1

®

FN9096.3

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

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ISL6556A

Optimized Multi-Phase PWM Controller

with 6-Bit DAC for VR10.X Application

The ISL6556A controls microprocessor core voltage

regulation by driving up to 4 synchronous-rectified buck

channels in parallel. Multi-phase buck converter architecture

uses interleaved timing to multiply channel ripple frequency

and reduce input and output ripple currents. Lower ripple

results in fewer components, lower component cost, reduced

power dissipation, and smaller implementation area.

phase for adaptive voltage positioning (droop), channel-

current balancing, and overcurrent protection. To ensure

droop accuracy, an external NTC compensation circuit can

be used to completely nullify the effect of temperature

A unity gain, differential amplifier is provided for remote

voltage sensing. Any potential difference between remote

and local grounds can be eliminated using the remote-sense

amplifier. The precision threshold-sensitive enable input is

available to accurately coordinate the start up of the

ISL6556A with Intersil MOSFET driver IC. Dynamic-VID™

technology allows seamless on-the-fly VID changes. The

offset pin allows accurate voltage offset settings that are

independent of VID setting. The ISL6556A uses 5V bias and

has a built-in shunt regulator to allow 12V bias using only a

small external limiting resistor.

Features

• Precision Multi-Phase Core Voltage Regulation

- Differential Remote Voltage Sensing

-

±0.5% System Accuracy Over Temperature and Life

- Adjustable Reference-Voltage Offset

- Accurate Load-Line Programming

- Accurate Channel-Current Balancing

- Low-Cost, Lossless Current Sensing

• Internal Shunt Regulator for 5V or 12V Biasing

• Microprocessor Voltage Identification Input

- Dynamic VID™ Technology

- 6-Bit VID Input

- 0.8375V to 1.600V in 12.5mV Steps

• Threshold Enable Function for Precision Sequencing

• Overcurrent Protection

• Overvoltage Protection

- No Additional External Components Needed

- OVP Pin to drive optional Crowbar Device

• 2, 3, or 4 Phase Operation up to 1.5MHz per Phase

• QFN Package Option

- QFN Compliant to JEDEC PUB95 MO-220 QFN - Quad

Flat No Leads - Product Outline

- QFN Near Chip Scale Package Footprint; Improves

PCB Efficiency, Thinner in Profile

• Pb-free Available (RoHS Compliant)

Ordering Information

PART NUMBER* TEMP. (°C)

PACKAGE

PKG. DWG. #

ISL6556ACB

0 to 70

28 Ld SOIC

M28.3

ISL6556ACBZ

(Note)

0 to 70

28 Ld SOIC

(Pb-free)

M28.3

ISL6556ACR

0 to 70

32 Ld 5x5B QFN L32.5x5B

ISL6556ACRZ

(Note)

0 to 70

32 Ld 5x5B QFN

(Pb-free)

L32.5x5B

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.

*Add “-T” suffix for tape and reel.

Data Sheet

December 29, 2004