Non zero-voltage switching (ZVS) detection in resonant converters

A resonant converter for detecting non-zero voltage switching, the resonant converter comprising:

• an oscillator configured to generate a first clock signal to drive a first power switch, and a second clock signal to drive a second power switch, each of the first clock signal and the second clock signal being activated during a switching cycle;
• and
• a non-zero voltage switching (non-ZVS) detection circuit configured to receive an integrated current sense signal sensed on a primary side of a transformer of a resonant network,
• the non-ZVS detection circuit including a clock sensor configured to generate a sensor signal at a predetermined time point in the first clock signal, and a clock calculator configured to determine a predetermined time point in the second clock signal based on the sensor signal and the second clock signal,
• the non-ZVS detection circuit configured to determine a polarity of a voltage of the integrated current sense signal using the predetermined time point in the second clock signal, the predetermined time point being later than an activation time of the second clock signal and being before a deactivation time of the second clock signal,
• the non-ZVS detection circuit configured to detect a non-ZVS event in response to the polarity of the voltage of the integrated current sense signal being negative or positive at the predetermined time point in the second clock signal.

A resonant converter for detecting non-zero voltage switching, the resonant converter comprising:

• an oscillator configured to generate a first clock signal to drive a first power switch, and a second clock signal to drive a second power switch, each of the first clock signal and the second clock signal being activated during a first switching cycle and a second switching cycle, the second switching cycle being after the first switching cycle;
• and
• a non-zero voltage switching (non-ZVS) detection circuit configured to receive an integrated current sense signal sensed on a primary side of a transformer of a resonant network,
• the non-ZVS detection circuit including a clock sensor configured to sense a predetermined time point in the first clock signal during the first switching cycle,
• the non-ZVS detection circuit configured to determine a polarity of a voltage of the integrated current sense signal using the predetermined time point in the first clock signal during the second switching cycle, the predetermined time point being later than an activation time of the first clock signal and being before a deactivation time of the first clock signal,
• the non-ZVS detection circuit configured to detect a non-ZVS event during the second switching cycle in response to the polarity of the voltage of the integrated current sense signal being positive at the predetermined time point in the first clock signal during the second switching cycle.