For more pspice circuit videos check out my channel and feel free to subscribe. Apr 21, 2018 pspice simulation of colpitts oscillator friends anytime. To make a vco, the oscillator needs to be tuned by a voltage. Chaotic colpitts oscillator for the ultrahigh frequency range. Since this is a new simulation profile, leave the inherit field at default value none. Low frequency amplifier and oscillator using simulated inductor. Colpitt oscillator with bjt and barkhausen criterion. Computeraided analysis and design is fast becoming a required skill for todays electronic engineerstechnicians. 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. The circuit diagram of the simulated colpitts oscillator in common emitter configuration is shown in fig. Spice a guide to circuit simulation and analysis using pspice. 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.
What causes the wave to become triangular and how can i make it more sinelike. 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. 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. I make a colpitts oscillator simulation with pspice. Pdf design and simulation of high frequency colpitts. Design and simulation of a 20 khz to 50 khz variable. However because it runs on a mainframe or vaxclass computer, it must usually be learned at the pc level using the pspice simulator. In pspice for analog communications engineering we simulate the difficult principles of analog modulation using the superb free simulation software cadence orcad pspice v10. 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. Everyting about colpitts crystal oscillator in ltspice on sat, 25 jul 2015 11. 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.
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. A novel version of the chaotic colpitts oscillator is proposed. The pierce oscillator is primarily a series resonant tuned. Note that a vco can also be implemented as a colpitts or clapp oscillator, or as an lc oscillator in the above circuit, which will produce a sinusoidal output.
As an nco is defined in terms of software rather than. 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. In the new simulation dialog box, type oscillator in the name field. The operation of an opamp colpitts oscillator is exactly the same as for the transistorised version with the frequency of operation calculated in the same manner. Jul 26, 2015 everyting about colpitts crystal oscillator in ltspice on sat, 25 jul 2015 11. Systematic synthesis for electroniccontrol colpitts oscillator using. The colpitts oscillator design uses two centretapped capacitors in series with a parallel inductor to form its resonance tank circuit producing sinusoidal. The video shows a tutorial on how to build a phase shifted oscillator. Colpitts oscillator circuit diagram working and applications. To design the oscillator for 100 hz and assuming c0. Apr 22, 2016 for more pspice circuit videos check out my channel and feel free to subscribe. Stop the simulation and place a spectrum analyzer on the workspace. 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. 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.
The project explains how to test the open loop circuit to verify the barkhausen criterion. In this research, a colpitts oscillator is comprised from a bipolar junction transistor bjt amplifier with lc tank. It will be noticed that the control line from the phase detector is isolated from the varactor diodes. This video takes a look at the colpitts oscillator circuit using pspice. A simplied introduction to circuit simulation using spice opus. Pspice is a simulator provided by orcad pcb design software. Nco for your synthesizer, pll, or coherent detector. Colpits oscillator pspice design all about circuits.
In order to design the 50mhz oscillator sensor, the following tasks have been carried out. A variable frequency oscillator have been design and simulated using electronic workbench software multisim 8. Colpitts oscillator tutorial and colpitts design electronicstutorials. 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. 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. 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. The simulation tools in pspice can help you choose between a vco vs. To create a simulation profile, click pspice new simulation profile. Pdf chaotic colpitts oscillator for the ultrahigh frequency. Jan 20, 2005 the simulation and experimental results for the colpitts oscillator circuit uses a 2n3819, an nchannel device, for the jfet. 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.
Jun 08, 2011 how to simulate pierce oscillator in pspice. The tune voltage for the vco can then be applied to the varactors. 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. The simulation is done using the analog simulation software pspice and the results are shown graphically using matlab a 2011 published by elsevier ltd. Therefore,whenever theres a devviation from this the circuit starts oscillating and this goes on indefinitely because of the feedback. Thirtytwo colpitts oscillators using ccciis are obtained in all. 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. 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. Archived simulation colpitts oscillator using opamp. It is designed between 20 khz to 50mhz using a colpitts oscillator configuration. Adjusted the max time step for better accuracy of the output waveform.
First, set the total simulation run time to about 20 of the expected cycles of oscillation. Edn jfets offer lc oscillators with few components. The basic block diagrams of the hartley oscillator and the colpitts oscillator are shown in fig. The zx device is used to implement a voltagecontrolled lossy inductor. Spice simulation of a jfet biased to implements a colpitt oscillator with a tank resonant circuit with resonance frequency of 9khz. Oscillators which utilizes the inductor l and capacitor c in their circuit are called as lc. Try using the use initial operating conditions option. Simulation shows the voltage gain of the amplifier circuit is 0.
