LP2953QML Datasheet, PDF (19/24 Pages) Texas Instruments – Adjustable Micropower Low-Dropout Voltage Regulators

5V Battery Powered Supply with Backup and Low Battery Flag
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The circuit switches to the NI-CAD backup battery when the main battery voltage drops below about 5.6V, and returns to the main battery when its voltage is
recharged to about 6V.
The 5V MAIN output powers circuitry which requires no backup, and the 5V MEMORY output powers critical circuitry which can not be allowed to lose power.
* The BATTERY LOW flag goes low whenever the circuit switches to the NI-CAD backup battery.
5V Regulator with Timed Power-On Reset
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Timing Diagram for Timed Power-On Reset
* R_T = 1 MEG, C_T = 0.1 μF
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