Digital reset circuits

Simple reset circuits for digital devices like MCUs and simple devices based on counters and triggers. Upper circuit is intended to briefly switch RESET pin to HIGH state on power cycle or reset button press. For 4017 counter and 4060 timer-counter based circuits this guarantee that on reset or power cycle counting will always begin from 0. FYI: 100 kOm resistor at left side IS NOT a part of circuit. It emulate resistance between VCC and ground in a real circuit. This resistance discharge capacitor in the reset circuit when the device is powered off. Bottom circuit switch RESET pin to LOW state on turning the device on and or pressing the reset button or on power loss. Add NOT logic gate or transistor inverter at output for opposite signal. Circuit works for both 3.3V and 5V logic. Transistor is general purpose PNP signal transistor like 2N3906. In both circuits logic gate with LED at right is not the part of circuit, but is general depiction of the connected logic.

published 1 year ago