A 20MHz CTIA ROIC for InGaAs focal plane array

Abstract

A low noise high-speed readout integrated circuit (ROIC) for InGaAs infrared focal plane array (FPA) is reported in this paper. To reduce the input reference noise, the correlated double sampling (CDS) is added into the pixel circuit, where the capacitance transimpedance amplifier (CTIA) structure is adopted as the input stage circuit. The selectable capacitance of CTIA can satisfy different values of full well capacity (FWC), such as 10ke- (very high gain, VHG), 20ke- (high gain, HG), 350ke-(low gain, LG). The input reference noise can be reduced to 127e- by the CDS in LG condition. The ROIC adopts monolithic integration and implements various functions, such as windowing, subsampling and different integration and readout modes. The readout rate can be reached to 20MHz and the analog circuit's power consumption is about 46mW.