Reset Time Extended CDS for low noise hyperspectral infrared focal plane readout circuits

Abstract

Low noise is a significant performance requirement of Hyperspectral Shortwave Infrared Focal Plane Arrays Readout Circuit (ROIC) for its low radiation. And the current Correlated Double Sampling (CDS) technology for noise reduction needs to be further improved. The mechanism of extended reset time CDS, which has an impact on noise, is analyzed; By establishing the "first-order low-pass filter, delay-subtractor, sample-hold" model, the output noise power spectral density of image pixel ROIC as a function of CDS extended reset time is analyzed. To verify the analysis, a pixel integrated with low-noise Capacitive trans-impedance amplifiers (CTIA) and adjustable reset time CDS is designed. By extending the CDS reset time, the simulation result is consistent with the analysis. The number of noise electrons reaches 24.42e-, which is better than 50.11e-without CDS and 34.45e-without extending the reset time. The design of Reset Time Extended CDS can improve the noise performance of hyperspectral readout circuits, and can be widely used.