Abstract: A capacitive sensor assembly is disclosed, including a capacitive motor coupled to a charge pump circuit via a low pass filter, and a frontend amplifier circuit having an input coupled to the capacitive motor interface and an output coupled to an output of the electrical circuit. An injection current source (ICS) is coupled to the charge pump circuit output and configured to control voltage across a diode-based resistive element of the low pass filter during a transient startup phase of the charge pump circuit, wherein a settling time of the charge pump is reduced.

Abstract: A capacitive sensor assembly is disclosed, including a capacitive motor coupled to a charge pump circuit via a low pass filter, and a frontend amplifier circuit having an input coupled to the capacitive motor interface and an output coupled to an output of the electrical circuit. An injection current source (ICS) is coupled to the charge pump circuit output and configured to control voltage across a diode-based resistive element of the low pass filter during a transient startup phase of the charge pump circuit, wherein a settling time of the charge pump is reduced.

Abstract: An amplifier circuit (AC) for amplifying an output signal (OS) of a capacitive sensor (M) comprises a first input terminal (AIN) to receive the output signal (OS) of the capacitive sensor (M) and a second input terminal (BIN) to receive a bias voltage (Vbias) of the capacitive sensor (M). The amplifier circuit (AC) comprises an amplifier (A) for amplifying the output signal (OS) and a control circuit (CF) arranged in a feedback loop (FL) of the amplifier (A) being configured to control a DC voltage level at an input connection (A1) of the amplifier (A). A bias voltage sensing circuit (BVS) senses a change of the level of the bias voltage (Vbias) at the second input terminal (BIN) and changes the bandwidth of the feedback loop (FL) in dependence on the sensed change of the level of the bias voltage (Vbias).