Understanding Efficiency of Switched Capacitor DC-DC Converters for Battery-Powered Applications
Switched Capacitor (SC) DC-DC converters are DC-DC switching regulators that use only capacitors and switches to transfer charges between the input and the output. This architecture is an alternative to inductor-based DC-DC converters that provide several advantages including better on-die integration (capacitors store 10 to 100 times more energy per volume than inductors), low Electro Magnetic Interference (EMI), and lower cost. These characteristics are of particular importance in battery-operated Internet of Things (IoT) applications where devices with high efficiency, low cost, and small footprint are a necessity.
This application note provides a brief theory on the efficiency in SC DC-DC converters and a comparative efficiency analysis between the two types of switched converter architectures using a typical application case.