292 Threads found on edaboard.com: Self Oscillator Circuit
When I talk about open loop analysis, I am talking about to cascade the active device itself with the resonator is being used in the oscillator. To properly open the loop you have to identify, looking at the oscillator topology you are using, what element is coupling signal to the input of the active device. For example regard (...)
RF, Microwave, Antennas and Optics :: 04.09.2003 01:14 :: nandopg :: Replies: 29 :: Views: 5761
Anyone can help with the above problem? Pls?
Also, in HB sim, non-linear models for FETs & BJTs are to be used. So when a feedback is required to make the active device unstable, should I use the linear (small-sig) model or the non-linear one (which will be the one eventually used in HB sim)???
Thanks in advance
RF, Microwave, Antennas and Optics :: 16.10.2004 22:29 :: BigBoss :: Replies: 10 :: Views: 1274
I wonder if it will be possible to switch in another loading element for a very short period to lower the overall Q of the resonator to speed up starting. I never tried this myself. It should be interesting to investigate with the aid of a simulator. Also oscillations can only start when the active biased region for the transistor is established. T
RF, Microwave, Antennas and Optics :: 24.09.2007 17:51 :: E-design :: Replies: 10 :: Views: 858
One option is discussed by kender, which is a boost converter. Other option is the self oscillator circuit, in which a small transformer (ofcourse ferrite) is self oscillated with one or two windings and produces a square wave stream, which can be rectified and regulated.
Microcontrollers :: 13.08.2008 07:32 :: AVIANO :: Replies: 4 :: Views: 632
rfmw that's interesting. With wich topology do you reach such a low wideband noise floor? In one design I came across one day using BFR93 it was only -150dBc/Hz, and that is typical.
Another topic I'd like to hear from you guys is FM noise from the crystal. I was trying to find out why we could not reach our spec @ 10/100 Hz offset, and I read t
RF, Microwave, Antennas and Optics :: 21.01.2009 23:52 :: radiohead :: Replies: 110 :: Views: 16448
If I talk about Hartley,Collpit oscillator,square wave general, it's said feedback must be positive,in phase and the close loop gain must be greater than 1 and there are various feedbacks also in shape of current-series/shunt,voltage series-shunt.Also in some oscillator no input signal is needed to start the oscillator going.Only cond
Analog Circuit Design :: 05.02.2010 13:55 :: umery2k75 :: Replies: 9 :: Views: 2060
... because there is a relation between the wavelength and the radius of the aperture (coil) as in optics and antenna optics, ...
Its relative unusual to make a coil with extreme high parasitic capacitances-but not inpossible.
I see the bigger problem on the secondary site/load coil, then it will maybe mobile and so are
Analog Circuit Design :: 01.05.2010 12:08 :: karesz :: Replies: 48 :: Views: 7806
Actually, I don't think that will work at all.
L1 is DC shorting the base and collector,
The combined inductance of L2 and L3 depends on their separation and orientation,
The total possible DC current is restricted to 0.5mA by R1,
Even if R1 was moved to a more sensible position between L1 and R2, the emitter current is still limited t
Hobby Circuits and Small Projects Problems :: 04.05.2010 15:50 :: SZ9000 :: Replies: 10 :: Views: 1429
I am trying to design a symmetrical load ring oscillator using the self biasing circuit shown in the maneatis paper.
Attached is a schematic showing the self bias circuit. My question is, it shows an OPAMP. How do I design this? Do I have to design each individual stage of the opamp (buffer + (...)
Analog IC Design and Layout :: 05.05.2010 01:34 :: design_oriented :: Replies: 2 :: Views: 718
It is a petty not to see your oscillator's display.
I have simulated it (using Micro Cap) and it seems to work properly. Nevertheless, the following items have to be considered:
1) The output oscillation range is no more than 2Vpp, taken at the COLLECTOR. This low range is due to the high value of R3, whi
RF, Microwave, Antennas and Optics :: 05.11.2010 17:37 :: zeller :: Replies: 65 :: Views: 2909
You're likely going to be stuck with a sine wave core,
and gain it up until it clips and looks digital.
And it's not true that you need to use discretes. Look
how long things like CD4000 logic have been around.
And it doesn't look like they're going anywhere.
In fact some of the "unbuffered inverter" gates are
useful for this sort of thin
Analog Circuit Design :: 24.10.2010 02:54 :: dick_freebird :: Replies: 13 :: Views: 1826
My apologies, I prefer the first option, with the volume fading after the 1 second tone. It can be a fairly quick fade, too. Just something to smooth out the end of it.
You will be able to select the timing yourself by changing C * and/or R.
