Method and device for protecting apd receiver

Abstract

The present invention relates to a method and a device for protecting an avalanche photo diode (APD) receiver. The method comprises the steps of in a protective mode, monitoring a sampling value of the APD receiver, and determining whether the sampling value obtained through sampling is within a preset first threshold range, wherein if the sampling value is within the preset first threshold range, the APD receiver is switched to a normal mode, and if the sampling value is beyond the preset first threshold range, the APD receiver is kept in the protective mode; and in the normal mode, monitoring a sampling value of the APD receiver, and determining whether the sampling value obtained through sampling is within a preset second threshold range, wherein if the sampling value is within the preset second threshold range, the APD receiver keeps working in the normal mode, if the sampling value is beyond the preset second threshold range, the APD receiver is switched to the protective mode, and a protective mode voltage in the protective mode is lower than a normal mode voltage in the normal mode. According to the method and device provided in embodiments of the present invention, the sampling value of the APD receiver is monitored in real time during work, and the sampling value is compared with the preset threshold ranges, so that the APD receiver can switch between the normal mode and the protective mode, and the APD receiver is prevented from being burned even if a sudden large input light comes.

Description

technical field [0001] The invention relates to the technical field of optical transceiver modules, in particular to a method and device for protecting an APD receiver. Background technique [0002] Avalanche photodiode (APD for short) is a receiver commonly used in optical transceiver modules. In order to obtain the best sensitivity, the bias voltage of the APD receiver is usually controlled near the avalanche point. At this time, the multiplication factor of the APD receiver is large, and a small light input can obtain a large photocurrent. When the input to When the optical power of the APD receiver is very high, excessive photocurrent flowing through the APD receiver will cause damage to the APD receiver. [0003] The traditional way to protect the APD receiver is to change the hardware circuit, such as setting a current limiting chip to limit the large current generated due to excessive optical power, so as to achieve the purpose of protecting the APD receiver. Howeve...

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Problems solved by technology

However, for optical modules that require high input damage light (that is, the minimum input optical power that will damage the APD receiver), if the current that the current limiting chip can limit cannot reach a low enough level, the purpose of protecting the APD receiver cannot be achieved.

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