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RT9228
Advanced PWM and Dual Linear Power Controller
General Description
The RT9228 is a 3-in-one power controller optimized for high-performance microprocessor and computer applications. The IC integrates a synchronous buck PWM controller, a linear regulator, and a linear controller as well as monitoring and protection functions into a 24-pin SOP package. The PWM controller regulates the microprocessor core voltage. The linear regulator provides power for the clock driver circuit and the linear controller regulates power for the GTL bus. The RT9228 features an Intel-compatible, TTL 5-bit programmable DAC that adjusts the core voltage from 2.1V to 3.5V in 0.1V increments and from 1.3V to 2.05V in 0.05V steps. The 5-bit DAC has a typical 1% tolerance. The linear regulator uses an internal drive device to provide 2.5V 2.5% output voltage. The linear controller drives an external N-channel MOSFET or a low cost NPN bipolar transistor to provide 1.5V 2.5%. The RT9228 monitors all the output voltages. A Power-good signal is issued when the core voltage is within 10% of the DAC setting and the other levels are above their under-voltage levels. Additional buildin over-voltage protection for the core output uses the lower MOSFET to prevent output voltage above 115% of the DAC setting. The PWM over-current function monitors the output current using the voltage drop across the upper MOSFET's RDS(ON), which eliminates the need for a current sensing resistor.
Features
3-in-one Regulated Voltages for Microprocessor Core, Clock, and GTL Compatible with HIP6018B Power-good Output Voltage Monitor Switching section 5-bit DAC Programmable from 1.3V to 3.5V 1% DAC Accuracy Fast Transient Response Full 0% to 100% Duty Cycle Driver Fixed 200kHz Switching Frequency Adaptive Non-overlapping Gate Driver Over-current Monitor Uses MOSFET RDS(ON) Over-voltage Protection Uses Lower MOSFET Linear Section User-adjustable Linear Regulator Output Voltage MOSFET or NPN Driving Capability Ultra Fast Response Speed Under-voltage Protection Internal Thermal Shutdown
Applications
Full Motherboard Power Regulation for Computer Low-voltage Distribution Power Supplies
Pin Configurations
Part Number RT9228CS (Plastic SOP-24)
VCC VID4 VID3 VID2 VID1 VID0
1 2 3 4 5 6
Pin Configurations
TOP VIEW
24 23 22 21 20 19 18 17 16 15
UGATE1 PHASE1 LGATE1 PGND OCSET1 VSEN1 FB1 NC
Ordering Information
RT9228 Package type S : SOP-24 Operating temperature range C: Commercial standard
PGOOD 7 FAULT 8 SS NC FB2 VIN2
9 10 11 12
FB3 GATE3 14 GND 13 VOT2
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Absolute Maximum Ratings
Supply Voltage PGOOD, FAULT and GATE Voltage Input, Output or I/O Voltage Ambient Temperature Range Junction Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 sec.) Package Thermal Resistance SOP-24, JA +15V GND-0.3V to VCC+0.3V GND-0.3V to 7V 0C to +70C 0C to +125C -65C to +150C 300C 75C/W
Recommended Operating Conditions
Supply Voltage Ambient Temperature Range Junction Temperature Range +12V10% 0C to 70C 0C to 125C
CAUTION: Stresses beyond the ratings specified in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Electrical Characteristics
(VCC = 12V, PGND = 0V, TA = 25C, unless otherwise specified) Parameter VCC Supply Current Nominal Supply Current Power-On Reset VCC Rising Threshold VCC Falling Threshold Rising VIN2 Under-voltage Threshold VIN2 Under-voltage Hysteresis Rising VOCSET1 Threshold Oscillator Free Running Frequency Ramp Amplitude VOSC 180 -200 1.9 225 -kHz VP-P VOCSET1 = 4.5V VOCSET1 = 4.5V 7.5 7 -----2.8 0.5 1.25 9.5 9 ---V V V V V ICC UGATE1, GATE3, LGATE1, and VOUT2 Open -10 -mA Symbol Test Conditions Min Typ Max Units
