There is provided a circuit assembly for time-discretizing an analog electrical signal, including an input terminal supplying the analog electrical signal, an output terminal providing a time-discrete signal depending on the supplied analog electrical signal and a sample and hold circuit, which comprises a capacitor connected to the output terminal, an electronic switching unit connected between the input terminal and the output terminal and a control unit controlling the switching unit, wherein the switching unit provides an off-state due to an off-signal of the control unit and an on-state due to an on-signal of the control unit, wherein the switching unit provides an electrical resistance in the on-state, which cooperates with the capacitor and comprises a preset resistance value, such that the sample and hold circuit provides a low-pass with preset cut-off frequency. There is further provided a detection device and lighting device with such a circuit assembly.