کنفرانس بین المللی میکروالکترونیک ایران

صفحه اصلی / پنجمین کنفرانس بین المللی میکروالکترونیک ایران

A Bootstrapped Switch Based Efficient CMOS Full-Wave Active Rectifier for Biomedical Implants

نویسندگان :

Mahmood Alibakhshi¹ Farshad Gozalpour² Yarallah Koolivand³

1- دانشگاه صنعتی خواجه نصیرالدین طوسی 2- دانشگاه صنعتی امیرکبیر 3- دانشگاه صنعتی خواجه نصیرالدین طوسی

کلمات کلیدی :

CMOS full-wave active rectifier،reverse current،power conversion efficiency (PCE)،bootstrapped switch

چکیده :

Abstract—In implantable medical devices (IMDs), CMOS active rectifiers convert the received AC signal to DC voltage with a high efficiency as possible. One of the main challenges in increasing the power conversion efficiency (PCE) is the reverse current caused by off-delay of the comparators and buffers in the rectifier. In this paper, a new technique has been proposed for the rectifier, which significantly reduces the reverse current without using any compensation loop. Instead of very large PMOS switches, NMOS bootstrapped switches are employed, which reduces the peak value of reverse current by 71% compared to the conventional rectifiers, for almost equal power delivered to the load (PDL). The proposed 6.78 MHz rectifier is implemented with TSMC 180-nm CMOS technology 3.3 V transistors, while the load resistor and off-chip capacitor are 500 Ω and 20 nF, respectively. The simulation results show that for 3 V input voltage amplitude, the PCE of the proposed rectifier is 87%, about 15% more respect to conventional design. Also, the voltage conversion ratio (VCR) of the proposed and conventional rectifiers are 91.6% and 87.5%, respectively.