To be continued
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Parameter Reference and DAC DAC (VID0-VID4) Input Low Voltage DAC (VID0-VID4) Input High Voltage DACOUT Voltage Accuracy DACOUT Voltage Accuracy Reference Voltage (Pin FB2 and FB3) Linear Regulator Regulation Under-voltage Level Under-voltage Hysteresis Over-current Protection Over-current Protection During Start-up Linear Controller Regulation Under-voltage Level Under-voltage Hysteresis Output Drive Current PWM Controller Error Amplifier DC Gain PWM Controller Gate Driver UGATE Source UGATE Sink LGATE Source LGATE Sink Protection VOUT1 Over-voltage Trip FAULT Souring Current OCSET1 Current Source Soft-start Current Power Good VOUT1 Upper Threshold VOUT1 Under Voltage VOUT1 Hysteresis (VSEN1/DACOUT) PGOOD Voltage Low
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Symbol
Test Conditions
Min
Typ
Max
Units
-2.0 DACOUT = 2.05 ~ 3.50V DACOUT = 1.30 ~ 2.00V VREF 10mA < IVOUT2 < 150mA FB2 Rising -1 -1% 1.240
----1.265
0.8 -1 20mV 1.290
V V % V
-2.5 ---
-75 100 230 700
2.5 87 ----
% % mV mA mA
IOVP
180 --
VSEN3 = GATE3 0 < IGATE3 < 20mA FB3 Rising VIN2 - VOUT3 > 1.5V
-2.5 --20
-75 100 40
2.5 87 ---
% % mV mA
--
65
--
dB
RUGATE1
VCC = 12V VCC - VUGATE1 = 1V VCC = 12V VLGATE1 = 2V
-----
3 3 1 2
7 7 -6
A
RUGATE1 VUGATE1 = 1V ILGATE1
RLGATE1 VLGATE1 = 1V VSEN1 Rising IOVP IOCSET ISS VFAULT = 8V VOCSET1 = 4.5V VSS = 1V VSEN1 Rising VSEN1 Rising Upper/Lower Threshold IPGOOD = -4mA
112 10 170 --
115 14 200 11
120 -230 --
% mA A A
108 89 ---
--2 --
112 95 -0.5
% % % V
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Function Block Diagram
VSEN1 OCSET1 VCC
FB3 GATE3
3.3V
_ +
0.3V
LINEAR UNDER VOLTAGE
200A
110% + _ 90%
POWER-ON 3.3V RESET (POR)
+ _ +
VIN2 + _
1.26V
PGOOD VCC UGATE1
+ _ 115% +
LUV OC2 0V
VOUT2 FB2 +
0.25A
SOFT-START & FAULT LOGIC
VCC 11A 5V
OC1
+
FAULT GATE CONTROL PWM LOGIC PWM COMP OSCILLATOR COMPENSATION LOWER DRIVE VCC + +
TTL D/A CONVERTER (DAC)
ERROR AMP
SS VID0 VID2 VID4 VID1 VID3
FB1
Functional Pin Description
VCC (Pin 1) Provide a 12V bias supply for the IC to this pin. This pin also provides the gate bias charge for all the MOSFETs controlled by the IC. VID0, VID1, VID2, VID3, VID4 (Pin 6, 5, 4, 3, and 2) VID0~4 are the input pins to the 5-bit DAC. The states of these five pins program the internal voltage reference, DACOUT. The level of DACOUT sets the core converter output voltage. It also sets the core PGOOD and OVP thresholds. Table 1 specifies the DACOUT voltage of 32 combinations of VID levels. PGOOD (Pin 7) PGOOD is an open collector output used to indicate the status of the output voltage. This pin is pulled low when the core output is not within 10% of the
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DACOUT reference voltage and the other outputs are below their under-voltage thresholds. The PGOOD output is open for `11111' VID codes that inhibit operation. See table 1. FAULT (Pin 8) This pin is low during normal operation, but it is pulled to about 8V (VCC = 12V) in the event of an over-voltage or over-current condition. SS (Pin 9) Connect a capacitor from this pin to ground. This capacitor, along with an internal 11A (VSS>1V) current source, sets the soft-start interval of the converter.
