$$ f \approx \frac0.8R \cdot C $$

) will be a "shark-fin" or exponential triangle wave, while the output of the 74HC14 will be a clean square wave. Final Calculation Summary To find your frequency, use the simplified estimation:

While specific chip manufacturers have slight variations due to internal threshold levels, the most common practical formula for a

Duty cycle D = ln[(VCC − V_T−)/(VCC − V_T+)] / ln( (VCC − V_T−)·V_T+ / ((VCC − V_T+)·V_T−) )

Some web calculators show the circuit diagram and waveform.

The input voltage at which the output switches from HIGH to LOW. Negative-going Threshold ( cap V sub cap T minus end-sub