TL7700A Series

April 2000

SUPPLY VOLTAGE SUPERVISORS

®

.

POWER-ON RESET GENERATOR

.

AUTOMATIC RESET GENERATION AFTER

VOLTAGE DROP

.

WIDE SUPPLY VOLTAGE RANGE ... 3V TO

18V

.

PRECISION VOLTAGE SENSOR

.

TEMPERATURE-COMPENSATED VOLTAGE

REFERENCE

.

TRUE AND COMPLEMENT RESET OUTPUTS

.

EXTERNALLY ADJUSTABLE PULSE WIDTH

N

Min idip

DESCRIPTION

The TL7700Aseriesaremonolithicintegratedcircuit

supplyvoltagesupervisorsspecifically desi-gned for

use as reset controllers in microcomputer and mi-

croprocessor systems. During power-up the device

tests the supply voltage and keeps the RESET and

RESET outputs active (high and low, respectively)

as long as the supply voltage has not reached its

nominal voltage value. Taking RESIN low has the

same effect. To ensure that the microcomputer sys-

tem hasreset, the TL7700Athen initiates an internal

time delay that delays the return of the reset outputs

to theirinactivestates. Since the timedelay for most

microcomputersand microprocessors is in the order

of several machine cycles, the device internal time

delay is determined by an external time delay is de-

termined by an external capacitor connected to the

addition, when the supply voltage drops below the

nominal value, the outputs will be active until the

supply voltage returns to the nominal value. An ex-

ternalcapacitor(typically0.1

µF)mustbe connected

to the REF output (pin 1) to reduce the influence of

fast transients in the supply voltage.

The TL7700AI series is characterized for operation

from – 25

acterized from 0

D

SO 8

ORDERING NUMBERS

Temperature Range

Minidip

S08

0to 70

TL77XXACP

TL77XXACD

-25 to 85

TL77XXAIP

TL77XXAID

PIN CONNECTION (top view)

1/7