In Equation 1, Eload represents the energy delivered to the load per switching cycle, and the other denominator terms represent sources of energy loss. At ultralow-power levels, leakage and control losses can significantly degrade overall efficiency and thus must be minimized. Simple control loops must be designed that allow for scaling power consumption with output power. Leakage can be mitigated through on-chip power gating and voltage scaling. Finally, high-quality passive components and switches are required for maximum efficiency. Figure 3 shows simplified circuit implementations for step-down switched capacitor– and inductor-based converters and highlights the key sources of efficiency losses.