Search Engine

524 Threads found on Oscillating
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 To s
Hi, can anyone post something on self-oscillating mixer design? Many Thanks!
No, you don't need initial conditions to simulate you negative feedback system. You may need .IC, however, if your schematic is large and complex, just to help it find the operating point or start running, but this is a different matter. Do run a step responce of your system to see if it settles well, meaning not oscillating.
I design a Colpitts oscillator f=2GHz.But the output is 500MHz and its this self oscillating?how to eliminate it?
10 turn coil should have full DC supply voltage if not oscillating. Check 215V supply without a load and when loaded with oscillator. When oscillator is not running it may draw significant current and overload supply. It could be a reason that you have only 100V. The reason why oscillator is not working can be wrong connection of transformer windin
Guys need you!!! I need articles or links regarding RCC or self oscillating flyback converter. Hope you'll provide one. I need it badly thanks a lot. rgds, your friendly neighborhood
Hi, I use a LM317T to build a current regulator 60mA. 15VDC Input (Pin 2) 680nF to ground. Output (Pin 3) 20 Ohms to Ref (Pin 1). Usually the circuit works fine. But with a new LM317T from ST (China) it's oscillating 1..10MHz and I found no solution to solve the Problem.
I cascade two stages of UPC2776 as a post amplifier to boost the signal from a Transimpedance amplifier. Since UPC2776 have 23dB gain and 2.7GHz bandwidth and TIA supposed to work at 70MHz, it should not be problem from bandwidth point of view. The wired thing happened once I power up UPC 2776. Output of the second stage oscillating very badly
Hi. Kinetic watches have oscillating weights inside them which in turn are connected to an electrical generator. like this: If one was to scale this up, would it generate enough power to actually be useful for other appliances? say... a battery charger f
berryfan wrote: Enquiry: Re: help!some like oscillating.what's the it? thanks.I have used spectrum analyzer ,and the I see in 980M and 1.8G there can be signal changing between -40--50dbm.I think if it's a oscillation ,it can be one power.not changing so much.what do you think Your situation is clear. You have bat test setup and you are pickin
i have designed a SC-CMFB for a folded cascode OTA and when i check its transient response it's output is oscillating, can any one tell me why and how to avoid it, help me please it's urgent. Thank you in advance.
I'm not sure how to describe oscillating electric point charges in FDTD scheme of the time domain Maxwell equations, but I would like to model the near-fields produced by an oscillating electric dipole and electric quadrupole. Then I will compare these solutions to analytical ones. I think a dipole could be just represented as a point current and t
HI What did you mean by "PWM pulse pk-pk is oscillating" ? Can you place a picture from scop? All the best Bobi The microcontroller specialist
Hi, Iam using IC 7107 LED Driver for my ?? Digital panel meter.Some DPM's are working some DPMs Ref voltage at 36 pin is oscillating.Why this problem is coming.Some one help me.
Please any one can post the Push-pull self-oscillating electronic ballast for battery application IEEE document number IAS.2005.1518786. Thanks before any one. Best regards, HG
Hi all, I found when simulating with ADS, the oscillating freq changes when impedance-matching circuits change without chaning DR setting ?Can anybody tell me the reason?Thanks. Yun
I'm trying to simulate a Class D amplifier with hysteretic self-oscillating modulator but the PSS simulation is not acepting the configuration. Basically the self-oscillating system frequency (fs around 500 KHz) will be modulated by an audio signal (fin around 1 KHz) and fs will be varying from 450KHz to 550KHz but in a non-linear fashion since
Hello! I have a LCD Samsung LE37M87BDX where the picture is black and white! I have measured, in the main board, all of the crystals oscillators and one has 1Vdc in one pin and in the other 3,2Vdc and it is not oscillating. Do you agree that this component is defective? Normally when I turn on the TV all the crystals will oscillate? Even i
"Costly" ICs or not, they at least need to implement a boost converter, using an inductor/transformer and an oscillator, possibly a self-oscillating switching stage. Achieving low quiescent current and high efficiency is kind of a challenge for a simple low part count boost converter.
