A communication system includes a supply generator configured to generate a modulated supply according to a data transmission; a light emitting diode (LED) emulator including an emulator input coupled to the supply generator and an emulator output configured to output a sense voltage, wherein the emulator input is configured to receive a forward current derived from the modulated supply and translate the forward current into the sense voltage; a voltage comparator coupled to the emulator output and configured to receive the sense voltage and translate the sense voltage into a modulated output signal based on a communication voltage threshold; and a transmitter coupled to a comparator output and configured to receive the modulated output signal and generate a communication signal according to the data transmission based on the modulated output signal.

A unidirectional transmission device includes at least one substrate, at least one light source, and at least one light-sensing element. The at least one substrate includes at least one recess. The at least one light source is configured to transform an electrical signal into an optical signal, and transmit the optical signal. The at least one light-sensing element is configured to receive the optical signal, and transform the optical signal into the electrical signal, wherein the at least one recess is configured to dispose the at least one light source, or configured to dispose the at least one light-sensing element, or configured to reflect the optical signal.

A coupling module can be used to communicate high speed signals between an optical transceiver and a processing module of an optical communication device, such as an optical line termination (OLT) or an optical network unit (ONU). The coupling module can adjust the common mode voltage level of a differential signal output by the optical transceiver to the common mode voltage level required by the processing module. In addition, the coupling module splits each of the differential output signals from the optical transceiver and passes the split signals to both a high-pass filter and a low-pass filter that are connected in parallel. An adapter module can be connected to the coupling module such that the coupling module can receive different differential signals from different optical transceivers.

A first optical splitter splits a light source to obtain a first optical signal, a second optical signal, and a third optical signal. A first MZ modulator modulates the first optical signal to output a fourth optical signal. A second MZ modulator modulates the second optical signal to output a fifth optical signal. A first optical coupler couples the fourth optical signal and the fifth optical signal to output a sixth optical signal and a seventh optical signal. A power regulator and a phase shifter respectively perform power adjustment and phase shifting on the third optical signal to output an eighth optical signal. A second optical splitter splits the eighth optical signal into a ninth optical signal and a tenth optical signal. A second optical coupler combines the sixth optical signal and the ninth optical signal. A third optical coupler combines the seventh optical signal and the tenth optical signal.

A power conversion device includes a switched-mode power supply (SMPS), a photocoupler and a controller. The SMPS receives a pulse width modulation (PWM) signal from the controller to generate a DC output voltage related to a DC input voltage. The photocoupler generates a reference voltage signal based on the DC output voltage. The controller adjusts at least one of a duty cycle or a frequency of the PWM signal based on the reference voltage signal.

An optocoupler having a transmitter unit and a receiver unit being electrically isolated from each other and optically coupled with each other and integrated into a shared housing. The receiver unit includes an energy source that has a first electrical contact and a second electrical contact. The transmitter unit includes at least one first transmitter diode having a first optical wavelength and a second transmitter diode having a second optical wavelength. The first optical wavelength differing from the second optical wavelength by a difference wavelength, and the energy source of the receiving unit including two partial sources. The energy source being designed as a current source or as a voltage source, and the first partial source including a first semiconductor diode, and the second partial source including a second semiconductor diode. Each partial source having multiple semiconductor layers for each partial source being arranged in the shape of a stack.

In the embodiments of the present invention, a transmit optical signal includes a reference optical signal and a quantum optical signal, optical splitting processing and coherent coupling are performed on the transmit optical signal by using a local oscillator optical signal to obtain at least two coherently coupled optical signals, and then optical-to-electrical conversion and amplification are separately performed on a first coherently coupled optical signal that includes the reference optical signal and a second coherently coupled optical signal that includes the quantum optical signal, to obtain a first electrical signal and a second electrical signal. Then, phase frequency information between the local oscillator optical signal and the reference optical signal is obtained from the first electrical signal, and an original key is recovered from the second electrical signal based on the phase frequency information.

An optocoupler is provided, including at least one light source and at least one matrix of photovoltaic cells facing the at least one light source, the at least one light source being configured to receive, at an input, an input electrical signal, and to generate, at an output, according to the input electrical signal, a light signal, sent to the at least one matrix of photovoltaic cells, the at least one matrix of photovoltaic cells being configured to receive, at the input, at least partially the light signal and to deliver, at the output, at least one output electrical signal, at the level of at least two connection pads, and the at least one light source being a matrix of laser diodes.

A communication system includes a supply generator configured to generate a modulated supply according to a data transmission; a light emitting diode (LED) emulator including an emulator input coupled to the supply generator and an emulator output configured to output a sense voltage, wherein the emulator input is configured to receive a forward current derived from the modulated supply and translate the forward current into the sense voltage; a voltage comparator coupled to the emulator output and configured to receive the sense voltage and translate the sense voltage into a modulated output signal based on a communication voltage threshold; and a transmitter coupled to a comparator output and configured to receive the modulated output signal and generate a communication signal according to the data transmission based on the modulated output signal.

An apparatus and method for diagnosing a watchdog timer is provided. The watchdog timer is used to detect and recover from a malfunction of a battery management system. Before entering a shutdown mode in response to a shutdown command from an external device, the apparatus outputs an invalid trigger signal to the watchdog timer and diagnoses a malfunction of the watchdog timer depending on whether the watchdog timer outputs a reset signal.