Abstract: A duty-cycle-shifted pulse-width modulation controlled half-bridge zero-voltage switching DC—DC converter has a primary side, a secondary side and a transformer coupling the primary side to the secondary side. The primary side has first and second primary switches coupled to a primary winding of the transformer and an auxiliary branch having one side coupled to a junction of the first and second primary switches and a second side coupled to common. The auxiliary branch includes a grounded auxiliary switch that is switched on when one of the first and second primary switches is on to trap leakage inductance energy of the transformer when that primary switch is turned off and thereafter switched off to release the trapped leakage inductance energy to provide a zero voltage switching condition for the other primary switch.

Abstract: A method and system of controlling half-bridge DC—DC converters to achieve Zero Voltage Switching (ZVS) for at least one of the switches. The soft-switching half-bridge DC—DC converter system includes soft-switching for all switches by adding an additional branch with a switch and a diode across the primary side of an isolation transformer and by applying a Duty-Cycle Shifted PWM Control.

Abstract: A multiphase DC/DC converter with voltage-mode hysteretic control and instantaneous current sharing functionality method and circuit. The disclosed method and circuit provides independent output voltage regulation and phases current regulation for the converter in two separate loops; one of which is concerned with voltage regulation preferably hysteretic regulation and the other which is concerned with phase current regulation. In one embodiment, each phase in the DC/DC converter is driven by a frequency divided signal derived directly from the output voltage ripple so that each phase has a switching frequency equal to the output voltage ripple frequency divided by the number of paralleled phase. In another embodiment, only the phase that carries the smallest current among a set of phases will be turned ON in each switching cycle to supply power to the output, avoiding multiple switching. Current sharing and regulation is achieved without shortening the ON time and with no multiple switching in any cycle.