 11010 11011 11100 11101 11110 11111 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 VID4 Float Float Float Float Float Float Float Float Float Float Float Float Float Float Float Float GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND
Table 1. VID Inputs and Corresponding Output Voltage
VID3 GND GND GND GND GND GND GND GND Float Float Float Float Float Float Float Float GND GND GND GND GND GND GND GND Float Float Float Float Float Float Float Float VID2 GND GND GND GND Float Float Float Float GND GND GND GND Float Float Float Float GND GND GND GND Float Float Float Float GND GND GND GND Float Float Float Float VID1 GND GND Float Float GND GND Float Float GND GND Float Float GND GND Float Float GND GND Float Float GND GND Float Float GND GND Float Float GND GND Float Float VID0 GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float GND Float OUTPUT 3.5V 3.4V 3.3V 3.2V 3.1V 3.0V 2.9V 2.8V 2.7V 2.6V 2.5V 2.4V 2.3V 2.2V 2.1V * 2.05V 2.00V 1.95V 1.90V 1.85V 1.80V 1.75V 1.70V 1.65V 1.60V 1.55V 1.50V 1.45V 1.40V 1.35V 1.30V
* Represents codes without a defined output voltage as specified in Intel specifications. The LTC1706-81 interprets these codes as a valid input and produces an output voltage as follows: (11111) = 2V
6
U
To program output voltages higher than 2.05V, the range bit should be set high (VID4 = High). In this range, when the four VID inputs are low, the output is 3.5V. Each increasing binary count is equivalent to a decrease of 100mV in the output voltage. When all five VID inputs are high or floating, such as when no CPU is present in a system, a regulated 2V output is generated at VSENSE. Each VID input pin is pulled up by a 40k resistor in series with a diode connected to VCC. Therefore, it should be grounded (or driven low) to produce a digital low input. It can either be floated or connected to VCC to get a digital high input. The series diode is included to prevent the input from being damaged or clamped when it is driven higher than VCC. Voltage Sensing and Feedback Pins The FB pin is a high impedance node that requires minimum layout distance to reduce extra loading and unwanted stray pickup. When used with the LTC1629 or LTC1929, the LTC1706-81's FB, SENSE, VCC and GND pins should be connected, respectively, with the EAIN, VDIFFOUT, INTVCC and SGND pins of the LTC1629 and LTC1929. The result of this application is a precisely controlled, multiphase, variable output voltage supply to any low voltage, high current system such as a powerful personal computer, workstation or network server. True remote sense capability is retained in this case. VID Input Characteristics The VID inputs should be driven with a maximum VIL of 0.4V and a minimum VIH of 1.6V. However, the VID input range is not limited to values less than VCC. Because of the internal diode between VCC and the pull-up resistor, the inputs can go higher than VCC without being clamped to VCC or damaging the input. This allows the LTC1706-81 to be fully logic compatible and operational over a higher input voltage range (less than the 7V absolute maximum rating).
LTC1706-81
APPLICATIONS INFORMATION
When a VID input is grounded, there will be a higher quiescent current flow from VCC because of a resistor from VCC through a series diode to each one of the inputs. This increase in quiescent current is calculated from: IQ = N(VCC - VDIODE)/RPULLUP N is the number of grounded VID inputs. VDIODE is typically 0.6V while RPULLUP has a typical pull-up resistance of 40k. In other words, each VID input has a typical pull-up current of 68A for a 3.3V system. Besides the LTC1629, the LTC1706-81 also programs a whole family of LTC DC/DC converters that have an onboard 0.8V reference. The LTC1628, LTC1735, LTC1622, LTC1772 and LTC1929 are just a few of the high efficiency step-down switching regulators that will work equally well with the LTC1706-81.
