Abstract: A device includes a semiconductor body having an active region and a substrate region that is beneath the active region. A bidirectional switch is formed in the semiconductor body having first and second gate structures that are configured to block voltage across two polarities as between first and second input-output terminals that are in ohmic contact with the electrically conductive channel. First and second switching devices are configured to electrically connect the substrate region to the first and second input-output terminals, respectively. A passive electrical network includes a first capacitance connected between a control terminal of the first switching device and the second input-output terminal and a second capacitance connected between a control terminal of the second switching device and the first input-output terminal. The passive electrical network is configured temporarily electrically connect the substrate region to the first and second input-output terminal at different voltage conditions.

Abstract: Circuits and devices are provided for reliably holding a normally-off Gallium Nitride (GaN) power transistor, such as a Gate Injection Transistor (GIT), in a non-conducting state when a gate of the power transistor is not driven with an active (turn-on) control signal. This is accomplished by coupling a normally-on pulldown transistor between the gate and the source of the power transistor, such that the pulldown transistor shorts the gate to the source when the power transistor is not set for its conducting state. The pulldown transistor is preferably located on the same semiconductor die as, and in close proximity to, the power transistor, so as to avoid spurious noise at the power transistor gate that may unintentionally turn on the power transistor. A pulldown control circuit is coupled to the gate of the pulldown transistor and autonomously turns off the pulldown transistor when the power transistor is set to conduct.

Abstract: In accordance with an embodiment, a method includes converting power by a power converter circuit having a plurality of converter cells coupled to a supply circuit. Converting the power includes a plurality of successive activation sequences and, in each activation sequence, activating at least some of the plurality of converter cells at an activation frequency. The activation frequency is dependent on at least one of an output power and an output current of the power converter circuit.

Abstract: A power converter circuit includes a plurality of input nodes, an output, a plurality of switch and inductor circuits, a plurality of rectifier circuits, a first capacitor network, and a second capacitor network. Each of the plurality of switch and inductor circuits is connected between a respective pair of the plurality of input nodes, and each of the plurality of rectifier circuits is connected between a respective one of the plurality of switch and inductor circuits and the output. The first capacitor network includes at least two capacitors connected between at least one of the plurality of input nodes and the output, and the second capacitor network includes at least one capacitor and is connected to the output. A capacitance of the at least one capacitor of the second capacitor network is greater than a capacitance of each of the at least two capacitors of the first capacitor network.

Abstract: A semiconductor device includes a main bi-directional switch formed on a semiconductor substrate and having first and second gates, a first source electrically connected to a first voltage terminal, a second source electrically connected to a second voltage terminal, and a common drain. The semiconductor device further includes a discharge circuit having a plurality of individual transistors or an auxiliary bi-directional switch monolithically integrated with the main bi-directional switch and connected in a common source configuration to the semiconductor substrate. The plurality of individual transistors or the auxiliary bi-directional switch includes a first drain connected to the first source of the main bi-directional switch, a second drain connected to the second source of the main bi-directional switch, and first and second gates each decoupled from gate drive circuitry so that the first and the second gates are controlled at least passively and based on a state of the main bi-directional switch.

Abstract: A device includes a semiconductor body having an active region and a substrate region that is beneath the active region. A bidirectional switch is formed in the semiconductor body having first and second gate structures that are configured to block voltage across two polarities as between first and second input-output terminals that are in ohmic contact with the electrically conductive channel. First and second switching devices are configured to electrically connect the substrate region to the first and second input-output terminals, respectively. A passive electrical network includes a first capacitance connected between a control terminal of the first switching device and the second input-output terminal and a second capacitance connected between a control terminal of the second switching device and the first input-output terminal. The passive electrical network is configured temporarily electrically connect the substrate region to the first and second input-output terminal at different voltage conditions.

