Experimental Validation of a High-Voltage Compliant Neural Stimulator implemented in a Standard 1.8V/3.3V CMOS Process

Abstract

This paper describes a neural stimulator with 4 × V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DD</inf> compliance voltage, delivering up to 2.08 mA, and implemented in the TSMC 180 nm 1.8V/3.3V CMOS Process. The wide range of stimulation currents and high compliance voltage makes it suitable for stimulation applications both in rodents and mammals. Besides, it can be configured both as electrical and optical stimulator. Stacked transistor cells with dynamic gate biasing have been used for withstanding voltages well above the nominal supply. An on-chip programmable high-voltage generator supplied the stimulator front-end. The system has been fabricated, occupying an active area of 2.34 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The circuit has been experimentally tested by connecting it to a custom µelectrode array which was immersed into a phosphate-buffered saline solution.