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted. MS10 Package 10-Lead Plastic MSOP
(LTC DWG # 05-08-1661)
0.118 0.004* (3.00 0.102)
0.007 (0.18) 0.021 0.006 (0.53 0.015)
* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
U
U
W
U
U
10 9 8 7 6
0.193 0.006 (4.90 0.15)
0.118 0.004** (3.00 0.102)
12345 0.040 0.006 (1.02 0.15) 0 - 6 TYP SEATING PLANE 0.009 (0.228) REF 0.034 0.004 (0.86 0.102)
0.0197 (0.50) BSC
0.006 0.004 (0.15 0.102)
MSOP (MS10) 1098
7
LTC1706-81
TYPICAL APPLICATION
VID Controlled High Current 70A 4-Phase Application
OPTIONAL SYNC CLOCK IN 1 0.33F 2 3 1000pF 4 5 1 2 FROM P 3 4 7 VCC VID0 VID1 VID2 VID3 FB VID4 GND 9 SENSE LTC1706-81 10 6 0.33F 100pF 47k 6800pF 5 6 7 8 9 10 11 12 1000pF 13 14 RUN/SS SENSE1+ SENSE1- EAIN PLLFLTR PLLIN PHASMD ITH SGND VDIFFOUT VOS- VOS+ SENSE2- SENSE2+ LTC1629 CLKOUT TG1 SW1 BOOST1 VIN BG1 EXTVCC INTVCC PGND BG2 BOOST2 SW2 TG2 AMPMD 28 27 26 25 24 23 22 21 20 19 18 17 16 15 L2 24k 75k 0.47F M5 M6 M4 D7 D8 1F 1F 25V 150F, 16V x2 0.47F 10 M2 M3 M1 D1 MBRS 340T3 5V 0.003 L1
1 2 47pF 10k 0.01F 3 1000pF 4 5 6 7 47k 100pF NC 6800pF 8 9 10 11 12 M1 TO M12: FDS7760A L1 TO L4: 1H SUMIDA CEPH149-IROMC D7 TO D10: CENTROI CMDSH-3TR COUT: KEMET T510X477M006AS fSW: 200kHz 1000pF 13 14
RUN/SS SENSE1+ SENSE1- EAIN PLLFLTR PLLIN PHASMD ITH SGND VDIFFOUT VOS- VOS+ SENSE2- SENSE2
+
CLKOUT TG1 SW1 BOOST1 VIN BG1 EXTVCC LTC1629 INTVCC PGND BG2 BOOST2 SW2 TG2 AMPMD
28 27 26 25 24 23 22 21 20 19 18 17 16 15 0.47F M10 M11 D9 D10 1F 1F 25V 150F, 16V x2 22F 6.3V 0.47F 10 M7 M8 5V
RELATED PARTS
PART NUMBER LTC1622 LTC1628 LTC1629 LTC1709 LTC1735 LTC1736 LTC1772 LTC1929 DESCRIPTION Low Voltage Step-Down Controller Dual High Efficiency, 2-Phase Synchronous Step-Down Controller PolyPhaseTM High Efficiency Step-Down DC/DC Controller 2-Phase Synchronous Step-Down Controller with 5-Bit VID High Efficiency Synchronous Step-Down Controller High Efficiency Synchronous Step-Down Controller with 5-Bit VID SOT-23 Low Voltage Step-Down Controller 2-Phase Synchronous Step-Down Controller COMMENTS 8-Pin MSOP, 2V VIN 10V, 550kHz, Burst ModeTM Operation Constant, Standby, 5V and 3.3V LDOs, 3.5V VIN 36V Expandable Up to 12 Phases, Up to 120A, Remote Sense Diff Amp 550kHz, 25MHz GBW, No RSENSETM, 2.7V VIN 7V 4V VIN 36V, PLL, 36-Pin SSOP, Current Mode Operation Burst Mode Operation, 16-Pin Narrow SSOP, Fault Protection, 3.5V VIN 36V GN-24, Power Good, Output Fault Protection, 3.5V VIN 36V 6-Pin SOT-23, 2V VIN 10V, 550kHz, Burst Mode Operation Current Mode Operation, IOUT Up to 40A, 3.5V VIN 36V
LTC1702/LTC1703 Dual High Efficiency, 2-Phase Synchronous Step-Down Controller
Burst Mode, PolyPhase and No RSENSE are trademarks of Linear Technology Corporation.
8
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com
+
+
U
22F 6.3V
+
COUT 470F, 6.3V x3 D2 MBRS 340T3 0.003
+
GND
VOUT 1.3V TO 3.5V 70A
L3 0.003 D3 MBRS 340T3 COUT 470F, 6.3V x3
M9
+
GND
+
VIN 12V D4 MBRS 340T3 0.003 L4
1706-81 TA02
M12
170681f LT/TP 0400 4K * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1999

▲Up To Search▲

Price & Availability of LTC1706EMS-81

	To Download LTC1706EMS-81 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .