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34 Threads found on Simulation Crystal Oscillator
As Brads simulation shows, there's no need to use a depletion type P channel transistor for the circuit. A regular unbuffered CMOS inverter built of complementary enhancement transistors will do. It's a standard circuit e.g. used for IC crystal oscillators. The schematic in post #3 has a wrongly connected PMOS transistor, please correct.
I have been doing simulations with it but in some practical circuit i see some oscillator on the 18 and 19th pin. In simulation I dont find any model for the the oscillator though.What happens if i dont add it in real life?
Hi Guys, I de-Q'd the crystal oscillator by adjusting the values of Cx and Lx to give the right w0, my transient simulation is dramatically faster but why the f0 is shifted a bit to ~33.5KHz? Thanks. tommydidi
Hi!! I am using Multisim to simulate a crystal 32.768khz using CD4069 CMOS!! the crystal cannot oscillate!!! when i simulate i always can get is 6Mhz not 32khz. i try different crystal value like 1Mhz but always 6mhz output!! i try using transistor as a oscillator but it does not oscillate too. i think there is a bug on (...)
Hi, You normally tell proteus what oscillator speed you want by right clicking on the pic chip, in the properties box enter your oscillator speed. If you connect a crystal or R/C to the osc pins in ISIS it will simply ignore them when running a simulation, it relies on the Properties box value. Of all the (...)
Hi WimRFP, No, I cannot look into the model. When I open the model parameters for editing, there are no options to edit Lm, Cm and other xtal parameters. Moreover, when I try to use these components in simulations, they do not work at all. See my attached circuit diagram. There is no option to put any initial condition in xtal model. htt
You should clarify, which circuit you are trying to get working. The simulation circuit in the original post (cross-coupled_crystal_oscillator_1604.jpg) hasn't reasonable component values, neither for the load resistors nor the crystal model.
I am designing an oscillator pad with working freq frm 10MHz to 30MHz. I have only 24MHz crystal model for simulation. Is there any1 can share with me 30MHz crystal model. Thanks. Rdgs YY
hi, How do I run the simulation of a colpitts crystal oscillator using what simulation for freq and output voltage? I have design the circuit with all the components value but what xtal to use and what parameters if i want a 2Mhz freq? thx.
Hello, i tried to design a colpitt oscillator (10mhz) in pspice, but there are some "start" problems. i got the data of the crystal oscillator (RLCC-network) of the german wikipedia (Schwingquarz ) and the dimension of the parts from this site: [url=www.electronics-r
You need external oscillator (crystal) to generate source clock. 100 MHz oscillator is available. If you want to generate from other clock frequency then use FPGA's inbuilt PLL/DCM. If you want to generate for the simulation purpose, use time command in your testbench. hope it helps
How long are you running the simulation for and what is the minimum time step? It can take a long time for oscillations to start - higher Q = longer start time. Sometimes the oscillations will seem to die away and then start to increase as the phase changes, so it may be that you aren't simulating for long enough. Keith.
Hello, I'm using OrCAD Capture trying to simulate a clapp crystal when i try to run any kind of simulation the output file says: **** INCLUDING **** * source KURSOVA1 .EXTERNAL OUTPUT out C_Co N22687 N24215 3p C_Cbl
I'm simulating the crystal oscillator proposed by Eric A.Vittoz(High-Performance crystal oscillator Circuits: Theory and Application).The schematic is as follow. When I run a transient simulation, the simulation results are strange .The current of PM0 is very unstable ultimately. But I (...)
Step time should be much smaller (at least 10 times) than the period of oscillation for accurate simulation. This is what makes simulating crystal oscillator circuits difficult especially when the crystal has a very high Q. It can take very long to start up in the simulator. One way around this for initial test purposes is (...)
I am doing ac simulation for my crystal osc. I would like to confirm the frequency response of my design. Please give me some comments. As the attached figure, which points (A, B, C and D?)is better to be broken in the loop? Many thanks.
