An Active Rectifier with Time-Domain Delay Compensation to Enhance the Power Conversion Efficiency

Authors: Shao-Ku Kao

Abstract:

This paper presents an active rectifier with time-domain delay compensation to enhance the efficiency. A delay calibration circuit is designed to convert delay time to voltage and adaptive control on/off delay in variable input voltage. This circuit is designed in 0.18 mm CMOS process. The input voltage range is from 2 V to 3.6 V with the output voltage from 1.8 V to 3.4 V. The efficiency can maintain more than 85% when the load from 50 Ω ~ 1500 Ω for 3.6 V input voltage. The maximum efficiency is 92.4 % at output power to be 38.6 mW for 3.6 V input voltage.

Keywords: Wireless power transfer, active diode, delay compensation, time to voltage converter, PCE.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.2643677

References:

[1] T. Campi, S. Cruciani, F. Palandrani, V. D. Santis, A. Hirata, and M. Feliziani, “Wireless power transfer charging system for AIMDs and pacemakers,” IEEE Trans. Microw. Theory Techn., vol. 64, no. 2, pp. 633–642, Feb. 2016.
[2] T. Akin, K. Najafi, and R. M. Bradley, “A wireless implantable multichannel digital neural recording system for a micromachined sieve electrode,” IEEE J. Solid- State Circuits, vol. 33, no. 1, pp. 109–118, Jan. 1998.
[3] P. T. Bhatti and K. D. Wise, “A 32-site 4-channel high density electrode array for a cochlear prosthesis,” IEEE J. Solid-State Circuits, vol. 41, no. 12, pp. 2965–2973, Dec. 2006.
[4] A. Rothermel, L. Liu, N. P. Aryan, M. Fischer, J. Wuenschmann, S. Kibbel, and A. Harscher, “A CMOS chip with active pixel array and specific test features for subretinal implantation,” IEEE J. Solid-State Circuits, vol. 44, no. 1, pp.290–300, Jan. 2009.
[5] M. M. Rana, W. Xiang,E. Wang , X. Li, B. J. Choi,” Internet of Things Infrastructure for Wireless Power Transfer Systems,” IEEE Access, Vol. 6, pp. 19295 – 19303, 2018.
[6] J. Fuh, S. Hsieh, F. Yang, and P. Chen, “A 13.56MHz Power-Efficient Active Rectifier with Digital Offset Compensation for Implantable Medical Devices” In IEEE WirelessPower Transfer Conference (WPTC), 2016, pg. 1-3.
[7] Y. Lu, and W. H. Ki, “A 13.56 MHz CMOS active rectifier with switched-offset and compensated biasing for biomedical wireless power transfer systems,” IEEE Trans. Biomed. Circuits Syst., vol. 7, no. 7, pp. 256–265, June. 2013.
[8] Y. Lu, W. Ki,” A 13.56 MHz CMOS Active Rectifier With Switched-Offset and Compensated Biasing for Biomedical Wireless Power Transfer Systems” IEEE Trans. Biomed. Circuits Syst., vol. 8, no. 3, June. 2014.
[9] X. Li, C. Tsui, and W. Ki, “A 13.56 MHz Wireless Power Transfer System With Reconfigurable Resonant Regulating Rectifier and Wireless Power Control for Implantable Medical Devices” IEEE J. Solid-State Circuits, vol. 50, no. 40, April 2015.
[10] C. Huang, T. Kawajiri, and H. Ishikuro, “A Near-Optimum 13.56 MHz CMOS Active Rectifier With Circuit-Delay Real-Time Calibrations for High-Current Biomedical Implants” IEEE J. Solid-State Circuits, vol. 51, no. 8, August 2016.
[11] L. Cheng, W. Ki, Y. Lu, and T. Yim,” Adaptive On/Off Delay-Compensated Active Rectifiers for Wireless Power Transfer Systems” IEEE J. Solid-State Circuits, vol. 51, no. 3, March 2016.