Passive integrator circuit
（重定向自Integrator circuit）
![Amplitude and phase transfer functions for a passive integrator circuit](/Images/godic/202501/20/Passive_integrator_circuit_transfer_function5051.png")
![An impulse response of a passive integrator circuit](/Images/godic/202501/20/Passive_integrator_circuit_impulse_response_15051.png")
Passive integrator circuit is a simple four-terminal network consisting of two passive elements. It is also the simplest (first-order) low-pass filter.
We'll analyze only the first circuit; the second is very similar.