A 20V-compliance implantable neural stimulator IC with closed-loop power control, active charge balancing, and electrode impedance check

Abstract

An inductively powered implantable neural stimulator IC is presented in this paper. It features closed-loop power control, active charge balancing, and electrode impedance check functions. The stimulator IC is powered through 13.56MHz inductive link and supports 33.3kbps bi-directional telemetry with ASK for forward command transmission and LSK for backward data transmission, achieving 20V high compliance voltage, maximum 1.24mA stimulation current, and the resting potential of 50mV. The IC has an active area of 2mm×2mm implemented in 0.18-μm CMOS process with 24V LDMOS option.