Hi all, I make a colpitts oscillator simulation with Pspice.But unfortunately it can not get reasonable can not oscillate stably.I set C1,C2,C3,and L1 initial condition is 1V.Attach schematics and result FYI.Anyone kindly help me why not oscillate stabily?And How can i tune
I want to perform loop gain and phase shift simulation for a common crystal oscillator showed in pasted figure. simulation results is very different from that of some papers, and oscillation seems not to occcur for phase shift less than 180 . is my method wrong ? pls give some help!
The resistor in the RTC crystal oscillator is about 5M, it is a very big value. How can I do the resistor? Can I use CMOS transfer-gate? I have used the mos transistor to be the resistor, and it works well in the simulation.
I'm now designing a 32.768k crystal oscillator use in real time clock(RTC). After I did my ac simulation, I found the point the loop gain phase =0 is 32.755k. So I want to know if the result is ok and if not how can I make the result more accurate. 3x!
ya it is a oscillator... the crystal gives 180 degree phase shift and the inverter gives 180 degree phase shift based on its sizing... Then how can i know the circuit is work well. Given the crystal equivalent model,you can run the simulation of AC,transient,etc.
32K Hz Xtal can be find in Chipset RTC cell .. as I know 32K is more difficut than 1M Hz .. and you need more large gain some XTAL have gate control (use AND gate) for disable /enable .. hspice simulation maybe OK you can enable/disable XTAL clock , but real chip test , when power on is work but disable XTAL -> restart will fail i
I am working at discrete level. I have tried many schematics either in simulation or in practical to build a Colpitts crystal oscillator at 10MHz but all fail. I used ORCAD for simulation but never get oscillation ,when I replace the crystal by a coil I get oscillation but I wants to work with (...)
Did anyone come across some design techniques for fast start-up XTAL? I did some previous designs already but always faced a problem for too long transient simulation for XTAL. What I always did was to simulate AC response to check the loop gain and got it done, however, it was not comfortable without a detailed transient performance to check t
Hi, Anybody knows the design of JFET crystal oscillator for 10MHz. I designed the oscillator it is running fine in simulation but when I am putting it on board its going weird-----No output.Please suggest me the changes to be made in order to make it oscillate.Please find oscillator cct attached
How to make simulation for crystal oscillator circuits , I tried Orcad pspice but i failed Thanx
The problem could be orcad. Use the .option statement to reduce the absolute tolerance and the relative tolerance values by several factors of ten. This will make the simulation take more time, but will produce the proper results. If you want a mundane performance circuit, look at an amateur radio handbook where you will find several circuits
maybe you also should increase simulation accuracy.
... xi0 xi xi xtal ... I haven't tried the simulation but in my opinion the problem is in the above line of your netlist - your crystal is shorted! Both terminals are connected to one node xi: xi0 xi xi xtal Best Regards Eric
Where external oscillator circuitry is present on an ISIS schematic it is there purely for aesthetic reasons and is excluded from simulation (by adding the property PRIMITIVE=NULL in the edit component dialogue form). Processor clock frequency is specified as a property of the microcontroller (edit the component and type in the clock frequency).
Hi all, I was trying to simulate colpitt oscillator using ADS, Please find the circuit given below. In my feedback I have quartz crystal, whose model is supplied by telequartz (bulid in library of ADS). My probelm is, when I use normal quartz model (serier LCR and parallel C) by my own the circuit is working properly, but when I replace th
it is hard to control 50 -50 duty for different corner . you can serires a resister to output circuit , adjust resister , you can get more gain , that you can gte better 50-50 in the corner process Added after 2 minutes: the simulation time , i add initial condition , and simulation about 200us for ss/tt/f
oscillator Design and Computer simulation Randall W. Rhea This book covers the design of L-C, transmission line, quartz crystal and SAW oscillators. The unified approach presented can be used with a wide range of active devices and resonator types. Valuable to experienced engineers and those new to (...)
when do an open-loop simulation, oscillator model should be included, ? If only use the inverter without oscillator model, we can get the gain of the inverter not open-loop gain. ?