Dual-Outputs Switched Capacitor Voltage Regulator

Abstract

Since multiple voltage levels are required simultaneously by the proposed wearable device in Fig. 1.12, multiple voltage regulators are needed. The switched capacitor (SC) voltage regulator is widely utilized in low power applications since the small capacitance can be fully integrated on-chip while driving μA current. Conventionally, multiple SC voltage regulators are required to generate simultaneous multiple regulated voltage levels. This way, each block in the chip operates at an optimum voltage level. However, this conventional PMU design suffers from a large area overhead because it is dominated by the area of the SC regulators. The number of SC regulators increases as the number of the required regulated output voltage levels increases. Hence, more passive components (flying and load capacitors) are needed which makes the PMU area large. As a result, it is imperative to find an efficient way to generate multiple output voltages with minimum area overhead that targets μW power devices.