tinytinker.toolselectronics555 timer calculator

555 timer calculator

calculate frequency, duty cycle and timing for 555 timer circuits in astable and monostable modes.

astable mode generates a continuous square wave. frequency and duty cycle are set by R1, R2 and C.

VCCR1R2Cpin 7 (discharge)pin 2/655572/6138pin 8 (VCC)pin 1 (GND)output
R1
R2
C
frequency480 Hz
period2.079 ms
duty cycle66.67%
time high1.386 ms
time low693 µs
duty cycle
0%50%100%
pin reference
1GND
2trigger
3output
4reset (active low)
5control voltage
6threshold
7discharge
8VCC