Energy-efficient high-voltage compliant implantable brain-machine interfaces

We present in this paper the architecture of an energy-efficient high-voltage compliant microstimulator and recording interface dedicated for intracortical visual prosthesis. The system consists of a capacitive-link based bidirectional transceiver, an inductive-link energy recovery unit, a flexible microstimulation module including a high-impedance microelectrode driver, and a recording interface based on an ultra-low power analog-to-digital converter. Two different technologies, IBM CMOS 0.13μm, and DALSA Teledyne 0.8μm 5V/20V CMOS/DMOS, are used to implement the device in 2 chips. The microelectrode driver is incorporated with an array of highly-configurable high-voltage switches, which are supplied with ±13 Volts. The measurement results show that the system delivers up to 180μA through emulated microelectrode-tissue interface impedance with an average value of 100kΩ. The measured static power consumption of the high-voltage chip is 0.735mW.