US Patent 7511527 Methods and apparatus to test power transistors

Methods and apparatus to test power transistors of integrated circuits on a wafer are disclosed. An example method comprises measuring a drain-source on resistance of a first transistor, measuring a drain-source on resistance of a second transistor, computing a scaling ratio between the transistors based on the drain-source on resistances of the transistors, measuring a first current indicative of an over-current condition of the first transistor, and computing a second current of the second transistor based on the current of the second transistor and the scaling ratio.