A 1.8V readout integrated circuit with adaptive transimpedance control amplifier for IR focal plane arrays

Abstract

A readout integrated circuit (ROIC) with adaptive transimpedance control (ATC) amplifier for Infrared Focal Plane Arrays (IR FPAs) is presented in this paper. The proposed ATC readout circuit is consisted of a front-end transimpedance amplifier (TIA) with an adaptive feedback capacitance. The output signal is fed to a comparator which determines a set of gain code (S0∼S1) to control the feedback capacitance selected from a capacitor array. A CMOS image sensor chip with 32x32 pixel array and 30x30μm 2 pixel size has been designed and fabricated in 0.18μm CMOS technology. It achieves a 24dB improvement of dynamic range, a frame rate of 22 fps, a power-per-pixel of 5μW/pixel and the total power of 5.5mW, respectively. The proposed ATC amplifier provides an optimized solution for IR FPA with wide dynamic range (WDR) operated at 1.8V supply. © 2011 IEEE.