An Integrated DC-DC Converter with Novel Asymmetrical Segmented Power-Stages for Sustained High Power-Efficiencies

• Main Authors: Lee, Jinhen, Adrian, Victor, Chang, Joseph, Sun, Yin, Tay, Sun-Yang
• Format: Conference Proceeding
• Language: English
• Subjects: Circuits and systems; Distance measurement; Inductors; integrated passives; Internet of Things; Power Supply in-Package (PSiP); Power transistors; segmented power stage; Simulation; switched-mode DC-DC buck converter; Switches; Switching frequency
• ISSN: 2158-1525
• DOI: 10.1109/ISCAS48785.2022.9937205

The average power-efficiency of integrated DC- DC converters for Internet-of-Things is generally compromised over a wide load current range. This is because their efficiency is typically severely compromised at light load currents. We present a novel asymmetrical segmented power-stage configuration to improve the average power-efficiency of integrated converters. We achieve this by configuring different power-stage segments with different sizes of power transistors and their inductors, and a circuit to enable the corresponding segment for high power-efficiencies at different load conditions. Specifically, the circuit enables the segment with small-sized power transistors and a large inductor for light-load operations, and conversely, it enables the segment with large-sized power transistors and a small inductor for heavy-load operations. The integrated converter employing our proposed configuration is designed using a CMOS 180 nm process for 2. 5-3.3V input, 1.2 V output, and 50 MHz switching frequency. Simulation results show the proposed converter achieves a high average power-efficiency at ~73% over a wide load current range of 5-200mA. When benchmarked against the competing contemporary designs, the proposed converter features 5-30% higher average power-efficiency over the wide load current range, and >34% higher power-efficiency at 20 mA light load.