Practical integrator
Practical integrator with circuit equations and operating-limit checks.
Development preview. Check the assumptions below before relying on a result. Calculations run in your browser.
How it calculates
Lossy integrator: H(s) = −(Rf/Rin)/(1+s Rf Cf)
Ideal ramp: dVout/dt = −Vin/(Rin Cf)
Offset drift bound: |dVout/dt| ≈ |Vos/Rin + Ib|/Cf
Assumptions
- Rf is in parallel with Cf. Step trace is the unclipped lossy-integrator response. Drift-to-rail assumes an ideal integrator without Rf and a constant worst-direction offset; the lossy circuit instead approaches a finite offset.
Worked example
These are the calculator's default inputs. Change any input above to recalculate.
Inputs
- Input resistor
- 10000 Ω
- DC feedback resistor
- 1000000 Ω
- Integration capacitor
- 1e-7 F
- Input step
- 0.1 V
- Initial output
- 0 V
- Input offset magnitude
- 0.001 V
- Inverting bias current
- 2e-8 A
- Output swing magnitude
- 12 V
Results
- Initial signal ramp slope
- -100 V/s
- Lossy steady-state output
- -10 V
- Ideal integrating unity frequency
- 159.155 Hz
- Lossy corner
- 1.59155 Hz
- Offset/bias initial drift
- 1.2 V/s
- Ideal-integrator drift to rail
- 10 s