电子线路学习方法(二十) 第十二讲 正弦波振荡器电路分析方法

正弦波振荡器是众多振荡器电路中的一种.所谓振荡器就是不需要外电路输入信号,自身能够产生某种频率信号的电路,正弦波振荡器是能够产生某一频率正弦信号的电路.一、正弦波振荡器准备知识用于各种场合下的振荡器,由于所要求的振荡频率不同,振荡信号不同,具体的振荡器电路形式很多,在这一节中将详细讲解正弦波振荡器的工作条件和电路工作基...     

基于OrCAD/PSpice的波形发生电路设计仿真

对正弦波振荡器工作原理及振荡电路的起振条件进行了分析与研究。根据LC三点式振荡电路的组成原则设计并改进了电容三点式振荡器电路,在O rCAD/PSp ice仿真软件中对电路进行了时域及频域仿真分析,给出了振荡波形,测量了振荡频率。仿真结果表明通过对电路的改进改善了波形,所设计电路波形与理论值相接近。     

新颖的基于MOCCCII的多相位正弦振荡器

提出了一种用多输出电流控制传输器(MOCCCII)实现的多相位正弦波振荡器.设计出的振荡器能同时产生n相等幅等相差的正弦电流和电压信号.振荡条件和振荡频率独立可调.电路结构简单,PSPICE仿真结果验证了理论分析的正确性.     

浅析正弦振荡器的原理和制作

本文介绍了电子技术领域中广泛应用的正弦波振荡器。主要介绍LC选频网络、振荡原理以及LC振荡器、RC振荡器和晶体振荡器的一般性原理以及制作需注意的问题。     

奇异振荡现象与多模振荡现象以及一类新型振荡器的研究

基于对电路起振问题的规范化分析,系统地阐释了相量分析的有效性与局限性,并且提出了用于判断φT(ω)/ω|ω=ω1符号的象限法。设计了六个电路,分别对它们解析并验证了多种振荡现象的存在与获得方式。首次提出了电路的奇异振荡现象,并证实了它作为一大类振荡现象的普遍性。首次提出并验证了单个电路中多模振荡现象的存在。另外,多个非常规的振荡器实例作为一类新型振荡器的存在,更是集中体现了对于传统振荡器理论基本要求的突破。据此,基本上可以建立起关于振荡现象和振荡器的新的、比较完整的阐释系统。     

基于OrCAD／PSpice的信号产生电路设计

设计了正弦波、矩形波和锯齿波发生电路,并在OrCAD/PSpice环境中完成仿真分析。给出文氏桥正弦波振荡电路、555时基电路组成的矩形波振荡电路和运算放大器组成的锯齿波发生电路三种信号产生电路的振荡波形,测量振荡周期和振荡频率,并与理论值做出比较。结果表明,设计的信号产生电路波形好,振荡频率稳定,易于实现,可广泛应用于工程设计领域。     

基于电路模型的标准圆周映射及其实验研究

通过两个电压振荡器相互耦合,得到标准圆周映射的公式,实验是在普通LC振荡电路上注入正弦波信号,观察其频率牵引,结果发现,振荡器若有了外界周期性的非线性耦合,其稳定振荡的相位与频率脱离了原来的固有值,振荡器的混沌运动极易观察到;该实验很好地验证了圆周映射中的同步锁频与混沌现象.     

一种施密特触发器型压控振荡器的设计与仿真

传统施密特型压控振荡器存在输入电压下限值较高、最高振荡频率较低等缺点。针对这两个问题,文中介绍了一种具有新型充放电电路结构的施密特型压控振荡器,并在0.18 μm工艺下对电路进行了仿真。结果表明,相对于传统施密特型压控振荡器,新型振荡器输入电压下限值有所下降,且最高振荡频率也有明显提升。     

