L5994 Datasheet, PDF (1/8 Pages) STMicroelectronics – ADJUSTABLE TRIPLE OUTPUT POWER SUPPLY CONTROLLER

®
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
50µA (@ 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
SYSTEM BLOCK DIAGRAM
TQFP32
ORDERING NUMBER: L5994
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.
5V
to
25V
SYNC
L5994
D98IN862
POWER
MANAGEMENT
& SYSTEM
SUPERVISOR
POWER
SECTION
2.5V
1.8V
12V LDO
5.1V LDO
3.39V REF
POWER GOOD
µP
MEMORY
PERIPHERALS
September 1999
1/8
This is preliminary information on a new product now in development. Details are subject to change without notice.