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_
_
DACOUT
_
_
UPPER DRIVE _ INHIBIT PHASE1
_
LGATE1 PGND GND
RT9228
FB2 (Pin 11) Connect this pin to a resistor divider to set the linear regulator output voltage. VIN2 (Pin 12) this pin supplies power to the internal regulator. Connect this pin to a suitable 3.3V source. Additionally, this pin is used to monitor the 3.3V supply. If, following a startup cycle, the voltage drops below 2.8V (typically), the chip shuts down. A new soft-start cycle is initiated upon return of the 3.3V supply above the under-voltage threshold. VOUT2 (Pin 13) Output of the linear regulator. Supplies current up to 230mA. GND (Pin 14) Signal ground for the IC. All voltage levels are measured with respect to this pin. GATE3 (Pin 15) Connect this pin to drive gate of an external MOSFET or NPN. This pin provides the drive for the linear controller's pass transistor. FB3 (Pin 16) Connect this pin to a resistor divider to set the linear controller output voltage. FB1 (Pin 18) The FB1 pin is the inverting input of the error amplifier. VSEN1 (Pin 19) This pin is connected to the PWM converter's output voltage. The PGOOD and OVP comparator circuits use this signal to report output voltage status and for over voltage protection. OCSET1 (Pin 20) Connect a resistor (ROCSET1) from this pin to the drain of the upper MOSFET. ROCSET, an internal 200A current source (IOCSET1), and the upper MOSFET on-resistance (RDS(ON)) set the PWM converter over-current (OC) trip point according to the following equation: IOCSET1N ROCSET1 IPEAK = RDS (ON) An over-current trip cycles the soft-start function. Sustaining an over-current for 2 soft-start intervals shuts down the controller. PGND (Pin 21) This is the power ground of UGATE1 and LGATE1. Tie the PWM converter's lower MOSFET source to this pin. LGATE1 (Pin 22) Connect LGATE1 to the PWM converter's lower MOSFET gate. This pin provides the gate drive for the lower MOSFET. PHASE1 (Pin 23) Connect the PHASE1 pin to the PWM converter's upper MOSFET source. This pin is used to monitor the voltage drop across the upper MOSFET for overcurrent protection. UGATE1 (Pin 24) Connect UGATE1 pin to the PWM converter's upper MOSFET gate. This pin provides the gate drive for the upper MOSFET.
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Table 1. VOUT1 Voltage Program Pin Name VID4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 VID3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 VID2 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 VID1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 VID0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 Normal OUT1 Voltage DACOUT 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 1.85 1.90 1.95 2.00 2.05 INHIBIT 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00 3.10 3.30 3.30 3.40 3.50
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Typical Application Circuit
12V F1 5V 15A GND L1 1H C1-4 4x1000F + C20 1F 3.3V 1 VCC 12 20 OCSET1 VIN2 PGOOD GATE3 FB3 UGATE1 PHASE1 LGATE1 PGND VSEN1 7 24 23 22 21 19 C11 R5 0.68F 732K Q1 PHB83N03LT L2 R1 10 C5-6 2x1F C7 1000pF R2 1.21k POWERGOOD R3 10K + V OUT1 1.3 to 3.5V
+ C8 1000F Q3 RFD3055 V OUT3 1.5V R6 + C9 187 1000F R8 + C10 270F 1K R7 1K 15 16
RT9228
13 11 R9 1K 6 VID0 5 4 3 2 VID1 VID2 VID3 VID4 GND 14 VOUT2 FB2
V OUT2 2.5V
PHB95N03LT 3.5H C13-19 Q2 7x1000F R4 4.99K
FB1 18 FAULT 8 SS 9 C12 0.039F
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Package Information
H M
B
B
J
A C F D
I
Symbol A B C D F H I J M
Dimensions In Millimeters Min 15.189 7.391 2.362 0.330 1.194 0.229 0.102 10.008 0.381 Max 15.596 7.595 2.642 0.508 1.346 0.330 0.305 10.643 1.270
Dimensions In Inches Min 0.598 0.291 0.093 0.013 0.047 0.009 0.004 0.394 0.015 Max 0.614 0.299 0.104 0.020 0.053 0.013 0.012 0.419 0.050
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RICHTEK TECHNOLOGY CORP.
Headquarter
5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611
RICHTEK TECHNOLOGY CORP.
Taipei Office (Marketing)
8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com
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