Method of forming a detection circuit and structure therefor

摘要

In one embodiment, a power supply controller is configured to use a current to detect two different operating conditions on a single input terminal.

主权项

1. A method of forming a power supply controller comprising:
configuring the power supply controller to form a switching drive signal to operate a switch and regulate and output voltage to a desired value; configuring a detection circuit to maintain a first input of the power supply controller at substantially a first voltage value and to couple a control current to the first input, the control current having a first portion and a second portion wherein a the first portion of the control current flows through the first input responsively to a first condition and wherein another current flows to the first input from external to the power supply controller responsively to a second condition; and configuring the power supply controller to negate the switching drive signal responsively to a first value of the first portion of the control current and to negate the switching drive signal responsively to a first value of the another current.