模拟电路实用知识讲座(10)——第十讲 正弦波振荡器

<正> 振荡器是一种能自动地将直流能量转换为一定波形的交变振荡信号的转换电路。它与放大器的主要区别在于,它无需外加激励信号,就能产生具有一定频率、一定波形和一定振幅的交流信号。 根据所产生的波形不同,振荡器可分为正弦波振荡器和非正弦波振荡器。前者产生正弦波,后者产生矩形波、三角波、锯齿波等。本讲只介绍正弦波振荡器。这是因为正弦波振荡器在无线电技术领域有着极为广泛的应用。在无线电发送设备中,正弦波振荡器可用来产生载波;在超外差接收机中,可用来构成本地振荡器;在各种定时系统中,可用作时间基准信号。在研制和调试各类电子设备时所需的信号源和各种测量仪器中,也大多包含有振荡器,例如高频信号发生器、音频信号发生器等等。总之,振荡器在电子测量、通信等系统中是必不可少的。     

MC10116放大器在波形转换中的应用

振荡频率测量电路中的振荡信号常常是含有不同频率的正弦波．因而不便于数字频率的测试且变化较大。文中介绍了一种利用可测试长距离不同信号的三路放大器MC10116来将正弦波换转成方波,从而通过产生适于测量的高低电平来测量频率的具体电路和实现方法。     

An AGC Circuit Design for a Variable-Frequency Sinusoidal Oscillator with Wide Frequency Range and Low Distortion Level

An up-down counter, multiplier, digital-to-analog (D/A) converter, and high-speed comparators are employed to achieve an automatic gain control (AGC) circuit, which corrects the pair of characteristic roots of the overall system automatically to the imaginary axis of the complex frequency plane. A negative feedback technique with digital hardware is applied on the loop gain control. No lowpass filter is needed to detect the oscillation amplitude. Thus, this technique is suitable for sinusoidal oscillators with a wide oscillation frequency range. Wien-bridge and phase-shift oscillators with an oscillation frequency range from 17 Hz to 1 MHz are tested with the proposed AGC circuit. The total harmonic distortions of the Wien-bridge sinusoidal oscillator with the proposed AGC circuit are verified to be very small. An application to a variable-frequency sinusoidal oscillator is also described. The experimental results demonstrate the static characteristics and dynamic responses of the overall system.     

基于CCII的集成混沌振荡器设计

集成化混沌振荡器是混沌在实际应用中的一种重要趋势,特别是在大规模的混沌系统的电子实现方面。为了使混沌振荡器的集成度更高,并且具有较宽的频带,本文提出了一种新型的电流模式混沌振荡器。通过对自治混沌振荡器的电路模型分析,在文氏混沌电路基础上,采用CCII电路代替电压运算放大器、跨导运算放大器等传统运算放大器,实现了正弦波振荡电路,通过采用NMOS管将两个正弦振荡电路耦合最终实现电流模式混沌振荡器,通过对该电流模式混沌振荡器建模并进行仿真分析,描述了该振荡器的混沌行为,验证了该混沌电路的有效性和可行性。再通过仿真结果对比表明该混沌振荡器相比于传统的文氏混沌振荡器功耗更小、噪声抑制能力更强,由其产生的混沌信号在频带宽度、随机程度方面都有明显提高,更适合芯片集成。     

CMOS realization of single-resistance-controlled and variable frequency dual-mode sinusoidal oscillators employing a single DVCCTA with all-grounded passive components

In this paper, two new designs are proposed for sinusoidal oscillators based on a single differential voltage current conveyor transconductance amplifier (DVCCTA). Each of the proposed circuits comprises a DVCCTA combined with passive components that simultaneously provides both voltage and current outputs. The first circuit is a DVCCTA-based single-resistance-controlled oscillator (SRCO) that provides independent control of the oscillation condition and oscillation frequency by using distinct circuit parameters. The second circuit is a DVCCTA-based variable frequency oscillator (VFO) that can provide independent control of the oscillation frequency by adjusting the bias current of the DVCCTA. In this paper, the DVCCTA and relevant formulations of the proposed oscillator circuits are first introduced, followed by the non-ideal effects, sensitivity analyses, frequency stability discussions, and design considerations. After using the 0.35-μm CMOS technology of the Taiwan Semiconductor Manufacturing Company (TSMC), the HSPICE simulation results confirmed the feasibility of the proposed oscillator circuits.     

