TPS3431: TPS3431

Zsolt Danyi

Part Number: TPS3431
Other Parts Discussed in Thread: TPS3430,

Hello,

I would like to ask about Watchdog timers, since I haven't used them so far. I would like to watch my uController on a WDI input and trigger an event if the uC is outside the startup delay. But with my WDO I would like to feed a logic AND gate which through a relay turns ON or OFF of my safety relevant circuit. My question is how to relize a watchdog timer circuit which output stays constant after a WDI trigger, and can be resettable if the system comes back to life.

Thank you very much in advance.

Zsolt

over 1 year ago

0 Joshua Garcia over 1 year ago

TI__Genius 10500 points

Hi Zsolt,

"Output stays constant after a WDI trigger" I believe what you are referring to is a feature we call latching. Latching can be achieved following the design example in section 8.2.3 Monitoring Microcontroller with a Latching Window Watchdog Timer - Design 3 of the TPS3430 datasheet https://www.ti.com/lit/ds/symlink/tps3430.pdf?ts=1706305839859&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS3430. Please note that although this design example is for the TPS3430 window watchdog device it also works for the TPS3431 standard timeout watchdog device.

Further information on latching and the difference between window and standard watchdogs can be found https://www.ti.com/seclit/eb/slyy167/slyy167.pdf?ts=1706306195836&ref_url=https%253A%252F%252Fe2e.ti.com%252F.

Thanks,
Joshua

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TPS3431: TPS3431