Readout Integrated Circuits1

This chapter provides an overview of the readout integrated circuit (ROIC) used for infrared, visible, and other arrayed sensors. The functions supported by the ROIC go well beyond processing and shaping of the image signal. The chapter covers unit cell preamplifier types and their characteristics. There are four major groups, or families, of integrating unit cell preamplifiers used in conjunction with photovoltaic detectors: self‐integrators, direct injection (DI), source follower per detector (SFD) and capacitor feedback transimpedance amplifier (CTIA). Many ROIC figures of merit can be measured at the ROIC level, however some ROIC testing cannot be done without detectors since the presence of the detector on the input node affects some characteristics of the ROIC. In those cases, additional measurements must be done at the sensor chip assembly (SCA) level. The ROIC is typically a primary source of problems relative to calibration of a sensor.