Design and implementation of array readout integrated circuit and image system for current mode sensors

Abstract

Considered that the dual band sensor system is the most popular design at present, this study discussed the design of a dual-band hybrid array readout circuit. The direct injection circuit structure was used in the unit pixel. The design, simulation, and layout were conducted in the 40um×40um unit pixel to complete middle and long waveband signal readouts, in order to achieve one sensor unit with two sensor modes. The readout circuit chip adopted TSMC 0.35um 2P4M CMOS 5V to design a 16×12 array readout circuit, with an input current range of the measured current at 1.9pA to 50 nA, an adjustable integration time, a maximum frame rate of 110Hz, the output swing of the chip signal of 2V, the maximum operating chip frequency of 3MHz, power dissipation of 18mW, system noise voltage Vrms of 0.68mV, and signal-noise ratio of 69dB. Finally, the tested chip was used to connect the detection system proxy board and digital signal board, and digital signal processing video through front-end filters and analog to digital converter, in order to complete signal conversion and digital signal processing. With the digital control signal provided by the signal board and signal capture, the back-end digital signal was processed and imaged on the screen. The readout circuit chip connected the signal proxy board for testing. The overall system resolution reached 10 bit.