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What are the main reset and supervisor IC categories?

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What are the main reset and supervisor IC

categories?

3.1

Reset and voltage detectors

These devices provide basic voltage monitoring and reset timing for the power-on reset

(POR) and low-voltage detect (LVD) function. Some devices feature an additional input

which can be used for push-button reset. Other devices are designed to monitor up to five

power supply voltages.

3.2

Microprocessor supervisors

These devices add additional features including a watchdog, early power fail warning, push-

button reset, and battery monitoring. Microprocessor supervisors with a switchover function

preserve SRAM data in the absence of system power by automatically switching to battery

backup when system power fails. A chip enable gate automatically write protects the SRAM

3.3

Smart resets

Smart resets extend the functional capability of existing buttons so that users can simply

reset their frozen device with a long push of one or two buttons simultaneously. Smart

Reset™ devices provide a useful feature that ensures inadvertent short reset push-button

closures do not cause system resets. This is done by implementing extended Smart

Reset™ input delay time and combined push-button inputs, which together ensure a safe

reset and eliminate the need for a specific dedicated reset button.

3.4

Watchdog timers

Watchdog timers are mandatory products for applications requiring the highest security

level. They are a robust and reliable way of monitoring software code execution or hardware

failure and taking appropriate action (example, system reboot, high level interrupt

generation).

For higher efficiency, the watchdog function is usually not integrated into the

microprocessor, but implemented with standalone products. STMicroelectronics offers

various watchdog implementations, allowing a match with most application environments.

3.5

Voltage protection

These devices provide the necessary protection that prevent external overvoltage peaks

from damaging the internal circuitry. They are commonly implemented on the power

charging patch of portable devices, to prevent a USB or an AC charger power failure.