Digital & PCB
555 Timer Astable Frequency Calculator
Design pulse generators, PWM clocks, and LED flashers instantly.
Input Parameters
Ω
Ω
μF
Calculation Results
Oscillation Frequency (Hz)
—
Duty Cycle (%)
—
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Formula & Theory
f = \frac{1.44}{(R_1 + 2R_2) \times C}
Frequently Asked Questions
Q: Can a 555 timer generate a 50% duty cycle?
Standard astable 555 duty cycle is always > 50%. A bypass diode across R2 is required for duty cycles <= 50%.