Reference-Less Time-Division Duplex Transceiver IC for a Renal Denervation System

Abstract

This paper presents the first time-division duplex transceiver integrated circuit (IC) for a 5 Fr (1.6 mm), six-electrode renal denervation (RDN) catheter for treating resistant hypertension. The diameter of the resulting RDN catheter, with each IC encapsulated in a platinum electrode, is 37.5% smaller than those of conventional catheters, enabling minimally invasive surgery with reduced complications. The six electrodes sharing only four electrical wires perform packet communication with an external power control unit for independent operation and deliver the designated radio-frequency (RF) energy to the renal artery wall while measuring the local temperature and impedance. The measured 3 sigma inaccuracy of a bipolar junction transistor (BJT)-based on-chip temperature sensor from 65 degrees C to 75 degrees C is +/- 0.5 degrees C after one-point trimming. Two 500-kHz, 21-V-rms ac signals with +/- 35-V dc potentials are used as power supplies to transfer up to 6-W RF ablation signals with 120-V-pp swing while keeping the maximum dc supply voltages of the ICs less than the breakdown voltage of 70 V. The proposed RDN IC fabricated using a 0.18-mu m high-voltage bipolar, CMOS, LDMOS (HV BCDMOS) occupies an area of 2.1 mm(2).