The disclosure provides a charging device, which includes an input terminal configured to receive an input voltage; an output terminal configured to connect a target load so as to charge the target load; a control terminal, configured to receive a control voltage; a junction field-effect transistor and a control circuit. The junction field-effect transistor includes at least: a drain, electrically connected to the input terminal so as to receive the input voltage; a source, electrically connected to the output terminal so as to output an output voltage and an output current; and a gate, electrically connected to the control terminal. The control circuit is electrically connected to the control terminal, and configured to change the control voltage based on a change in a load voltage so as to change a pinch-off voltage of the JFET by controlling a bias voltage on the gate, thereby controlling the output current.

Circuits and methods to mitigate or eliminate potentially damaging events (e.g., damaging current spikes from in-rush current, charge transfer current, short circuits, etc.) in DC-DC power converters. Embodiments enable dynamic switching of conversion ratios in reconfigurable power converters while under load without turning off the power converter circuitry or suspending switching of the charge pump power switches. Embodiments selectively increase the ON resistance, R.sub.ON, for at least some power FETs in a power converter by actively controlling the driver voltage to the gates of the power FETs. During normal operation, the power FET driver voltage may be set to overdrive the FET gate to lower R.sub.ON to a desired level that allows high current flow. For other scenarios, the power FET driver voltage may be reduced so as to increase R.sub.ON while ON and thus impede current flow to provide protection against potentially damaging events.

There is described a snubber circuit comprising an electronic switch. The circuit includes an impedance network comprising reactive circuit elements to smooth energy transients if the electronic switch is turned off and if the switch is turned on. A resistive element dissipates energy released by at least one of the reactive circuit elements. The resistive element is of a load to be driven using the electronic switch. A power supply unit may include the described snubber circuit.

Techniques are disclosed to allow for a switched capacitor digital power amplifier (PA) that operates using high supply voltage levels beyond twice the maximum voltage rating for any of the transistor terminals such as Vds/Vdg/Vsg.

An aspect includes an apparatus including a first amplifier; a first field effect transistor (FET) including a first source coupled to an output of the first amplifier, and a first drain for coupling to a first load; and a first gate drive circuit including an input coupled to the output of the first amplifier and an output coupled to a first gate of the first FET. Another aspect includes a method including amplifying a first audio signal using a first audio amplifier to generate a first voltage; generating a first gate voltage based on the first voltage; applying the first gate voltage to a first gate of a first field effect transistor (FET) coupled between the first audio amplifier and a first audio transducer; and applying the first voltage to a first source of the first FET.

A power supply control device controls power supply by switching on or off a first semiconductor switch and a second semiconductor switch that are arranged on a current path. A first diode and a second diode are connected between a drain and a source of the first semiconductor switch and the second semiconductor switch, respectively. Cathodes of the first diode and the second diode are arranged downstream and upstream of the respective anode on the current path. If current flows through the current path even though a microcomputer has given an instruction to switch the first semiconductor switch and the second semiconductor switch off, a first drive circuit switches the first semiconductor switch on.

A power converter apparatus comprises a set of switching elements communicatively coupled with a set of gate drive circuits. Each gate drive circuit is configured to provide a respective drive signal to a corresponding switching element, each switching element being switchably responsive to the respective drive signal. The apparatus includes a controller module configured to control an output state of the power converter, and selectively change one of a respective gate resistance and a respective gate current of a corresponding subset of the gate drive circuits based on the output state of the power converter.

Disclosed is an RF switch device and, more particularly, an RF switch device that reduces or eliminates a voltage imbalance by implementing at least one stage in a stacked switch device with a different width, and thus the voltage applied to each stage in the OFF state may be more equally distributed among the individual stages.

The present description concerns a method of controlling a bidirectional switch (200), including: first (210 1) and (210 2) field-effect transistors electrically in series between first (262 1) and second (262 2) terminals of the bidirectional switch; third (614) and fourth (612) field-effect transistors electrically in series between said first and second terminals of the bidirectional switch, a first connection node (252) in series with the first and second transistors being common with a second connection node (616) in series with the third and fourth transistors, including steps of: receiving a voltage (V200) between the terminals of the bidirectional switch; detecting, from the received voltage, a first sign of said voltage; at least while the first sign is being detected, coupling the first terminal to said first node (252), potentials of control terminals of the first, second, third, and fourth transistors being referenced to the potential (REF) of the first and second nodes having common sources of the first, second, third, and fourth transistors connected thereto.

Provided is a driver circuit that controls an output unit that switches whether or not to supply a current to an output line, in accordance with a potential difference between a first control signal to be input and a voltage of the output line. The driver circuit comprises a control line that transmits the first control signal to the output unit; a low potential line to which a predetermined reference potential is applied; a first connection switching unit that switches whether or not to connect the control line and the low potential line, in accordance with a second control signal; and a cutoff unit that is provided in series with the first connection switching unit between the control line and the low potential line and cuts off the control line and the low potential line based on a potential of the low potential line.