Design of reliable current recycling linear regulators for biomedical implants

A novel linear regulating power supply circuit with our unique current recycling technique for biomedical implants is proposed in this paper. In implantable neural stimulation systems, besides high-voltage actuation power supplies dedicated to stimulation electrodes, a number of low-voltage power supplies generated by linear regulators are often required for efficient electronic system operations. We design a stacked dual linear regulating power supply with full considerations of process variations and mismatch in 0.35 μm high-voltage CMOS process and Monte Carlo simulation results demonstrate power supplies with less than 6.2% of variation on low voltage power rails and a power saving factor as well as current efficiency up to 48.8% and 97.6% respectively are achieved.