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100 Threads found on Vco And Control And Voltage
Hello, does anybody know that why a resistance is made in series with the control coltage of LC oscillator and in which range should be this resistance? Thanks
If you're set up for SPICE analysis then I'd just step through the practical range (0 - VDD) and observe waveshape and frequency; you can pick off the freq value by an expression and plot vs the vcoNT value (either in a decent waveform viewer, or exported to Excel). (...)
It surely is specified in the datasheets Notice that this is an IC design question, there's no datasheet, instead the IC designer (the OP) has to answer the question himself. I agree that the useful control voltage will be restricted by the linear PFD and vco linear range.
Hi everybody, I met a problem in PLL design. Actually design has finished, the problem found in verification. TI PLL chip 4816B is used, and follow is the external 2nd order LPF. 122208 For VCXO, we have several vendor to select. All of the VCXOs works well except one. The phenomena is the PLL will unlock with onl
I have created an integer and fractional PLL. The integer PLL is locking fine. The fractional PLL has a delta-sigma modulator which varies the feedback frequency divider modulus. Maybe that's why the control voltage on the vco is varying periodically? Is there a way to mitigate the periodic variation of (...)
My PLL output frequency is 8GHz.and I have a problem,my control voltage of vco variation is high? how can eleminate this issue? I have R=9k ohm and C1=80p and C2=2p ????
Actually a VFC is a vco, just with a broader frequency range, and without the feedBack control mechanism via PFD. So the noise calculation should be similar.
Only 45MHz ? Is that nominal , min or max? Being a linear vco with wide variations of stray and PN junction capacitance , nominal f is not precise. But figure 2 shows Cx=10 pF (1e-11) for Vf=Vrng=2V Both voltages can span from 1-5V but are more linear from 1.5 to 4.5V. Vrng is lowest range at 1V I.e. 10%, while f increase (...)
Did you ever inspect the ring oscillator waveforms to understand how the current control works? There might be an unwanted voltage swing at the inner supply nodes. A standard vco technology uses differential stages, and if I remember right, (...)
You can sweep the control voltage of vco in transient simulation, collect the vco frequency data and handle them in excel to plot the frequency vs control voltage.
Hi guys, The following is my measure commands: .HBOSC TONE=2500e6 NHARMS=12 PROBENODE=vin,vip,1 + SWEEP v_control LIN 10 0.1 1.6 .measure hbosc fh find 'hertz' at=0.1 .measure hbosc fl find 'hertz' at=1.6 v_control is the control voltage for my vco. I wanna to (...)
Do a pxf analysis and plot the outputs from the control voltage source (Signal) and the power supply (Noise). Look for the "-1" ref sideband to observe the frequencies that matter. Note their relative levels and model it as (...)
This is a loop filter used in the PLL loop. The input is current and the output is the control voltage of the vco Yes - that`s what I have expected. As said - derive the transfer function Vout/Iin and determine poles and zeros. This (...)
Hello from Greece !!! This is a voltage-controlled oscillator (vco). Αn oscillator that its frequency is controlled using a voltage signal. The vco described here provide both triangular and square wave output. The control (...)
Some original joysticks used the Pot to control a vco and thus frequency was the output, however DMM use constant current ( 0.0001mA to 1mA) to drive the probes and thus Resistance is the voltage on the probes.
Hi, I am new to vco, I am trying to design a vco at 2.5GHZ. but I found that the gain of my vco appear positive or negitive with the control voltage seems totally different from what I find in the textbook. I want to know why the gain of vco performance like that? (...)
I'm doing simulations on a vco using Cadence at the moment (relative n00b to Cadence). I've got my circuit functioning and have a plot of the transient performance of the circuit for a set control voltage. What I'd like to do is sweep my control voltage (...)
Hi, 1. I have attached transient response of the control voltage of my PLL in Cadence. This is NOT behavioral reponse. 2. From t=0 to 100us it is the startup time. No frequency step provided 3. At t=170us a frequency step of 40MHz (max size for the pll) is provided and resulting transient response is shown. The (...)
Hi all ! I have a vco IC with code MQK001-896-T7- 896MHZ. I find datasheet with link below : But i unknow frequency range output and control voltage range. Anyone that done,can help me ?Thank all!
Hi, i simulated my pll using simulink n time domain and ended up with peculiar control voltage even with 60 deg/75deg PM. Fig 1 shows the output of loop filter. Fig. 2 shows output after VDD saturation. I want my vco control voltage to slightly rise from 0 at t=0 (...)