An adjustable power supply suitable for a power switch driver circuit takes an input voltage and generates output voltages at three output terminals. Two of the output terminals provide gate voltage signals to a power switch control device while the third is connected to a reference voltage. The output voltages may be adjusted using a first and second external resistor enabling power requirements for a wide variety of power switch devices to be satisfied.

A gate drive circuit in a switching circuit including a switching terminal connected to a node that is connected to a high-side transistor and a low-side transistor, and connected to an end of a boot-strap capacitor, a bootstrap terminal connected to another end of the bootstrap capacitor, a high-side driver having an output terminal connected to a gate of the high-side transistor, an upper power supply node connected to the bootstrap terminal, and a lower power supply node connected to the switching terminal, a low-side driver having an output terminal connected to a gate of the low-side transistor, a rectifying device for applying a constant voltage to the bootstrap terminal, and a dead time controller for controlling a length of a dead time during which the high-side transistor and the low-side transistor are simultaneously turned off, based on a potential difference between the bootstrap terminal and the switching terminal.

A power supply system for USB Power Delivery includes a current source drive circuit to control a power FET to regulate the supply of power along a power path. The current source drive circuit includes a cascode current source and a cascode protection circuit formed by a source follower and a feedback voltage divider. The source follower can be a transistor with its gate connected to a cascode node between upper- and lower-stage transistors of the cascode current source. The divider node of the voltage divider is connected to the gate of the lower-stage transistor. The current source drive circuit can operate within the gate-source voltage specifications of 30-volt DEPMOS devices, and can provide high output impedance to the gate of power FET and a current limit circuit during current limiting operation, without requiring an extra high-voltage mask during fabrication.

A gate driver, which drives an N-channel type transistor connected between an application terminal of an input voltage and an application terminal of a switch voltage, includes a capacitor circuit connected between an application terminal of a boot voltage higher than the switch voltage by a voltage between both ends of the boot capacitor and the application terminal of the switch voltage, and a timing control circuit that charges an input gate capacitance of the transistor with the boot voltage after precharging the same with the input voltage during turn-on transition of the transistor, and decreases capacitance value of the capacitor circuit after the turn-on transition of the transistor.

In an embodiment, a switching circuit is provided that includes a Group III nitride-based semiconductor body including a first monolithically integrated Group III nitride-based transistor device and a second monolithically integrated Group III nitride based transistor device that are coupled to form a half-bridge circuit and are arranged on a common foreign substrate having a common doping level. The switching circuit is configured to operate the half-bridge circuit at a voltage of at least 300 V.

A gate driver circuit comprises an auxiliary winding, a voltage summer, an auxiliary voltage bus, a gate driver integrated circuit (IC), and a controller. The auxiliary winding is positioned adjacently to the inductor and configured to inductively couple with the inductor. The voltage summer comprises a pair of diodes coupled to the auxiliary winding and a pair of capacitors coupled to the pair of diodes. The auxiliary voltage bus is configured to receive a summed voltage from the voltage summer based on a sum of voltages stored in the pair of capacitors. The gate driver IC is configured to receive a voltage from a positive rail of the auxiliary voltage bus and to output a gate control signal to control a switching device based on the received voltage and based on a pulse signal generated by the controller.

An isolated gate driver has a first portion in a first voltage domain and a second portion in a second voltage domain. The first and second portions are coupled by an isolation communication channel. The isolated gate driver transmits across the isolation communication channel a serial word containing first drive strength information and simultaneously transmits gate information with the serial word across the isolation communication channel. The gate information indicates a state of a gate signal for a transistor coupled to the second portion of the isolated gate driver. A demodulator circuit demodulates a signal containing the gate information and the drive strength information transmitted across the isolation communication channel in the serial word. A gate signal output circuit coupled to the demodulator circuit supplies the gate signal based on the gate information with a drive strength of the gate signal being based on the drive strength information.

An apparatus comprises an energy transfer device configured to supply power from a primary side of an isolation barrier through the isolation barrier to a secondary side of the of the isolation barrier for driving a gate of a switch for controlling output of the switch at the secondary side. The apparatus comprises a monitoring component. The monitoring component is configured to monitor an operating state of the switch. The monitoring component is configured to evaluate the operating state to determine whether a fault has occurred, perform a countermeasure, and/or provide a signal of the fault.

A device includes a charge pump configured to provide a current to a bootstrap capacitor responsive to a charge pump switch being closed. The device also includes a current limiter coupled in series between the charge pump switch and the charge pump. The current limiter is configured to receive a control signal from a controller that indicates whether the device is to operate in a first mode or in a second mode; responsive to the control signal indicating the first mode, allow a first value of current to the charge pump switch; and, responsive to the control signal indicating the second mode, limit the current to the charge pump switch to a second value. The second value is less than the first value.

The present disclosure provides a controller for controlling a GaN-based semiconductor device. The controller is configured to receive a current sensing signal V.sub.CS which is indicative of a drain-to-source current of the GaN-based semiconductor device and generate a control driving signal V.sub.DRV to the GaN-based semiconductor device such that a gate-to-source voltage V.sub.GS applied to the GaN-based semiconductor device for switching on the GaN-based semiconductor device is stabilized to a voltage value equal to a reference voltage V.sub.ref over an on-time duration. Impact of the change in the voltage drop across the current sensing resistor to the operation of the GaN-based semiconductor device is eliminated.