Circuit path configuration for enhancing overvoltage protection in a switching power supply

A switching power supply comprising:

• a primary switch comprising a gate, a source, and a drain and configured to receive a drain-to-source voltage between the source and the drain;
• a first circuit path comprising a first circuit path node and electrically coupled between a first node and the drain, the first node configured to receive a rectified alternating current (AC) voltage;
• a second circuit path electrically coupled with the first circuit path and comprising a second circuit path node;
• and
• a controller comprising a voltage monitor input electrically coupled to the first circuit path node via the second circuit path and configured to drive the gate according to a switching cycle,
• wherein the first circuit path node is configured to provide a clamp voltage having comprehensive information indicative of the drain-to-source voltage,
• wherein the second circuit path node is configured to provide a node voltage determined, at least in part, by a first current, a second current, and a third current,
• wherein the second circuit path is configured to provide the first current and the third current, and the second circuit path node is between the first circuit path node and the voltage monitor input, and
• wherein the controller further comprises a control input, the control input electrically coupled to the second circuit path node via a fourth circuit path, the fourth circuit path comprising a resistor and configured to provide the second current.