My wall wart outputs 12v, so I can use that for the amplifier
Hobby Circuits and Small Projects Problems :: 02.01.2011 06:33 :: ljcox :: Replies: 90 :: Views: 4061
Quote: Do you mean that the first OP in loop or the separate gain controller in my circuit?
What is the "first" OP in a closed loop? Sorry for this unnecessary comment.
As I`ve mentioned, it is the gain-of-four amplifier that suffers from clipping (always the amplifier with the highest gain in the loop). But - as shown in your diagram - it i
Electronic Elementary Questions :: 15.02.2011 12:37 :: LvW :: Replies: 159 :: Views: 6764
I have a question about self-oscillation schmitt trigger frequency? Can I get 10 MHz square wave from self-oscillation schmitt trigger. I build up schematic that is given below. Also, I must use LM158. Anyone can give me an idea if it is possible to
Electronic Elementary Questions :: 17.08.2011 09:38 :: OsmanH :: Replies: 4 :: Views: 743
That necessary condition that makes that a linear system becomes a quasi-sinusoidal oscillator (i.e. Phase vs. frequency must have negative slope) is frequently overlooked.
Let's try an intuitive, non rigorous justification:
Imagine a linear circuit with an input and an output. Supose thet we connect a sinusoidal generator at the input
Analog Circuit Design :: 20.01.2012 15:45 :: zorro :: Replies: 24 :: Views: 1782
I wonder, if there are additional specifications besides frequency range and voltage range. Strictly spoken, the latter isn't a matter of oscillator design rather than using a reasonable amplifier. For the oscillator itself, you'll need to think about waveform quality respectively distortion, frequency accuracy, amplitude constancy, method (...)
Analog Circuit Design :: 06.01.2012 00:56 :: FvM :: Replies: 100 :: Views: 4277
I think the best you can do is try to understand how the various DC to AC topologies function. Also check how they behave under your load (inclusive load variations if present).
Application notes may be helpful in mastering DC to AC conversion. "Solid state radio engineering" also has a chapter on efficient RF power amplifier
Analog Circuit Design :: 29.02.2012 14:57 :: WimRFP :: Replies: 12 :: Views: 935
My teacher is strictly forbidden to use crystal oscillator. So if I asked for it from market then it is of no use for me.
I don't know what is your teacher's reas reason , but no problem , you can use this circuit as your oscillator stage , easily , see below , please :
RF, Microwave, Antennas and Optics :: 02.09.2012 23:21 :: goldsmith :: Replies: 149 :: Views: 4904
First of all, let me state that I have very little understanding of electronics, as I just started self-learning not too long ago. So, I thought that it will be a good way to learn electronics by working on fun projects. Thus, I have decided to make a digital clock using a crystal oscillator.
Are you really
Electronic Elementary Questions :: 21.11.2012 20:32 :: LvW :: Replies: 5 :: Views: 373
If your circuit is a parallel circuit , to increase the Q factor , decrease L value and
increase the C value to maintain the resonance frequency.
Another solution , in a a parallel resonance circuit there two resonance point. One of them comes from parasitic capacitance of the coil and self inductance of the coil and (...)
RF, Microwave, Antennas and Optics :: 05.02.2002 02:04 :: BigBoss :: Replies: 5 :: Views: 2757
This stun gun circuit any one have other circuit like this :evil:
S 8O KRAT
Hobby Circuits and Small Projects Problems :: 28.12.2003 16:15 :: sokrat :: Replies: 7 :: Views: 2692
This is an official HP document from 1998. It appears to be part of a class or a self study course.
RF, Microwave, Antennas and Optics :: 02.04.2004 04:47 :: flatulent :: Replies: 17 :: Views: 5558
Try Agilent App Note A008 too.
Also, I need some help:
I need to design a self-oscillating mixer (SOM) at 2.4GHz. A DR is coupled to 2 microstrips connected to gate and drain of FET forming the feedback like in many DRO designs.
1. How do i model a DR coupled to 2 microstrips? (Technical papers show that they did it, but not
RF, Microwave, Antennas and Optics :: 18.08.2004 13:16 :: gecky :: Replies: 8 :: Views: 3472
As others above have explained, an oscillator is a self-contained module that outputs a square wave at the desired frequency. A crystal needs a surrounding circuit to be useful, typically for PICs, a Pierce circuit with neighboring capacitors going to ground.
An oscillator is more expensive and draws (...)
Electronic Elementary Questions :: 31.10.2007 19:13 :: CuriousInventor :: Replies: 28 :: Views: 20256
Yea I have implemented the self-biased ckt. I am trying to meet the spec of Δf/ΔVdd<1%. How much variation in Vdd should I design up to? I am using 2.8 V supply voltage in TSMC 0.18 process.
