Watchdog Timer

Watchdog Timer

Safety Features Application

Watchdog timers are used for automatically generating a system reset signal if the microcontroller or microprocessor neglects to periodically send a pulse. Monitoring for low supply voltage is an additional, common feature of watchdog ICs.

 

Ingredients

  • Any GreenPAK w/ ACMP’s
  • No other components are needed

GreenPAK Diagram

Design Steps

  1. Set undervoltage threshold with an ACMP.
  2. Configure two CNT/DLY blocks as Frequency detects.
  3. Design the digital logic to combine active signals from undervoltage and watchdog timeout.
  4. Add a One-shot counter to trigger the reset pulse. It can be inverted to be active low.

Resources

GreenPAK Designer files