Area saving stimulator cells for multielectrode arrays featuring adaptive waveform generation and monitoring

A new area saving stimulator cell is described, which is suitable for implantable microstimulators with large numbers of electrodes. The cell generates biphasic charge balanced voltage waveforms by continuous monitoring of the microelectrode voltage during the cathodic and anodic phases. The stimulator provides high voltage compliance and is intended for use with indium oxide micro electrodes with a limited electrochemical potential window. Thus, the new approach can improve electrode count, microelectrode reliability, stimulation efficiency, and power supply longevity. It saves chip area, since large w/l transistors or large capacitors are not required for a CMOS integration of the stimulator cell. The system can be easily extended for action potential recording.