Thirty Two-Stage CMOS TDI Image Sensor With On-Chip Analog Accumulator

Abstract

This brief presents a 32-stage CMOS time delay integration image sensor with on-chip column parallel analog accumulator. Temporal oversampling technique is applied in the sensor to realize synchronous signal capturing. A column parallel analog accumulator with layout size of 0.09 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is integrated at both sides of pixel array. Through adopting input-offset storing technique, a column fixed pattern noise because of the amplifier's offset variations is reduced by the accumulator. The accumulator also acts as a pixel noise canceller. The fabricated chip in 0.18- μm one-poly four-metal 1.8/3.3-V CMOS technology achieves the maximum line rate of 3875 lines/s. The measured signal-to-noise ratio of the fabricated sensor is improved on average by 11.9 dB at 16 stages and 14.2 dB at 32 stages. The presented sensor is suitable for application in low illumination, high scanning speed, and remote sensing systems.