Module 21 min
Why Low Power Matters
Why Low Power Matters
Pro Tip
Mobile & IoT — Battery-powered devices have a fixed energy budget. A smartphone SoC must deliver maximum compute performance within a thermal envelope of 3–5W. Every milliwatt saved = longer battery life or higher performance headroom. Low power is a competitive differentiator - not an afterthought.
Pro Tip
Thermal Constraints — High power = high heat. Excess heat degrades reliability (electromigration, NBTI, TDDB), slows transistors (thermal throttling), and requires expensive cooling. Data center chips (GPUs, AI accelerators) must stay within package thermal limits - power management is as important as performance.
| Technique | Targets | Power Saving | Implementation |
|---|---|---|---|
| Clock Gating | Dynamic (clock) | 20–40% | Synthesis / RTL |
| Multi-Vt | Static (leakage) | 10–30% | Synthesis optimization |
| Operand Isolation | Dynamic (data) | 5–15% | RTL / synthesis |
| Power Gating | Static (full block) | Up to 95% | UPF + PD flow |
| Voltage Scaling (DVS) | Dynamic + Static | Up to 50% | PMIC + UPF |
| Retention Registers | State preservation | Enables power gating | UPF + special cells |