Dynamic vs Static IR-Drop Targets Yes - the dynamic IR-drop target is generally kept at or below about three times the static IR-drop target. Static analysis works on an average-power basis, while dynamic analysis works on the peak, average or RMS current waveform. KEY Dynamic IR-drop target is roughly <= 3x the static target; static uses average power, dynamic uses current waveforms.

Ramp-Up Voltage and IR Drop Ramp-up (or wake-up) time is the time taken to bring the supply voltage from 0 to its peak during system bring-up. A ramp-up analysis flow reports the wake-up time and voltage, and how many cells are switching versus not switching. If all the cells switch at once, demand exceeds supply and IR drop becomes severe, so we prefer to connect all the power-switch cells in a chain and bring them up serially. KEY Ramp-up time is the wake-up duration to reach peak voltage; chaining power switches serially limits IR drop during bring-up.

Off-State Leakage and IR Drop Using header power switches relieves leakage when the block is in the off state. With power gating in place there is control over leakage current - and therefore leakage power - so it stays automatically under control. KEY Power gating with header switches controls off-state leakage current and the associated leakage power.

Components of Power Dynamic power has three parts: short-circuit power, switching power driven by external (load/wire) capacitance, and switching power from the internal capacitances inside a cell. Static or leakage power includes sub-threshold leakage current flowing drain-to-source when an NMOS sees VSS or a PMOS sees VDD, the reverse saturation current through the PN junction diodes formed