TL7702A, TL7705A, TL7709A, TL7712A, TL7715A

SUPPLY-VOLTAGE SUPERVISORS

SLVS028I − APRIL 1983 − REVISED JULY 2009

2

POST OFFICE BOX 655303

description/ordering information (continued)

The TL77xxA family of integrated-circuit supply-voltage supervisors is designed specifically for use as reset

controllers in microcomputer and microprocessor systems. The supply-voltage supervisor monitors the supply

for undervoltage conditions at the SENSE input. During power up, the RESET output becomes active (low)

function activates a time delay, after which outputs RESET and RESET go inactive (high and low, respectively).

When an undervoltage condition occurs during normal operation, RESET and RESET go active. To ensure that

a complete reset occurs, the reset outputs remain active for a time delay after the voltage at the SENSE input

exceeds the positive-going threshold value. The time delay is determined by the value of the external capacitor

this, the outputs are undefined.

An external capacitor (typically 0.1

µF) must be connected to REF to reduce the influence of fast transients in

the supply voltage.

functional block diagram

The functional block diagram is shown for illustrative purposes only; the actual circuit includes a trimming

network to adjust the reference voltage and sense-comparator trip point.

RESIN

≈100 µA

R1

(see Note A)

6

5

1

Reference

Voltage

SENSE

GND

8

3

7

2

4

CT

REF

NOTES: A. TL7702A: R1 = 0

Ω, R2 = open

TL7705A: R1 = 7.8 k

Ω, R2 = 10 kΩ

TL7709A: R1 = 19.7 k

Ω, R2 = 10 kΩ

TL7712A: R1 = 32.7 k

Ω, R2 = 10 kΩ

TL7715A: R1 = 43.4 k

Ω, R2 = 10 kΩ

B. Resistor values shown are nominal.

RESET

RESET

R2

(see Note A)