Column readout circuit calibration system and method for CMOS image sensor

Abstract

The invention discloses a column readout circuit calibration system and method for a CMOS image sensor. The column readout circuit calibration method comprises the steps of: integrating a calibrationcolumn readout circuit connected with an effective column readout circuit in parallel through a gating switch on the CMOS image sensor; judging the failure condition of an effective column readout circuit column on the CMOS image sensor by utilizing readout data of the effective column readout circuit; acquiring the readout data of the calibration column readout circuit on the CMOS image sensor through using the calibration column readout circuit, and judging the failure condition of the calibration column readout circuit column according to the readout data of the calibration column readout circuit; and replacing a failure column circuit of the effective column readout circuit with an effective column circuit of the calibration column readout circuit, thereby realizing column readout circuit calibration of the CMOS image sensor. According to the column readout circuit calibration method, the failure column in the effective column readout circuit is determined through testing, failurecolumn calibration is achieved through using the calibration column readout circuit, the influence of bad columns can be effectively reduced, and the circuit yield is increased.

Description

technical field [0001] The invention relates to a column readout circuit failure calibration method caused by a CMOS image sensor (CIS) process defect, in particular to the field of column readout circuit optimization design, and in particular to a column readout circuit calibration system and method for a CMOS image sensor. Background technique [0002] CMOS image sensors are widely used in "high resolution" and "deep space exploration" optical satellites. In order to improve the observation resolution and field of view, high-end CMOS image sensors are developing towards high resolution. At present, the area array size of the area array CMOS image sensor has reached 10K×10K, 15K×15K, 20K×20K, and adopts a general-purpose column-level readout circuit architecture. 10,000 columns, 20,000 columns. The design of a large number of column readout circuits is a repetitive design, and tiny dust or impurities in the manufacturing process will cause a short circuit in a single colum...

AI Technical Summary

Problems solved by technology

Due to the small size of the area array, the traditional CMOS image sensor does not adopt calibration measures for the failure of the column readout circuit caused by process defects. With the expansion of the area array size of the CMOS image sensor, the failure of the single column readout circuit will cause the image to appear bad columns. Causes a decrease in imaging quality or a decrease in yield, and currently there is no calibration measure for the failure of the readout circuit caused by process defects, and it is impossible to calibrate the readout circuit caused by process defects

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