以多輸出端電流式主動元件設計濾波電路與振盪電路

Design of active filters and oscillators using active Multi-Output Current-Mode elements

洪志文(Chih-Wen Hung)

指導教授 ： 張俊明 ； 侯俊禮

中原大學/工學院/電機工程研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200312

摘要

摘要
本論文將會證實使用多輸出端為主動元件來設計電路，其優點是可以在電路設計中大幅度的減少主動及被動元件的使用，有較低的功率損耗，更簡單的結構，且其主被動靈敏度相當低，尤其是在二十一世紀，現今電路簡單化及多功能化的日益要求下，單輸出主動元件已不能滿足設計者的需求。
在本論文中，我們成功的發表了七個多功能電流式或電壓式二階濾波電路，二個一階濾波電路及二個振盪電路。我們使用五種不同的電流式主動元件：運算轉導放大器(OTA)、第二代電流傳輸器(CCII)、第三代電流傳輸器(CCIII)、第二代電流控制電流傳輸器(CCCII)、及第二代完全差動電流傳輸器(FDCCII)。在「無阻抗匹配」條件下，以最簡單的電路結構，使用最少主動元件及被動元件(除第一個電路之外)，配合兩個易積體化的接地電容，考慮非常低的主被動靈敏度來設計包含以上所有優點的濾波電路和振盪電路。

電流式的部份：
首先，我們提出一個只使用一個第三代電流傳輸器(CCIII)及一個第二代電流傳輸器(CCII)配合兩個接地電容及兩個接地電阻設計出三輸入單輸出及兩輸入三輸出之二階萬用電流式濾波電路。兩輸入三輸出可同時實現低通、帶通、帶拒三種濾波電路。所設計的電路具有所有被動元件均接地，使用兩個電容均接地適合積體化，不需要任何阻抗匹配條件，低主動與被動靈敏度和可直接串接等優點。
其次，我們提出只使用兩個正型第二代電流控制電流傳輸器(CCCII)配合兩個接地電容設計出三輸入單輸出及兩輸入三輸出之二階電流式萬用濾波電路。此電路可同時實現低通、帶通、帶拒三種濾波信號，輸出端具有高輸出阻抗，且可正交控制ω0與ω0/Q。
另外，首度提出一個正型運算轉導放大器(OTA)與一個正型第二代電流控制電流傳輸器(CCCII)配合兩個接地電容設計出四輸入同時五輸出之電流式萬用二階濾波電路，此電路除具電子可調之特性外，在無須改變任何被動元件的情況下，其高輸出阻抗端可同時實現高通、帶通、低通、帶拒、全通五種濾波信號，此電路無需任何匹配條件，且皆為簡單的正型結構。
最後，提出一個只使用「單一」第二代完全差動電流傳輸器(FDCCII)，配合接地的被動元件設計出三輸入單輸出及兩輸入三輸出之二階電流式萬用濾波電路。可在同一個結構下實現五種基本的電流式濾波信號，無需任何匹配條件，電容接地有利於積體化，兩個電阻接地適合電壓控制，經兩接地電阻可達正交調整ω0/Q與ω0，高輸出阻抗有利於串接且有相當低的主被動靈敏度。

一階電路的部份：
新的一階全通濾波電路使用一個第二代電流控制電流傳輸器(CCCII)與一個運算轉導放大器(OTA)被發表出來。僅僅使用一個主動元件與一接地電容設計出三輸入三輸出電流式一階濾波電路。時間常數與全通信號條件均可電子調整，另外還可同時實現全通及反相全通信號。

電壓式電路的部份：
首先僅使用「單一」第二代完全差動電流傳輸器(FDCCII)元件設計電壓式多功能濾波電路。此電路具有一輸入及三輸出，可同時實現低通、帶通、高通、帶拒四種信號，為具有最少主被動元件之架構，使用兩個接地電阻，無需任何阻抗匹配條件，兩個電容均接地適合積體化，ω0/Q與ω0可以循序調整、低主動與被動靈敏度和高輸入阻抗可直接串接等優點。
再者，針對三輸入一輸出及兩輸入四輸出的部份則以「單一」第二代完全差動電流傳輸器(FDCCII)配合兩個電阻及兩個接地電容設計一個電壓式萬用濾波電路。除具上一個電路無法實現的全通信號及三輸入一輸出可實現五種基本的信號外，仍具有上一個電路的優點。

振盪電路的部份：
我們知道第二代完全差動電流傳輸器(FDCCII)是一個多樣化的主動元件，當用來設計「單一」電阻控制振盪條件(SRCO)時竟有非常好的成果。所提出的振盪電路具有以下優點：三個電阻接地易於調整，可經由一接地電阻控制頻率，兩個電容接地有利於電路之積體化，可改變成電壓控制振盪器，電流式輸出端有高輸出阻抗，其頻率穩定度相當良好。
在論文的最後我們去實現一新的弦波振盪電路，使用了兩個正形OTA與兩個接地電容設計一振盪電路，其優點是使用兩接地電容有利IC積體化，振盪頻率可經由偏壓電流源IB1和IB2獨立調整，振盪條件簡單，且IOUT輸出端在OTA-C結構下有著相當高的輸出阻抗有利於電流式的串接。

對於本論文所提出之所有電路，均以Pspice 和Matlab用現今最新製程CMOS技術來模擬驗證電路的可行性及精確性，其結果均與理論相當一致。

關鍵字

類比電路設計 ； 電流式主動元件 ； 濾波電路

並列摘要

Abstract
This paper will be verified that the circuits constructed by current-mode multi-output active elements have the advantages of less number of active and passive element, less power dissipation and simpler configuration than those proposed before as well as low active and passive sensitivities. Especially in 21th-century, the first requirement of circuit design is simple and with many functions in construction. Therefore, traditional current-mode single-output active element will be not powerful again.
In this thesis, we successfully present seven multifunction current/voltage-mode biquadratic filters, two current-mode first-order filters, and two oscillators employing current-mode active devices such as operational transconductance amplifier (OTA), second-generation current conveyor (CCII), current-controlled current conveyor (CCCII), third-generation current conveyor (CCIII), and fully differential second-generation current conveyor (FDCCII). “No requirement of critical component matching conditions”, very low active and passive sensitivities, two grounded capacitors ideal for integration, and the simplest structure with minimum components (only for the first circuit) are the advantageous features of all the proposed filters and oscillators.

