Novel Si-APD (Silicon-Avalanche Photo Diode) device

Abstract

The invention discloses a novel Si-APD (Silicon-Avalanche Photo Diode) device. The novel Si-APD device comprises a first single Si-APD and a second single Si-APD which are arranged adjacently in parallel, wherein the first single Si-APD corresponds to a light window and serves as a light detection unit; the second single Si-APD is set in backlight and serves as a breakdown voltage detection unit; the first single Si-APD and the second single Si-APD share the same negative pole. Based on the principle that the properties of adjacent devices in the integrated circuit technology are consistent with each other, and paired Si-APDs are adopted; the first single Si-APD is used for detecting light and the second single Si-APD serves as the breakdown voltage detection unit; an optimal bias effect can be achieved, just by means of detecting the dark current of the second single Si-APD, stabilizing the value of the dark current via a negative feedback control loop, and utilizing the voltage when the value of the dark current is maintained at a set value to serve as the work bias voltage of the first single Si-APD, so that the complicacy problem of the traditional dynamic bias is solved, the complicacy degree and cost of a distance measuring system are lowered, and the novel Si-APD device is simple and practical.

Description

technical field [0001] The invention belongs to the field of laser ranging, and in particular relates to a novel Si-APD device. Background technique [0002] Si-APD, the Chinese name is silicon avalanche photodiode, which is mainly used in the field of laser ranging. This photoelectric conversion device has high sensitivity, and its gain (M) is usually related to the bias voltage. The ideal bias voltage is the breakdown Gain is highest near voltage, so a good design of the bias voltage circuit will result in high gain. However, the breakdown voltage of Si-APD is related to temperature, and its temperature coefficient is large. In normal use, the ambient temperature changes by 125°C (-45°C~+85°C), and the bias voltage will change with the change of temperature. Ten volts to keep the high gain steady. [0003] The current bias methods are: 1), fixed bias, the bias voltage is much lower than the breakdown voltage, even if the temperature changes, the bias voltage will not exc...

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Problems solved by technology

[0004] In view of the deficiencies in the above-mentioned prior art, the present invention aims to provide a simple and effective new Si-APD d

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