A High-Efficiency High-Data-Rate Wireless Power and Data Transfer IC Using Orthogonal Codes for Miniatureized Multi-Channel Neural Interface Systems

This paper presents a novel multi-channel Wireless-Power-and-Data-Transfer (WPDT) system using orthogonal codes for high-efficiency and high-data-rate miniaturized Implantable Medical Devices (IMDs). The proposed structure comprises a single 50 mm diameter Tx coil and 8-channel 3.2 mm diameter Rx coils. Initially, the proposed system operates with a cross-coupled (CC) passive rectifier to drive type-2 PLL. Once the PLL is locked, the passive rectifier transitions to a Time-Domain based Adaptive Active Doubler (TD-AAD) to optimize Power Conversion Efficiency (PCE). The proposed system is implemented in a 65-nm CMOS process. In simulations of a 10 mm distance 153.6 MHz inductive link, the PCE of proposed TD-ADD can reach 92.2% delivering 1.1 mW power to the load. The total data rate of 8channels is 25.6 Mb/s with a bit error rate (BER) of ≤ 1×10-8.