Patent ID: 6487099
Filing Date: 2002-11-26
Classification: H02M,Y02B

Abstract:
A current mode controller for a series resonant power converter having a primary current, a conduction period and a pulse width modulator controller, the current mode controller comprising:a) a current ramp generator in electrical communication with the primary current, the current ramp generator being operative to generate a current ramp having a voltage proportional to the primary current; b) a voltage ramp generator in electrical communication with the power converter, the voltage ramp generator being operative to generate a voltage ramp; c) a multiplier in electrical communication with the current ramp generator and the voltage ramp generator, the multiplier being operative to generate a time-dependent current ramp having an amplitude proportional to the conduction period of the power converter; d) a limited voltage ramp generator in electrical communication with the voltage ramp generator, the limited voltage ramp generator being operative to generate a limited voltage ramp; and e) an adder in electrical communication with the limited voltage ramp generator and the multiplier, the adder being operative to generate a controlling ramp proportional to the limited voltage ramp and the time-dependent current ramp; f) wherein the adder is in electrical communication with the pulse width modulator controller such that the controlling ramp controls the conduction period of the power converter.