Resonant power supply converter circuit and method therefor

A circuit for controlling a light-load operation of a resonant converter circuit comprising:

• the resonant converter circuit configured to drive one or more transistors connected to an inductor to control a current through the inductor and form an output voltage to a load wherein the inductor and the one or more transistors are connected together at a bridge node wherein a bridge signal is formed at the bridge node by switching of the one or more transistors;
• a pulse set generator circuit configured to form a digital representation of a pulse set for operating the one or more transistors including forming the pulse set to cause switching of the one or more transistors at least once;
• a drive pattern circuit configured to form a drive signal to switchingly drive the one or more transistors during a drive interval with a repeated sequence of the pulse set in response to an output parameter of one of the output voltage or power delivered to the load being no greater than a first value and greater than a second value that is less than the first value;
• the drive pattern circuit configured to form an Off-interval of the drive signal by not switching the drive signal in response to the output parameter being no greater than the second value and to subsequently switchingly drive the one or more transistors in response to the output parameter being greater than a third value wherein the third value is less than the first value and greater than the second value;
• and
• the pulse set generator circuit configured to form one or more non-switching intervals between each pulse set in response to a duration of one of the drive interval or the Off-interval.

A method of forming a resonant converter circuit comprising:

• configuring a light-load control circuit to, during a light-load operating mode, control driving of one or more transistors to form an output parameter of one of an output voltage for a load or power delivered to the load wherein the one or more transistors are connected to an inductor at a switch node;
• configuring the light-load control circuit to form a sequence to control the one or more transistors wherein the sequence includes a drive interval having a drive pattern and a subsequent Off-interval wherein the one or more transistors are switched with the drive pattern during the drive interval and are not switched during the Off-interval;
• and
• configuring a first circuit of the light-load control circuit to form the drive pattern as a repeated sequence of a pulse set that sequentially enables the one or more transistors with a base set followed by a number of non-switching intervals wherein each non-switching interval is a period of a signal received from the switch node in response to driving the one or more transistors with the base set.