Active pixel swing extension system and method for cmos image sensor

Abstract

The invention discloses an active pixel swing expansion method for a CMOS image sensor, which solves the problem of limited swing of the active pixel unit due to threshold value loss and other reasons during the electrical signal output process, and is characterized in that the sampling is switched by a switch The lower plate method of the holding capacitor makes the lower plate of the sampling and holding capacitor connected to the ground level or low voltage when the pixel unit is sampled, and the lower plate of the sampling and holding capacitor is connected to the power supply level when the pixel unit is output. Or high voltage, to realize the swing increase of the photoelectric signal on the column line. In order to ensure the effect of this method on the filling factor of the pixel unit, the switching and high and low voltages are realized outside the active pixel unit area array. The present invention proposes a swing boost mechanism based on the programmable bootstrap voltage outside the array, which provides a solution for the large array and full well active pixel CMOS image sensor, and ensures the complete response of the active pixel circuit to the full well charge. The full well capability and dynamic range of the CMOS image sensor are improved.

Description

technical field [0001] The invention belongs to the technical field of semiconductor integrated circuits, and specifically relates to an image sensor, array data reading, high-speed and high-precision photoelectric conversion front-end acquisition system, and also relates to an active pixel swing expansion method for a CMOS image sensor. Background technique [0002] In high-speed photography, automation and industrial applications, due to the requirements of shooting fast moving targets, CMOS image sensors with global exposure function are usually used. In low-orbit aerospace applications, because the object moves faster at the focal plane, if the imaging device uses a rolling shutter exposure device, the "motion distortion" of the image will occur. Similarly, in high-orbit applications, "motion distortion" can occur due to platform stability issues. Therefore, the current aerospace models have a strong demand for global exposure CMOS image sensor devices. It can be seen ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide an active pixel swing expansion method for CMOS image sensors, which solves the problem of swing attenuation in the readout process of the CMOS image sensor 8T structure that exists in the prior art

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