Abstract: A high speed transimpedance amplifier includes an inverting unit, at least one gain module, and a feedback resistor. The inverting unit has an input terminal coupled to a photodiode for receiving an input voltage, and an output terminal for outputting a first voltage. The at least one gain module has an input terminal coupled to the output terminal of the inverting unit for receiving the first voltage, and an output terminal for outputting an output voltage. Each gain module includes a first gain inverting unit and a second gain inverting unit which are coupled to each other. The first gain inverting unit and the second gain inverting unit dominate bandwidth of the high speed transimpedance amplifier. The feedback resistor is coupled to the input terminal of the inverting unit and the output terminal of the at least one gain module for determining a transimpedance of the high speed transimpedance amplifier.

Abstract: A driving method of a laser diode includes setting a bias current, a modulation current, a first target corresponding to a predetermined average power, and a second target corresponding to a predetermined average modulation power; executing a first adjusting current step group; generating a temporary modulation current according to the modulation current; executing a second adjusting current step group; and executing the first adjusting current step group again.

Abstract: A high speed transimpedance amplifier includes an inverting unit, at least one gain module, and a feedback resistor. The inverting unit has an input terminal coupled to a photodiode for receiving an input voltage, and an output terminal for outputting a first voltage. The at least one gain module has an input terminal coupled to the output terminal of the inverting unit for receiving the first voltage, and an output terminal for outputting an output voltage. Each gain module includes a first gain inverting unit and a second gain inverting unit which are coupled to each other. The first gain inverting unit and the second gain inverting unit dominate bandwidth of the high speed transimpedance amplifier. The feedback resistor is coupled to the input terminal of the inverting unit and the output terminal of the at least one gain module for determining a transimpedance of the high speed transimpedance amplifier.

Abstract: A laser diode control circuit loop comprises a reference circuit with a programmable reference current, a first endpoint thereof providing a first voltage and a second endpoint thereof providing a second voltage, according as the reference current passing through the first endpoint and the second endpoint; and a driving circuit, a third endpoint thereof connected to the first endpoint of the reference circuit, a fourth thereof connected to the second endpoint of the reference circuit, a output end thereof providing a driving voltage and an output current, and the reference current of the reference circuit and the output current of the driving circuit are as direct ratio. With regard to the operation field of the laser diode driving circuit, the operation limitation within low voltage can be got over, according as the output current from the reference current matching.