ISL6553
TM
Data Sheet
November 2000
File Number 4931
Microprocessor CORE Voltage Regulator
Multi-Phase Buck PWM Controller
Features
• Multi-Phase Power Conversion
The ISL6553 multi-phase PWM control IC together with its
companion gate drivers, the HIP6601, HIP6602 or HIP6603
and Intersil MOSFETs provides a precision voltage
regulation system for advanced microprocessors. Multi-
phase power conversion is a marked departure from earlier
single phase converter configurations previously employed
to satisfy the ever increasing current demands of modern
microprocessors. Multi-phase converters, by distributing the
power and load current results in smaller and lower cost
transistors with fewer input and output capacitors. These
reductions accrue from the higher effective conversion
frequency with higher frequency ripple current due to the
phase interleaving process of this topology. For example, a
two phase converter operating at 350kHz will have a ripple
frequency of 700kHz. Moreover, greater converter
bandwidth of this design results in faster response to load
transients.
• Precision Channel Current Sharing
- Loss Less Current Sampling - Uses r
DS(ON)
• Precision CORE Voltage Regulation
- ±1% System Accuracy Over Temperature
• Microprocessor Voltage Identification Input
- 5-Bit VID Input
- 1.05V to 1.825V in 25mV Steps
- Programmable “Droop” Voltage
• Fast Transient Recovery Time
• Over Current Protection
• High Ripple Frequency, (Channel Frequency) Times
Number Channels . . . . . . . . . . . . . . . . . 100kHz to 3MHz
Related Literature
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
Outstanding features of this controller IC include
programmable VID codes from the microprocessor that
range from 1.05V to 1.825V with a system accuracy of ±1%.
Pull up currents on these VID pins eliminates the need for
external pull up resistors. In addition “droop” compensation,
used to reduce the overshoot or undershoot of the CORE
voltage, is easily programmed with a single resistor.
Ordering Information
o
PART NUMBER
TEMP. ( C)
PACKAGE
PKG. NO.
ISL6553CB
0 to 70
16 Ld SOIC
M16.15
ISL6553CB-T
ISL6553EVAL1
16 Ld SOIC Tape and Reel
Evaluation Platform
Another feature of this controller IC is the PGOOD monitor
circuit which is held low until the CORE voltage increases,
during its Soft-Start sequence, to within 10% of the
programmed voltage. Over-voltage, 15% above programmed
CORE voltage, results in the converter shutting down and
turning the lower MOSFETs ON to clamp and protect the
microprocessor. Under voltage is also detected and results
in PGOOD low if the CORE voltage falls 10% below the
programmed level. Over-current protection reduces the
regulator RMS output current to 41% of the programmed
over-current trip value. These features provide monitoring
and protection for the microprocessor and power system.
Pinout
ISL6553 (SOIC)
TOP VIEW
VID3
1
2
3
4
5
6
7
8
16 VCC
VID2
VID1
15 PGOOD
14 ISEN1
13 PWM1
12 PWM2
11 ISEN2
10 VSEN
VID0
VID25mV
COMP
FB
FS/DIS
9
GND
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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