A 256×256 CMOS imaging array with wide dynamic range pixels and column-parallel digital output

Abstract

A stepped reset-gate voltage technique is applied to a CMOS active pixel sensor array to increase dynamic range by 26 dB. A frame rate of 390 frames/s is achieved using column-parallel output circuits. Switched-capacitor correlated double-sampling circuits reduce fixed-pattern noise to 4.0 mV (dark). Cyclic analog-to-digital converters achieve approximately 9-b accuracy. At 30 frames/s, random noise is 0.56 mV (dark), optical dynamic range is 96 dB, and power is 52 mW.