Patent ID: 8472212

Claim:
A method for controlling operation of a resonant converter, the method to be implemented by a control module that generates a drive signal for controlling a power switch of the resonant converter to thereby control an output voltage and an output current provided by the resonant converter to a load, said method comprising: (A) configuring the control module to determine if the load is operating in a first mode or a second mode; (B) configuring the control module to generate the drive signal according to the output voltage when the control module determines that the load is operating in the first mode; and (C) configuring the control module to generate the drive signal according to the output current when the control module determines that the load is operating in the second mode; wherein step (A) includes: configuring the control module to generate a voltage-frequency signal according to a difference between the output voltage and a predetermined reference voltage; configuring the control module to generate a current-frequency signal according to a difference between the output current and a predetermined reference current; and configuring the control module to determine that the load is operating in the first mode if magnitude of the voltage-frequency signal is smaller than that of the current-frequency signal, and to determine that the load is operating in the second mode if the magnitude of the voltage-frequency signal is greater than that of the current-frequency signal.