Regulator PSRR and ripple filtering
Ripple attenuation at a selected frequency with an optional loaded RC or LC output filter.
Development preview. Check the assumptions below before relying on a result. Calculations run in your browser.
How it calculates
Assumptions
- PSRR is a user-supplied value at the actual ripple frequency, headroom, current and bypass configuration; it is not assumed flat over the plotted sweep.
- Input and output ripple use the same amplitude convention (peak, RMS or peak-to-peak). Filter plot shows only passive-filter gain.
- Regulator output impedance and feedback interaction are omitted. Verify regulator stability and LC damping in the complete circuit.
Worked example
These are the calculator's default inputs. Change any input above to recalculate.
Inputs
- Input ripple amplitude (use one convention)
- 0.1 V
- Ripple frequency
- 100 Hz
- Regulator PSRR at this frequency/load
- 60 dB
- Output filter
- none
- Series R or inductor DCR
- 1 Ω
- Series inductance
- 0.001 H
- Shunt capacitance
- 0.0001 F
- Capacitor ESR
- 0.05 Ω
- Load resistance
- 100 Ω
- DC load current
- 0.05 A
Results
- Filtered ripple amplitude
- 0.0001 V
- Ripple before passive filter
- 0.0001 V
- Passive-filter voltage gain
- 1
- Combined attenuation
- 60 dB
- Passive-filter DC drop
- 0 V