Abstract: In accordance with an embodiment of the present invention, a method of controlling current through a transistor includes measuring a voltage across the transistor, measuring a current through the transistor, determining a safe operating current for the measured voltage across the transistor, and adjusting a voltage of a control node of the transistor using a feedback controller until the measured current through the transistor is not greater than the determined safe operating current.

Abstract: In accordance with an embodiment, a method of controlling a switch driver includes energizing a first inductor in a first direction with a first energy; transferring the first energy from the first inductor to a second inductor, wherein the second inductor is coupled between a second switch-driving terminal of the switch driver and a second internal node, and the second inductor is magnetically coupled to the first inductor; asserting a first turn-on signal at the second switch-driving terminal using the transferred first energy; energizing the first inductor in a second direction opposite the first direction with a second energy after asserting the first turn-on signal at the second switch-driving terminal; transferring the second energy from the first inductor to the second inductor; and asserting a first turn-off signal at the second switch-driving terminal using the transferred second energy.

Abstract: A device includes a semiconductor body having an active region and a substrate region that is beneath the active region. A bidirectional switch is formed in the semiconductor body having first and second gate structures that are configured to block voltage across two polarities as between first and second input-output terminals that are in ohmic contact with the electrically conductive channel. First and second switching devices are configured to electrically connect the substrate region to the first and second input-output terminals, respectively. A passive electrical network includes a first capacitance connected between a control terminal of the first switching device and the second input-output terminal and a second capacitance connected between a control terminal of the second switching device and the first input-output terminal. The passive electrical network is configured temporarily electrically connect the substrate region to the first and second input-output terminal at different voltage conditions.

Abstract: A device includes a semiconductor body having an active region and a substrate region that is beneath the active region. A bidirectional switch is formed in the semiconductor body having first and second gate structures that are configured to block voltage across two polarities as between first and second input-output terminals that are in ohmic contact with the electrically conductive channel. First and second switching devices are configured to electrically connect the substrate region to the first and second input-output terminals, respectively. A passive electrical network includes a first capacitance connected between a control terminal of the first switching device and the second input-output terminal and a second capacitance connected between a control terminal of the second switching device and the first input-output terminal. The passive electrical network is configured temporarily electrically connect the substrate region to the first and second input-output terminal at different voltage conditions.

Abstract: In accordance with an embodiment, a method includes converting power by a power converter circuit having a plurality of converter cells coupled to a supply circuit. Converting the power includes a plurality of successive activation sequences and, in each activation sequence, activating at least some of the plurality of converter cells at an activation frequency. The activation frequency is dependent on at least one of an output power and an output current of the power converter circuit.

Abstract: Power converters that use bi-directional switches to rectify an AC power source, rather than diode bridges, are provided. In additional to performing rectification, the bi-directional switches also control power flow through the power converter, i.e., the switches effectively implement a switching power supply to provide a desired DC voltage to a load. The use of bi-directional switches that can block current flow in either direction enables a power converter that uses minimal circuitry, has low conduction losses (high efficiency), and can operate in buck and boost modes. Furthermore, via appropriate control, the described power converter circuitry may be used both for converting from AC voltage to DC voltage, and from DC voltage to AC voltage.

Abstract: A circuit includes a bridgeless flyback converter having a primary side electromagnetically coupled to a secondary side by a transformer, the primary side being devoid of a diode bridge rectifier, an input capacitor coupled to the primary side of the bridgeless flyback converter, an output capacitor coupled to the secondary side of the bridgeless flyback converter, an EMI (electromagnetic interference) filter coupled between an AC input and the input capacitor, and a compensation stage coupled in parallel with the output capacitor and including a storage capacitor. The input capacitor has a capacitance such that the compensation stage filters the AC mains frequency ripple of the AC input from the secondary side. The compensation stage is configured to store energy in the storage capacitor and regulate the voltage across the output capacitor. The bridgeless flyback converter is configured to regulate the voltage across the storage capacitor.

