TLC7701-Q1, TLC7705-Q1, TLC7733-Q1

MICROPOWER SUPPLY VOLTAGE SUPERVISORS

SGLS208A − OCTOBER 2003 − REVISED MAY 2008

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POST OFFICE BOX 655303

Voltage Drop

Reference

Capacitor

RAM With Battery Backup

description

The TLC77xx family of micropower supply voltage supervisors provide reset control, primarily in microcomputer

and microprocessor systems.

remains below the threshold voltage. An internal timer delays return of the output to the inactive state to ensure

Where

Except for the TLC7701, which can be customized with two external resistors, each supervisor has a fixed

SENSE threshold voltage set by an internal voltage divider. When SENSE voltage drops below the threshold

voltage, the outputs become active and stay in that state until SENSE voltage returns above threshold voltage

In addition to the power-on-reset and undervoltage-supervisor function, the TLC77xx adds power-down control

support for static RAM. When CONTROL is tied to GND, RESET will act as active high. The voltage monitor

contains additional logic intended for control of static memories with battery backup during power failure. By

driving the chip select (CS) of the memory circuit with the RESET output of the TLC77xx and with the CONTROL

driven by the memory bank select signal (CSH1) of the microprocessor (see Figure 10), the memory circuit is

automatically disabled during a power loss. (In this application the TLC77xx power has to be supplied by the

battery.)

Copyright

© 2008, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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CONTROL

RESIN

CT

GND

SENSE

RESET

RESET

PW PACKAGE

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