Low-power consumption column circuit for CMOS image sensor

Abstract

The invention discloses a low-power consumption column circuit for a CMOS image sensor, and the low-power-consumption column circuit comprises a comparator and a counter and further comprises a feedback control circuit and a corresponding control transistor. The drain electrode of the control transistor is connected with an output signal of the pixel unit, and a source electrode is connected with the bias current tube; the input of the feedback control circuit is respectively connected with the output of the comparator and the output of the time sequence controller, and the generated output signals are respectively connected with the grid electrode of the control transistor and the control end of the comparator so as to respectively control the bias of the reading circuit of the pixel unit and the comparator; and after the quantization of the column circuit is finished, the reading circuit and the comparator of the pixel unit are closed by using the output signal of the feedback control circuit. The bias of the pixel unit reading circuit and the bias of the comparator circuit are controlled by using the output of a feedback control circuit, and after the quantization is completed, a response circuit is closed through the bias control, so that the purpose of reducing the power consumption is achieved.

Description

technical field [0001] The invention relates to the field of CMOS (Complementary Metal-Oxide-Semiconductor) image sensors, in particular to a low-power column circuit for CMOS image sensors. Background technique [0002] CMOS image sensors are widely used in many fields such as electronic consumption, security monitoring, automatic control, medical treatment, and national defense. Especially in recent years, with the rise of smart terminals, more attention has been paid to the demand for low power consumption. [0003] figure 1 It is an example of CMOS image sensor structure. The CMOS image sensor 1 includes a pixel array 100 , a timing controller 101 , a row decoder 102 , a column circuit array 103 , a Ramp generator 104 , a memory 105 , and a column decoder 106 . Wherein the pixel array 100 is composed of a pixel unit 200 (see the pixel unit example figure 2 ) to form an array, and the column circuit array 103 is composed of a column circuit 220 (see the example of the...

AI Technical Summary

Problems solved by technology

[0007] The power consumption of the existing column circuit structure always exists, no matter whether it has been quantized or not, it causes a lot of waste, especially when the output signal is small, the waste is more, which restricts the low power consumption application of the image sensor

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