Abstract: A method of operating a converter includes: charging an LC tank coupled between a switching network and a primary winding of a transformer for a first period of time by connecting the LC tank to one or more input capacitors via the switching network, where the switching network includes a first half-bridge coupled between a first supply terminal and a center node, and a second half-bridge coupled between the center node and a second supply terminal; preventing energy transfer from the primary winding of the transformer to a secondary winding of the transformer during the charging of the LC tank; and after charging the LC tank, discharging the LC tank for a second period of time by disconnecting a terminal of the LC tank from the one or more input capacitors.

Abstract: In accordance with an embodiment, a method includes converting power by a power converter circuit having a plurality of converter cells coupled to a supply circuit. Converting the power includes a plurality of successive activation sequences and, in each activation sequence, activating at least some of the plurality of converter cells at an activation frequency. The activation frequency is dependent on at least one of an output power and an output current of the power converter circuit.

Abstract: In accordance with an embodiment, a converter includes: a rectifying stage having a first supply terminal and a second supply terminal, the first supply terminal and the second supply terminal configured to receive a bipolar ac signal from an AC power source, the rectifying stage including a half-bridge circuit coupled between the first supply terminal and the second supply terminal, a transformer, and a resonant tank coupled between an output of the half-bridge circuit and a primary winding of the transformer; and a DC-DC converter stage coupled between the rectifying stage and an output terminal.

Abstract: In an example, a circuit for voltage regulation includes a capacitor module, a multiple winding transformer, and a switching module. The capacitor module includes a first capacitor and a second capacitor. The multiple winding transformer includes a first primary side winding, a second primary side winding, and a secondary side winding. The switching module is configured to selectively switch the multiple winding transformer in a first state and a second state. During the first state, the switching module electrically couples the capacitor module to the multiple winding transformer. During the first state, the switching module electrically couples the first capacitor to the first primary side winding and electrically couples the second capacitor to the second primary side winding. During the second state, the switching module electrically couples the secondary side winding to a load. In another example, a circuit includes a voltage doubler module, transformer, and switching module.

Abstract: In one example, a circuit includes an alternating current (AC) voltage source, a voltage rail, a reference rail, a first capacitor, a second capacitor, and a switching unit. The AC voltage source is configured to supply voltage in a first direction during a first half of a cycle and supply voltage in a second direction during a second half of the cycle. During a first state of the circuit, the voltage in the first direction supplied by the AC voltage source charges the first capacitor and the voltage in the second direction supplied by the AC voltage source charges the first capacitor. During a second state of the circuit, the voltage in the first direction supplied by the AC voltage source charges the first capacitor and the voltage in the second direction supplied by the AC voltage source charges the second capacitor.

Abstract: A circuit includes a bridgeless flyback converter having a primary side electromagnetically coupled to a secondary side by a transformer, the primary side being devoid of a diode bridge rectifier, an input capacitor coupled to the primary side of the bridgeless flyback converter, an output capacitor coupled to the secondary side of the bridgeless flyback converter, an EMI (electromagnetic interference) filter coupled between an AC input and the input capacitor, and a compensation stage coupled in parallel with the output capacitor and including a storage capacitor. The input capacitor has a capacitance such that the compensation stage filters the AC mains frequency ripple of the AC input from the secondary side. The compensation stage is configured to store energy in the storage capacitor and regulate the voltage across the output capacitor. The bridgeless flyback converter is configured to regulate the voltage across the storage capacitor.

Abstract: In accordance with an embodiment, method of controlling a switching transistor includes applying a first voltage to a first node of a switchable tank circuit, where the first node is coupled to a control node of the switching transistor, the first voltage has a first polarity with respect to a reference terminal of the switching transistor, and the first voltage is configured to place the switching transistor into a first state. After applying the first voltage, the switchable tank circuit is activated, where a voltage of the first node transitions from the first voltage to a second voltage that is configured to place the switching transistor in a second state different from the first state. The switchable tank circuit is deactivated after the voltage of the first node attains the second polarity.