A 14-bit Column-level ADC for IRFPA

A 14-bit Column-level ADC for Infrared Focal Plane Array (IRFPA) is proposed in this paper. Correlated switch structure is designed, which helps to cancel the offset generated by injected charge and then achieves accurate sampling and holding. Odd-even structure is realized to make longer converting time after sampling. Comparators with two-stage pre amplifiers use low power supply voltages, which ensures low power operation, as well as low noise. Conversion accuracy of the ADC circuit can reach 14-bit. The structure is used for a 640×512 array.