74hc14 Oscillator Calculator Jun 2026
Multiply R×C, then look up f:
is too low, the output drive current limits of the IC will distort the waveform. If
+---[ R ]---+ | | -----[Inverter]---+---- Output | (74HC14) +-[C]- Ground The Switching Cycle When the circuit powers up, the capacitor 74hc14 oscillator calculator
thigh=R⋅C⋅ln(VCC−VT−VCC−VT+)t sub h i g h end-sub equals cap R center dot cap C center dot l n open paren the fraction with numerator cap V sub cap C cap C end-sub minus cap V sub cap T minus end-sub and denominator cap V sub cap C cap C end-sub minus cap V sub cap T plus end-sub end-fraction close paren
The frequency of the oscillator is not simply determined by a fixed time constant (RC). It is dictated by the switching thresholds of the Schmitt trigger ( ) relative to the VCCcap V sub cap C cap C end-sub supply voltage. The Formula Multiply R×C, then look up f: is too
) depends on the time it takes the capacitor to charge and discharge between the chip's upper and lower switching thresholds.
The output pin of the 74HC14 has a maximum current rating. The Formula ) depends on the time it
, the standard RC charge/discharge formulas yield the following timing equations:
) connected to it. While theoretical physics provides complex exponential equations, the most common empirical formula for a quick calculation is:
are not perfectly fixed, this oscillator is excellent for clocking simple logic but is not recommended for high-precision timing applications where a crystal oscillator would be more appropriate.