Successive approximation type ADC adjusting reference voltage adaptively

Abstract

The invention relates to a successive approximation type ADC adjusting a reference voltage adaptively, belongs to the technical field of design of analog integrated circuit, and aims at using a high reference voltage under high illumination, using a low reference under low illumination and further realizing high-precision quantification under the lower illumination needless of increase of extra power consumption and conversion periods. The successive approximation type ADC is composed of a front-end comparator module, an SAR ADC main body module, four reference voltage control switches of the SAR ADC main body module and a digital filter module; an input signal Vin is connected with the positive input end of the front-end comparator, and the negative input end of the front-end comparator is connected with a reference level Vcomp; output of the front-end comparator is connected with the reference voltage control switches 1 and 2; and the input signal is also connected with the input end of the SAR ADC main body module. The successive approximation type ADC adjusting a reference voltage adaptively is mainly applied to design and manufacture occasions of the analog integrated circuit.

Description

technical field [0001] The invention relates to the field of analog integrated circuit design, in particular to the problem of adjusting the precision of an analog-to-digital converter by adjusting the feedback voltage as the illumination conditions change in the application of an image sensor. Background technique [0002] In recent years, image sensors have developed rapidly, and are widely used in consumer electronics, automotive electronics, intelligent monitoring, military reconnaissance and other fields. In the readout circuit of the image sensor, SAR ADC (Successive Approximation Analog-to-Digital Converter) is widely used because of its simple structure, low power consumption, small area and many other advantages. [0003] At present, the image sensor is constantly developing towards high speed and low power consumption. In order to comply with this development trend, the accuracy of the ADC (Analog to Digital Converter) can be adjusted under different lighting condi...

AI Technical Summary

Problems solved by technology

[0003] At present, the image sensor is constantly developing towards high speed and low power consumption. In order to comply with this development trend, the accuracy of the ADC (Analog to Digital Converter) can be adjusted under different lighting conditions. In the case of illumination, a higher-precision ADC is required, and in the case of high illumination, the accuracy of the ADC can be reduced

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