NE555 as PWM generator

Post date: Mar 12, 2019 4:20:40 AM

NE555 as PWM Generator

The output frequency of the PWM signal is controlled by selecting the variable resistor R3 and capacitor C2. A variable resistor in place of fixed resistor is used for changing duty cycle of the output signal. Capacitor Charging through D1 diode and Discharge through D2 diode will generates PWM signal at 555 timer's output pin.

Below formula is used for deriving the frequency of the PWM signal:

F = 0.693*RV3*C2