A 9-Bit configurable current source with enhanced output resistance for cochlear stimulators

This paper presents a configurable current source for cochlear stimulators. A switchable multi-bias active-cascode architecture is developed to provide a 9-bit output current in a small implementation area. A stacking MOS structure enables the current source to achieve high output resistance and large voltage compliance. Implemented in a standard 0.35 mum CMOS process, the current source can source a maximum 1 mA current, provide ges4.77 V voltage compliance under a 5 V supply and achieve >50 MOmega output resistance in 0.26 mm2.

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