학술논문

A Near-Optimum 13.56 MHz CMOS Active Rectifier With Circuit-Delay Real-Time Calibrations for High-Current Biomedical Implants
Document Type
Periodical
Source
IEEE Journal of Solid-State Circuits IEEE J. Solid-State Circuits Solid-State Circuits, IEEE Journal of. 51(8):1797-1809 Aug, 2016
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Computing and Processing
MOS devices
Delays
Calibration
Real-time systems
Video recording
Loading
Active rectifier
wireless power transfer
biomedical implants
circuit delays
real-time calibrations
reverse current
conduction time
adaptive sizing
power conversion efficiency
voltage conversion ratio
Language
ISSN
0018-9200
1558-173X
Abstract
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 $\text{k}\Omega $ loading, and a maximum output power of 248.1 mW are achieved with 2.5 V input amplitude.