A Single-Inductor Dual-Ouput (SIDO) DC-DC Converter for Implantable Medical Devices in 180nm Standard CMOS Process

In this paper, a single-inductor dual-output (SIDO) buck converter is developed for implantable medical devices. The stacked power stage with startup circuit is designed to avoid overstress issue in 180nm CMOS process for 3.4 V to 5 V battery input. The converter provides two regulated outputs for the charge pump ($\mathrm{V}_{\mathrm{OUT}1}=3\ \mathrm{V}$) and the digital circuits ($\mathrm{V}_{\mathrm{OUT}2}=2\ \mathrm{V}$) with low cross regulation with pulse-skip modulation. An adaptive on-time (AOT) circuit adjusts on time dynamically based on the input voltage (VIN) to obtain high conversion efficiency and low output voltage ripple under different VIN. The measurement results demonstrates that the proposed converter achieves peak efficiency of 93.6% with an available input voltage of 3.4 V to 5 V.

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