In one embodiment of the present invention, the performance of an electronic circuit having a clock path between a clock source cell and a clock leaf cell is characterized over a simulation duration, where the clock path has one or more intermediate cells. Variations in the effective power supply voltage level least one intermediate cell over the simulation duration are determined using a system-level power-grid simulation tool. Static timing analysis (STA) software is used to determine cell delays for at least one of the intermediate cells for different clock-signal transitions at different times during the simulation duration. The cell delays are then used to generate one or more metrics characterizing the performance of the electronic circuit, such as maximum and minimum pulse widths, maximum cycle-to-cycle jitter, and maximum periodic jitter.