A bootstrapping circuit that utilizes multiple pre-charged capacitor voltages and applies the capacitor voltages to the high side FET of a GaN bootstrapping driver. During the pre-charging phase of the bootstrapping driver, multiple capacitors are charged in parallel to the supply voltage. During the driving phase of the bootstrapping driver, the capacitors are connected in series through a number of FETs and connected to the gate terminal of the high side FET of the bootstrapping driver. As a result, the gate-to-source voltage of the high side FET is equal to or greater than the supply voltage during the driving phase, increasing the driving capability of the high side FET and reducing the total required capacitance and die area of the bootstrapping driver.

A circuit to enhance the driving capability of conventional inverting bootstrapping GaN drivers. When the inverting driver input is logic high and the driver output is off, the voltage stored on the first bootstrap capacitor for turning on the high side (pull-up) FET of the inverting driver is charged to the full supply voltage using an active charging FET, instead of using a diode or diode-connected FET in a conventional bootstrapping driver. The gate voltage of the active charging FET is bootstrapped to a voltage higher than supply voltage by a second bootstrap capacitor that connects to the inverting driver input, which is at a logic high. The second bootstrap capacitor is charged by an additional diode or diode-connected FET connected to the supply voltage when the inverting driver input is a logic low.

A semiconductor device includes a galvanic isolator; a transmitting circuit that transmits a transmission signal via the galvanic isolator; a receiving circuit that receives a received signal corresponding to the transmission signal via the galvanic isolator; an encoding circuit that encodes two input signals and generates the transmission signal; and a decoding circuit that decodes the two input signals from the received signals.

A gate driver circuit comprises a gate-driver assembly, a transformer, first and second circuit voltage outputs, first and second switching devices, and a controller. The gate-driver assembly comprises a first and second voltage inputs and a first and second voltage outputs coupled to a primary winding of the transformer. The first and second switching devices are coupled to the secondary winding and respectively coupled to the first and second circuit voltage outputs. The controller is configured to cause the first circuit voltage output to supply a positive output voltage by supplying a higher first input voltage to the first voltage input than to the second voltage input and is also configured to cause the first circuit voltage output to supply a negative output voltage by supplying a higher second input voltage to the second voltage input than to the first voltage input.

The efficient control of a plurality of high side switches, e.g. the high side switches of half bridges is presented. A control circuit contains a charge provisioning unit to provide an electrical charge. The control circuit contains a plurality of sets of high control switches for the plurality of high side switches, respectively; wherein each set of high control switches is used to arrange the charge provisioning unit in parallel to a gate-source capacitance of the respective high side switch. The control circuit comprises a controller to, during a phase of a plurality of different phases, control a respective set of high control switches from the plurality of sets of high control switches to arrange the charge provisioning unit in parallel to the gate-source capacitance of the respective high side switch from the plurality of high side switches, to switch on the respective high side switch.

This disclosure describes techniques for controlling a power supply voltage for a high-side gate driver that is used in a power converter. In some examples, in response to an overvoltage condition that occurs on an input voltage lead of a power converter, a power converter may decouple a terminal of a charge pump capacitor from the input voltage lead, and couple the terminal of the capacitor to a reference voltage lead. In further examples, in response to an overvoltage condition that occurs on an input voltage lead of a power converter, a power converter may turn off both switching transistors.

A semiconductor device includes: a first conductivity type base body; a second conductivity type well region provided on the base body and formed with a high potential side circuit; a second conductivity type voltage blocking area provided to surround a periphery of the well region; a level shifter having a second conductivity type drift region provided on the base body, a second conductivity type carrier reception region provided in an upper part of the drift region, a first conductivity type base region provided in contact with the drift region, a first gate electrode provided on the base region, and a second conductivity type carrier supply region provided in an upper part of the base region; a first conductivity type isolation region provided between the voltage blocking area and the drift region on the base body; and a second gate electrode on the isolation region.

Disclosed examples provide DC-DC converters and control circuits to provide high and low-side driver signals and to selectively adjust a delay time between a low-side switching device turning off and a high-side switching device turning on according to a comparator signal, including a clocked comparator circuit referenced to a switching node to sample the voltage across the high-side switching device in response to a first edge of the high-side driver signal, and to generate the comparator signal indicating a polarity of the sampled high-side switch voltage to facilitate zero voltage switching of the high-side switching device.

A circuit and method for digital controlling the slew rate of load voltage are provided. The circuit is comprised of a digital slew-rate control unit that utilizes a feedback signal to generate control signals where the feedback signal indicates the observed rate of voltage change on the load. The circuit is further comprised of a load driver circuit that is operated by the control signals and provides a slew-rate controlled output voltage used to operate a load switch, where the load switch provides power to the load. The circuit is configured to operate the load switch using a slew-rate controlling driver, depending on the state of the load switch transition, and a non-controlling driver.

A driver and a driving control method for a power converter are provided. The driver includes a level shift circuit, a negative voltage generator and a first PMOS transistor. The level shift circuit provides an output signal, wherein the output signal has a first operation voltage and a second operation voltage. When the output signal received by the negative voltage generator is the first operation voltage, the negative voltage generator outputs the first operation voltage. When the output signal received by the negative voltage generator is the second operation voltage, the negative voltage generator generates and outputs a third operation voltage, and the third operation voltage is lower than the second operation voltage. A control terminal of the first PMOS transistor is coupled to an output terminal of the negative voltage generator. An output terminal of the first PMOS transistor provides a driving voltage.