A CMOS MICROPOWER INPUT AMPLIFIER FOR HEARING-AIDS

This paper describes a CMOS input amplifier for integrated circuits in hearing aids. It has a differential-input differential-output topolog y, which allows direct driving of cascaded fully-differential processi ng stages. The adoption of the voltage-to-current conversion and curre nt feedback technique in the amplifying structure, together with the u se of a simple differential stage in the offset reduction and in the c ommon-mode feedback loops, allows micropower consumption to be achieve d. Experimental results show very good noise and total harmonic distor tion performance. (C) 1996 Elsevier Science Ltd.