Ixys Corporation

Littelfuse, Inc.

Other

Anatoliy V Tsyrganovich

Leonid A Neyman

James F Anderson

Eric David Blom

Vladimir Tsukanov

Md Abdus Sattar

A gate driver integrated circuit drives an output signal onto its output terminal and onto the gate of a power transistor. In a turn-on episode, a digital input signal transitions to a digital logic high level. In response, the gate driver integrated circuit couples the output terminal to a positive supply voltage terminal, thereby driving a positive voltage onto the gate of the power transistor. In response to a high-to-low transition of the digital input signal, the driver drives a negative voltage onto the output terminal and power transistor gate for a short self-timed period of time, and then couples the output terminal to a ground terminal, thereby driving the output terminal and power transistor gate up to ground potential. The output terminal and power transistor gate are then held at ground potential in anticipation of the next turn-on episode of the power transistor.

High-speed MOSFET and IGBT gate driver

A sense resistor is placed in series with an output capacitor of a buck converter. The buck converter operates in a discontinuous mode such that there is a dead time in each switching cycle. A control circuit senses a voltage across the sense resistor and thereby generates a first signal I. The control circuit detects an offset voltage in I, where the offset voltage is the voltage of Iduring the dead time in a first switching cycle. The control circuit level shifts the entire Iby the offset voltage, thereby generating a second signal I. Ihas the same waveform as the waveform of the inductor current. In a second cycle, Iis used to determine when to turn off the main switch and when the start of the dead time occurs. Iand the offset voltage are used together to determine when to turn the main switch on.

Synchronous sensing of inductor current in a buck converter control circuit

In a switching converter having an inductive load, a current may flow through the body diode of a transistor even though the gate of the transistor is being controlled to keep the transistor off. Then when the other transistor of the switch leg is turned on, a reverse recovery current flows in the reverse direction through the body diode. To reduce switching losses associated with such current flows, a gate driver integrated circuit detects when current flow through the body diode rises above a threshold current. The gate driver integrated circuit then controls the transistor to turn on. Then when the other transistor of the switch leg is made to turn on, the gate driver first turns the transistor off. When the gate-to-source voltage of the turning off transistor drops below a threshold voltage, then the gate driver integrated circuit allows and controls the other transistor to turn on.

Gate driver for switching converter having body diode power loss minimization

A programmable temperature compensated voltage reference is disclosed. In an exemplary embodiment, an apparatus includes a digital-to-analog converter (DAC) that uses a reference voltage and a code to generate a DAC output voltage. The apparatus also includes a temperature compensator that uses a temperature measurement (T) and the DAC code to generate a temperature compensation signal. The temperature compensation signal is represented by a third order polynomial equation. The apparatus also includes a signal combiner that combines the DAC output voltage and the temperature compensation signal to generate a temperature compensated programmable reference voltage.

Programmable temperature compensated voltage generator

A rectifier includes a larger Field Effect Transistor (FET) and a smaller FET (FET). A sense resistor is in series with FET's body diode between a cathode terminal and an anode terminal. If the cathode terminal voltage is greater than the voltage on the anode terminal, then body diodes of FETs are reverse biased, the FETs are controlled to be off, and there is no current flow through the rectifier. If, however, the voltage on the anode terminal becomes positive with respect to the cathode terminal, then the body diode of FETstarts to conduct and there is a voltage drop across the sense resistor. A comparator detects this condition and turns both FETs on. The rectifier is then conductive, so current can flow from the anode terminal, through the larger FET, and to the cathode terminal, with a small forward voltage drop and without passing across the sense resistor.

Low forward voltage rectifier

An AC-to-DC converter involves a rectifier, an inductor, a storage capacitor, a switch, and a microcontroller. In a capacitor pre-charge operation, the periodicity and voltage amplitude of an AC supply voltage are determined. Based on this, the microcontroller identifies one of a plurality of stored sequences. Each sequence is a list of values. The microcontroller turns off the switch on AC supply voltage zero crossings and turns on the switch in accordance with the values. As a result, a sequence of identical pulses of charging current flows into the storage capacitor. Each pulse passes in a current path from the rectifier, through the inductor, through the capacitor, through the switch, and back to the rectifier. During the pre-charge operation, the microcontroller does not measure the capacitor voltage and use that to calculate when to the turn the switch on next, but rather the sequence of precalculated stored values is used.

Growing community of inventors

Woodside, CA, United States of America

Anatoliy V Tsyrganovich