Colpitt oscillator with bjt and barkhausen criterion youspice. With the transistor removed, the inductor and two capacitors form a resonant circuit, like the lrc example. The oscillation frequency is the transmission phase zerocrossing, 0. These tools allow students, hobbyists, and professional engineers to design and analyze analog and digital systems before ever building a prototype. 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. Download orcad free trial now to have a full evaluation of all orcad tools with no functionality limitations. Colpitts oscillator simulation problem with pspice. I placed components and xtal, but it is like a dead horse. Low frequency amplifier and oscillator using simulated. One way to do that is to add a short single pulse of current to the oscillator loop using a current source.
After selecting skip the initial transient bias point calculation skipbp in pspice simulations options everything got better. I cant perform ac sweep cause theres no ac source that means. Pspice simulation of colpitts oscillator friends anytime. A colpitts oscillator is a discrete lc oscillator that uses a pair of tapped capacitors and an inductor to produce regenerative feedback. 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. This sounds like this is a software settings issue, because. The oscillator may take a few seconds to stabilize. The pspice parameters for this transistor are i dss of 12 ma and v p of 3v. Dont use a voltage source since that will short the loop to ground. Another common design of the quartz crystal oscillator is that of the pierce oscillator.
Colpitts oscillator is a type of lc oscillator which falls under the category of harmonic oscillator and was invented by edwin colpitts in 1918. Twostage chaotic colpitts oscillator electronics letters dtu orbit. The schematic diagram of the proposed colpitts oscillator under investigation is depicted in fig. Design and simulation of high frequency colpitts oscillator. It is type of feedback lc oscillator where feedback is supplied capacitively. Combination of inductor and capacitors determine frequency of oscillator. Ive tried to simulate several different oscillators, the last being a colpitts xtal oscillator. Oscillator simulation modeling and simulation circuitlab. Identical and mismatched cases chaos in the colpitts oscillator has been demonstrated by tmeans of pspice simulations and hardware experiments 1.
Spice simulation program with integrated circuit emphasis is a. Ni multisim live lets you create, share, collaborate, and discover circuits and electronics online with spice simulation included. This is a colpitts oscillator, an oscillator that uses an lc circuit combined with a transistor for feedback. Simulation is an essential link in the process of pcb design. Mar 11, 2012 these tools allow students, hobbyists, and professional engineers to design and analyze analog and digital systems before ever building a prototype. Related threads on pspice ring oscillator pspice and ring oscillator. Pspice simulation and experimental results demonstrating chaotic performance of the colpitts oscillator in the ultrahigh frequency 300 mhz range are presented. The complete circuit is made up of a 2n3904 pnp transistor amplifier and two tank circuits which form the feedback network. The simulation and experimental results for the colpitts oscillator circuit uses a 2n3819, an nchannel device, for the jfet.
Pspice student is sometimes distributed under different names, such as pspice student thinstalled. Current moves back and forth as the capacitors charge and discharge through the inductor. After selecting skip the initial transient bias point calculation skipbp in pspice simulation s options everything got better. This can be achieved by making the variable capacitor from varactor diodes.
A separate agilent software, empro, is a full 3d electromagnetic simulator that. 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. Sometimes to get a oscillator started in simulation you need to add a little perturbation to simulate the noise in a real circuit. Select simulateinteractive simulation settings, and select set to zero for initial conditions. You are trying for a frequency of about 700khz, so go to a larger current and a much smaller capacitor 0. The paperand pencil analysis and pspice simulation results have. 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.
Complex dynamic behaviors in a new colpitts oscillator. I read that i should inject some noise in circuit to make it work, but i dont know how to do that. Pdf design and simulation of high frequency colpitts oscillator. The current source will take forever charge a f capacitor t c3vi 51e6 5e9 seconds or about 158years.
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. In many ways, the colpitts oscillator is the exact opposite of the hartley oscillator we looked at in the previous tutorial. This video takes a look at the colpitts oscillator circuit using. Pspice simulation of the bjt colpitts oscillator using the deck shown in fig. This download was checked by our antivirus and was rated as virus free. The parameters of the lumped circuit elements are listed in table 6. While use is made of analog behavioral model parts abm, we use actual circuitry in most of the simulation circuits. 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.
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