A flexible Power Management System-On-Chip for Implantable Brain-Machine-Interfaces

Implantable electronics are found manifold in literature. While most published work focuses on the sensing and driving interfaces e.g., in neural recording or neuromodulation systems, the surrounding system functions are often neglected or treated as incidental. In many devices, the power management circuits are realized with off-the-shelf components as this is quick and flexible, but it comes at the cost of area, volume and power inefficiency. While many tailored solutions for implantable power management integrated circuits (ICs) have been proposed in literature, a circuit combining many of the needed functions in a flexible way, such that it is reusable for various applications, is the goal of this work. We thus propose a power management IC for a neural implant, which is designed to accommodate most of the required functionality, while requiring only few external components. The system is highly flexible and can be programmed via SPI. A prototype in 180nm HV-CMOS occupies 2.56 mm$^{2}$ and provides 7 LDOs (5 programmable), a HV shunt regulator, current monitoring, and a temperature sensor.