Pixel circuit and infrared imager

Abstract

The invention provides a pixel circuit and an infrared imager, and relates to the field of infrared imaging. The integration module performs integration and coarse quantization through the common module and the charge injection module at the same time; the charge injection module injects charges into an integrating capacitor in the integrating module; the dynamic comparator generates a counting signal in the process of carrying out fine quantization on the residual voltage, the linear feedback shift register counter counts, the counting result is a coarse quantization result, the dynamic comparator generates the counting signal in the process of carrying out fine quantization on the residual voltage, the linear feedback shift register counter receives the counting signal and counts from 0, and the counting result is a fine quantization result. According to the pixel circuit, coarse and fine quantization share the same module, so that the pixel area is reduced. According to the pixel circuit, part of charges are injected into the integrating capacitor in stages, compared with the injection of equal charges, the introduced noise is lower, the noise charges injected every time are reduced on the whole, the signal-to-noise ratio is improved, and therefore the overall power consumption of the pixel circuit is reduced. The pixel circuit has lower power consumption and better quality factor.

Description

technical field [0001] The invention relates to the field of infrared imaging, in particular to a pixel circuit and an infrared imager. Background technique [0002] Infrared imaging is a technology to identify objects by detecting the infrared radiation emitted by objects. It is currently widely used in military, space technology, medicine and other fields. The infrared focal plane array component is the main body of the infrared imaging system, which is composed of an infrared detector and an infrared focal plane readout circuit. The readout circuit converts the electrical signal generated by the infrared detector and outputs it to an off-chip signal processing system. For infrared focal plane arrays, especially for long-wave infrared, the use of pixel-level analog-to-digital converters (ADCs) can significantly increase the charge-handling capability. [0003] Due to the demand for equipment miniaturization, the current pixel size needs to be further reduced. This reduct...

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Problems solved by technology

But the above scheme increases the pixel area

[0004] It has also been proposed to send the residual charge to and be quantized by a column-level ADC, but this would cause a mismatch between the pixel and the column, resulting in greater fixed-pattern noise and more readout noise

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