Abstract: Provided in the present invention is an automatic gain control method for a burst-mode transimpedance amplifier. A transistor is connected in parallel at either end of a feedback resistor of a transimpedance amplifier. A gate-source voltage of the transistor is controlled by detecting and then reversely amplifying an output voltage of the transimpedance amplifier. The present invention also provides a circuit implementing the method, obviates the need for support from any particular process, and is implementable using conventional components.

Abstract: Provided in the invention is a circuit for multiplexing an MON pin of a receiver optical sub-assembly for optical communication. Through a first clamping circuit, the high precision of a whole monitoring dynamic range is kept. Through a second clamping circuit, a voltage of the MON pin is clamped into an input voltage Vcont_in of the second clamping circuit, so that an external control signal Vcont_in is copied and input into the trans-impedance amplifier, and then the Vcont_in is converted into various control variables through a comparator or analog-to-digital converter.

Abstract: An automatic gain control circuit of a transimpedance amplifier includes a transimpedance amplifier TIA1, a transimpedance amplifier TIA2, an NMOS transistor Q1, an NMOS transistor Q2, an error amplifier U3, and a bias current source Ib. An input terminal and an output terminal of the transimpedance amplifier TIA1 are connected to a drain and a source of the NMOS transistor Q1, respectively. An input terminal and an output terminal of the transimpedance amplifier TIA2 are connected to a drain and a source of the NMOS transistor Q2, respectively. An output terminal of the bias current source Ib is connected to a positive input terminal of the error amplifier U3 and the drain of the MOS transistor Q2.

Abstract: Provided in the present invention is an automatic gain control method for a burst-mode transimpedance amplifier. A transistor is connected in parallel at either end of a feedback resistor of a transimpedance amplifier. A gate-source voltage of the transistor is controlled by detecting and then reversely amplifying an output voltage of the transimpedance amplifier. The present invention also provides a circuit implementing the method, obviates the need for support from any particular process, and is implementable using conventional components.

Abstract: Provided in the invention is a circuit for multiplexing an MON pin of a receiver optical sub-assembly for optical communication. Through a first clamping circuit, the high precision of a whole monitoring dynamic range is kept. Through a second clamping circuit, a voltage of the MON pin is clamped into an input voltage Vcont_in of the second clamping circuit, so that an external control signal Vcont_in is copied and input into the trans-impedance amplifier, and then the Vcont_in is converted into various control variables through a comparator or analog-to-digital converter.

Abstract: An automatic gain control circuit of a transimpedance amplifier includes a transimpedance amplifier TIA1, a transimpedance amplifier TIA2, an NMOS transistor Q1, an NMOS transistor Q2, an error amplifier U3, and a bias current source Ib. An input terminal and an output terminal of the transimpedance amplifier TIA1 are connected to a drain and a source of the NMOS transistor Q1, respectively. An input terminal and an output terminal of the transimpedance amplifier TIA2 are connected to a drain and a source of the NMOS transistor Q2, respectively. An output terminal of the bias current source Ib is connected to a positive input terminal of the error amplifier U3 and the drain of the MOS transistor Q2.

Abstract: A circuit for automatically measuring gain of a built-in trans-impedance amplifier includes a current source built in a trans-impedance amplifier chip for generating a constant current to an input end of the trans-impedance amplifier. The circuit samples a voltage amplitude at an output end of the trans-impedance amplifier using a voltage amplitude sampling device, and calculates the gain of the trans-impedance amplifier. The current source has a constant reference voltage source, a reference current generator, a clock source, an AC switch, and an off-chip precision resistor. The circuit is configured to measure gain of trans-impedance amplifiers directly.

Abstract: A circuit for automatically measuring gain of a built-in trans-impedance amplifier includes a current source built in a trans-impedance amplifier chip for generating a constant current to an input end of the trans-impedance amplifier. The circuit samples a voltage amplitude at an output end of the trans-impedance amplifier using a voltage amplitude sampling device, and calculates the gain of the trans-impedance amplifier. The current source has a constant reference voltage source, a reference current generator, a clock source, an AC switch, and an off-chip precision resistor. The circuit is configured to measure gain of trans-impedance amplifiers directly.