ISL6523A Datasheet, PDF (1/16 Pages) Intersil Corporation – VRM8.5 Dual PWM and Dual Linear Power System Controller

TM
Data Sheet
February 2002
ISL6523A
FN9063
VRM8.5 Dual PWM and Dual Linear Power
System Controller
The ISL6523A provides the power control and protection for
four output voltages in high-performance microprocessor
and computer applications. The IC integrates two PWM
controllers and two linear controllers, as well as the
monitoring and protection functions into a 28-pin SOIC
package. One PWM controller regulates the microprocessor
core voltage with a synchronous-rectified buck converter.
The second PWM controller supplies the computer system’s
AGTL+ 1.2V bus power with a standard buck converter. The
linear controllers regulate power for the 1.5V AGP bus and
the 1.8V power for the chipset core voltage and/or cache
memory circuits.
The ISL6523A includes an Intel VRM8.5 compatible, TTL
5-input digital-to-analog converter (DAC) that adjusts the
microprocessor core-targeted PWM output voltage from
1.050V to 1.825V in 25mV steps. The precision reference
and voltage-mode control provide ±1% static regulation. The
second PWM controller’s output provides a voltage level of
1.2V with ±3% accuracy. The linear regulators use external
N-channel MOSFETs or bipolar NPN pass transistors to
provide fixed output voltages of 1.5V ±3% (V_OUT3) and 1.8V
±3% (V_OUT4).
The ISL6523A monitors all the output voltages. A delayed-
rising VTT (standard buck output) Power Good signal is
issued before the core PWM starts to ramp up. Another
system Power Good signal is issued when the core is within
±10% of the DAC setting and all other outputs are above
their under- voltage levels. Additional built-in overvoltage
protection for the core output uses the lower MOSFET to
prevent output voltages above 115% of the DAC setting. The
PWM controllers’ overcurrent function monitors the output
current by using the voltage drop across the upper
MOSFET’s r_DS(ON), eliminating the need for a current
sensing resistor.
Ordering Information
TEMP.
PART NUMBER RANGE (^oC)
PACKAGE
ISL6523ACB
0 to 70 28 Ld SOIC
ISL6523EVAL1
Evaluation Board
PKG.
NO.
M28.3
Features
• Provides 4 Regulated Voltages
- Microprocessor Core, AGTL+ Bus, AGP Bus Power,
and North/South Bridge Core
• Drives N-Channel MOSFETs
• Linear Regulator Drives Compatible with both MOSFET
and Bipolar Series Pass Transistors
• Simple Single-Loop Control Designs
- Voltage-Mode PWM Control
• Fast PWM Converter Transient Response
- High-Bandwidth Error Amplifiers
- Full 0% to 100% Duty Ratios
• Excellent Output Voltage Regulation
- Core PWM Output . . . . . . . . . . ±1% Over Temperature
- All Other Outputs . . . . . . . . . . . . . ±3% Over Temperature
• VRM8.5 TTL-Compatible 5-Bit DAC Microprocessor Core
Output Voltage Selection
- Wide Range . . . . . . . . . . . . . . . . . . . . 1.050V to 1.825V
• Power-Good Output Voltage Monitors
- Separate delayed VTT Power Good
• Overcurrent Fault Monitors
- Switching Regulators Do Not Require Extra Current
Sensing Elements, Use MOSFET’s r_DS(ON)
• Small Converter Size
- Constant Frequency Operation
- 200kHz Internal Oscillator
Applications
• _{Motherboard Power Regulation for Computers}
Pinout
ISL6523A (SOIC)
TOP VIEW
UGATE2 1
PHASE2 2
VID3 3
VID2 4
VID1 5
VID0 6
VID25 7
PGOOD 8
VTTPG 9
OCSET2 10
VSEN2 11
SS24 12
SS13 13
VSEN4 14
28 VCC
27 UGATE1
26 PHASE1
25 LGATE1
24 PGND
23 OCSET1
22 VSEN1
21 FB1
20 COMP1
19 VSEN3
18 DRIVE3
17 GND
16 VAUX
15 DRIVE4
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2002. All Rights Reserved