Patent ID: 8018740

Claim:
An LLC converter comprising: a switching circuit having a first switch, a second switch, an input and an output, the input connected to a DC (Direct Current) voltage; a resonant circuit connected to the output of the switching circuit; a rectification circuit connected to the resonant circuit; wherein the first switch is controllable by a first PWM (Pulse Width Modulated) signal having a fixed period and variable duty cycle during start up of the LLC converter; wherein the second switch is controllable by a second PWM signal having a fixed period and variable duty cycle during start up of the LLC converter; wherein the first switch is controllable by a first resonant mode signal having a variable period and a fixed duty cycle when the voltage on a load configured to be coupled to the rectification circuit is equal to or greater than the predetermined first voltage; wherein the second switch is controllable by a second resonant mode signal having a variable period and a fixed duty cycle when the voltage on the load is equal to or greater than the predetermined first voltage.