A 1.3-V, 9.1μW wide-dynamic range logarithmic amplifier for cochlear implant system

2014 ◽  
Author(s):  
Yuwadee Sundarasaradula ◽  
Apinunt Thanachayanont
Keyword(s):  
Cochlear Implant ◽  
Dynamic Range ◽  
Wide Dynamic Range ◽  
Logarithmic Amplifier ◽  
Implant System

A Low-Noise, Low-Power, Wide Dynamic Range Logarithmic Amplifier for Biomedical Applications

2018 ◽  
Vol 27 (07) ◽  
pp. 1850104 ◽  
Author(s):  
Yuwadee Sundarasaradula ◽  
Apinunt Thanachayanont
Keyword(s):  
Low Power ◽  
Biomedical Applications ◽  
Dynamic Range ◽  
Supply Voltage ◽  
Low Noise ◽  
Power Supply Voltage ◽  
Wide Dynamic Range ◽  
Dc Offset ◽  
Limiting Amplifier ◽  
Logarithmic Amplifier

This paper presents the design and realization of a low-noise, low-power, wide dynamic range CMOS logarithmic amplifier for biomedical applications. The proposed amplifier is based on the true piecewise linear function by using progressive-compression parallel-summation architecture. A DC offset cancellation feedback loop is used to prevent output saturation and deteriorated input sensitivity from inherent DC offset voltages. The proposed logarithmic amplifier was designed and fabricated in a standard 0.18[Formula: see text][Formula: see text]m CMOS technology. The prototype chip includes six limiting amplifier stages and an on-chip bias generator, occupying a die area of 0.027[Formula: see text]mm2. The overall circuit consumes 9.75[Formula: see text][Formula: see text]W from a single 1.5[Formula: see text]V power supply voltage. Measured results showed that the prototype logarithmic amplifier exhibited an 80[Formula: see text]dB input dynamic range (from 10[Formula: see text][Formula: see text]V to 100[Formula: see text]mV), a bandwidth of 4[Formula: see text]Hz–10[Formula: see text]kHz, and a total input-referred noise of 5.52[Formula: see text][Formula: see text]V.

A Wideband Extended-Dynamic-Range Successive Detection Logarithmic Amplifier Based on 0.15 μm GaAs pHEMT Technology

2019 ◽  
Vol 28 (04) ◽  
pp. 1950069
Author(s):  
Nader Javadifar ◽  
Massoud Dousti ◽  
Hassan Hajghassem
Keyword(s):  
Mathematical Modeling ◽  
Dynamic Range ◽  
High Electron Mobility Transistor ◽  
Power Supplies ◽  
High Electron ◽  
Wide Dynamic Range ◽  
High Electron Mobility ◽  
Logarithmic Amplifier ◽  
Detection Unit ◽  
Extended Dynamic

This paper puts forward an extended-dynamic-range successive detection logarithmic amplifier (SDLA) for [Formula: see text]-band (18–26.5[Formula: see text]GHz) applications. A novel single-transistor power detection unit (PDU) is used instead of a conventional rectifier to effectively improve the dynamic range–bandwidth product of the amplifier. Circuit analysis and mathematical modeling are performed for the proposed PDU and the SDLA, respectively. Transistor level design is carried out for the whole circuit using 0.15[Formula: see text][Formula: see text]m GaAs pseudomorphic high electron mobility transistor (pHEMT) technology. The SDLA presents a wide dynamic range of 75[Formula: see text]dB with a [Formula: see text] 1.5[Formula: see text]dB logarithmic error, over the entire band of interest, and consumes 340[Formula: see text]mW from [Formula: see text] 2.5[Formula: see text]V and –0.8[Formula: see text]V power supplies. All requirements are verified in post-layout simulation using ADS software. Thermal simulation and statistical yield analysis are performed to ensure the robustness of the proposed architecture.

