Patent ID: 8385498

Claim:
An apparatus for transferring charge in a charge-domain signal processing circuit, comprising: an input charge holding device having a first terminal, disposed in series with and directly coupled to a first voltage input charge source, for holding an input charge; an output charge holding device, for holding an output charge; a charge transfer device, having an input terminal, an output terminal, and a control terminal, the input terminal coupled to a second terminal of the input charge holding device, the input terminal thereof not being directly coupled to the input charge source, and the the output terminal coupled to provide charge to the output charge holding device under control of a charge transfer control signal applied to the control terminal; and an amplifier, having a first input coupled to the second terminal of the input charge holding device, a second input coupled to a reference voltage, and an output terminal coupled to the control terminal of the charge transfer device, for providing the charge transfer control signal, the amplifier configured to control a voltage at the control terminal of the charge transfer device to increase the rate at which the voltage at the input terminal of the charge transfer device settles to the reference voltage.