earticle

영어

For sensorineural hearing loss, auditory perception can be activated by electrical stimulation of a nervous system via electrode implanted into cochlea or auditory nerves. As the tonotopic map of the human auditory nerve has not been absolutely identified, the recording of its signal with electrode is desirable to determine the map. This paper proposes a 16-channel analog front-end for auditory nerve signal detection. Its channel consists of an AC coupling circuit, a 4th-order Gm-C lowpass filter (LPF), and a single-slope analog-to-digital converter (ADC). While blocking DC level, the AC coupling circuit transfers only AC signal. The Gm-C LPF is designed with operational transconductance amplifiers (OTAs) using floating-gate technique for small Gm. The channel-wise single-slope ADC is used because it has the small area and low power consumption. Experiment results show the prototype chip fabricated in 0.35-μm CMOS process has the bandwidth of 0.1 ~ 6.95 kHz with the gain of 19.9 dB, the effective resolution of 7.7 bits and the power consumption per a channel of 12 μW.