Abstract
This paper presents a tri-mode digital buck converter in 0.18-μm CMOS technology for photovoltaic energy harvesting. The on-chip gate-boosted digital pulsewidth modulation (DPWM) improves the conversion efficiency at heavy load conditions. Pulse-frequency modulation (PFM) along with digital self-tracking zero current detection is proposed to avoid reverse current at light load. The asynchronous mode (AM) operation further reduces the controller loss and improves the conversion efficiency at ultra-light load conditions. By applying DPWM, PFM, and AM at different load conditions, the proposed converter provides a maximum conversion efficiency of 92% with output power ranging from 50 nW to 10 mW. In addition, the proposed buck converter achieves more than 70% efficiency from 400 nW to 10 mW output power.
Original language | English |
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Article number | 7383220 |
Pages (from-to) | 523-532 |
Number of pages | 10 |
Journal | IEEE Journal of Solid-State Circuits |
Volume | 51 |
Issue number | 2 |
DOIs | |
State | Published - 1 Feb 2016 |
Keywords
- Asynchronous mode (AM)
- buck converter
- digital pulsewidth modulation (DPWM)
- digital zero current detection
- pulse-frequency modulation (PFM)
- tri-mode