What are Decaps?
- Decaps are on-chip decoupling capacitors that are attached to the power mesh to decrease noise effects
- Decaps are most effective when placed closest to the loads
What are Decaps?
- Decaps are on-chip decoupling capacitors that are attached to the power mesh to decrease noise effects
- Decaps are most effective when placed closest to the loads
Why need Decap cells：
- Modern designs are very sensitive to noise due to the presence of a larger number of potential noise generators that eat into the noise margins built into a design. The power grid, which provides the Vdd and ground signals throughout the chips, is one of the most important sources of noise, since supply voltage variations can lead not only to problems related to spurious transitions in some cases, particularly when dynamic logic is used, but also to delay variations
- Signal integrity is emerging as a limiting factor in the nano regime VLSI chip designs as technology scales. This is especially true on global networks like power/ground networks where noise margins have been reduced greatly in VLSI designs due to decreasing supply voltages. For dynamic voltage fluctuations on a P/G network, adding decap is regarded as the most efficient way to reduce such noises