Biomedical 3xVDD current micro-stimulator using standard 0.35um CMOS process

This paper proposes a 3xVDD current micro-stimulator using the 3.3 V devices in standard 0.35 μm CMOS process for the implantable biomedical application. Traditional implantable biomedical micro-stimulators suffer from the reliability and saturation problem when the high impedance electrode and tissue are driven. By using the HV (high-voltage) protection circuit, the proposed design can avoid the gate-oxide overstress and reliability problem due to the 3xVDD voltage supply. The proposed design is applied to the 3xVDD power supply voltage and provides a maximum stimulating current of 108 uA with the output voltage swing of 7.56 V for the high-impedance load of 70 kΩ. The maximum stimulating current frequency is simulated to be 100 kHz.