ISL6523 Datasheet, PDF (1/16 Pages) Intersil Corporation – VRM8.5 Dual PWM and Dual Linear Power System Controller

®
Data Sheet
July 2004
ISL6523
FN9024.2
VRM8.5 Dual PWM and Dual Linear Power
System Controller
The ISL6523 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 ISL6523 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 ISL6523 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
ISL6523CB
0 to 70 28 Ld SOIC
ISL6523CBZ
(See Note)
0 to 70
28 Ld SOIC
(Pb-free)
ISL6523EVAL1 Evaluation Board
*Add “-T” suffix to part number for tape and reel packaging.
PKG.
DWG. #
M28.3
M28.3
NOTE: Intersil Pb-free products employ special Pb-free material sets; molding
compounds/die attach materials and 100% matte tin plate termination finish, which
is compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free
products are MSL classified at Pb-free peak reflow temperatures that meet or
exceed the Pb-free requirements of IPC/JEDEC J Std-020B.
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
• Pb-free available
Applications
• _{Motherboard Power Regulation for Computers}
Pinout
ISL6523 (SOIC)
TOP VIEW
UGATE2 1
28 VCC
PHASE2 2
27 UGATE1
VID3 3
VID2 4
VID1 5
26 PHASE1
25 LGATE1
24 PGND
VID0 6
23 OCSET1
VID25 7
22 VSEN1
PGOOD 8
21 FB1
VTTPG 9
20 COMP1
OCSET2 10
19 VSEN3
VSEN2 11
18 DRIVE3
SS24 12
17 GND
SS13 13
16 VAUX
VSEN4 14
15 DRIVE4
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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