The zx device is used to implement a voltagecontrolled lossy inductor. Identical and mismatched cases chaos in the colpitts oscillator has been demonstrated by tmeans of pspice simulations and hardware experiments 1. Therefore,whenever theres a devviation from this the circuit starts oscillating and this goes on indefinitely because of the feedback. The complete circuit is made up of a 2n3904 pnp transistor amplifier and two tank circuits which form the feedback network. After selecting skip the initial transient bias point calculation skipbp in pspice simulation s options everything got better. Colpits oscillator pspice design all about circuits. Simulation shows the voltage gain of the amplifier circuit is 0.
Pdf design and simulation of high frequency colpitts oscillator. Pspice student is sometimes distributed under different names, such as pspice student thinstalled. Jun 08, 2011 how to simulate pierce oscillator in pspice. Computeraided analysis and design is fast becoming a required skill for todays electronic engineerstechnicians. Building different types of oscillator circuits or adding a waveform generation ic is much easier when you use the right pcb design and analysis software package.
Colpitts oscillator simulation problem with pspice. It is designed between 20 khz to 50mhz using a colpitts oscillator configuration. The project explains how to test the open loop circuit to verify the barkhausen criterion. In pspice for analog communications engineering we simulate the difficult principles of analog modulation using the superb free simulation software cadence orcad pspice v10.
The oscillator may take a few seconds to stabilize. Complex dynamic behaviors in a new colpitts oscillator. What causes the wave to become triangular and how can i make it more sinelike. Sometimes an oscillator simulation will not start because the initial dc operating point part of the simulation finds a quasistable state with no oscillation which would not likely occur in a real circuit due to intrinsic circuit noise. To create a simulation profile, click pspice new simulation profile.
While use is made of analog behavioral model parts abm, we use actual circuitry in most of the simulation circuits. The video shows a tutorial on how to build a phase shifted oscillator. Colpitt oscillator with bjt and barkhausen criterion youspice. A separate agilent software, empro, is a full 3d electromagnetic simulator that.
The current source will take forever charge a f capacitor t c3vi 51e6 5e9 seconds or about 158years. A colpitts oscillator is a discrete lc oscillator that uses a pair of tapped. For more pspice circuit videos check out my channel and feel free to subscribe. This is a colpitts oscillator, an oscillator that uses an lc circuit combined with a transistor for feedback with the transistor removed, the inductor and two capacitors form a resonant circuit, like the lrc example. First, the circuit is implemented on pspice to test the circuit whether it giving the correct value or not. Colpitt oscillator with bjt and barkhausen criterion.
Select simulateinteractive simulation settings, and select set to zero for initial conditions. Apr 22, 2016 for more pspice circuit videos check out my channel and feel free to subscribe. A simplied introduction to circuit simulation using spice opus 3 1 about this document this document has been prepared without the help of any proprietary software products using the following. Spice simulation program with integrated circuit emphasis is a. Not a one of them has showed oscillation when being simulated.
Simulation is an essential link in the process of pcb design. I placed components and xtal, but it is like a dead horse. As an nco is defined in terms of software rather than. I cant perform ac sweep cause theres no ac source that means. Online schematic capture lets hobbyists easily share and discuss their designs, while online circuit simulation allows for quick design iteration and accelerated learning about electronics. This video takes a look at the colpitts oscillator circuit using. In this research, a colpitts oscillator is comprised from a bipolar junction transistor bjt amplifier with lc tank.
Design and simulation of high frequency colpitts oscillator. The pspice parameters for this transistor are i dss of 12 ma and v p of 3v. In order to design the 50mhz oscillator sensor, the following tasks have been carried out. Types of oscillator circuits for sinusoidal wave generation.
Another common design of the quartz crystal oscillator is that of the pierce oscillator. Figure 1 shows a typical colpitts oscillator with a tank circuit in which an inductor l is connected in parallel to the serial combination of capacitors c 1 and c 2 shown by the red enclosure. First, set the total simulation run time to about 20 of the expected cycles of oscillation. Just like the previous hartley oscillator, as well as using a bipolar junction transistor bjt as the oscillators active stage, we can also an operational amplifier, opamp.
