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TN0941

What are the following additional options of reset and supervisor ICs used for?

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What are the following additional options of reset

and supervisor ICs used for?

6.1

Backup battery switchover

A common task of battery switchover devices is to provide an uninterrupted power supply to

external devices (SRAM for example) in the event of a power failure (voltage drops,

brownout). Battery switchover devices can also be useful in portable devices. When the

external power supply (such as the AC power supply adapter) is disconnected, the battery

switchover device switches to the internal supply (such as a battery). Battery switchover

devices can be used as a main power supply backup for MCUs, memories, and other

peripherals, and to prevent system failures.

Advantages of battery switchover devices

•

They provide continuous and reliable operation, even if the external supply fails

•

They extend the battery lifetime

•

They allow debouncing of the power spikes while connecting and disconnecting the AC

adapter.

Note:

switchover operate. This mode allows a battery to be attached during manufacturing but not

used until the system has been activated for the first time. As a result, no battery power is

consumed by the device during storage and shipment. If the backup battery is not used,

More details

See AN1957: Microprocessor Supervisor Functions, page 13

Suggested products

For further information on battery switchover devices, please refer to the following products:

STM690, STM704, STM795, STM802, STM804, STM805, STM806, STM817, STM818,

and STM819.

Design tip

power-up transients such as charging a decoupling capacitor - destroys the device.

0.1

μF capacitors as close to the device as possible.