Analytical expression for the equivalent input noise current spectral density of HBT distributed amplifier based optical receivers

1999 ◽  
Author(s):  
A. Iqbal
Keyword(s):  
Spectral Density ◽  
Optical Receivers ◽  
Analytical Expression ◽  
Noise Current ◽  
Input Noise ◽  
Distributed Amplifier ◽  
Equivalent Input Noise

A 40Gb/s Transimpedance Amplifier Using Modified Regulated Cascode for Optical Fiber Communication

2012 ◽  
Vol 236-237 ◽  
pp. 958-963
Author(s):  
Ying Mei Chen ◽  
Tao Wang ◽  
Jin Fei Wang ◽  
Jian Wei Gong ◽  
Lei Zhu
Keyword(s):  
Optical Fiber ◽  
Optical Fiber Communication ◽  
Cmos Technology ◽  
Transimpedance Amplifier ◽  
Fiber Communication ◽  
Noise Current ◽  
Input Noise ◽  
Dc Power ◽  
Active Feedback ◽  
Equivalent Input Noise

This paper describes the design of a 40 Gb/s transimpedance amplifier (TIA) for high-density optical fiber communication system. This TIA incorporates modified regulated cascode (RGC), three order intersecting active feedback and passive feedback. Consuming a DC power of 14.5 mW, the single-ended circuit provides a transimpedance gain of 49.5 dB and a -3dB bandwidth up to 40 GHz in IBM 90-nm CMOS technology with a 1.2 V supply. Simulation results show the equivalent input noise current integrated from 1 MHz to 30 GHz is about 6.6 Arms

Do Modern Hearing Aids Meet ANSI Standards?

2016 ◽  
Vol 27 (08) ◽  
pp. 619-627 ◽  
Author(s):  
Jourdan T. Holder ◽  
Erin M. Picou ◽  
Jill M. Gruenwald ◽  
Todd A. Ricketts
Keyword(s):  
Quality Control ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Analysis Data ◽  
National Standards ◽  
Control Measures ◽  
Input Noise ◽  
Release Times ◽  
Quality Control Testing ◽  
Equivalent Input Noise

Background: The American National Standards Institute (ANSI) provides standards used to govern standardization of all hearing aids. If hearing aids do not meet specifications, there are potential negative implications for hearing aid users, professionals, and the industry. Recent literature has not investigated the proportion of new hearing aids in compliance with the ANSI specifications for quality control standards when they arrive in the clinic before dispensing. Purpose: The aims of this study were to determine the percentage of new hearing aids compliant with the relevant ANSI standard and to report trends in electroacoustic analysis data. Research Design: New hearing aids were evaluated for quality control via the ANSI S3.22-2009 standard. In addition, quality control of directional processing was also assessed. Study Sample: Seventy-three behind-the-ear hearing aids from four major manufacturers, that were purchased for clinical patients were evaluated before dispensing. Data Collection and Analysis: Audioscan Verifit (version 3.1) hearing instrument fitting system was used to complete electroacoustic analysis and directional processing evaluation of the hearing aids. Frye’s Fonix 8000 test box system (Fonix 8000) was also used to cross-check equivalent input noise (EIN) measurements. These measurements were then analyzed for trends across brands and specifications. Results: All of the hearing aids evaluated were found to be out of specification for at least one measure. EIN and attack and release times were the measures most frequently out of specification. EIN was found to be affected by test box isolation for two of the four brands tested. Systematic discrepancies accounted for ˜93% of the noncompliance issues, while unsystematic quality control issues accounted for the remaining 7%. Conclusions: The high number of systematic discrepancies between the data collected and the specifications published by the manufacturers suggests there are clear issues related to the specific protocols used for quality control testing. These issues present a significant barrier for hearing aid dispensers when attempting to accurately determine if a hearing aid is functioning appropriately. The significant number of unsystematic discrepancies supports the continued importance of quality control measures of new and repaired hearing aids to ensure that the device is functioning properly before it is dispensed and to avoid future negative implications of fitting a faulty device.

scholarly journals A Compact Low-Distortion Low-Power Instrumentation Amplifier

2010 ◽  
Vol 5 (1) ◽  
pp. 33-41
Author(s):  
Jader A. De Lima
Keyword(s):  
Low Frequency ◽  
Design Parameters ◽  
Instrumentation Amplifier ◽  
Cmos Process ◽  
Output Stage ◽  
Noise Spectral Density ◽  
Class Ab ◽  
Input Noise ◽  
Low Distortion ◽  
Equivalent Input Noise

A CMOS instrumentation amplifier based on a simple topology that comprises a double-input Gm-stage and a low-distortion class-AB output stage is presented. Sub-threshold design techniques are applied to attain high figures of differential-gain and rejection parameters. Analyses of input-referred noise and CMRR are comprehensively carried out and their dependence on design parameters determined. The prototype was fabricated in standard n-well CMOS process. For 5V-rail-to-rail supply and bias current of 100nA, stand-by consumption is only 16μW. Low-frequency parameters are ADM=86dB, CMRR=89.3dB, PSRR+=87dB, PSRR-=74dB. For a 6.5pF-damping capacitor, ΦM=73º and GBW=47KHz. The amplifier exhibits a THD of –64.5dB @100Hz for a 1Vpp-output swing. Input-noise spectral density is 5.2μV/ Hz @1Hz and 1.9μV/ Hz @10Hz, which gives an equivalent input-noise of 37.6μV, over 1Hz-200Hz bandwidth. This circuit may be employed for low-frequency, low-distortion signal processing, advantageously replacing the conventional 3-opamp approach for instrumentation amplifiers.

Sign in / Sign up

Export Citation Format

Share Document