Abtastschalter mit unabhängiger Impedanz im Ein-Zustand

A sampling device (20) for sampling an input signal (Vin) in response to a pulse train of a sample signal. The sampling device includes a sampling transistor (Ms) for creating samples in response to the sample signal. The sampling transistor has an impedance corresponding with the difference between the gate to source voltage and the threshold voltage of the sampling transistor. The sampling device also includes a control device (55) for generating a control signal. The control device includes a bootstrap reference voltage source (CBOOT) for providing a reference voltage in response to the sample signal, and a control circuit (Mc, 60, 65) for generating the control circuit voltage in response to the sample signal. By this design, the control signal comprises the sum of the input signal and the sampling threshold voltage, the control signal comprises the sum of control circuit voltage and the reference voltage, and the gate to source voltage comprises the difference between the control signal and the input signal.