A high-voltage-tolerant stimulator realized in the low-voltage CMOS process for cochlear implant

A biomedical stimulator with four high-voltagetolerant output channels, combined with on-chip positive high voltage generator, is proposed. For the purpose of integration with other circuit blocks into a system-on-chip (SoC) for cochlear implant biomedical applications, this design has been realized with the 1.8-V/3.3-V transistors in a 0.18-μm CMOS process. This stimulator only needs one single supply voltage of 1.8 V, but the maximum stimulation voltage can be as high as 7 V. The dynamic bias technique and stacked MOS configuration are used to implement this stimulator in the low-voltage CMOS process, without causing the issues of electrical overstress and gate-oxide reliability during circuit operation.