Schmitt RC oscillator
Frequency and duty from actual high/low output levels and Schmitt thresholds.
Development preview. Check the assumptions below before relying on a result. Calculations run in your browser.
How it calculates
Model: tH=RC ln[(VOH−VT−)/(VOH−VT+)]; tL=RC ln[(VT+−VOL)/(VT−−VOL)]
Assumptions
- Use the selected device’s thresholds at actual supply and temperature. Defaults are illustrative, not guaranteed SN74HC14 or LVC thresholds.
- Inverting Schmitt gate with resistor from output to input and capacitor from input to ground; propagation delay is neglected.
Worked example
These are the calculator's default inputs. Change any input above to recalculate.
Inputs
- Feedback resistance
- 10000 Ω
- Timing capacitance
- 1e-8 F
- Output high voltage
- 3.3 V
- Output low voltage
- 0 V
- Upper input threshold
- 2 V
- Lower input threshold
- 1 V
Results
- Frequency
- 7913.32 Hz
- Output-high duty
- 45.149 %
- High time
- 0.0000570545 s
- Low time
- 0.0000693147 s