An Electronically Tunable Transconductance Amplifier for Use in Auditory Prostheses
| Autor: | FARAGO, P., FARAGO, C., OLTEAN, G., HINTEA, S. |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Advances in Electrical and Computer Engineering, Vol 15, Iss 4, Pp 95-100 (2015) |
| Druh dokumentu: | article |
| ISSN: | 1582-7445 1844-7600 |
| DOI: | 10.4316/AECE.2015.04013 |
| Popis: | Low-voltage and low-power trends in analog electronics enable novel features in modern bio-medical devices, such as extensive portability, autonomy and even battery-less operation. One specific example is the cochlear implant (CI), which emulates the physiology of hearing to produce auditory sensations via neural stimulation. Besides low-voltage and low-power operation, a key feature in modern CIs is wide-range programmability of the speech processing parameters. This paper proposes an operational transconductance amplifier (OTA) for use in CIs, with wide-range electronic tuning of the transconductance value. The proposed OTA is developed around a cascade of two transconductor stages, making the transconductance dependent on the bias current ratio. A combination of linearization techniques: bulk input, parallel differential pairs and feedback, is used to achieve sufficient linear range for CI speech processing. Wide-range parameter tuning of the speech processing sections is illustrated on a variable gain amplifier, a bandpass Tow-Thomas biquad and an envelope detector. Finally, the complete CI speech processing chain is illustrated. The proposed OTA and its employment in CI analog speech processing are validated on a 350 nm CMOS process. |
| Databáze: | Directory of Open Access Journals |
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