A 15-Channel 30-V Neural Stimulator for Spinal Cord Repair

This brief presents a 15-channel, 30-V, implantable current stimulator for restoring locomotion control after spinal cord injuries. The stimulator features performance specifications comparable to those of large desktop instrumentation: high linearity, high precision of the delivered currents, small channel-to-channel mismatches, and a fast settling time of $0.3~\mu \text{s}$ . An analog-to-digital converter-based active charge balancing scheme using a digital proportional–integral controller was implemented in firmware.