Programmable Gain Amplifier and Method for Reducing Column Fixed Pattern Noise

Abstract

The programmable gain amplifier of the present invention minimizes the impact of the offset voltage of the operational amplifier on the output voltage by subtracting the common-mode voltage output by the amplifier and the output voltage at the time of sampling the reset signal as an analog domain signal or after analog-to-digital conversion. , thereby reducing the image column fixed pattern noise caused by the offset voltage of the op amp. The beneficial technical effect of the programmable gain amplifier of the present invention and the method for reducing column fixed mode noise is to reduce the influence of the offset voltage of the operational amplifier on the output of the programmable gain amplifier through the DC offset elimination circuit of negative feedback, and subtract it through the analog domain or the digital domain. The influence of the offset voltage of the operational amplifier on the output voltage is minimized, and the fixed pattern noise of the image column caused by the offset voltage of the operational amplifier is effectively reduced, thereby improving the imaging quality of the image.

Description

field of invention [0001] The invention relates to the technical field of image sensors, in particular to a programmable gain amplifier for image sensors and a method for reducing column fixed pattern noise. Background technique [0002] With the development of modern computer technology and information processing technology, intelligent systems are increasingly helping humans process various complex information from the outside world, including sound, light, temperature, pressure, and smell in nature. Human beings receive external information through the five sense organs, among which the human eye obtains the largest amount of information by obtaining images. According to statistics, 75% of the information obtained by human beings is obtained through the visual organs. Based on the huge amount of information in visual images, advanced image acquisition technology has become an important part of modern intelligent systems. [0003] The image sensor is the core of the image...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem that the existing programmable gain amplifier can only reduce the column fixed pattern noise caused by the offset voltage of the op amp, but cannot completely eliminate it, resulting in the problem that the column fixed pattern noise may still have a great impact on the image quality. , the present invention proposes a programmable gain amplifier and a method for reducing column fixed pattern noise

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