A reconfigurable 2× / 2.5× / 3× / 4× SC DC-DC regulator for enhancing area and power efficiencies in transcutaneous power transmission

A reconfigurable 2× / 2.5× / 3× / 4× switched-capacitor DC-DC regulator for transcutaneous power transmission is presented in this paper. The proposed power stage enables the regulator to maintain high power efficiencies under different input voltages caused by coupling variations. A fixed on-time regulation scheme is developed to minimize the switching power loss and to achieve small output ripple voltages of the regulator. Implemented in a standard 0.35-µm n-well CMOS process, the proposed regulator delivers a maximum output current of 10 mA and achieves the peak power efficiency of 82%. When the input voltage varies by 1.6 V, the power efficiency of the proposed regulator can be improved by 40% compared to that of the fixed-ratio 4× counterpart. The output ripple reaches 0.5% of the output voltage.

[1]  Hoi Lee,et al.  An Efficiency-Enhanced Auto-Reconfigurable 2$\times$/3$\times$ SC Charge Pump for Transcutaneous Power Transmission , 2010, IEEE Journal of Solid-State Circuits.

[2]  Hoi Lee,et al.  An SC Voltage Doubler with Pseudo-Continuous Output Regulation Using a Three-Stage Switchable Opamp , 2007, IEEE Journal of Solid-State Circuits.

[3]  B. Robert Gregoire,et al.  A switched capacitor regulated charge pump power supply , 2005, Proceedings of the IEEE 2005 Custom Integrated Circuits Conference, 2005..

[4]  Maysam Ghovanloo,et al.  Fully-Integrated CMOS Power Regulator for Telemetry-Powered Implantable Biomedical Microsystems , 2006, IEEE Custom Integrated Circuits Conference 2006.

[5]  Anantha Chandrakasan,et al.  A Fully-Integrated Switched-Capacitor Step-Down DC-DC Converter With Digital Capacitance Modulation in 45 nm CMOS , 2010, IEEE Journal of Solid-State Circuits.

[6]  Hoi Lee,et al.  An Efficiency-Enhanced CMOS Rectifier With Unbalanced-Biased Comparators for Transcutaneous-Powered High-Current Implants , 2009, IEEE Journal of Solid-State Circuits.

[7]  Dongsheng Ma,et al.  Design and Analysis of Monolithic Step-Down SC Power Converter With Subthreshold DPWM Control for Self-Powered Wireless Sensors , 2010, IEEE Transactions on Circuits and Systems I: Regular Papers.

[8]  Hoi Lee,et al.  An 88%-Power-Efficiency Accuracy-Enhanced DC-DC Conversion System for Transcutaneous-Powered Cochlear Implants , 2007, 2007 IEEE Biomedical Circuits and Systems Conference.

[9]  Hoi Lee,et al.  An efficiency-enhanced auto-reconfigurable 2x/3x SC charge pump for transcutaneous power transmission , 2009, 2009 IEEE Custom Integrated Circuits Conference.