One way to do that is to add a short single pulse of current to the oscillator loop using a current source. However because it runs on a mainframe or vaxclass computer, it must usually be learned at the pc level using the pspice simulator. After selecting skip the initial transient bias point calculation skipbp in pspice simulations options everything got better. Spice a guide to circuit simulation and analysis using pspice. The colpitts oscillator design uses two centretapped capacitors in series with a parallel inductor to form its resonance tank circuit producing sinusoidal. Thirtytwo colpitts oscillators using ccciis are obtained in all. How to size the components to get a fixed resonant frequency, how to test the open loop gain to verify the satisfaction of the barkhausen criterion. Pspice simulation of colpitts oscillator friends anytime. Dont use a voltage source since that will short the loop to ground. Jul 26, 2015 everyting about colpitts crystal oscillator in ltspice on sat, 25 jul 2015 11. Pdf design and simulation of high frequency colpitts. Colpitts oscillator tutorial and colpitts design electronicstutorials. This can be achieved by making the variable capacitor from varactor diodes.
Archived simulation colpitts oscillator using opamp. With the transistor removed, the inductor and two capacitors form a resonant circuit, like the lrc example. Combination of inductor and capacitors determine frequency of oscillator. Stop the simulation and place a spectrum analyzer on the workspace. Nco for your synthesizer, pll, or coherent detector. Pspice simulation of the bjt colpitts oscillator using the deck shown in fig.
Jan 20, 2005 the simulation and experimental results for the colpitts oscillator circuit uses a 2n3819, an nchannel device, for the jfet. The parameters of the lumped circuit elements are listed in table 6. The paperand pencil analysis and pspice simulation results have. Adjusted the max time step for better accuracy of the output waveform. The simulation tools in pspice can help you choose between a vco vs. The schematic diagram of the proposed colpitts oscillator under investigation is depicted in fig. The simulation and experimental results for the colpitts oscillator circuit uses a 2n3819, an nchannel device, for the jfet. The oscillation frequency is the transmission phase zerocrossing, 0. Oscillator is an amplifier with the positive feedback and it converts dc input signal into ac output waveform with certain variable frequency drive and certain shape of output waveform like sine wave or square wave, etc by using the positive feedback instead of input signal.
To design the oscillator for 100 hz and assuming c0. Edn jfets offer lc oscillators with few components. It is type of feedback lc oscillator where feedback is supplied capacitively. Try using the use initial operating conditions option. Sometimes to get a oscillator started in simulation you need to add a little perturbation to simulate the noise in a real circuit. Pspice simulation and experimental results demonstrating chaotic performance of the colpitts oscillator in the ultrahigh frequency 300 mhz range are presented. Apr 21, 2018 pspice simulation of colpitts oscillator friends anytime. The basic block diagrams of the hartley oscillator and the colpitts oscillator are shown in fig. In many ways, the colpitts oscillator is the exact opposite of the hartley oscillator we looked at in the previous tutorial. Pdf chaotic colpitts oscillator for the ultrahigh frequency. A more circuit oriented approach to build a vco is to take a simple tank oscillator and use a voltagedependent reactance for one of the tank components. In the new simulation dialog box, type oscillator in the name field. I have simulated a colpitts oscillator in ltspice, however, i do not understand why the signal starts out as a sine wave and then becomes triangular. Design and simulation of a 20 khz to 50 khz variable.
Everyting about colpitts crystal oscillator in ltspice on sat, 25 jul 2015 11. This is a colpitts oscillator, an oscillator that uses an lc circuit combined with a transistor for feedback. You are trying for a frequency of about 700khz, so go to a larger current and a much smaller capacitor 0. The pierce oscillator is very similar in design to the previous colpitts oscillator and is well suited for implementing crystal oscillator circuits using a crystal as part of its feedback circuit. Ive tried to simulate several different oscillators, the last being a colpitts xtal oscillator. Ni multisim live lets you create, share, collaborate, and discover circuits and electronics online with spice simulation included. A novel version of the chaotic colpitts oscillator is proposed. Download orcad free trial now to have a full evaluation of all orcad tools with no functionality limitations. A colpitts oscillator is a discrete lc oscillator that uses a pair of tapped capacitors and an inductor to produce regenerative feedback. Colpitts oscillator circuit diagram working and applications. Jan 21, 2020 the simulation tools in pspice simulator for orcad and the full suite of analysis tools from cadence are ideal for analyzing the behavior of your vco or nco circuit. The pierce oscillator is primarily a series resonant tuned. It simulates complex mixedsignal designs containing both analog and digital parts, and it supports a wide range of simulation models such as igbts, pulse width modulators, dacs, and. Low frequency amplifier and oscillator using simulated inductor.
