Synchronous reset pulse output pixel structure for realizing correlated double sampling

Abstract

The invention discloses a synchronous reset pulse output pixel structure for realizing correlated double sampling. The synchronous reset pulse output pixel structure consists of a photodiode PD, a reset switch Sr, a comparator, selection switches S1 and S2, a feedback switch S3, a sampling capacitor Cs and pixel control logic, wherein the PD is connected to the non-inverting input end of the comparator and is connected to a reset voltage Vpix through the reset switch Sr; the output comp of the comparator is connected to the input of the pixel control logic and is connected to the inverting input end of the comparator through the feedback switch S3; one polar plate of the sampling capacitor Cs is connected to the inverting input end of the comparator, and the other polar plate of the sampling capacitor Cs is connected to the Vpix through the switch S2 and is connected to the reference voltage Vref through the switch S2; the pixel control logic generates control signals S1, S2 and S3, areset signal Sr and single-bit output of a pixel. The structure solves the problems that a traditional pulse output pixel cannot carry out correlated double sampling, and noise in a fixed mode is large.

Description

technical field [0001] The invention belongs to the field of analog integrated circuit design, in particular to a synchronous reset pulse output pixel structure for realizing correlated double sampling in image sensor applications. 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. The pulse-type pixel structure only outputs single-bit or multi-bit pulses, which greatly reduces the amount of data and improves the transmission speed, and has attracted widespread attention. [0003] The classic pulse-type pixel structure such as figure 1 As shown, it consists of photodiode, reset transistor, comparator and pixel control logic. The photodiode PD is connected to the reset voltage Vpix through the reset transistor M1; PD is connected to the negative phase input terminal of the comparator at the same time; the po...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems existing in the prior art, the present invention proposes a synchronous reset pulse output pixel structure that realizes correlated double sampling, uses the amplifier in the pixel to store offset voltage and reset noise, and solves the problem that traditional pulse output pixels cannot perform correlated double sampling, fixed mode loud noise problem

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