A Near-Optimum 13.56 MHz CMOS Active Rectifier With Circuit-Delay Real-Time Calibrations for High-Current Biomedical Implants

作者：Huang Cheng; Kawajiri Toru; Ishikuro Hiroki

来源：IEEE Journal of Solid-State Circuits, 2016, 51(8): 1797-1809.

DOI：10.1109/JSSC.2016.2582871

• Active rectifier
• wireless power transfer
• biomedical implants
• circuit delays
• real-time calibrations
• reverse current
• conduction time
• adaptive sizing
• power conversion efficiency
• voltage conversion ratio

In this paper, a near-optimum active rectifier is proposed to achieve well-optimized power conversion efficiency (PCE) and voltage conversion ratio (VCR) under various process, voltage, temperature (PVT) and loading conditions. The near-optimum operation includes: eliminated reverse current loss and maximized conduction time achieved by the proposed sampling-based real-time calibrations with automatic circuit-delay compensation for both on-and off-time of active diodes considering PVT variations; and power stage optimizations with adaptive sizing over a wide loading range. The design is fabricated in TSMC 65 nm process with standard I/O devices. Measurement results show more than 36% and 17% improvement in PCE and VCR, respectively, by the proposed techniques. A peak PCE of 94.8% with an 80 Omega loading, a peak VCR of 98.7% with 1 k Omega loading, and a maximum output power of 248.1 mW are achieved with 2.5 V input amplitude.

• 出版日期2016-8