Improvement of Voltage-Mode Filter Structures in Cardiograph

• Main Authors: Mao-Chih Ho, 何貿馳
• Other Authors: Chun-Ming Chang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/00057658397566881281

碩士 === 中原大學 === 電機工程研究所 === 98 === Abstract As society gradually enter the aging society, the devices of electronic medical monitor was most notably playing a major role in the society. As a matter of fact, it was very weakly to get of the biomedical signal message. The mood of patient and environment can affects on the measuring performance. So, it is true that study of analog filter circuit by performance and accuracy. The study improved the performance and accuracy by analog filter circuit. In the past, it is designs by the operational amplifier to the active components. The study using the actively material of to design the filter circuit in order to improve the performance and the accurate: (1) using single-ended-input OTAs (overcoming the feed-through effect due to the use of differential-input OTAs), (2) using grounded capacitors (absorbing the shunt parasitic capacitance), and, (3) using the minimum components and all the parasitic capacitances have the same places as those of all the given capacitors in the realized circuits. On the improvement circuit, using the OTAs, the capacitance role of design a single-ended-input single-ended-Output minimum active and passive components is voltage-mode N-order universal structures and compare the result with OA circuit. In 150Hz Low-Pass Filter section: using the OTA circuit by 4-order. The accuracy result is that f3db is error form 3.95% to 0.01％. The reduce slope is largest from -1.872 to -3.335. In 0.05Hz High-Pass Filter section: using the OTA circuit by 4-order. The accuracy results is that f3db is error form 5.24% to 0.37%. The reduce slope is largest from 1.619 to 3.466. In 60Hz Notch filter section: using the OTA circuit by 10-order. There of accuracy by center frequency maintain the performance on 0.23%. The band-wide is lower from 24.41Hz~142.39Hz to 51.83Hz~68.76Hz. The results are a great improvement the performance of filter circuit. Finally, the project is proceeding simulate by the H-spice. The OTA circuit of demonstrate parameter by TSMC035μm. The OA circuit material of parameter by LM 741, and the finally results will compare around the improving.