| Summary: | 碩士 === 中原大學 === 電機工程研究所 === 98 === In recent years, most of active component of circuits using Operational Transconductance Amplifier( OTA ) was announced on the famous international journals, the property of Operational Transconductance Amplifier is that the product of difference of voltage at input terminal and conductance would get a current value, and the active component of the circuit in this paper is Operational Transresistance Amplifier( OTRA ), which property is that the product of difference of current at input terminal and resistance would get a voltage value, so we can found that the property of OTA and OTRA are duality. Besides, the input terminal of OTRA is virtual grounded, so the paarasitic effect is only half of OTA. That is why we choice OTRA to be the active component of this paper.
This paper is mainly to realize a Voltage-Mode Third-Order Elliptic Filter structure employing Operational Transresistance Amplifier with Design of Nodal Analytical Method, the structure is totally using 3 OTRAs、3 capacitors and 7 resistors. The minimum capacitors used on the third order filter is three, so this design of capacitor of circuit is minimum.
The simulation of this paper uses H-SPICE with TSMC035μm process, and we use MatLab to verify the result and theoretical value. Because of the parasitic effect of input terminal is low,we are directed against the tendency of sensitivity of capacitor to tune the capacitance, and the accruacy of output signal is obviously improved when tuning the resistance. It is easy to have the circuit be realized after we make the resistance integer, the accuracy of ouput signal is accurate. The sensitivity is low when the frequency is operating under 100kMHz. It is also the point to make this circuit to be integrated, we substitute MosFet for resistor and simulation by referring the page of famous scholar. The result is almost the same as have not change resistor yet, for the integrated circuit realized, we simplify the ratio of length and width of MosFet, and simulate again, the result of output is more improved than using resistor.
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