Charge amplifier for MOS imaging array and method of making same

摘要

A charge amplifier with DC offset canceling for use in a pixel element of an MOS image sensor is disclosed. The charge amplifier can be manufactured using a standard CMOS single polycrystalline process, making it much more cost effective than prior art designs. The charge amplifier includes an operational amplifier, a source capacitor, a series capacitor, and a feedback capacitor. The source capacitor holds the input signal. The output of the operational amplifier provides the output signal. Switches control the routing of the signal flow from the source capacitor, the series capacitor, and the feedback capacitor.