L4957

UP TO 4A ULDO LINEAR REGULATOR

1.5V AND 2.5V FIXED OUTPUT VOLTAGE

3V TO 6.5V INPUT VOLTAGE RANGE

200m

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

200m

Ω 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.

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 22

µF 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.

February 2000

®

L4957

GND

OUT

IN

3

2

1

C1

3V to 6.5V

C2

D97IN657E

TYPICAL APPLICATION

ORDERING NUMBERS:

L4957V1.5

L4957D1.5

L4957V2.5

L4957D2.5

MULTIPOWER BCD TECHNOLOGY

1

3

D

Versawatt TO-220

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