A 180 fps WVGA CIS with 3.2e− TRN and dual-readout modes

Abstract

In order to broaden the application scenarios and reduce the noise performance for global shutter CMOS image sensors (CISs), this paper proposes a low-noise and dual-readout-modes global shutter WVGA CIS. By implementing buried channel nMOS and pMOS without body effect as the source followers of 8-transistors active pixel (8TAP), the noise performance of the sensor is optimized. Moreover, based on correlated double sampling and correlated multiple sampling, two timing schemes are configured in the same readout circuit to achieve high frame rate and low noise readout modes. The layout of 8TAP is also optimized to improve the pixel fill factor and quantum efficiency. Measurement results show that the sensor achieves a maximum frame rate of 180 fps and a minimum temporal random noise (TRN) of less than 3.2e−. The proposed dual-mode readout method can be used as an extended functionality for CIS products.