Patent ID: 6867574
Filing Date: 2005-03-15
Classification: H02M,H03F,H03K

Abstract:
1. A method of driving a switch mode power supply in accordance with a duty cycle determining a power output of the power supply, using a driving circuit having a first transistor operative during a first portion of the duty cycle for coupling a circuit node of the switch mode power supply to an operating potential and a second transistor operative during a second portion of duty cycle for coupling the circuit node of the switch mode power supply to a reference potential, the method comprising: driving at least one of the first and second transistors with a pulse having a duration that is less than a duration of a corresponding one of the first portion of the duty cycle and the second portion of the duty cycle; and charging a parasitic capacitance of a power switching transistor during driving the one transistor of the first and second transistors, wherein the charge transferred to the parasitic capacitance maintains the power switching transistor in an on condition for the duration of the corresponding one of the first portion of the duty cycle and the second portion of the duty cycle.