Apparatus and method for soft switching of parallel switch assemblies

A method for reducing the power loss due to switching of a switch mode power converter having a first switch assembly connected through an inductor to a common node and a second switch assembly connected to the common node in parallel with the first switch assembly, the method comprising:

• activating the first switch assembly before activation of the second switch assembly;
• detecting a zero voltage condition at the common node;
• activating the second switch assembly in response to detection of the zero voltage condition;
• deactivating the first switch assembly when the second switch assembly is activated;
• detecting a zero voltage condition at the first switch assembly;
• and
• reactivating the first switch assembly in response to detection of the zero voltage condition at the first switch assembly.

A method of reducing the power loss due to switching of a switch mode power converter having a first switch assembly connected through a first inductor to a common node and a second switch assembly connected through a second inductor to the common node, the first switch assembly in parallel with the second switch assembly, the method comprising:

• activating the first switch assembly;
• activating the second switch assembly after activation of the first switch assembly as a function of a zero voltage condition sensed at a common node;
• deactivating the first switch assembly concurrent with activating the second switch assembly;
• and
• reactivating the first switch assembly as a function of a zero voltage condition sensed across the first switch assembly and the second switch assembly.

A switch mode power converter, comprising:

• a first switch and a second switch connected in parallel to a common node, the first switch including an inductor;
• and
• a controller coupled with the first and second switches, the controller operable to activate the first switch followed by the second switch during a switching cycle,
• where the controller includes a delay generator, the delay generator operable to sense zero voltage conditions, where the second switch is activated and the first switch is deactivated during the switching cycle in response to a zero voltage condition sensed at the common node, the first switch reactivated in response to a zero voltage condition sensed across the first switch and the second switch during the switching cycle.