A novel variable frequency sinusoidal oscillator using a single current conveyor

A new active RC second-order sinusoidal oscillator using a single second generation current conveyor is described. A single grounded resistor adjusts the circuit for oscillation and a single grounded capacitor controls the oscillation frequency without affecting the oscilllation condition.     

A Novel Single-Resistance-Controlled Sinusoidal Oscillator Employing Single Operational Transresistance Amplifier

A novel operational transresistance amplifier (OTRA)-based single-resistance-controlled sinusoidal oscillator (SRCO) is proposed. It uses single OTRA, three resistors and two capacitors. To the best knowledge of author, this is the first oscillator constructed with single OTRA. The oscillator circuit provides independent control of oscillation frequency without disturbing oscillation condition by a resistor. It has also low passive sensitivities. The oscillator circuit is insensitive to parasitic input capacitances and input resistances due to zero internally grounded input terminals of OTRA. PSPICE simulations are given to verify the theoretical analysis.     

New voltage-mode universal filter and sinusoidal oscillator using only single DBTA

In this article, a new voltage-mode second-order universal frequency filter and sinusoidal oscillator using only single differential-input buffered and transconductance amplifier (DBTA) is presented. The proposed voltage-mode filter structure using single DBTA and four passive elements can provide all standard filter functions, i.e. low-, band-, high-pass, band-stop, and all-pass without changing the circuit topology and enables independent control of the quality factor Q using single passive element. The circuit requires the minimal number of active and passive elements with no conditions for component matching. By slight modification of the proposed filter structure, the new DBTA-based sinusoidal oscillator is easily obtained. The oscillation condition and the oscillation frequency are independently adjustable by different virtually grounded passive elements. The proposed sinusoidal oscillator employs only grounded capacitors. The passive and active sensitivities of all the proposed circuit configurations are low. PSPICE simulations using a BJT realisation of DBTA and experimental results based on commercially available amplifiers OPA860 and MAX436 are included, which prove the workability of the proposed circuits.     

New Rc-Active oscillator configuration employing unity-gain amplifiers

A new sinusoidal oscillator configuration is proposed which employs op-amps as unity-gain amplifiers. The proposed circuit offers independent single-element controls for adjusting the condition of oscillation and oscillation frequency and has very good frequency stability. Practically, the circuit works well over a frequency range much higher than possible with other known types of oscillators (which use op-amps as ±K-gain or infinite-gain VCVSs). The proposed configuration also provides useful prototypes to derive novel switched-capacitor oscillators.     

Current‐mode quadrature oscillator using current differencing transconductance amplifiers

This article presents a new electronically tunable single‐element‐controlled current‐mode quadrature sinusoidal oscillator circuit using current differencing transconductance amplifiers (CDTAs). The proposed oscillator is consisted of two CDTAs, two grounded capacitors and one grounded resistor, which is beneficial to monolithic integrated circuit implementation both in CMOS and bipolar technologies. The condition of oscillation and the frequency of oscillation are independently controllable. The frequency of oscillation can also be electronically controlled by adjusting the bias current of CDTA. The circuit provides four quadrature current outputs and two quadrature voltage outputs. The current output terminals possess high impedance level. PSPICE simulation results are used to verify the performance of the proposed circuit implemented at the transistor level. The measurement results support the computer simulations.     

Single-resistance-controlled quadrature oscillator using current differencing buffered amplifiers

A single-resistance-controlled quadrature oscillator circuit using current differencing buffered amplifiers (CDBAs) as active components is proposed. The proposed circuit is realised through the employment of two CDBAs, three resistors and two grounded capacitors. Outputs of two sinusoidal with 90° phase difference are available. The oscillation condition and the oscillation frequency of the proposed quadrature oscillator can be controlled independently by a single resistor. In comparison with the previously reported circuits, the proposed configuration considerably reduces the number of passive elements.