PLL-Based Contactless Energy Transfer Analog FSK Demodulator Using High-Efficiency Rectifier

• Published in: IEEE transactions on industrial electronics (1982) Vol. 60; no. 1; pp. 280 - 290
• Main Authors: Hwang, Yuh-Shyan, Hwang, Bo-Han, Lin, Ho-Cheng, Chen, Jiann-Jong
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2013; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: American Depositary Receipts; Capacitors; CMOS; Contactless energy transfer (CET); Demodulation; Demodulators; Devices; Efficiency; Electric potential; Energy transfer; Frequency shift keying; frequency-shift keying (FSK) demodulator; Inverters; phase-locked loop (PLL); power conversion efficiency; rectifier; Rectifiers; Semiconductors; Transistors; Voltage control
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2011.2181135

This paper proposes a new phase-locked-loop (PLL)-based inductive coupled contactless energy transfer (CET) analog frequency-shift keying (FSK) demodulator using a high-efficiency RF-to-dc rectifier for biomedical implanted devices. The analog FSK demodulator is composed of a modified CMOS three-stage rectifier, a voltage regulator, an FSK signal generator, and a PLL. The proposed modified single-stage rectifier with both positive and negative output voltages using a PMOS and an NMOS pass transistor, an inverter, and two capacitors has a small active area and can enhance the power conversion efficiency. The proposed RF-to-dc rectifier achieves an efficiency of 64% at 8.4 dBm. The power consumption of the demodulator is as low as 0.76 mW, and the active area is 0.084 mm 2 . The analog FSK demodulator supports a data rate of 100 kb/s to 1 Mb/s. The chip was implemented in a Taiwan Semiconductor Manufacturing Company (TSMC) 0.35- μm double-poly quadruple-metal CMOS technology to verify the proposed CET circuit. Two figures of merit are provided to illustrate the advantages of the proposed architecture.