IR Drop Analysis
Keep supply voltage stable under real switching load.
Overview
IR drop is the voltage loss across the power grid due to resistance. Static IR drop is the steady-state loss, while dynamic IR drop occurs during switching bursts.
Severe IR drop can slow cells or cause functional failure.
Causes
Insufficient strap width or via density in the PDN.
High local switching activity without nearby decap support.
Long power paths from pads to active regions.
Mitigation
Widen straps, add straps, or use higher metal layers.
Insert decap cells near high-activity blocks.
Balance power distribution across the die.