An analog front-end IC with regulated R-I amplifier and CDS CTIA for microbolometer

Abstract

An analog front-end design that can improve the performance of the readout integrated circuit (ROIC) for the microbolometer infrared (IR) focal plane array (FPA) is presented. The analog front-end circuit for the microbolometer generally consists of the resistance-to-current (R-I) converter and the capacitive transimpedance amplifier (CTIA). The resistances of the microbolometer FPA are changed when absorbing IR. These resistance changes are converted to the output voltages by R-I converters and CTIAs. To eliminate the VTH-variations and to reduce the 1/f noise, a novel regulated R-I converter with current mirror amplifier and a correlated double sampled (CDS) CTIA are proposed. The output noise of the proposed design is -19.15 dB lower than conventional design at 1 Hz. The chip is designed using the standard 0.18 μm 1P6M CMOS process.