Semiconductor Components Industries, LLC

Dhruv Chopra

Ajay Karthik Hari

Tomas Tichy

Karel Ptacek

Hyunchul Eum

Minha Hwang

Reducing total harmonic distortion of power-factor correction switching converters. At least one example is a method of operating a power-factor-correction (PFC) converter, the method comprising: charging an inductance of the PFC converter, thereby creating a charge mode; asserting, during the charge mode, an initial-reset signal by a reset circuit implementing voltage-mode control; ending the charge mode a compensated time after assertion of the initial-reset signal, the compensated time inversely proportional to a magnitude of an input voltage of the PFC converter; and then discharging the inductance of the PFC converter.

Method and system of reducing total harmonic distortion of power-factor correction converters

A driver is suitable for use with a gallium nitride (GaN) power stage, and includes a voltage regulator and a high side driver. The voltage regulator provides a boot voltage between first and second terminals thereof that varies within a range between a turn-on voltage of a GaN transistor, and a safe voltage limit between a gate and a source thereof throughout an active time of said GaN transistor. The high side driver has an input for receiving a high side drive signal, an output for coupling to said gate of said GaN transistor, a power supply terminal coupled to said first terminal of said voltage regulator, and a ground terminal for coupled to said second terminal of said voltage regulator.

Bootstrap clamp circuit and method

Reduced voltage switching of the primary switch. At least one example is a method comprising: activating, during a first switching period, a primary switch coupled to a primary winding of a transformer of a flyback topology, the activating induces a positive current in the primary winding; deactivating the primary switch and activating a secondary switch coupled to the secondary of the transformer, the activating the secondary switch during the first switching period and for a duration selected based on a signal indicative of negative current from a prior switching period, and the activating the secondary switch results in a positive current through the secondary winding followed by a negative current through the secondary winding; and discharging capacitance of the primary switch by a negative current in the primary winding responsive to the negative current in the secondary winding.

Switching power converter with reduced voltage switching of the primary switch

Synchronous rectification in active clamp flyback power converters. At least some example embodiments are methods including: sensing a first slope of voltage on a secondary winding of the transformer, the first slope indicative of the power converter entering a charge mode of the transformer; modifying, responsive the sensing, an operational state of a secondary rectifier (SR), driver coupled to a secondary rectifier; making the secondary rectifier conductive by the SR driver during a discharge mode of the transformer; sensing a second slope of voltage on the secondary of the transformer, the second slope indicative of ending of the discharge mode of the power converter; and then returning, responsive to sensing the second slope, the SR driver to an original operational state.

Systems and methods of synchronous rectification in active clamp flyback power converters

Synchronous rectification in active clamp flyback power converters. At least some example embodiments are methods including: sensing, based on a rate of change of voltage on a drain of a synchronous rectifier field effect transistor (SR FET), that the power converter has entered a charge mode of a transformer arranged for flyback operation; changing, responsive the sensing, a parameter within a SR driver from an original state to a modified state, the SR driver coupled to the SR FET; making the SR FET conductive during a discharge mode of the transformer; sensing, based on a voltage at the drain of the SR FET, that the discharge mode of the converter has ended; returning, responsive to sensing that the discharge mode has ended, the parameter to the original state.

Power conversion efficiency using variable switching frequency. At least some of the example embodiments are power circuit controllers including a voltage sense input and a control signal output. The power circuit controller varies an output frequency of the control signal output between a first frequency and a second frequency based on a source voltage supplied to the power controller. Both the first frequency and the second frequency are non-zero.

Power conversion efficiency using variable switching frequency

A power conversion circuit is provided. An input of the power conversion circuit is coupled to a first voltage potential. A switching frequency of the power conversion circuit is set based on a magnitude of the first voltage potential.

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Gilbert, AZ, United States of America

Dhruv Chopra