Resonant power converter driving an inductive load like a discharge lamp

Resonant power converter (1) for driving an inductive load having a first input terminal (13) and a second input terminal (14), the converter being designed for operation at an operational frequency (Fop) of 13.56 MHz and comprising:

• a series arrangement of a first inductor (L1) and a first controllable switch (Q1) connected to a DC voltage source (DC);
• a series arrangement of a second inductor (L2) and a second controllable switch (Q2) connected to said DC voltage source (DC), wherein the second inductor (L2) is connected to the same voltage source terminal as the first inductor (L1);
• a first parallel capacitance (Cds1) associated with the first controllable switch (Q1);
• a second parallel capacitance (Cds2) associated with the second controllable switch (Q2);
• a controller (30) for driving the switches (Q1, Q2);
• wherein the first load input terminal (13) is coupled to the node (A) between the first inductor (L1) and the first controllable switch (Q1);
• wherein the second load input terminal (14) is coupled to the node (B) between the second inductor (L2) and the second controllable switch (Q2);
• wherein the controller (30) is designed to generate control signals for the first and second controllable switches (Q1, Q2) such that each controllable switch (Q1, Q2) alternates between a conductive state and a non-conductive state at a duty cycle of 50%;
• wherein the controller (30) is designed to set the switching frequency (Fsw) of said switches (Q1, Q2) at one-third of said operational frequency (Fop) or at a value close to one-third of said operational frequency (Fop).