Digitally self-calibrated zero-voltage switching (ZVS) detection system

A threshold calibration system to provide a zero voltage switching signal, comprising:

• a divider coupled to a switching node;
• a calibration ramp generator;
• a reference voltage generator;
• a comparator;
• a first multiplexer coupled to receive a divider output signal from the divider and a calibration ramp signal from the calibration ramp generator and provide a signal to the comparator based on a calibration enable signal;
• a second multiplexer coupled to receive reference voltages from the reference voltage generator, the second multiplexer providing a threshold signal to the comparator;
• a digital feedback circuit receiving an output signal from the comparator and providing the zero voltage switching signal;
• and
• a backup comparator coupled to the second multiplexer and the divider, the backup comparator providing for uninterrupted operation during a calibration cycle.