Stmicroelectronics S.r.l.

Lorenzo Trevisan

Massimiliano Picca

Roberto Cardu

Cristian Porta

A driving module of a resonant converter receives an enabling signal and a voltage across a switch of a secondary side, and generates a control signal for first and second switches of the secondary side. The driving module cyclically controls switches of a primary full-bridge switching stage and both switches of the secondary side. After a fixed time, the driving module turns off the low-side switch and turns on the high-side switch, waits for a rising edge of the enabling signal, waits for zero current in the secondary side switches, turns off the first switch via the control signal after a variable delay relative to the rising edge of the enabling signal, keeps the second switch on, waits for zero voltage across the first switch, switches back on the first switch via the control signal when the voltage measured across the first switch drops below a variable threshold.

Method for driving a resonant converter, and corresponding converter and computer program product

A resonant converter includes a primary switching circuit including a primary winding and upper and lower switching half-bridge circuits alternately activated during switching cycles of the resonant converter responsive to switching control signals. The switching half-bridge circuits each include a phase node to drive the primary winding. A resonance inductor is coupled to the primary winding. A secondary resonant circuit has a secondary winding magnetically coupled to the primary winding and a resonance capacitor electrically coupled to the secondary winding. A driving circuit generates the switching control signals and senses if a voltage on the phase node of one of the upper and lower switching half-bridge circuits is a negative voltage. The driving circuit adjusts the switching control signals for the switching half-bridge circuit to be activated next switching cycle by a shift time reduced each switching cycle until the negative voltage is less than a negligible under-voltage value.

Method for driving a resonant converter, and corresponding device and computer program product

A resonant converter includes a primary switching circuit with a primary winding and a primary full-bridge switching stage that drives the primary winding. A resonance inductor is in series with the primary winding. A secondary resonant circuit has a secondary winding magnetically coupled to the primary winding and a resonance capacitor electrically connected in parallel with the secondary winding. A secondary rectification stage is electrically connected in parallel to the resonance capacitor. A driving module receives a signal representing the voltage measured across an upper or lower switching half-bridge. The drive module detects a negative voltage in the signal. At each cycle, the drive module anticipates a control signal for control of the switches of the lower or upper switching half-bridge that is to be activated the next switching cycle by a shift time that is reduced cycle until the condition of absence of negative voltage in the signal is satisfied.

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Tavazzano con Villavesco, Italy

Lorenzo Trevisan