Signal intensity indicating circuit applied to optical receiver and control method thereof

Abstract

The invention provides a signal intensity indicating circuit applied to an optical receiver, which comprises an amplifier AMP1, an amplifier AMP2, a first auxiliary clamping circuit, a second auxiliary clamping circuit, a photodiode and current sources I1, I2, I3 and I4, wherein the non-inverting input end of the amplifier AMP1 is connected with an external reference voltage Vref_in. The signal intensity indicating circuit can detect the magnitude of the current flowing through a photodiode so as to obtain the intensity of the current optical signal. Meanwhile, in order to overcome the defects of a basic signal intensity indicating circuit, the signal intensity indicating circuit provided by the invention has relatively high stability, and can provide current and bias voltage in a relatively wide range for the photodiode. Further, the current in the photodiode is obtained by utilizing a high-precision current source, so that indication information of the intensity of the received optical signal is provided for the optical receiver circuit.

Description

Technical field [0001] The present invention belongs to the field of electronic technology, particularly to an optical receiver applied to a signal strength indicating circuit and a control method. Background technique [0002] In the field of optical communication, an optical transmitter transmitting optical signals using an optical fiber to the optical receiver, the optical receiver in charge of the photodiode to convert an optical signal into a corresponding current signal, due to non-ideality, the same transmission signal fiber, after the fiber transfer, it may produce different degrees of attenuation and distortion, so that the light signal received by the receiver may fluctuate within a wide range, resulting in the photodiode output current range from a few to several tens uA mA. [0003] Signal strength indication of the prior art feedback loop phase margin of the circuit will be insufficient, easily lead to the closed loop feedback circuit to oscillate, will further incre...

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Problems solved by technology

[0003] In the prior art, the phase margin of the feedback loop in the signal strength indicating circuit will be insufficient, which will easily cause the closed-loop feedback circuit to oscillate, and will further increase the risk caused by the large variation range of the current flowing through the transistor in the circuit

Increase the design difficulty and design complexity of the signal strength indicator circuit

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