Analog IC Design and Layout :: 15.12.2004 02:00 :: ccw27 :: Replies: 17 :: Views: 4218
in order to generaste self oscillating on opamp circuit yuo must put opamp in feedback mode (some kind like that idon't know the term) and the feedback gain should have -1 magnitude in order to make positive feedback so if there is little bust voltage either from change at power supply or noise spike (maybe) could generate voltage on opamp output
Electronic Elementary Questions :: 09.01.2005 11:47 :: e_eja :: Replies: 9 :: Views: 1680
I hope this will help:
1.) U cant use cond2 as bottom ground plane, cond and cond2 are metalization layers of the top plane as far as I know. GRND is regarded as a close boundary in Layout.
2.) Use Via2 (round Via) from the TLines-Microstrip Menu to connect the pin to the ground plane. Set diamaterer for your hole and just export your d
RF, Microwave, Antennas and Optics :: 20.10.2005 02:25 :: Soben :: Replies: 2 :: Views: 1344
I design a Colpitts oscillator f=2GHz.But the output is 500MHz and its this self oscillating?how to eliminate it?
RF, Microwave, Antennas and Optics :: 21.04.2005 14:10 :: liberal :: Replies: 1 :: Views: 612
I want if anyone help me to design a selfexcited mixer ( BJT Mixer ) in general circuit and using ADS tool .. I just want this as a training to the ADS software ..
Thank you very much ..
RF, Microwave, Antennas and Optics :: 10.07.2005 21:17 :: ahmad_abdulghany :: Replies: 10 :: Views: 959
Allright, here is one concept. Modern military aircraft achieve great agility by operating in the unstable region of flight. That is, if there were not some very fast control loops keeping the plane flying properly, the pilot would not be able to pilot it for more than a few seconds before it augered in.
In the old days, when vacuum tubes were
RF, Microwave, Antennas and Optics :: 16.07.2005 04:27 :: biff44 :: Replies: 2 :: Views: 820
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 oscillator design. Topics include: (...)
Electromagnetic Design and Simulation :: 12.08.2005 02:34 :: h_a_p_y :: Replies: 0 :: Views: 5648
of course you can.
1. such as two stage opa, the last stage can be an inveter
2. use self-biased, you can use the inverter as an opa
Analog IC Design and Layout :: 14.11.2005 02:43 :: sunking :: Replies: 19 :: Views: 4052
i think knowing the reason for which your simulation don't start!!!
Obviously we start from the point that the circuit gets the Barkausen conditions....
u should verify these conditions opening the loop in a good point and verify that they are fulfilled.
Then u must put a time varying discontinue in your circuits...
for example u put a p
Electronic Elementary Questions :: 13.01.2006 11:05 :: alex_vettoriale :: Replies: 4 :: Views: 2708
Commercial could mean more user friendly but possible more power consuming.
That is because the highest sensitivity and lowest power is where the divider operate as injection locked oscillator. I think you have the lowest required power level for correct operation where the selfoscillation is.
If selfoscillation should be blocked you (...)
RF, Microwave, Antennas and Optics :: 20.03.2006 08:10 :: rfsystem :: Replies: 6 :: Views: 627
I am not sure if you have come across this site but I think you will find a lot of interesting info on induction heating ..
A conceptual MOSFET self resonant oscillator
This design is a result of small scale experimentation. I originally wanted to use SCRs because of the simplicity of the design. But it turns out that low cost, readily ava
Hobby Circuits and Small Projects Problems :: 29.03.2006 02:56 :: IanP :: Replies: 14 :: Views: 24219
The right-hand transistor in the oscillator circuit is supposed to be an oscillator. It is meant to make a
carrier signal by itself.
The transmitter input is a microphone. It is intended for audio frequency signals around 300Hz to 5KHz.
An AM radio link can only carry signals at much less than the carrier frequency. (...)
Electronic Elementary Questions :: 27.03.2006 19:29 :: throwaway18 :: Replies: 10 :: Views: 4400
You might try a dual gate fet mixer at this frequency. THere is a zip file in this link. It is very useful.
For self oscilating dual fet mixer
It is a US patent
RF, Microwave, Antennas and Optics :: 23.04.2006 06:48 :: boy :: Replies: 6 :: Views: 831
I once read two papers about clock duty cycle cerrection, one is
G J.Maneatis, "Low jitter process-independant DLL and PLL based on self-biased techniques", JSSC VOL.31.NO11,1996.
the other is
J.Lee," A low-noise fast-lock phase-lock phase-locked loop with adaptive bandwidth control,JSSC VOL35.NO8,2000.
hope this will help.
