A novel method to realize automatic gain adjust for infrared readout integrated circuit

摘要

A novel method to adjust gain in CMOS infrared (IR) readout integrated circuit (ROIC) which is suitable for the application of small pixel size has been proposed in this paper. Current mirror is inserted in the pixel to adjust gain. Two comparators have been added outside of the pixel and provide the decision to select different gains. Adjustable gain makes the design of following signal process circuit easier and allows long integration time to increase SNR. With this method of automatic gain adjust, ROIC can deal with the current that varies from 40nA to 300nA, with the integration capacitor of 2pF and the integration time of 40/spl mu/s. An experimental 4/spl times/4-pixel ROIC has been designed and it will be fabricated with 0.5/spl mu/m DPDM n-well CMOS process.