A 0.49W 120.230V_RMS to 8.12V_DC Power Converter with Switched-Capacitor Regulation and Rectifier Short Flipping Achieving Maximized Bridge Conduction Time

AC mains supply is often used as the energy source for smart home appliances due to its accessibility and stability. However, its high alternating voltage is not directly usable, requiring a power converter to convert the AC voltage of 120–230 VRMS to a low DC voltage of 3.3-12V. The transformer-based AC-DC converter uses a flyback structure to freely convert voltage with a wide operation range. However, the transformer makes the converter bulky and expensive. In contrast, the resistor-drop-based AC-DC converter shows a compact system with low cost [1], but it faces low efficiency because of resistor losses. Alternatively, the capacitor-drop or capacitive-division-based AC-DC converter can offer a better trade-off between size and efficiency due to the capacitor's small form factor and lossless nature [2]–[7]. Nonetheless, it poses challenges to limited power delivered to loads (PDL) and power density. [8]–[10] implements on-chip full-bridge rectifiers (FBRs) to extract energy from the main grid directly, which achieves high power density but requires high voltage techniques e.g., SOI process.