A watchdog is a timer and activates its output when the IC lost an input pulse for a period.

It is a building block and can use for any application.

So, they can use in any application, for example, change data routing in fail-safe mode. When the MCU clock fails, we can't disable some critical outputs.

external watchdog not related to the complex clock domain of MCU, some of them has their analog RC charge timing or internal clock.

Digital circuits in radiation may trigger the outputs when charge hits its flip-flops. But some analog circuit is safer because they integrate charge in a capacitor and it is safe when we integrating it.

A watchdog is a timer and activates its output when the IC lost an input pulse for a period.

It is a building block and can be used for any application.

So, they can be used in any application, for example, change data routing in fail-safe mode. When the microcontroller clock fails, we can't disable some critical outputs.

An external watchdog is not related to the complex clock domain of the microcontroller, and some of them have their analog RC charge timing or internal clock.

Digital circuits in radiation may trigger the outputs when charge hits their flip-flops. But some analog circuit is safer because they integrate charge in a capacitor, and it is safe when we integrate it.