Analog Circuit Design :: 21.07.2006 03:18 :: jfyan :: Replies: 3 :: Views: 2642
Kindly share u'r ideas, suggestions and experience in self building and experimenting a 100 Mhz frequency generator. Is it possible to make it work accurately without using any specialized soldering technique etc.?
Hobby Circuits and Small Projects Problems :: 10.09.2006 22:23 :: WISDOM :: Replies: 1 :: Views: 1097
Well, superregen is a strange beast indeed. Lets say you had a transistor that had 20 dB of gain at your RF frequency of interest. It will boost up a weak signal by 20 dB, nothing more, nothing less, if it is used as a linear amplifier.
However, if you set up that same transistor with positive feedback, it will, for a brief period of time, hav
RF, Microwave, Antennas and Optics :: 11.09.2006 13:09 :: biff44 :: Replies: 3 :: Views: 923
CMOS DLL-based 2-V 3.2-ps jitter 1-GHz clock synthesizer and temperature-compensated tunable oscillator
Foley, D.J. Flynn, M.P.
Dept. of Microelectron, Nat. Univ. of Ireland, Cork, Ireland;
This paper appears in: Solid-State circuits, IEEE Journal of
Publication Date: March 2001
Volume: 36 , Issue: 3
On page(s): 417 - 423
Analog Circuit Design :: 19.11.2006 19:37 :: zakrotta :: Replies: 5 :: Views: 2130
you simply need a 10uh choke and a decoupling cap on the vdd rail to the buffer and amp stages replace the 10k resistor with a paxilon peg and wind 10 T .28mm dia ecw 1.2mm dia the rf is using the resistor as a coil and this has the effect of a dampener on the system as the rf leek away haphazardly
finaly clamp it with a zener at +5.1v before the
Analog Circuit Design :: 10.02.2007 00:44 :: VSMVDD :: Replies: 13 :: Views: 1214
the crystal it self is not an oscillator , so u can't connect it to the input of the PLL , u need a crystal oscillator to use crystall as the resonator , and the output of the crystal oscillator will be the input of the PLL
ASIC Design Methodologies and Tools (Digital) :: 24.05.2007 08:29 :: khouly :: Replies: 3 :: Views: 492
R provides control to the rate of charging and discharging, without resistance, the capacitor will charge &/or discharge instantaneously, R limits the current, thereby allowing the charging and discharging to happen gradually, governed by:
Where V=system/total/ supply voltage
Electronic Elementary Questions :: 23.04.2007 09:33 :: fazan83 :: Replies: 13 :: Views: 7712
the oscillator don't want to oscillate :cry: I removed the 8M and tryed another bf245c, choke of 1.9mH nothing. the inductor is a iron core self (transformer hf type)
RF, Microwave, Antennas and Optics :: 19.06.2007 20:50 :: falcone :: Replies: 6 :: Views: 679
I have a litte different problem.
Suppose, I have a charger to charge optimaly according to my need, and suppose
that I have an apropriate source of power, via AC-DC adapter, to drive my
intended load (led, motor, whtever).
I want to have a system which should run normaly from power source (AC-DC adapter)
and want to have the battery
Microcontrollers :: 06.01.2008 03:09 :: donkey41 :: Replies: 187 :: Views: 91677
I'm designing a 2 legged robot, which will be able to move backward when bumping into an object. But now i only concern how to change from moving forward to backward, by triggering the changes my self, no need bumping into an object. Still testing.
Can anyone give me some ideas? I'm really stuck here.
Analog Circuit Design :: 24.11.2007 12:13 :: menirva :: Replies: 0 :: Views: 315
Yeah I know the last post stated to use the caps, but, for some reason the original poster refuses to use the caps because he thinks they are for no reason.... I strongly recomend to use the 22pF caps! you are dealing with data communications that require some what accurate timing... If you have a pic running an Xtal with no caps, the timing would
Microcontrollers :: 30.10.2008 15:54 :: chevymn1964 :: Replies: 71 :: Views: 14774
would be much easier, if we would know the said board's purpose (if known at all)...
If the part is cylindrical with axial wires, than it's probably a surge arrestor or switching sparg-gap. This is actually the same device, but for different applications. Together with the said resistor and capacitor, it forms a very simp
Hobby Circuits and Small Projects Problems :: 23.01.2008 22:33 :: FvM :: Replies: 5 :: Views: 1984
So, the charge pump circuit must have self-osillator circuit??
Analog IC Design and Layout :: 03.03.2008 09:45 :: anhtuan :: Replies: 7 :: Views: 640