Patent attributes
A packaged semiconductor device uses built-in self test to characterize voltage between points within the semiconductor die during a current discontinuity generated in the semiconductor die. The semiconductor die is operated to generate a current discontinuity, or several sequential current discontinuities, and the voltage is measured with an on-chip ADC. Measuring the voltage within the semiconductor die, rather than measuring at external test points, provides a more accurate prediction of device operation. Multiple test points are measured using a multiplexer, multiple ADCs, or by reconfiguring an FPGA. Impedance versus frequency information of the greater power distribution system connected to the semiconductor die is obtained by transforming the voltage and current through the semiconductor die measured during a current discontinuity.