Gain and offset control for charge based signals

摘要

A device and method for controlling the gain of a charge based signal is described. The described device and method may be used for both offset correction and for gain control. First and second charge holding gates are provided for receiving a charge packet representing a signal. A control gate partitions off at least a portion of the charge on the secondary charge holding gate. The charge not so partitioned off is then transferred onto the output line as the adjusted charge packet representing the adjusted signal, where the gain is now the ratio of areas of first charge holding gate to the sum of areas of both first and second charge holding gates. The offset of a signal can also be corrected by segregating the portion of charge representing the offset of an input signal onto the second charge holding gate.