Analog-to-digital conversion unit and related image sensor and electronic device

Abstract

The invention discloses an analog-to-digital conversion unit, a related image sensor and an electronic device. The analog-to-digital conversion unit comprises a ramp signal generating circuit, a shielding signal generator, an MSB counter and at least one (m + n) bit column analog-to-digital converter. Wherein the mask signal generator is used for generating a mask signal according to an MSB clock, the mask signal is used for indicating a plurality of mask periods, and the occurrence frequency of the plurality of mask periods is the same as the frequency of the MSB clock. An (m + n) bit column analog-to-digital converter includes a comparator, a mask unit configured to adjust the comparator output signal according to the mask signal and output a masked comparator output signal, where a voltage level of the masked comparator output signal changes at a third time point, a latch configured to latch the comparator output signal, and an LSB counter configured to counter the masked comparator output signal. The third time point is equal to or later than the second time point, and the third time point does not fall in the plurality of shielding time periods.

Description

technical field [0001] The present application relates to the technical field of electronic circuits, in particular to an analog-to-digital conversion unit, related image sensors and electronic devices. Background technique [0002] With the advancement of technology, CMOS image sensors require not only a large-scale pixel array, but also a high signal processing speed. However, as the size of the pixel array increases, the size of a single pixel in the pixel array continues to shrink. , making it difficult to realize a single analog-to-digital conversion circuit design, and the column-based analog-to-digital converter is thus produced. However, the high power consumption of the existing column A / D converters used in CMOS image sensors is a problem criticized by people, but in order to reduce power consumption, the differential nonlinearity (differential nonlinearity, DNL) error, so how to solve the above problems has become one of the urgent problems in this field. Conte...

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Problems solved by technology

[0002] With the advancement of technology, CMOS image sensors require not only a large-scale pixel array, but also a high signal processing speed. However, with the increase in the size of the pixel array, the size of a single pixel in the pixel array is constantly shrinking. , making it difficult to design a single analog-to-digital conversion circuit, and the column-based analog-to-digital converter is thus produced

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