Patent ID: 7855864

Claim:
A switched mode power supply circuit comprising: a regulation circuit configured to operate selectively in a discontinuous conduction mode (DCM) wherein the regulation circuit stops cycling high-side and low-side switches in a switched output of the regulation circuit, such that the high-side and low-side switches are off and the switched output floats, and in a continuous conduction mode (CCM) wherein the regulation circuit cyclically switches the high-side and low-side switches on and off; and a control circuit configured to monitor an output voltage of the switched mode supply circuit during DCM operation of the regulation circuit and temporarily revert the regulation circuit to CCM operation responsive to the output voltage reaching a defined over-voltage limit by being configured to: temporarily reactivate the regulation circuit such that it performs one or more cycles of on/off switching of the high-side and low-side switches to relieve the over-voltage condition; detect that that inductor current in a switching circuit inductor transitions from positive load current to zero or negative load current, said switching circuit inductor being associated with generating the output voltage via switching by the regulation circuit; and responsive to said detecting, deactivate the regulation circuit such that it returns to DCM operation.