A new current stimulator architecture for visual cortex stimulation

In this paper a new switched reference stimulator architecture for the visual cortex stimulation is presented. Compared with the present alternatives the architecture allows to relax twice requirements of the stimulator output voltage tolerance and to simplify the design of high voltage (HV) switches. The stimulator functionality was proven by fabrication with AMS HV 0.35 μm CMOS technology and the measurement of test chip. The measurement results show the possibility to drive currents from -10 mA up to 10 mA into the tissue, while the electrode-tissue interface resistance is up to 8 kΩ with the effectively high-voltage output compliance of up to 180 V. Wherein the need for HV VDD voltage is limited to 90 V.