Abstract: The relative timing of triggering switching events in a circuit block of an IC device is dynamically adjusted in response to fluctuations in device's supply voltage to minimize clock jitter caused by supply voltage noise. A control circuit monitors supply voltage fluctuations, and in response thereto dynamically phase-shifts a clock signal that triggers the switching events so that the switching events occur during relatively quiet time intervals in which fluctuations in the supply voltage are minimal.

Abstract: 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.