Abstract: A controller and method for operating a controller are disclosed. In an embodiment, a method involves in a mode-setting phase, polling connection pins to sense the presence and/or magnitude of a respective relatively high impedance connected between a respective connection pin and a predetermined electrical potential, and/or other connection pins to sense the presence and/or magnitude of a respective further impedance connected between the respective connection pin and a predetermined electrical potential. The method also involves selecting an operational mode from a plurality of possible operational modes. In an operational phase, the method involves operating in the selected operational mode, including providing a respective drive signal having a relatively low output impedance from each of the first group of connection pins, and measuring a sense voltage on each of the second group of connection pins.

Abstract: A method is disclosed of operating a controller for a switch mode power converter and having connection pins, the method comprising a mode-setting phase and an operational phase and comprising: in the mode-setting phase: polling connection pins to sense the presence and/or magnitude of a respective relatively high impedance connected between a respective connection pin and a predetermined electrical potential, and/or other connection pins to sense the presence and/or magnitude of a respective further impedance connected between the respective connection pin and a predetermined electrical potential, and selecting an operational mode from a plurality of possible operational modes; and in the operational phase: operating in the selected operational mode, comprising providing a respective drive signal having a relatively low output impedance from each of the first group of connection pins; and measuring a sense voltage on each of the second group of connection pins.