Design of a Configurable Bit-Resolution CMOS Image Sensor for the Image Depth Extraction

Abstract

Design of a configurable bit-resolution CMOS image sensor(CIS) is described. Recently, CIS pixel matrixes composed of both RGB and Infrared(IR) color filters are used for the implementation of an image depth extraction. However, in order to compensate the light density between RGB and IR, the single slope ADC inside of CIS must have a configurable bit-resolution. For example, RGB signal has a 8-hit resolution, while IR signal has an 12-bit resolution. The proposed CIS has 4 different bit resolutions for RGB pixel, such as 8-bit, 6-bit, 4-bit and 2-bit. The proposed ADC has a maximum resolution of 12-bit for IR pixels with the architecture of two-step single-slope(TS SS) type. The proposed CIS has a 100MHz clock, and it has been designed with 0.18 m CIS technology.