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ISL6554
Microprocessor CORE Voltage Regulator
Using Multi-Phase Buck PWM Control
Without Programmable Droop
The ISL6554 is the first controller in the Intersil Multi-Phase
family without the programmable droop feature. The
ISL6554 in combination with the HIP6601A, HIP6602A or
HIP6603A companion gate drivers and Intersil MOSFETs
form a complete solution for high-current, high slew-rate
applications. The ISL6554 regulates output voltage,
balances load currents and provides protective functions for
two to four synchronous-rectified buck-converter channels.
A novel approach to current sensing is used to reduce
overall solution cost. The voltage developed across the
lower MOSFET’s parasitic on-resistance during conduction
is sampled and fed back to the controller. This lossless
current-sensing approach allows the controller to maintain
phase-current balance between the power channels and
overcurrent protection.
A 5-bit DAC allows digital programming of the output voltage
in 25mV steps over a range from 0.95V to 1.70V with a
system accuracy of 1%. Internal pull ups on each DAC
input make external pull-up resistors unnecessary when
interfacing with open-drain output signals.
The PGOOD signal is held low during soft-start until the
output voltage increases to within 4% of the programmed.
When the CORE voltage falls 9% below the programmed
VID level, an undervoltage condition is detected and results
in PGOOD transitioning low.
In the event of an overvoltage condition, The converter shuts
down and turns ON the lower MOSFETs to clamp and
protect the microprocessor. Overcurrent protection reduces
the regulator RMS output current to 41% of the programmed
overcurrent trip value. These features provide monitoring
and protection for the microprocessor and power system.
Pinout
ISL6554 (SOIC)
TOP VIEW
Features
• Multi-Phase Power Conversion
• Precision Channel Current Balance
- Lossless Current Sampling - Uses r
DS(ON)
• Precision CORE Voltage Regulation
- 1% System Accuracy Over Temperature
- No Programmable Droop
• Microprocessor Voltage Identification Input
- 5-Bit VID Decoder
- 0.95V to 1.70V in 25mV Steps
• Fast Transient Response
• Overcurrent Protection
• Selection of 2, 3, or 4 Phase Operation
• High Ripple Frequency (80kHz to 2MHz)
• Pb-Free Available (RoHS Compliant)
Applications
• Power Supply Controller for Intel® Itanium™ Processor
Family
• Voltage Regulator Modules
• Servers and Workstations
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12
13
14
15
16
17
18
20
19
10
9
8
7
6
5
4
3
2
1
VID4
VID3
VID2
VID1
VID0
FS/DIS
PWM2
PGOOD
PWM3
ISEN4
ISEN1
VCC
GND
ISEN3
FB
PWM4
VSEN
COMP
PWM1
ISEN2
Ordering Information
PART NUMBER TEMP. (°C) PACKAGE
PKG.
DWG. #
ISL6554CB 0 to 70 20 Ld SOIC M20.3
ISL6554CB-T 20 Ld SOIC Tape and Reel
ISL6554CBZ (Note) 0 to 70 20 Ld SOIC
(PB-free)
M20.3
ISL6554CBZ-T (Note) 20 Ld SOIC Tape and Reel (PB-free)
ISL6554CBZA (Note) 0 to 70 20 Ld SOIC
(PB-free)
M20.3
ISL6554CBZA-T (Note) 20 Ld SOIC Tape and Reel (PB-free)
NOTE: Intersil Pb-free products employ special Pb-free material sets;
molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and 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-020C.
FN9003.3Data Sheet February 11, 2005
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. 2001, 2004, 2005. All Rights Reserved. Intel® is a registered trademark of Intel Corporation.
Itanium™ is a trademark of Intel Corporation. All other trademarks mentioned are the property of their respective owners.
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