Programmable Current Source for Implantable Neural Stimulation Systems

In this paper we present an ASIC, built in a 350 nm CMOS technology, as a component for a neural measurement and stimulation system. The ASIC consists of an adjustable current source and a switch matrix, which allows selecting sources and sinks out of 8 connected electrodes. The ASIC also contains a microsequencer and a memory, which can be configured and programmed using a serial data interface. The circuit allows to apply charge-balanced biphasic current stimulation to nervous tissue, as needed in implantable neural interfaces.