In the part of current-mode universal biquadratic filters:
First, a new universal current-mode biquad with two inputs and three outputs or three inputs and single output using one second-generation current conveyor and one third-generation current conveyor is presented. The proposed circuit has two inputs and three outputs and can simultaneously realize low-pass, band-pass, and notch responses. The structure, which has all the passive elements be grounded and two grounded capacitors ideal for integration, presents low sensitivities, high output impedance and no requirement of any critical component matching condition.
Secondly, a new current-mode current-controlled universal filter with two inputs and three outputs or three inputs and single output is presented. The proposed circuit uses two plus-type current controlled conveyors (CCCIIs) and two grounded capacitors which can simultaneously realize low-pass, band-pass, and notch filter functions with high output impedances. Moreover, the circuit enjoys orthogonal current control of the parametersω0 and ω0/Q without using passive resistors.
Thirdly, a novel four inputs and five outputs current-mode universal biquadratic filter with high-output impedance using one plus-type OTA and one plus-type CCCII is presented. The proposed circuit uses two grounded capacitors and can be electronically adjusted. It can simultaneously realize five generic filter functions with high output impedances, and doesn’t need any component matching conditions. The use of only plus-type active elements simplifies the circuit configuration.
Finally, a new universal current-mode biquad with two inputs and three outputs or three inputs and single output using only one fully different second-generation current conveyor and four grounded passive elements is proposed. The proposed circuit has the following advantageous features: realization of five generic current-mode filter signals from the same configuration, no requirements of any cancellation constraints, employment of two grounded capacitors ideal for integrated circuit implementation, employment of two grounded resistors suitable for voltage control, orthogonal adjustment of ω0/Q andω0 through two separate grounded resistors, high output impedance good for cascadability, and very low active and passive sensitivities.

In the part of current-mode first-order filter:
New canonical first-order all-pass filters with three inputs and three outputs based on one current controlled current conveyor and one operational transconductance amplifier are proposed. The proposed first-order all-pass filters employ only a single active element and a bare minimum number of one grounded capacitor. Both of them are electronically adjusted. It should be noted that the proposed filters can simultaneously realize inverting and non-inverting all-pass signal.

In the part of voltage-mode multifunction/universal biquadratic filters:
A voltage-mode low-pass, band-pass, high-pass, and notch filter with single input and four outputs, employing the minimum components: only one fully differential second-generation current conveyor (FDCCII), two grounded capacitors and two grounded resistors, is proposed. The proposed circuit offers the following advantageous features: realization of voltage-mode low-pass, band-pass, high-pass, and notch filter responses from the same configuration; no requirement of critical component matching conditions; employment of grounded resistors good for adjustment; orthogonal control of ω0/Q andω0 through two separate grounded resistors, high input impedance good for cascadability, and very low active and passive sensitivities.
A new universal voltage-mode biquad with two inputs and three outputs or three inputs and two outputs using only one fully different second-generation current conveyor and four passive elements is proposed. The proposed circuit can realize five generic signals. Moreover, it offers the same advantages features as the last one.

In the part of oscillators:
We have shown that a fully differential second-generation current conveyor (FDCCII) is so versatile that the single-resistance-controlled oscillators (SRCOs) have the perfect configuration: “fully grounded passive components” in addition to the single active building block (ABB). The proposed oscillators offer the following advantageous: employment of three grounded resistors for ease of adjustment, independent frequency control through a single grounded resistor, employment of two grounded capacitors ideal for integration, ease of convertibility into a voltage-controlled oscillator, current-mode output signal with high output impedance, and very good frequency stability.
The last part of the paper is concentrated on the realization of a new sinusoidal oscillator by using two plus-type OTAs and two grounded capacitors. The proposed oscillators offer the following advantageous: Use of grounded capacitors beneficial to IC implementation, independent frequency control through the bias current IB1 and IB2, simple oscillation condition and very high output impedance.
The feasibility and accuracy of the proposed circuit are verified very well by using Pspice and Matlab simulations.

並列關鍵字

active current conveyors ； filters ； active current-mode elements

參考文獻

[2] K. C. Smith and A. Sedra, “The current conveyor-a new circuit building block,” IEEE Proc, vol. 56, pp. 1368-1369, 1968.

[3] B. Wilson, “Constant bandwidth voltage amplification using current conveyor,” Int. J. Electronics, vol. 65, no.5, pp. 983-988, 1988.

[4] Sedra/Smith,: “Microelectronic Circuits”, Third Edition.

[5] Masami Higashimura and Yutaka FuKui, “Simulation of lossless floating inductance using two current conveyors and an operational transconductance amplifier,” Int. J. Electron., vol. 66, no 4, pp. 633-638,1989.

[6] K. C. Smith and A. Sedra, “A second-generation current conveyor and it’s applications,” IEEE Trans., CT-17, pp. 132-134, 1970.