High dynamic focal plane readout circuit and sampling method thereof

Abstract

The invention relates to a high dynamic focal plane readout circuit and a sampling method thereof. The circuit comprises a capacitor transconductance amplifier, a sampling circuit and a source follower, wherein the capacitor transconductance amplifier comprises an amplifier, an amplifier reset switch and a first integrating capacitor which are arranged between a signal voltage input end and a signal voltage output end of the amplifier in parallel in a bridge connection manner, and a low-gain enable switch and a second integrating capacitor; and the low-gain enable switch and the second integrating capacitor are arranged between the signal voltage input end and the signal voltage output end of the amplifier in series. According to the high dynamic focal plane readout circuit provided by the invention, the first integrating capacitor and the second integrating capacitor constitute a low-gain integrating capacitor together, large full-well capacity can be realized, and serving as a high-gain integrating capacitor, the first integrating capacitor can provide small readout noise and a high conversion gain. Therefore, the high dynamic range focal plane readout circuit provided by the invention can meet the large full-well capacity and a small noise electron number at the same time and achieve a relatively high dynamic range.

Description

technical field [0001] The invention belongs to the technical field of detection, and relates to a high dynamic range focal plane readout circuit based on a capacitive transconductance amplifier and a sampling method thereof. Background technique [0002] Today, with the rapid development of microelectronics, photoelectric detection technology plays an important role in military, civilian and other economic fields. As an important part of photodetection, the focal plane readout circuit plays a very important role. [0003] Conventional focal plane readout circuit structure based on capacitive transconductance amplifier (CTIA) see figure 1 , the pixel circuit mainly includes a capacitive transconductance amplifier CTIA, a sampling circuit SH, and a source follower SF. The capacitive transconductance amplifier puts the integrating capacitor in the feedback loop, and the integrating capacitor integrates the photocurrent into a voltage for output during the integration process...

AI Technical Summary

Problems solved by technology

But both are closely related to the integral capacitance, the larger the integral capacitance, the larger the full well capacity, but at the same time the greater the number of equivalent noise electrons

For a conventional circuit with a fixed integral capacitance, it is difficult to achieve a high dynamic range because it cannot satisfy both a large full well capacity and a small number of noise electrons

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