L5994

ADJUSTABLE TRIPLE OUTPUT

POWER SUPPLY CONTROLLER

PRODUCT PREVIEW

DUAL PWM BUCK CONTROLLERS

ADJUSTABLE

1.9V to 5V (Section 1)

1.66V to 3.5V (Section 2)

12V/120mA LINEAR REGULATOR

DUAL SYNCH RECTIFIERS DRIVERS

96% EFFICIENCY ACHIEVABLE

50

µA (@ 12V) STAND BY CONSUMPTION

5.0V TO 25V SUPPLY VOLTAGE

EXCELLENT LOAD TRANSIENT RESPONSE

DISABLE PULSE SKIPPING FUNCTION

OUTPUT UNDERVOLTAGE SHUTDOWN

POWER MANAGEMENT:

- UNDER AND OVERVOLTAGE OUTPUT

DETECTION

- POWER GOOD SIGNAL

- SEPARATED DISABLE

THERMAL SHUTDOWN

PACKAGE: TQFP32

APPLICATION

NOTEBOOK AND SUBNOTEBOOK COM-

PUTERS

PEN TOP AND PORTABLE EQUIPMENT

COMMUNICATING COMPUTERS

DESCRIPTION

The L5994 is a sophisticated dual PWM step-

down controller and power monitor intended for

Notebook computer and/or battery powered

equipment. The device produces regulated 1.8V,

2.5V (both adjustable) and 12V supplies for use in

portable and PCMCIA applications.

The internal architecture allows to operate with

minimum external components count. A very high

switching frequency (200/300 KHz or externally

synchronizable) optimizes their physical dimen-

sions.

Synchronous rectification and pulse skipping

mode for the buck sections optimise the overall

efficiency over a wide load current range.

The two high performance PWM controllers for

1.8V and 2.5V lines are monitored for overvol-

tage, undervoltage and overcurrent conditions.

On detection of a fault, a POWER GOOD signal

is generated and a specific shutdown procedure

takes place to prevent physical damage and data

corruption.

A disable function allows to manage the output

power sections separately, optimising the quies-

cent consumption of the IC in stand-by conditions.

This is preliminary information on a new product now in development. Details are subject to change without notice.

September 1999

®

SYNC

POWER

MANAGEMENT

& SYSTEM

SUPERVISOR

5V

to

25V

2.5V

1.8V

POWER

SECTION

L5994

µP

MEMORY

PERIPHERALS

12V LDO

5.1V LDO

3.39V REF

D98IN862

POWER GOOD

SYSTEM BLOCK DIAGRAM

TQFP32

ORDERING NUMBER: L5994

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