Non-ideal diodes have a non-zero resistance across a PN junction when the junction is forward biased. When a diode comprising a power supply has a voltage drop across the junction that exceeds a predetermined threshold, the threshold-exceeding voltage drop trips a comparator, the output of which controls a switch between a power supply and a load.

A switch circuit that can control an electrical connection state without additionally providing a control circuit is provided. The switch circuit includes a transistor, a first switch which control an electrical connection state between a gate of the transistor and a wiring, a second switch, a first diode including an anode and a cathode, a third switch, and a second diode including an anode and a cathode. An electrical connection state between the anode of the first diode and the gate of the transistor is controlled by the second switch, and the cathode of the first diode is electrically connected to a source of the transistor. An electrical connection state between the anode of the second diode and the gate of the transistor is controlled by the third switch, and the cathode of the second diode is electrically connected to a drain of the transistor.

Power switch driver for driving a control terminal of a power switch to drive a load, the power switch driver having a in negative feedback circuit to control current delivered to the control terminal, the negative feedback circuit comprising:—a current output circuit comprising at least one of a current source and a current sink, the current output circuit for providing a said current of a said control terminal and configured to receive an output current control signal to control magnitude of the current provided by the current output circuit;—a terminal voltage input circuit for receiving a voltage from a said control terminal and to output an indication of said voltage;—an amplifier coupled to amplify the terminal voltage indication to generate an amplifier output; and—a reference voltage input circuit for receiving a reference voltage, comprising at least one resistor, the reference voltage input circuit coupled to a charge supply input of the amplifier, wherein—the power switch driver is configured to generate the output current control signal dependent on the amplifier output, and—the power switch driver is configured to reduce the current provided by the current output circuit responsive to an increase in the voltage received by the terminal voltage input circuit.

A drive circuit includes: a current capability switch configured to switch a current capability of driving an output transistor of a switching power supply according to whether a switch current flowing through the output transistor is in a continuous mode or in a discontinuous mode.

The invention relates to a driver circuit and an active transmitter device, a series circuit consisting of a first capacitor (4) and a second capacitor (12) being charged to a reference voltage by way of a charging current and the charged capacitors being discharged via the inductor (1) by an oscillating discharge, the discharge being terminated when the current through the inductor has completed an entire oscillation period or a multiple thereof.

A switching element drive device that reduces a switching loss while suppressing noise with an inexpensive configuration, is provided. The switching element drive device includes a current sensor configured to measure a load current flowing through a load, a voltage sensor configured to measure an input voltage inputted from a power supply, and a control part configured to output a command value of a gate drive voltage to a gate drive voltage supply part, the gate drive voltage supply part being configured to supply the gate drive voltage for driving a switching element disposed between the power supply and the load, wherein the control part is further configured to determine the command value of the gate drive voltage based on the load current and the input voltage.

A design technique is disclosed that divides up a cellular power switch into different size segments. Each segment is driven by a different driver circuit. The selection of the combination of segments is made to minimize the combined conduction and switching losses of the power switch. For example, for very light loads, switching losses dominate so only a small segment is activated for driving the load. For medium and high load currents, conduction losses become more significant, so additional segments are activated to minimize the total losses. In one embodiment, the number of cells in the segments is binary weighted, such as 1×, 2×, and 4×, so that there are seven different combinations of segments. The drivers may be configured to achieve the same or different slew rates of the segments, such as to reduce transients. The segments may all be in the same die or a plurality of dies.

Certain aspects of the present disclosure provide methods and apparatus for dynamically managing the dead time between turning on output power stage transistors in amplifiers, such as audio amplifiers. One example method of operating an amplifier generally includes generating a drive signal based on an input signal; amplifying the drive signal by alternatively driving a first transistor and a second transistor with a time between deactivating the first transistor and activating the second transistor; and adjusting the time based on a parameter of the input signal or the drive signal, during the amplifying. For example, the parameter may include an amplitude of the input signal, a duty cycle of the drive signal, or a duty cycle of a modulated signal (e.g., a pulse-width modulated signal) generated based on the input signal. The input signal may be a digital audio input signal.

A direct current circuit breaker includes main circuit for carrying a main-path current, and a transient circuit for carrying a transient-path current. The main circuit includes a first solid state switch and a main contactor. The first solid state switch is coupled in series with the main contactor. The transient circuit is coupled in parallel with the main circuit. The transient circuit includes an auxiliary contactor coupled in series with a second solid state switch. The second solid state switch closes when the main-path current exceeds a first threshold. The first solid state switch then opens. The main contactor opens when the main-path current falls below a second threshold. Then the second solid state switch opens. The auxiliary contactor opens when the transient-path current falls below the second threshold and after the second solid state switch opens.

A switching apparatus (20) comprises first and second current paths, each current path configured to be capable of conducting an electrical current, the first current path including a first switching element (28) connected in parallel with a first passive current check element (30), the switching apparatus (20) further including a switching controller configured to selectively control the switching of the first switching element (28), wherein the switching controller is configured to selectively switch the first switching element (28) at a first intra-current path switching speed to commutate the electrical current between the first switching element (30) and the first passive current check element (32), the switching controller is configured to selectively switch the first switching element (28) at a first inter-current path switching speed to commutate the electrical current between the first and second current paths, and the first intra-current path switching speed is faster or slower than the first inter-current path switching speed.