High-efficiency high-current drive power converter IC for wearable medical devices

Nowadays multi-functional wearable devices generally require high current drive capability because microcontrollers (MCU) or rechargeable batteries are embedded inside. To achieve both high current and high power efficiency, this article presents a switched-inductor-based AC-DC buck converter that is implemented on a 0.18μm chip manufacturing process for transcutaneously powered wearable devices. Different from multi-stage AC-DC converters that were widely used for wearable devices, the presented single-stage circuit has concise structure but provides flexible voltage output, high efficiency, and high current drive capability. The maximum output current can go up to 250 mA, and the peak efficiency is measured as 80.1% for 100mA load current. The chip size is 185μm × 260 μm.