Hello, I wish to add slope compensation to a self oscillating boost converter, it is 12V input and Vout = 90V (its 36 amber leds in series at I = 30mA). The circuit inductor squeals like mad, and i wish to add slope compensation, -there is no oscillator, so i suppose i have to couple the drain volage back to the source current sense as a kind
I have just constructed the truxgraphics power supply but it just wont stop oscillating and it is gives a maximum voltage within 1v of the preset maximum CAN SOMEONE HELP
Another remark re crystals; They can be somewhat tuned, either by applying capacitance/inductance in series or capacitance in parallel. The tuning range is however very very limited. What method to prefer for finetuning depends on whether one wants to tune the frequency up or down. When byuing crystals they are usually specified (at least in fa
Hi Dlancia, If you wish to build a high voltage supply, there is an interesting solution on J. Naudin's page at the very bottom of that page where he uses the secondary coil of a small (probably portable) televison set's discarded line output transformer to get 20kV wound on a normal ferrit rod! Of cour
Hmmm... the age old debate... hsim or powermill. Interestingly enough I was a big hsim lover for no other aparent reason than it was something new. Painful experience has shown me that although both have annoying shortcomings, Powermill's I can overcome, Hsim's I cannot. Case in point: pll's. I simulated the exact same pll on both simulat
Look at the digital waveform out of your comparator to see if it is oscillating on the transitions. To add the hystersis to your comparator circuit, put a large value resistor from the digital output to the non-inverting analog input. Then put a small resistor from the non-inverting analog input to ground. Apply the signal to me be measured to
The ADS OscPort model for HB analysis is based on the Nyquist stability test critetion, which is described in "Microwave Transistor Amplifiers, Analysis and Design, 2nd Ed, G. Gonzalez", chapter 5, section 2. The idea is measuring the close-loop gain and phase to determine the oscillating condition and frequency. The following is my opinion abou
I have used ATF 54143 to design a LNA for 1.9 GHz. When I test it use Agilent's Noise Meter, there is a peak in NF. In band 1.9 - 2GHz The Gain is within + /- 1 dB, and is correct hign 15dB except one point, NF is very low 1.2 dB but at that point is nearly 10dB Does any body meet the same problem in LNA test. Seems not self oscillatin
Hi all, I'm trying to match the theory with a simulation of a three stage ring oscillator using CMOS inverters (ie a P & N device with the gates connected together on the input and the drains connected together on the output). The theory says you match the W/L ratios (because Kp & Kn are different) to get a symetrical waveform - so far so goo
One common technique is to just sample the oscillating device's DC current in a 1MHz BW and then feed that back out of phase into the bias network. This can reduce 1/f effects up to 40dB.
I have a sony 5 disc cd changer (cdp-c325) that has a tray that continously keeps turning clockwise and counterclockwise. i checked the voltage on one of the pins that goes to the motor that spins the tray and it is oscillating from about -2.5v to +2.5 volts. Does anybody have a schematic for this model or any idea whats causing this?????
Hi, just to add one more detail. If you have to make a lot of vias, especially if you have to ground the sources of the transistors, than the via can be an important issue to adress if it is critical to achieve enough gain or precise oscillating condition. In that case, vias will be more closer to short circuits in 10mils rather then on 20mils s
Hi, I think that you may have incorrect or non-accurate transistor model, which results a non-oscillating circuit to modulate. :D
Here is a list of things (rules) to-know that I found helpful over the years. 1/ Capacitors and resistors have parasitic inductance, about 0.4nH for surface mount and 4nH for a leaded component. 2/ If you don't want a high bandwidth transistor to oscillate place lossy components in at least 2 of the 3 leads. Ferrite beads work well. 3/
clock? you can say that. there are one input & one output ports, connected with a inverter in circuit. supply a oscillating signal (clock) to circuit.
