A chip for an implantable neural stimulator

This paper describes a chip for a multichannel neural stimulator for functional electrical stimulation (FES). The purpose of FES is to restore muscular control in disabled patients. The chip performs all the signal processing required in an implanted neural stimulator. The power and digital data transmission to the stimulator passes through a 5 MHz inductive link. From the signals transmitted to the stimulator, the chip is able to generate charge-balanced current pulses with a controllable length up to 256 mu s and an amplitude up to 2 mA, for stimulation of nerve fibers. The quiescent current consumption of the chip is approx. 650 mu A at supply voltages of 6-12 V, and its size is 3.9x3.5 mm(2). It has 4 output channels for use in a multipolar cuff electrode.