عنوان مقاله
بهبود عملکردISFET با استفاده از تکنیک های مدار بهبود یافته
فهرست مطالب
مقدمه
اثر بدن درISFET
طراحی رابط سنسور
نتایج و بحث
نتیجه گیری
بخشی از مقاله
تست دریفت بلند مدت
نرخ دریفت پس از زمان اولیه پایدارسازی ISFET به صورت تغییر خطی Vgs در واحد زمان ارزیابی و نرخ دریفت، ضریب دریفت، cd (mV/h) نامیده می شود. شکل 9 پاسخ زمانی ISFET بدون و با تعدیل و جبران وارد شده را نشان می دهد. تست در یک دوره زمانی 18 ساعته برای ISFET فعال در محلول بافر استاندارد در pH 6 و 10 در دمای کنترل شده 25 ± 0.5 ◦C انجام شد.
کلمات کلیدی:
ISFET performance enhancement by using the improved circuit techniques Wen-Yaw Chung a,∗, Chung-Huang Yang a,b, Dorota G. Pijanowska c, Piotr B. Grabiec d, Wladyslaw Torbicz c a Department of Electronic Engineering, Chung Yuan Christian University, 200 Chung Pei Road, Chung Li, Taiwan 32023, ROC b Department of Electronic Engineering, Vanung University of Science and Technology, 1 Van-Nung Road, Chung-Li, Taiwan 32061, ROC c Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland d Department of Silicon Microsystem and Nanostructure Technology, Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw, Poland Received 11 April 2005; received in revised form 5 June 2005; accepted 13 June 2005 Available online 2 August 2005 Abstract An approach to enhance accuracy of the output signal obtained from ISFET interface electronics due to the body effect is proposed. Based on an MOS drawing the same drain current as the ISFET, the scheme allows reduction of influence of body effect. The presented readout interface improves the accuracy of pH measurements, while maintaining operation at constant drain-source voltage and current condition. Using only one ISFET with a differential output configuration, we obtained temperature-dependency and long-term drift as well as common noise compensation. The proposed technique is simple and has a universal use for different ISFETs. In addition, a voltage-controlled dc offset error compensation circuit modulates the extracted signal to the desired dc level for the A/D converter for each sensor. Simulation and experimental results show a great effect on
