An optical receiver disclosed includes a bias terminal, an input terminal, a photodiode, an amplifier circuit, a first resistor, a bypass circuit, a filter circuit, and a control circuit. The photodiode receives a bias from the filter circuit through the bias terminal, and outputs a current signal to the amplifier circuit through the input terminal. The amplifier circuit converts an input current to an output voltage. The bypass circuit electrically connected to the input terminal decreases a first input impedance viewed from the input terminal, when activated, and increases the first input impedance, when deactivated. The filter circuit increases a second input impedance viewed from the bias terminal, when a dumping function thereof is activated, and decreases the second input impedance, when the dumping function is deactivated. The control circuit activates the dumping function and the bypass circuit, when the output voltage is larger than a certain voltage.

An amplifier circuit with an overshoot suppress scheme is provided. The amplifier circuit includes an input amplifier, an output amplifier and a diode device. The output amplifier is coupled to the input amplifier and outputs an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

A transimpedance amplifier (TIA) circuit disclosed includes an input terminal, a first TIA circuit, a second TIA circuit, a field effect transistor (FET), and a gain control circuit. The first TIA circuit outputs a voltage signal from a first output in accordance with an input current received at a first input electrically connected to the input terminal. The second TIA circuit outputs a reference signal from a second output. The FET varies a resistance between a first current terminal and a second current terminal in accordance with a control signal applied to a control terminal. The first current terminal is electrically connected to the input terminal. The second current terminal is electrically connected to the second output of the second TIA circuit. The gain control circuit detects an amplitude of the voltage signal and generates the control signal according to a detection result of the amplitude.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier includes a PMOSFET and an NMOSFET. The PMOSFET has a gate electrode serving as a first input end and a drain coupled to an output end. The NMOSFET has a gate electrode serving as a second input end and a drain coupled to the output end. The output amplifier outputs an output voltage at the output end, and is coupled to the input amplifier via at least one of the first and second input ends. The diode device is coupled between the output end and the at least one of the first and second input ends of the output amplifier. When a voltage difference between the output end and the at least one of the first and second input ends of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An optical receiver disclosed includes a bias terminal, an input terminal, a photodiode, an amplifier circuit, a first resistor, a bypass circuit, a filter circuit, and a control circuit. The photodiode receives a bias from the filter circuit through the bias terminal, and outputs a current signal to the amplifier circuit through the input terminal. The amplifier circuit converts an input current to an output voltage. The bypass circuit electrically connected to the input terminal decreases a first input impedance viewed from the input terminal, when activated, and increases the first input impedance, when deactivated. The filter circuit increases a second input impedance viewed from the bias terminal, when a dumping function thereof is activated, and decreases the second input impedance, when the dumping function is deactivated. The control circuit activates the dumping function and the bypass circuit, when the output voltage is larger than a certain voltage.

A transimpedance amplifier (TIA) circuit disclosed includes an input terminal, a first TIA circuit, a second TIA circuit, a field effect transistor (FET), and a gain control circuit. The first TIA circuit outputs a voltage signal from a first output in accordance with an input current received at a first input electrically connected to the input terminal. The second TIA circuit outputs a reference signal from a second output. The FET varies a resistance between a first current terminal and a second current terminal in accordance with a control signal applied to a control terminal. The first current terminal is electrically connected to the input terminal. The second current terminal is electrically connected to the second output of the second TIA circuit. The gain control circuit detects an amplitude of the voltage signal and generates the control signal according to a detection result of the amplitude.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier includes a PMOSFET and an NMOSFET. The PMOSFET has a gate electrode serving as a first input end and a drain coupled to an output end. The NMOSFET has a gate electrode serving as a second input end and a drain coupled to the output end. The output amplifier outputs an output voltage at the output end, and is coupled to the input amplifier via at least one of the first and second input ends. The diode device is coupled between the output end and the at least one of the first and second input ends of the output amplifier. When a voltage difference between the output end and the at least one of the first and second input ends of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier is coupled to the input amplifier and outputs an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

According to an aspect, there is provided a comparator comprising input terminals, first, second and third biasing current sources configured to output first, second and third biasing currents, an input circuit driven by the first biasing current source and comprising an amplification circuit and a load circuit configured to provide positive feedback for the amplification circuit, first and second current mirroring circuits for forming, with the input circuit, first and second current mirrors producing first and second current mode signals, first and second current-controlled driver circuits configured to be controlled by the second and third biasing currents, respectively, and the first and second current mode signals, respectively, a latch circuit comprising first and second cross-coupled complementary metal-oxide semiconductor transistors acting as a latch having substantially rail-to-rail output voltage swing and being driven, respectively, by the first and second current-controlled driver circuits and an output circuit implementing a current starved inverter.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier is coupled to the input amplifier and outputs an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.