Non-inverting integrator
7 parts
Four equal resistors around one op-amp make a Howland current source: the current it delivers is set by the input voltage alone, not by what the load is doing. Hang a capacitor on that current and you have an integrator with a plus sign — the capacitor ramps up while the input is high, the opposite of the classic one-resistor-one-capacitor integrator. The op-amp output rides at exactly twice the capacitor voltage, which is where you would normally take the signal from. Input offset and bias current default to zero in this op-amp model, so the triangle holds its place (3 mV of drift over 40 ms measured); a real integrator walks into a rail without a reset path.
- V1 1V·500Hz
- R1 5kΩ
- R2 5kΩ
- R3 5kΩ
- R4 5kΩ
- C1 100nF
- OP1
