ADC intrinsic noise analysis method for CMOS image sensor

Abstract

The invention discloses an ADC intrinsic noise analysis method for a CMOS image sensor, and belongs to the field of simulation analysis. An ADC intrinsic noise analysis method for a CMOS image sensorcomprises the following steps: 1) performing simulation analysis on the inversion of an ADC comparator to obtain inversion interval offset; 2) calculating the probability that the inversion interval offset is distributed in one clock period of the ADC counter and the probability that the inversion interval offset spans a plurality of clock periods, and calculating the noise voltage of the CMOS image sensor caused accordingly; and 3) multiplying the noise voltage of the CMOS image sensor by the corresponding probability to obtain a calculated value of the noise of the CMOS image sensor caused by the intrinsic noise of the ADC. According to the analysis method, the overall noise of the CMOS image sensor caused by ADC intrinsic noise is determined, whether the design value meets the design requirement or not can be determined in the design stage, and a basis is provided for noise design improvement.

Description

technical field [0001] The invention belongs to the field of simulation analysis, in particular to an ADC inherent noise analysis method for a CMOS image sensor. Background technique [0002] In low-brightness scenes or video applications, noise seriously affects the quality of captured images or videos. Noise broadly refers to disturbances in other forms than signals. There are many types of noise in CMOS sensor circuits, which can be roughly divided into device electronic noise and "environmental" noise according to the cause of its generation. The electronic noise of the device is caused by the physical properties of the device itself. In CMOS visible light image sensors, it generally includes thermal noise, shot noise, flicker noise, and dark current; Low-level random interference, or environmental temperature changes, clock jitter, electromagnetic interference, etc. Various noises are coupled to the sensor array through peripheral circuits to damage image sensor perf...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to overcome the shortcoming that the inherent noise of the ADC used for CMOS image sensors cannot be obtained, and a kind of ADC inherent noise analysis method for CMOS image sensors is provided

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