A DC-AC converter is disclosed. The DC-AC converter generates an output AC signal, and has an input DC-AC converter which generates a first AC signal, a transformer device which receives the first AC signal and generates a second AC signal, and a first bidirectional switch which selectively connects a first transformer output terminal and a first output terminal. The DC-AC converter also has a first capacitor which powers the first bidirectional switch, a first charging circuit which charges the first capacitor, and a second bidirectional which selectively conduct connects a second transformer output terminal and a second output terminal. The DC-AC converter also has a second capacitor which powers the second bidirectional switch, and a second charging circuit which charges the second capacitor. Each of the bidirectional switches includes series connected transistors between first and second input/output terminals, and a transistor driver which drives the transistors.

A power supply control circuit includes a power storage that stores power generated by energy harvesting, a function circuit that operates a specific function, a first switch allocated between the power storage and the function circuit and supplies or not supplies the power to the function circuit, a supply controller that monitors a voltage corresponding to the power stored in the power storage, and when the voltage of the power storage is equal to or above a first voltage, controls the first switch so that the function circuit is supplied with the power stored in the power storage, and a power consumption controller that controls, based on the voltage of the power storage, power to be consumed by the function circuit, the power being supplied from the power storage to the function circuit by switching of the first switch.

Provided are a semiconductor device and a method of operating the same. A semiconductor device may include a comparator which compares a first voltage with a rectified voltage and provides a second voltage in accordance with the comparison. A timer circuit may operate a timer according to the second voltage and output a third voltage in correspondence with an operation time of the timer. A driver may drive a transistor with a fourth voltage generated by the driver according to the third voltage. A calibration circuit may generate a timer calibration signal based on the second voltage and the fourth voltage. The timer calibration signal may be provided to the timer circuit and used to calibrate the operation time of the timer. More efficient rectification, with reduced occurrence of reverse current, may thereby be realized.

Provided is a reverse current switch. The reverse current switch includes: a comparison unit including a first input end, a second input end, and a first output end; and a switch resistance unit, where a first end of the switch resistance unit is connected to the first input end, a second end of the switch resistance unit is connected to the second input end, and a third end of the switch resistance unit is connected to the output end of the comparison unit, and the switch resistance unit is controlled by a voltage of the first output end. This reverse current switch has a simple structure and can implement working under low voltage conditions.

Channel switchover power multiplexer circuits, and methods of operating the same are disclosed. An example power multiplexer a first transistor coupled to a first input, a second transistor coupled to the first transistor to couple a first voltage at the first input to an output, a third transistor coupled to a second input, a fourth transistor coupled to the third transistor to couple a second voltage at the second input to the output, a diode amplifier to provide a third voltage to a gate of the first transistor to block a reverse current, and a soft-start amplifier to provide a fourth voltage to a gate of the fourth transistor to turn on (with adjustable VOUT ramp rate) the fourth transistor with a constant ramp rate.

A one-way conduction device includes a first transistor and a driving circuit. The driving circuit includes a first circuit, a second circuit and a detection circuit. The first transistor is coupled between an input end and an output end of the one-way conduction device. In the first circuit, a first conduction unit is coupled between the input end of the one-way conduction device and a first resistor. In the second circuit, a second conduction unit is coupled between the output end of the one-way conduction device and a second resistor. In the driving circuit, the detection circuit detects whether a current flows from the first circuit to the second circuit, and accordingly turns on or turns off the first transistor. In this manner, the driving circuit can control the turning on and off of the one-way conduction device.

A switching circuit with switches between a charging path and a low-impedance active path. The charging path comprises a zener diode substantially in parallel with a charging capacitor. Current flows through the charging path when the circuit is powered on and a power supply charges the charging capacitor while current flows through the charging path. The low-impedance bypass path comprises a switch that remains closed until a voltage across the charging capacitor exceeds a threshold voltage. The switch opens when the charging capacitor exceeds the threshold voltage.

A rectifier device is described herein. In accordance with one embodiment, the rectifier device includes a semiconductor body doped with dopants of a first doping type and one or more well regions arranged in the semiconductor body and doped with dopants of a second doping type. Thereby, the one or more well regions and the surrounding semiconductor body form a pn-junction. The rectifier device further includes an anode terminal and a cathode terminal connected by a load current path of a first MOS transistor and a diode, which is parallel to the load current path. An alternating input voltage is applied between the anode terminal and the cathode terminal during operation of the rectifier device. The rectifier device includes a control circuit that is configured to switch on the first MOS transistor for an on-time period, during which the diode is forward biased, wherein the first MOS transistor and the diode are integrated in the semiconductor body and the control circuit is at least partly arranged in the one or more well regions. Further, the rectifier device includes a switching circuit that is configured to electrically connect a first well region of the one or more well regions with the anode terminal, as long as the alternating input voltage is above a threshold value, and, to pull the voltage of first well region towards the alternating input voltage, as long as the alternating input voltage is at or below the threshold value.

A converter comprises a first switching element and a second switching element coupled between an input power source and an output capacitor and an inductor coupled to a common node of the first switching element and the second switching element, wherein the second switching element comprises a first diode and a first switch connected in series between a first terminal and a second terminal of the second switching element and a second diode connected between the first terminal and the second terminal of the second switching element.

Voltage stabilizing and voltage regulating circuits implemented in GaN HEMT technology provide stable output voltages suitable for use in applications such as GaN power transistor gate drivers and low voltage auxiliary power supplies for GaN integrated circuits. Gate driver and voltage regulator modules include at least one GaN D-mode HEMT (DHEMT) and at least two GaN E-mode HEMTs (EHEMTs) connected together in series, so that the at least one DHEMT operates as a variable resistor and the at least two EHEMTs operate as a Zener diode that limits the output voltage. The gate driver and voltage regulator modules may be implemented as a GaN integrated circuits, and may be monolithically integrated together with other components such as amplifiers and power HEMTs on a single die to provide a GaN HEMT power module IC.