Imbalance calibration method for CMOS passive pixel sensor circuit and imbalance calibration circuit

Abstract

The invention relates to the technical field of an image sensor and provides an imbalance calibration method for a CMOS passive pixel sensor circuit and an imbalance calibration circuit. The imbalancecalibration method for the CMOS passive pixel sensor circuit comprises the steps of setting an input reference voltage of an integral amplifier of a readout circuit of the CMOS passive pixel sensor circuit as a preset initial value; measuring an imbalance value; comparing the imbalance value with a preset allowed value; and deciding whether to adjust the initial value or not according to a comparison result and moreover, setting the input reference voltage and entering the step of measuring the imbalance value. A feedback control input reference voltage generator is controlled through feedback, thereby changing the value of the input reference voltage VCM of the integral amplifier AND a voltage V- of the inverted input end of the integral amplifier is changed along with the VCM, so a potential on a readout line connected with the inverted input end of the integral amplifier is changed, and influences of leakage on the output potential of the integral amplifier are reduced to the lowest.

Description

technical field [0001] The present disclosure relates to the technical field of image sensors, in particular, to an offset correction method for a CMOS passive pixel image sensor circuit. Background technique [0002] In modern human life, people urgently need to obtain all kinds of information, and most of the image information is obtained through visual organs. With the continuous improvement of semiconductor technology, image sensors, as a basic device for visual information acquisition, have been more and more widely used in modern social life because they can achieve information acquisition, conversion and visual function expansion. Among them, image sensors manufactured by CMOS (Complementary Metal-Oxide Semiconductor Field-Effect Transistor) technology are developing rapidly. At present, the application fields of CMOS image sensors cover digital electronic products, video email, car rear view, medical equipment, security monitoring, visual All aspects of social life ...

AI Technical Summary

Problems solved by technology

However, since many pixels are connected to the readout line (column bus), the leakage generated by all the pixels on the column will be accumulated to the output of the integrating amplifier at the same time, resulting in an offset voltage, resulting in insufficient dynamic range, and the dynamic range is decisive. Important indicators of image sensor imaging quality

Images