Design diode clipping circuits with realistic soft-knee behavior based on the Shockley diode equation. Supports feedback (soft) and shunt (hard) clipping topologies.
| Clipping type: |
| Input (peak): | V |
| Rin: | Ω |
| Rf: | Ω |
| R series: | Ω |
| Pre-clip gain: | V/V |
| Supply (±): | V |
| Symmetric: | Same diodes for +/- |
| Positive clip: | |
| Negative clip: |
Clipping thresholds based on real diode Shockley parameters. Forward voltage varies with current - shown at 1mA reference and actual signal current.
| D+ Vf (@ 1mA): | |
| D- Vf (@ 1mA): | |
| Positive clip threshold: | |
| Negative clip threshold: | |
| Peak diode current: |
| Pre-clipping gain: | |
| Unclipped output: | |
| Clipped output: |
Output vs input showing the soft-knee clipping behavior. The gradual rolloff is characteristic of real diodes following the Shockley equation.
Input sine wave (blue) and clipped output (red). Notice the soft knee - real diodes don't clip sharply like ideal limiters.
Harmonic content of the clipped signal. Symmetric clipping produces odd harmonics (3rd, 5th...), while asymmetric clipping adds even harmonics (2nd, 4th...).
Shockley diode equation: I = Is × (eV/(n×Vt) - 1)
Vt (thermal voltage) = 25.85 mV at 25°C
| Type | Is | n | Vf @ 1mA |
|---|---|---|---|
| Silicon 1N4148 | 2.5 nA | 1.8 | ~0.65V |
| Germanium 1N34A | 200 nA | 1.3 | ~0.25V |
| Schottky BAT41 | 100 nA | 1.05 | ~0.27V |
| GaAs | 1 pA | 1.5 | ~1.0V |
| Red LED | 1 pA | 2.0 | ~1.7V |
| Green LED | 0.1 pA | 2.0 | ~2.0V |
| Blue LED | 0.01 pA | 2.0 | ~2.7V |