Effect of Increased IIDR in the Nucleus Freedom Cochlear Implant System

2007 ◽  
Vol 18 (09) ◽  
pp. 777-793 ◽  
Author(s):  
Laura K. Holden ◽  
Margaret W. Skinner ◽  
Marios S. Fourakis ◽  
Timothy A. Holden
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Sound Field ◽  
The Other ◽  
Threshold Levels ◽  
Speech In Noise ◽  
El Sistema ◽  
Initial Activation ◽  
Implant System

The objective of this study was to evaluate the effect of the increased instantaneous input dynamic range (IIDR) in the Nucleus Freedom cochlear implant (CI) system on recipients' ability to perceive soft speech and speech in noise. Ten adult Freedom CI recipients participated. Two maps differing in IIDR were placed on each subject's processor at initial activation. The IIDR was set to 30 dB for one map and 40 dB for the other. Subjects used both maps for at least one month prior to speech perception testing. Results revealed significantly higher scores for words (50 dB SPL), for sentences in background babble (65 dB SPL), and significantly lower sound field threshold levels with the 40 compared to the 30 dB IIDR map. Ceiling effects may have contributed to non-significant findings for sentences in quiet (50 dB SPL). The Freedom's increased IIDR allows better perception of soft speech and speech in noise. El objetivo de este estudio fue evaluar el efecto del rango dinámico aumentado instantáneo de ingreso (IIDR) en el sistema de implante coclear (IC) Nucleus Freedom, sobre la capacidad de sujetos implantados para percibir lenguaje a bajo volumen y lenguaje en ruido. Diez sujetos implantados con el IC Freedom participaron. En la activación inicial, dos mapas con una diferencia en cuanto al IIDR se colocaron en el procesador de cada sujeto. El IIDR fue ajustado a 30 dB para un mapa y a 40 dB para el otro. Los sujetos utilizaron ambos mapas por al menos un mes, antes de una evaluación de percepción del lenguaje. Los resultados revelaron puntajes significativamente más altos para palabras (50 dB SPL), para frases en balbuceo de fondo (65 dB SPL), y niveles umbrales en campo libre significativamente más bajos con el mapa de IIDR de 40 comparado con el de 30. Efectos tope pueden haber contribuido a los hallazgos no significativos para frases en silencio (50 dB SPL). El IIDR aumentado para Freedom permite mejor percepción para el lenguaje a bajo volumen y el lenguaje en medio de ruido.

Slow-Scan CCD Observation of Backscattering Patterns in SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1308-1309
Author(s):  
F. Ouyang ◽  
D. A. Ray ◽  
O. L. Krivanek
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Lens System ◽  
Wide Dynamic Range ◽  
Peltier Cooler ◽  
Diffraction Patterns ◽  
Scanning Electron

Electron backscattering Kikuchi diffraction patterns (BKDP) reveal useful information about the structure and orientation of crystals under study. With the well focused electron beam in a scanning electron microscope (SEM), one can use BKDP as a microanalysis tool. BKDPs have been recorded in SEMs using a phosphor screen coupled to an intensified TV camera through a lens system, and by photographic negatives. With the development of fiber-optically coupled slow scan CCD (SSC) cameras for electron beam imaging, one can take advantage of their high sensitivity and wide dynamic range for observing BKDP in SEM.We have used the Gatan 690 SSC camera to observe backscattering patterns in a JEOL JSM-840A SEM. The CCD sensor has an active area of 13.25 mm × 8.83 mm and 576 × 384 pixels. The camera head, which consists of a single crystal YAG scintillator fiber optically coupled to the CCD chip, is located inside the SEM specimen chamber. The whole camera head is cooled to about -30°C by a Peltier cooler, which permits long integration times (up to 100 seconds).

Effect of different input dynamic range variables on cochlear implant performance in postlingual cochlear implant in adults

2019 ◽  
Vol 69 (3) ◽  
Author(s):  
Tarek A. Ghannoum ◽  
Mona H. Selim ◽  
Amira M. El-Shennawy ◽  
Zahraa M. Elbohy
Keyword(s):  
Cochlear Implant ◽  
Dynamic Range

Design of an Offner convex grating radiation calibration light source with a wide dynamic range

2020 ◽  
Vol 13 (5) ◽  
pp. 1085-1093
Author(s):  
XU Da ◽  
◽  
YUE Shi-xin ◽  
ZHANG Guo-yu ◽  
SUN Gao-fei ◽  
...  
Keyword(s):  
Light Source ◽  
Dynamic Range ◽  
Wide Dynamic Range
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