L4987

SERIES

VERY LOW DROP VOLTAGE REGULATORS

WITH INHIBIT AND DROPOUT CONTROL FLAG

October 1998

s

VERY LOW DROPOUT VOLTAGE (0.25V

TYP.)

s

DROPOUT CONTROL FLAG

s

VERY LOW QUIESCENT CURRENT

(TYP. 90

µA IN OFF MODE, 500µAIN ON

MODE)

s

OUTPUT CURRENT UP TO 200 mA

s

LOGIC-CONTROLLED ELECTRONIC

SHUTDOWN

s

OUTPUT VOLTAGES OF 3V, 5V 8.7V 12V

s

INTERNAL CURRENT AND THERMAL LIMIT

s

ONLY 2.2

µF FOR STABILITY

s

AVAILABLE IN

s

SUPPLY VOLTAGE REJECTION: 70 dB (TYP.)

DESCRIPTION

The L4987 is a very low drop regulator available

in PPAK. The very low drop-voltage (0.5V Max at

200 mA) and the very low quiescent current make

it particularly suitable for low noise, low power

applications, and in battey powered systems. The

input dump protection up to 40V makes it ideal for

automotive

applications.

a

shutdown

Logic

Control

function

is

available

(pin2,

TTL

compatible). This means that when the device is

used as a local regulator, it is possible to put a

part of the boad in standby, decreasing the total

power consumption. The regulator employs an

output pin (open collector) providing a logic signal

when the pass transistor is in saturation at low

input voltage, this signal can be used to prevent

the pop-up phenomenon in the car radio. In

battery powered systems (the cellular phone,

notebook) it is possible to use the flag to monitor

the battery charge status through the dropout of

the regulator.

SCHEMATIC DIAGRAM

PPAK

®

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