L4957 Datasheet, PDF (1/7 Pages) STMicroelectronics – UP TO 4A ULDO LINEAR REGULATOR

®
L4957
UP TO 4A ULDO LINEAR REGULATOR
1.5V AND 2.5V FIXED OUTPUT VOLTAGE
3V TO 6.5V INPUT VOLTAGE RANGE
200mΩ Rdson TYPICAL @ Tj = 125°C
0.6V max. DROP-OUT AT 2A
EXCELLENT LOAD REGULATION
0.6mA QUIESCENT CURRENT AT ANY LOAD
SHORT CIRCUIT PROTECTION WITH FOLD-
BACK
THERMAL SHUTDOWN
APPLICATIONS
MOTHER BOARDS
PROCESSOR I/O & SUPPLIES
LOW VOLTAGE MEMORY & CHIP SET SUP-
PLIES
GRAPHIC & SOUND CARDS
LOW VOLTAGE LOGIC SUPPLIES
POST REGULATOR FOR SMPS
DESCRIPTION
The L4957 devices are Ultra Low Drop Output lin-
ear regulators with an internal N-channel MOS of
200mΩ particulary suitable for low voltage/low
dropout applications.
Operating with a input voltage from 3V to 6.5V
they are capable to deliver up to 4A at 1.5V or
2.5V fixed output voltages.
MULTIPOWER BCD TECHNOLOGY
3
1
Versawatt TO-220
D²PAK
ORDERING NUMBERS:
L4957V1.5
L4957V2.5
L4957D1.5
L4957D2.5
The devices are ideal for use as one of the sup-
plies required by processor, for example they are
the cost effective and efficient solution for conver-
sion from 3.3V (rail bus) to 2.5V @ 2.5A or to
1.5V with high current rating.
Fast response transient minimise the output ca-
pacitor value. A minimum of 22µF assures the
stability in all load conditions.
The on-chip trimming technique offers a tighter
voltage reference tolerance (with ± 2% including
line and load variation) beside to ensure a con-
trolled short circuit current. Thermal shutdown
provides protection against overload conditions
that creates excessive junction temperature.
TYPICAL APPLICATION
3V to 6.5V
IN
1
L4957
OUT
3
V_OUT=1.5V/2.5V
C1
C2
2
GND
D97IN657E
February 2000
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