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SC1474

Power Supply Controller

POWER MANAGEMENT

Revision 6, December 2002

Description

Features

Applications

Typical Application Circuit

IMVP3 compliant single chip solution

High speed Dual phase hysteretic controller

VID programmable output

Dual integrated 2A/4A drivers

Integrated VID regulator controller

Automatic performance/battery mode detection

Dynamic phase current matching

Under-voltage lock out on all Vcc inputs

Over-voltage protection on CORE

Current Limit protection on CORE

Thermal protection

Programmable soft-start

Powergood flag with blanking during VID changes

Automatic powersave at light load

TSSOP-38 package

Industrial temperature range

The SC1474 PowerStep III™ IC is a single chip high-per-

formance Hysteretic PWM controller. With dual integrated

Smart™ Drivers, it powers advanced Pentium® 4 pro-

cessors. The SC1474 features extended Intel Mobile Volt-

age Positioning (IMVP) to increase battery life by reduc-

ing the voltage at the processor when it is heavily loaded.

It directly supports Intel’s SpeedStep™ requirements for

even longer battery life. The SC1474 automatically de-

tects performance and battery mode VIDs. In addition, it

integrates direct “deeper sleep” mode support. All op-

erating modes incorporate automatic “power-save” to

prevent negative current flow in the low-side FET during

light loading conditions, saving even more power.

A 5-bit DAC, accurate to 0.85%, sets the output voltage

reference, and implements the 0.600V to 1.750V range

required by the processor. The hysteretic converter uses

a comparator without an error amplifier, and so provides

the fastest possible transient response, while avoiding

the stability issues inherent to classical PWM controllers.

The SC1474 incorporates a controller for V_VID and au-

tomatically provides the proper sequencing.

The SC1474 operates from +3.3Vdc Vcca and dual 5V

DC drive inputs. It also features soft-start, an open-drain

PWRGD signal with power-good blanking, and an enable

input. Programmable current limiting latches the SC1474

off after 32 current limit pulses. It comes in a space-

saving TSSOP-38 package.

Advanced Intel microprocessors

SC1474

Dual Phase

Extended IMVP

CONTROLLER

VID [4:0]

Lo

+VCORE

+V_IN

+V_5

0.600V-1.75V

Up to 40A

Extended

IMVP

Logic

Controller

Power

Control

Signals

Smart

Driver

VID

Multiplexer

Lo

Co

Smart

Driver

Rcs

Rcs

+V_3

+V_VID

VID

Regulator

Controller

SC1474

Dual Phase

Extended IMVP

CONTROLLER

VID [4:0]

Lo

+VCORE

+V_IN

+V_5

0.600V-1.75V

Up to 40A

Extended

IMVP

Logic

Controller

Power

Control

Signals

Smart

Driver

VID

Multiplexer

Lo

Co

Smart

Driver

Rcs

Rcs

+V_3

+V_VID

VID

Regulator

Controller