A low-power, high-gain operational amplifier for the preamplification circuit of cooled infrared sensor

Refrigerated infrared focal plane detectors are widely used in military equipment and astronomical detection fields due to their advantages of high detection accuracy, long detection distance and short response time. The preamplifier circuit mainly receives and amplifies the weak signal of the detector, and its signal processing effect directly affects the imaging quality of the detector. Based on SMIC 180nm CMOS technology, an operational amplifier with low power consumption and high gain is designed to meet the requirements of the preamplifier circuit of the cooled infrared detector for the working environment and performance.We mainly analyze the low-temperature characteristics and circuit principle of CMOS,further simulation and testing was also performed. Simulation test results reveal that the operational amplifier has an open-loop gain of 124dB, and its power consumption is only 4.75mW when driving 200-400PF under heavy load. Under the premise of low noise, it can well meet the requirements of lower power consumption, high gain and load capacity of the pre-amplifier circuit of the refrigerated infrared detector. It can be widely used to readout infrared (IR) sensors and focal plane imaging arrays (FPA).