Texas Instruments Corporation

National Semiconductor Corporation

David I Anderson

Peter J Hopper

Peter Smeys

Sandeep Raj Bahl

Giovanni Frattini

Ann Gabrys

Roberto Giampiero Massolini

Maurizio Granato

Jianhui Zhang

Michael Douglas Seeman

Barry Signoretti

In described examples, a first transistor has: a drain coupled to a source of a depletion-mode transistor; a source coupled to a first voltage node; and a gate coupled to a control node. A second transistor has: a drain coupled to a gate of the depletion-mode transistor; a source coupled to the first voltage node; and a gate coupled through at least one first logic device to an input node. A third transistor has: a drain coupled to the gate of the depletion-mode transistor; a source coupled to a second voltage node; and a gate coupled through at least one second logic device to the input node.

Method and circuitry for controlling a depletion-mode transistor

A converter circuit includes a primary side having a resonator and a first control circuit configured to control the resonator. The converter circuit also includes a secondary side having a resonant rectifier and a second control circuit configured to control the resonant rectifier. The converter circuit further includes a transformer configured to electrically isolate the primary side from the secondary side. The second control circuit is configured to turn the resonant rectifier on and off. The first control circuit may be configured to detect when the resonant rectifier is off and, in response, turn the resonator off without using a feedback signal from the secondary side. The first control circuit may be configured to detect when the resonant rectifier is off by detecting when input power to the primary side decreases. The resonant rectifier could be turned on and off by detuning the resonant rectifier.

Resonant isolated converters for power supply charge balancing systems and other systems

A gate driving circuit includes a driving stage configured to receive an input signal and generate a gate drive signal for a gate of a transistor switch. The gate driving circuit also includes an LC circuit having an inductor and a gate capacitance of the transistor switch. The LC circuit is configured so that a pulse in the gate drive signal generates a ringing in the LC circuit at a resonance frequency of the LC circuit to transfer energy into and out of the gate capacitance of the transistor switch. A switch could selectively couple the gate of the transistor switch to ground in order to discharge the gate capacitance. A control circuit could be used to provide the input signal, and the control circuit could be configured to regulate a duty cycle of the gate drive signal by adjusting an off-time between consecutive pulses in the input signal.

Single-pulse resonant gate driver for driving switches in resonant isolated converters and other systems

The invention relates to an apparatus and method for driving high-side switching devices in an H-Bridge circuit. The apparatus includes first and second N-Channel high-side switching devices. Each of the high-side switching devices is associated with, and is selectively driven by, a driver circuit. Each of the driver circuits is associated with, and is powered from, a bootstrap capacitor. The apparatus further includes a cross-couple circuit that is arranged to charge each of the bootstrap capacitors based, at least in part, on whether the low-side switching device that is associated with the other bootstrap capacitor is open or closed.

Bootstrap circuit for H-bridge structure utilizing N-channel high-side fets

A circuit for voltage regulation is provided. The circuit includes a variable output voltage regulator and an output capacitor circuit. The output capacitor circuit includes at least two output capacitors and at least one switch. The variable output voltage regulator is capable of providing a regulated DC output voltage at two or more different voltage levels. When the output voltage is changed to a lower output voltage level, one of the output capacitors in the output capacitor circuit is switched out of the circuit to conserve the charge stored on it. When the output voltage returns to the higher output voltage level, the output capacitor that was switched out is switched back in.

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Saratoga, CA, United States of America

David I Anderson