A 28 nm Bulk CMOS Fully Digital BPSK Demodulator for US-Powered IMDs Downlink Communications

Abstract

Low-invasive and battery-less implantable medical devices (IMDs) have been increasingly emerging in recent years. The developed solutions in the literature often concentrate on the Bidirectional Data-Link for long-term monitoring devices. Indeed, their ability to collect data and communicate them to the external world, namely Data Up-Link, has revealed a promising solution for bioelectronic medicine. Furthermore, the capacity to control organs such as the brain, nerves, heart-beat and gastrointestinal activities, made up through the manipulation of electrical transducers, could optimise therapeutic protocols and help patients’ pain relief. These kinds of stimulations come from the modulation of a powering signal generated from an externally placed unit coupled to the implanted receivers for power/data exchanging. The established communication is also defined as a Data Down-Link. In this framework, a new solution of the Binary Phase-Shift Keying (BPSK) demodulator is presented in this paper in order to design a robust, low-area, and low-power Down-Link for ultrasound (US)-powered IMDs. The implemented system is fully digital and PLL-free, thus reducing area occupation and making it fully synthesizable. Post-layout simulation results are reported using a 28 nm Bulk CMOS technology provided by TSMC. Using a 2 MHz carrier input signal and an implant depth of 1 cm, the data rate is up to 1.33 Mbit/s with a 50% duty cycle, while the minimum average power consumption is cut-down to 3.3 μW in the typical corner.

A Design of Analog Front-End with DBPSK Demodulator for Magnetic Field Wireless Network Sensors

“…To compare the performance of the proposed DBPSK demodulator with previous structures, two figure of merits (FoMs) are suggested [ 11 , 12 ]. The maximum DRCF, power consumption, and occupied area are the most important factors to summarize the performance of a demodulator.…”

“…The maximum DRCF, power consumption, and occupied area are the most important factors to summarize the performance of a demodulator. Therefore, the suggested and can be written by following expressions [ 11 , 12 ]: …”

An ultra‐low‐power CWM/SCM demodulator for inductive‐powered IMDs with the DRCF ratio of 50% and the powering index of 75%

“…NEAR-FIELD inductive links are one of the most popular methods for wireless data and power transmission in implantable medical devices (IMDs), radio-frequency identification, and near-field communication. [1][2][3][4][5][6][7][8][9] In IMDs, it is necessary to achieve high-bandwidth wireless telemetry with the external unit (Downlink), 10 like cochlear implants and visual prostheses, and to send high data rate to the external processing unit (Uplink), like neural recording applications. 11 However, this must happen at the lowest possible carrier frequencies, because as the carrier frequency increases, the electromagnetic field absorption rate in the tissue also increases significantly, and as a result, the power transfer efficiency (PTE) will decrease.…”

“…NEAR‐FIELD inductive links are one of the most popular methods for wireless data and power transmission in implantable medical devices (IMDs), radio‐frequency identification, and near‐field communication 1–9 . In IMDs, it is necessary to achieve high‐bandwidth wireless telemetry with the external unit (Downlink), 10 like cochlear implants and visual prostheses, and to send high data rate to the external processing unit (Uplink), like neural recording applications 11 .…”