The simulation is done using the analog simulation software pspice and the results are shown graphically using matlab a 2011 published by elsevier ltd. The tune voltage for the vco can then be applied to the varactors. Related threads on pspice ring oscillator pspice and ring oscillator. Current moves back and forth as the capacitors charge and discharge through the inductor. Twostage chaotic colpitts oscillator electronics letters dtu orbit. Oscillator simulation modeling and simulation circuitlab. This sounds like this is a software settings issue, because. To obtain a very high level of oscillator stability a quartz crystal is generally used as the frequency determining device to produce another types of oscillator circuit known generally as a quartz crystal oscillator, xo when a voltage source is applied to a small thin piece of quartz crystal, it begins to change shape producing a characteristic known as the piezoelectric effect. Design and simulation of high frequency colpitts oscillator based on bjt amplifier. These tools allow students, hobbyists, and professional engineers to design and analyze analog and digital systems before ever building a prototype. Apr 12, 2012 sometimes to get a oscillator started in simulation you need to add a little perturbation to simulate the noise in a real circuit. Systematic synthesis for electroniccontrol colpitts oscillator using.
A simplied introduction to circuit simulation using spice opus. Colpitts oscillator is a type of lc oscillator which falls under the category of harmonic oscillator and was invented by edwin colpitts in 1918. Mar 11, 2012 these tools allow students, hobbyists, and professional engineers to design and analyze analog and digital systems before ever building a prototype. The layout and simulation tools in capability of orcad pspice simulator and the full suite of analysis tools from cadence allow you to build and analyze the behavior of your. Spice simulation of a jfet biased to implements a colpitt oscillator with a tank resonant circuit with resonance frequency of 9khz. The circuit diagram of the simulated colpitts oscillator in common emitter configuration is shown in fig. Dec 09, 2019 building different types of oscillator circuits or adding a waveform generation ic is much easier when you use the right pcb design and analysis software package. Orcad free trialorcad trial provides full version of the latest release of orcad electronic design software solutions for free for a limited time, including orcad capture cis, orcad pspice designer, orcad pcb designer professional, orcad sigrity erc, and more. This video takes a look at the colpitts oscillator circuit using pspice. Coupled with work flow of orcad capture, pspice provides a fast trailer prior to board design in order to increase pcb manufacturing efficiency and ensure the final performance of pcbs. Youll also have access to manufacturer part search tools as you prepare to source components for your system if you want to build these circuits in your pcb layout from discrete. Just like the hartley oscillator, the tuned tank circuit consists of an lc resonance subcircuit connected between the collector and the base of a single stage transistor amplifier producing a sinusoidal output waveform. Mar, 2015 basically,what i know of a ring oscillator it is a circuit with only one stable operating point that is vinvoutthreshold of the inverter. Pspice is a simulator provided by orcad pcb design software.
Low frequency amplifier and oscillator using simulated. A variable frequency oscillator have been design and simulated using electronic workbench software multisim 8. Oscillators which utilizes the inductor l and capacitor c in their circuit are called as lc. Since this is a new simulation profile, leave the inherit field at default value none. A similar oscillator in the examples miscellaneus circuits claposcillator works great, adn the book where i found it also simulated it in multisim and according to it, simulation works fine as well book is electronic devices eighth edition, by floyd, page 84x. I read that i should inject some noise in circuit to make it work, but i dont know how to do that. This download was checked by our antivirus and was rated as virus free. It will be noticed that the control line from the phase detector is isolated from the varactor diodes. Chaotic colpitts oscillator for the ultrahigh frequency range.
554 1060 722 315 284 1049 1345 1424 1384 1595 213 1482 483 119 1314 686 1295 416 792 265 958 639 331 854 1107 956 1142 526 831 426 617 715 1385 1615 247 339 1058 1119 1386 345 851 322 1117 615 702 1210 15 76