Patent ID: 6815936
Filing Date: 2004-11-09
Classification: H02M,Y02B

Abstract:
For use with a DCâ€”DC voltage converter, having a controller which generates a pulse width modulation (PWM) switching signal, that switchably controls operation of a switching circuit, containing first and second electronic power switching devices coupled between respective power supply terminals, and having a common node thereof coupled through an inductor element to an output voltage terminal and a capacitor element, a method of emulating diode operation of said switching circuit during off time of said PWM switching signal, said method comprising the steps of:(a) during an interval other than a switch-on state of said PWM switching signal, sensing a state of a voltage at said common node; (b) generating a switch off signal for turning off one of said first or second electronic power switching devices; and (c) over successive cycles of said PWM switching signal, adjusting the turn off time of said switch off signal in accordance with successively sensed states of said voltage at said common node.