An amplifier circuit may include an isolated amplifier circuit, disposed on a high voltage side of the amplifier circuit, and arranged to generate an isolated output signal. The amplifier circuit may include a first optocoupler circuit, disposed to receive the isolated output signal from the isolated amplifier circuit and an output amplifier circuit, disposed on a low voltage side of the amplifier circuit, and coupled to receive an optical output signal from the optocoupler circuit. The amplifier circuit may also include a calibration circuit, coupled to the output amplifier circuit, to generate a calibration initiation signal, and a second optocoupler circuit, disposed to receive the calibration initiation signal, and to output a switch signal, wherein a reference voltage is output to the isolated amplifier circuit.

A system for optical data interconnect of a source and a sink includes a first HDMI compatible electrical connector able to receive electrical signals from the source. A first signal converter is connected to the first HDMI compatible electrical connector and includes electronics for conversion of TMDS or FRL electrical signals to optical signals, with the electronics including an optical conversion device. At least one optical fiber is connected to the first signal converter. A second signal converter is connected to the at least one optical fiber and includes electronics for conversion of optical signals to differential electrical signals. A power module for the second signal converter includes a power tap connected to TMDS or FRL circuitry and a first voltage regulator connected to the power tap to provide power to an electrical signal amplifier. A rechargeable battery module is used to trigger power activation of connected ports, with the battery module being connected to the power tap. A second HDMI compatible electrical connector is connected to the second signal converter and able to send signals to the sink.

A driving circuit includes a first transistor that includes a first terminal, a second terminal, and a third terminal; a second transistor having a fourth terminal, a fifth terminal, and a sixth terminal; and an output portion that outputs a signal between the second transistor and a second current source to a light emitting element, wherein the first terminal is coupled to a first power source, a signal is input to the second terminal, and the third terminal is grounded through a first current source which is different from the second current source, and the fourth terminal is coupled to a second power source which is the same as or different from the first power source via the second current source, the fifth terminal is coupled to a voltage source or a bias circuit, and the sixth terminal is coupled between the first transistor and the first current source.

A digital isolator comprising a set of bipolar transistors and an inductor capacitor (LC) oscillator coupled to the set of bipolar transistors in series, wherein the LC oscillator is configured to be turned on and off based on the current applied to the set of bipolar transistors or the LC oscillator and generate a set of differential signals based on the current flowing through the set of bipolar transistors and mimicking the operational characteristics of an optocoupler.

Methods and systems for a distributed optoelectronic receiver are disclosed and may include an optoelectronic receiver having a grating coupler, a splitter, a plurality of photodiodes, and a plurality of transimpedance amplifiers (TIAs). The receiver receives a modulated optical signal utilizing the grating coupler, splits the received signal into a plurality of optical signals, generates a plurality of electrical signals from the plurality of optical signals utilizing the plurality of photodiodes, communicates the plurality of electrical signals to the plurality of TIAs, amplifies the plurality of electrical signals utilizing the plurality of TIAs, and generates an output electrical signal from coupled outputs of the plurality of TIAs. Each TIA may be configured to amplify signals in a different frequency range. One of the plurality of electrical signals may be DC coupled to a low frequency TIA of the plurality of TIAs.

Isolators and methods for operating the same are described for opto-isolators with improved common mode transient immunity (CMTI). In some embodiments, a pair of photodetectors are provided in the opto-isolator and configured to generate photocurrents of opposite signs or directions in response to a light signal. Photocurrents from the pair of photodetectors are combined in a differential manner to represent data transmitted in a light signal, while common mode transient noise at the two photodetectors is attenuated or eliminated.

An amplifier includes an amplifying device and a bias circuit for providing a bias voltage for the amplifying device. The bias circuit is configured to provide the bias voltage in dependence of an output signal of an optical coupling arrangement which provides for electrical isolation.

A driving circuit includes a first transistor that includes a first terminal, a second terminal, and a third terminal; a second transistor having a fourth terminal, a fifth terminal, and a sixth terminal; and an output portion that outputs a signal between the second transistor and a second current source to a light emitting element, wherein the first terminal is coupled to a first power source, a signal is input to the second terminal, and the third terminal is grounded through a first current source which is different from the second current source, and the fourth terminal is coupled to a second power source which is the same as or different from the first power source via the second current source, the fifth terminal is coupled to a voltage source or a bias circuit, and the sixth terminal is coupled between the first transistor and the first current source.

A constant current generation circuit for optocoupler isolation amplifier and a current precision adjustment method are provided. The constant current generation circuit includes a start circuit, a current generation circuit and a precision adjustment and output circuit integrated into a same substrate. The start circuit can generate and output a first start current and a second start current. The current generation circuit includes a negative temperature change rate current generation circuit connected to a first start current output and a positive temperature change rate current generation circuit connected to a second start current output. The precision adjustment and output circuit outputs constant current meeting application requirements of optocoupler isolation amplifier by adjusting proportional precision of two currents output from a current generation circuit.

Disclosed are a method, system and electronic device method for adaptively adjusting frequency of a switching power supply. The method includes: obtaining a SNR threshold, obtaining a SNR value of an AM/FM radio demodulator; when the SNR value is smaller than a SNR threshold, outputting a plurality of control signals to the switching power supply, obtaining a plurality of corresponding operation frequencies of the switching power supply; obtaining a plurality of SNR values of the AM/FM radio demodulator at each of the plurality of operation frequencies, obtaining a maximum SNR value among the plurality of SNR values; outputting a control signal corresponding to the maximum SNR value, controlling the operation frequency of the switching power supply with the control signal; obtaining the SNR value of the AM/FM radio demodulator at a preset time period, and comparing the SNR value to the SNR threshold.