Method and apparatus for a control circuit responsive to an impedance coupled to a control circuit terminal

Abstract

A power supply controller method and apparatus measuring impedance is disclosed. An apparatus according to aspects of the present invention includes a sense circuit coupled to a sense terminal. A regulation circuit coupled to the sense circuit and coupled to regulate the sense terminal to a first voltage level when a current flowing through the sense terminal is less than a first threshold current level. The regulation circuit is further coupled to regulate the sense terminal to a second voltage level when the current flowing through the sense terminal reaches the first threshold current level. A response circuit is coupled to the sense circuit and is responsive to the current flowing through the sense terminal when the sense terminal is regulated at the second voltage level.

Dependencies are inferred from the claim text.