A radio frequency rectifier circuit including a rectifier circuit and a controller circuit is provided. The rectifier circuit receives a radio frequency signal and converts the radio frequency signal into a direct-current voltage serving as an output voltage. The rectifier circuit includes multiple power stages and multiple switch circuits. Each of the switch circuits is coupled between two of the power stages. The controller circuit is coupled to the rectifier circuit. The controller circuit outputs a control signal to control a conduction number of the switch circuits according to a value of the output voltage.

A radio frequency rectifier circuit including a rectifier circuit and a controller circuit is provided. The rectifier circuit receives a radio frequency signal and converts the radio frequency signal into a direct-current voltage serving as an output voltage. The rectifier circuit includes multiple power stages and multiple switch circuits. Each of the switch circuits is coupled between two of the power stages. The controller circuit is coupled to the rectifier circuit. The controller circuit outputs a control signal to control a conduction number of the switch circuits according to a value of the output voltage.

In described examples, an integrated circuit includes an on-off keying (OOK) digital isolator, which includes a first circuitry, a multiplexer, an OOK modulator, an isolation barrier, an OOK envelope detector, and a second circuitry. The first circuitry generates and outputs a calibration signal. The multiplexer has a data signal input, and an input coupled to a first circuitry output. An OOK modulator input is coupled to a multiplexer output. An isolation barrier input is coupled to an OOK modulator output. An OOK envelope detector input is coupled to an isolation barrier output. The second circuitry includes an input coupled to an OOK envelope detector output, and an output coupled to an OOK envelope detector control input. The second circuitry detects a duty cycle distortion (DCD) of the OOK envelope detector output, and outputs a control signal to change the OOK envelope detector output's duty cycle based on the detected DCD.

In described examples, an integrated circuit includes an on-off keying (OOK) digital isolator, which includes a first circuitry, a multiplexer, an OOK modulator, an isolation barrier, an OOK envelope detector, and a second circuitry. The first circuitry generates and outputs a calibration signal. The multiplexer has a data signal input, and an input coupled to a first circuitry output. An OOK modulator input is coupled to a multiplexer output. An isolation barrier input is coupled to an OOK modulator output. An OOK envelope detector input is coupled to an isolation barrier output. The second circuitry includes an input coupled to an OOK envelope detector output, and an output coupled to an OOK envelope detector control input. The second circuitry detects a duty cycle distortion (DCD) of the OOK envelope detector output, and outputs a control signal to change the OOK envelope detector output's duty cycle based on the detected DCD.

A control method of a switching circuit, a control circuit of the switching circuit, and the switching circuit are provided. The switching circuit includes an inductor or a transformer. An operational amplification is performed on an output feedback voltage and a first reference voltage of the switching circuit to obtain a compensation voltage. The compensation voltage controls an on-time of a main switch of the switching circuit. When the current of the inductor or the transformer drops to a threshold, after a time, the main switch is switched from off to on, and the output feedback voltage controls the time. When the output feedback voltage is higher than a first threshold voltage, the compensation voltage is pulled down. When the output feedback voltage is lower than a second threshold voltage, the compensation voltage is pulled up.

A control method of a switching circuit, a control circuit of the switching circuit, and the switching circuit are provided. The switching circuit includes an inductor or a transformer. An operational amplification is performed on an output feedback voltage and a first reference voltage of the switching circuit to obtain a compensation voltage. The compensation voltage controls an on-time of a main switch of the switching circuit. When the current of the inductor or the transformer drops to a threshold, after a time, the main switch is switched from off to on, and the output feedback voltage controls the time. When the output feedback voltage is higher than a first threshold voltage, the compensation voltage is pulled down. When the output feedback voltage is lower than a second threshold voltage, the compensation voltage is pulled up.

A converter operable to convert an input voltage at an input node to an output voltage at an output node coupled to a load by switching on and off a transistor at a switching frequency, the converter comprising: an error amplifier circuit having a first input coupled to a reference voltage, a second input coupled to the output node through a resistive divider, a first output operable to output a control current and a second output operable to output a current equivalent to the control current; a peak current comparator circuit having a first input coupled to the second output of the error amplifier circuit, a second input and an output, the second input is coupled to the input node through an inductor; an off-time timer circuit having an input coupled to the first output of the error amplifier circuit and an output, the off-time timer circuit operable to set the switching frequency based on the control current; and a control circuit having a first input coupled to the output of the peak current comparator circuit, a second input coupled to the output of the off-time timer circuit and an output coupled to a control terminal of the transistor.

A converter operable to convert an input voltage at an input node to an output voltage at an output node coupled to a load by switching on and off a transistor at a switching frequency, the converter comprising: an error amplifier circuit having a first input coupled to a reference voltage, a second input coupled to the output node through a resistive divider, a first output operable to output a control current and a second output operable to output a current equivalent to the control current; a peak current comparator circuit having a first input coupled to the second output of the error amplifier circuit, a second input and an output, the second input is coupled to the input node through an inductor; an off-time timer circuit having an input coupled to the first output of the error amplifier circuit and an output, the off-time timer circuit operable to set the switching frequency based on the control current; and a control circuit having a first input coupled to the output of the peak current comparator circuit, a second input coupled to the output of the off-time timer circuit and an output coupled to a control terminal of the transistor.

An apparatus, system and method of controlling the supply of DC current from a power source to an electrical load provides for a protective circuit that senses the characteristics of the connected load prior to permitting the enablement of a switch connecting the supply and the load. A voltage arising from applying a constant current to the load during a time period is compared with a predetermined threshold determined by the intended capacity of the switch so that, when closed, the current through the switch is compatible with the switch. The protective circuit may be used in conjunction with semiconductor switches, electromechanical contactors or relays. A plurality of such devices may be incorporated in an enclosure and controlled by logic so as to manage the supply of power from a power source to a plurality of electrical loads having differing power requirements.

An apparatus, system and method of controlling the supply of DC current from a power source to an electrical load provides for a protective circuit that senses the characteristics of the connected load prior to permitting the enablement of a switch connecting the supply and the load. A voltage arising from applying a constant current to the load during a time period is compared with a predetermined threshold determined by the intended capacity of the switch so that, when closed, the current through the switch is compatible with the switch. The protective circuit may be used in conjunction with semiconductor switches, electromechanical contactors or relays. A plurality of such devices may be incorporated in an enclosure and controlled by logic so as to manage the supply of power from a power source to a plurality of electrical loads having differing power requirements.