Fault detection for switched-mode conversion circuit

A switched-mode conversion circuit comprising:

• a switching node coupling a power switching device to an inductive element;
• and
• a control circuit comprising a fault detection circuit, the fault detection circuit comprising:
• an excitation circuit configured to generate a reference current routed to the switching node to flow through a path including the inductive element;
• and
• a detection circuit configured to monitor a voltage elicited at the switching node in response to a discontinuity in the reference current generated by the excitation circuit;
• wherein the control circuit is configured to determine, using the detection circuit, a presence or absence of a ringing signal in response to the discontinuity in the reference current, and, in response, to declare a fault in the absence of the ringing signal.

A switched-mode conversion circuit comprising:

• a switching node coupling a power switching device to an inductive element;
• a control circuit comprising a fault detection circuit, the fault detection circuit comprising:
• an excitation circuit configured to generate a reference current routed to the switching node to flow through a path including the inductive element;
• and
• a detection circuit configured to monitor a voltage elicited at the switching node in response to a discontinuity in the reference current generated by the excitation circuit;
• wherein the control circuit is configured to:
• determine, using the detection circuit, a presence or absence of a ringing signal in response to the discontinuity in the reference current, and, in response, to declare a fault in the absence of the ringing signal;
• hold the power switching device in a non-conducting state during which the current discontinuity is established;
• and
• inhibit the power switching from entering a conductive state in response to the fault being declared.