A high performance CMOS reference current generator with negative feedback loop for biomedical neural stimulator

摘要

This paper presents a novel current reference circuit with negative feedback loop for biomedical neural current stimulator using the mutual compensation of threshold voltage and mobility. The negative feedback loop in this circuit effectively reduces the sensitivity both to the process and temperature variations. The nominal current output is designed to be 4 μA, and the temperature coefficient is 312 ppm/°C over temperature range of −45 °C to 125 °C. The simulated worst case variation at 25 °C is 0.75 μA.