A Global Shutter High Speed TDI CMOS Image Sensor With Pipelined Charge Transfer Pixel

Abstract

In this paper, a $120\,\times \, 45$ global shutter high speed time delay integration (TDI) CMOS image sensor with pipelined charge transfer pixel (PCT-pixel) is presented. Offset free and low noise pipelined signal accumulation are achieved by the PCT-pixel, and a novel layout is also proposed to increase the equivalent photosensitive area’s fill factor of the proposed pixel. Due to the parallelism of the proposed PCT-pixel, global shutter exposure method is applied in this sensor, which can eliminate nonsynchronous signal capturing problem. The proposed TDI sensor is implemented in a 0.11- $\mu \text{m}$ one-poly three-metal CMOS image sensor technology with a line rate of 100 KHz, a PCT-pixel size of $30\,\times \, 15 \,\,\mu \text{m}^{2}$ , and a fill factor of 43.5%. Measurement results show that the sensor can achieve a maximum sensitivity of 95 V/lux $\,\times \, $ sec and an energy consumption of 0.12 nJ/pixel. Measured signal-to-noise ratio boost value follows theoretical value well. The proposed sensor has the potential to achieve high scanning speed and high TDI stage while costing less power and silicon area.