Dear all, Could anyone explain to me that why the phase noise in the CMOS LC-Tank VCO is better than the CMOS Ring Oscillator? I have this explanataion. I don't know is correct or not. I hope any one could correct me if I am wrong. Since in the Ring Oscillator, the oscillating frequency is due to the delay time of each NOT
A few of my observations.... (1)Firstly your Iprobe should be in series with Rd if you want it to measure drain current, it won't measure anything where it is. (2) for this oscillator to work you want 0/360 degrees around the loop - therefore at 4GHz the device and resonator will add electrical length - you must add more electrical length - i
some of my circuit components need dc supply voltage. but some needs ac supply voltage (i.e. vibration sensor). how can i design the power supply circuit to cater all these components need? is it ok with a normal voltage oscillator and amplifier to convert 12V(dc) to 24V(ac). i'm thinking of oscillating the regulated voltage and drive it to the
Hi, I'm trying to test an active circuit (FET with feedback) on the VNA. However, the circuit starts to oscillate before I can reach the desired FET biasing and the warning msg pops up on the VNA. Seems like the spikes due to the oscillation is too much for the VNA to handle and I should not proceed to advoid spoiling the equipment. The feedb
Hey, anyone knows how I can simulate a self-oscillating mixer? Thanks!
I am not too sure what else is the major difference but the following is one big difference....and by the way spectre and spectre simulator!!!...they are the same... I am talking about diff. bet. hspice and spectre HSpice simulator:- Treats the circuit as a Linear Time Invariant system if u simulate something like an oscillator
I use hundreds of 1307 except a few where the xtal is not oscillating I never had a problem with functions and I also use the weekday and other "goodies". best regards
marty, If is oscillating you will see the spurs on the Spectrum Analyzer (that is connected at the output of your amplifier). These spurs could appear with, or without signal at the input of your amplifier. Another indicator of unstable amplifier is when S11 is going positive (S11 > 0). Check in your simulation for K factor, that for a stable am
Hi I try to interface a small piezo disk (a non-oscillating piezo buzzer) as a shock sensor to a PIC ADC converter in order to get the instant shock value (in G for example) Any knows such a project ? Thx
Your incoming data has been clocked at the transmitter end with a certain frequency which you should know approximately - say 10MHz. Why not lock your VCO first to a regular clock of 10MHz using a PFD, charge pump etc. like a PLL and after it is locked then switch over to a phase detector receiving your real data and do the recovery. This way your
Can anyone offer me tips on how to size the transistors for the buffer stage shown, particularly the PMOS transistors because I am having a hard time keeping PMOS load in triode and PMOS diode in saturation. I am trying to build a four stage ring oscillator. From my calculations I need at least a Gain of 1.4 in each delay cell and I am target
Can anyone offer me tips on how to size the transistors for the buffer stage shown, particularly the PMOS transistors because I am having a hard time keeping PMOS load in triode and PMOS diode in saturation. I am trying to build a four stage ring oscillator. From my calculations I need at least a Gain of 1.4 in each delay cell and I am target
I am just designing the VCO. As I change Vdd from 2.8 to 2.52 the frequency changes around 40 MHz. I am trying to meet the spec of Δf/ΔVdd < 1% for oscillating frequency of 250 MHz. And I am using TSMC 0.18 process. Thanks
Hi, I have designed a relection, common source FET DRO at 6GHz. Making use of the existing design, I need to design for a RF (5Mhz) feed to convert the DRO into a self-oscillating mixer. I need some advice on how I can acheive RF input matching without affecting the oscillator. All the papers I found use SOM for down-convertion so the RF
Hi all I want to build a circuit that can simulate the birds singing. Something similar to a technology called Sonic Bloom. They produce an oscillating sound of frequencies between 3000 and 8000 hz and amplify it to stimulate plants growing. I need some help in that order. If something can help, I could upload a sample of the sound extracted fro
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