A differential amplifier includes an amplifying stage that outputs an output signal by amplifying an input signal with a gain set by a control signal, and an adjusting stage that stabilizes a DC level of the output signal. The amplifying stage includes a first source supplying a first current, and a load, and determines a ratio of a current flowing through the load to the first current depending on the input signal and the control signal, and generates the output signal from a voltage drop of the load. The adjusting stage includes a second source supplying a second current, and a monitor resistor, and generates a monitor current divided from the second current by the ratio, and duplicates the DC level as a voltage drop of the monitor resistor caused by the monitor current, and controls the first current source and the second current source depending on the DC level.

A distance measuring method includes: emitting a pulse of measuring light towards an object; receiving a pulse measuring light from the object and generating a pulse signal corresponding to the pulse of measuring light received from the object; delaying a first portion of the generated pulse signal for a predetermined time; generating an intensity signal indicative of an intensity of the generated pulse signal, while delaying the first portion of the generated pulse signal; amplifying the delayed first portion of the generated pulse signal using a gain dependent on the generated intensity signal; and determining a value representing a distance based on the amplified delayed first portion of the generated pulse signal.

A wireless communication device includes a delay circuit to generate four or more delay signals, an amplifier circuit amplifying the four or more delay signals to generate four or more amplified delay signals, and a combiner circuit combining at least two amplified delay signals to generate an output signal, a second phase of a second amplified delay signal is between a first phase of a first amplified delay signal and a third phase of a third amplified delay signal, gains of the amplifier circuit for the four or more delay signals are controlled such that the output signal is generated by combining the first amplified delay signal and the third amplified delay signal, and a phase of the output signal is between the first phase of the first amplified delay signal and the third phase of the third amplified delay signal.

An imaging system includes an array of photodetectors and electronic circuitry associated with the photodetectors to read intensity values from the photodetectors. The electronic circuitry can include an integrator with an integrator capacitor having a nominal capacitance, wherein a gain of the electronic circuitry associated with a photodetector can depend at least in part on the actual capacitance of the integrator capacitor, the actual capacitance differing from the nominal capacitance. The imaging system can be configured to determine a gain factor that depends at least in part on the actual capacitance and/or a signal voltage input to the integrator. The imaging system can be configured to apply the gain factor based at least in part on the actual capacitance of the integrator capacitor calculated. The imaging system can be a thermal imaging system and may include an infrared camera core.

A current voltage conversion circuit includes first to fourth signal amplifiers; and first and second resistive passive elements, an input terminal of the first signal amplifier being connected to a terminal for inputting a current signal, one and the other terminals of the first resistive passive element being connected to output and input terminals of the first signal amplifier, respectively, an input terminal of the second signal amplifier being connected to a first connection point, input and output terminals of the third signal amplifier being connected to an output terminal of the second signal amplifier and the first connection point, respectively, an input terminal of the fourth signal amplifier being connected to a second connection point, and one and the other terminals of the second resistive passive element being connected to an output terminal of the fourth signal amplifier and the second connection point.

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedence amplifer (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

According to one embodiment, an amplification circuit includes an amplifier having a gain based on a gain control signal and amplifying an input signal by the gain, and a control portion outputting the gain control signal for increasing the gain after decreasing the gain based on an amplitude of the input signal, when the amplitude of the input signal is detected.

A method and circuit are provided for implementing enhanced CMOS inverter based optical Transimpedance Amplifiers (TIAs). A transimpedance amplifier (TIA) includes a photo-detector, and the TIA is formed by a first TIA inverter and a second TIA inverter. The first TIA inverter has an input from a cathode side of the photo-detector and the second inverter has an input from an anode side of the photo-detector. A replica TIA is formed by two replica inverters, coupled to a respective input to a first operational amplifier and a second operational amplifier. The first operational amplifier and the second operational amplifier have a feedback configuration for respectively regulating a set voltage level at the cathode side of the photo-detector input of the first inverter and at the anode side of the photo-detector input of the second inverter.

According to one embodiment, an amplification circuit includes an amplifier having a gain and amplifying the input signal based on the gain, and a gain control signal generator controlling the gain based on an amplitude of the input signal. The gain obtained when the amplitude of the input signal is less than a first amplitude and when the amplitude of the input signal is greater than a second amplitude is lower than the gain obtained when the amplitude of the input signal is between the first and second amplitudes or when the amplitude of the input signal is one of the first and second amplitudes. The second amplitude is greater than or equal to the first amplitude.

This disclosure relates to the field of amplifiers for multi-level optical communication and more particularly to techniques for trans-impedance amplifiers (TIA) with gain control. The claimed embodiments address the problem of implementing a low cost TIA that exhibits high linearity, low noise, low power, and wide bandwidth. More specifically, some claims are directed to approaches for providing TIA gain control using a plurality of inverter-based replica gain control cells controlled by a feedback loop to manage the current into the amplifying output stage and thereby the TIA output voltage.