Protection circuit and optical module of an APD detector in an optical module

Abstract

The invention relates to a protection circuit of an APD detector in an optical module and an optical module. The protection circuit is used in an optical module above 25G, and the protection circuit includes: a freewheeling circuit component located in a slow start circuit, which is used Continue to supply power to the TIA when the power is on, so that the power-off time of the APD detector is earlier than the power-off time of the TIA power supply voltage; the MCU control circuit, the power switch combination circuit and the voltage monitoring circuit of the APD boost circuit; when the optical module is powered on, the MCU controls The circuit controls and enables the power switch combination circuit to provide the APD voltage to the APD detector after the APD boost circuit works normally, and at the same time makes the power-on time of the APD detector later than the power-on time of the TIA power supply voltage in the optical module. The above structure enables the APD detector to provide protection for the APD detector in the power-on sequence and power-off sequence, and also realizes the function of the MCU to monitor the APD boost circuit in real time to prevent abnormal APD voltage from being supplied to the APD detector.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to a protection circuit of an APD detector in an optical module and an optical module. Background technique [0002] Photodetectors are devices that convert light signals into electrical signals. In a semiconductor photodetector, the photogenerated carriers excited by incident photons enter the external circuit under an applied bias voltage to form a measurable photocurrent. Even under the maximum responsivity, a PIN photodiode can only generate a pair of electron-hole pairs at most, and it is a device without internal gain. For greater responsivity, an avalanche photodiode (APD) can be used. The amplification effect of APD on photocurrent is based on the ionization collision effect. Under certain conditions, the accelerated electrons and holes gain enough energy to collide with the crystal lattice to generate a new pair of electron-hole pairs. This process is A cha...

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Problems solved by technology

[0003] However, in the specific optical module application or optical module manufacturing process, due to repeated power-off and power-on of the module, program operation errors, power supply voltage surges, APD voltage debugging errors, etc., it is easy to cause the detector to fail due to APD voltage overvoltage. The phenomenon

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