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47 Threads found on edaboard.com: Phase Detector For Pll
I am looking for a design to implement phase locked DRO or PLDRO. During literature survey, I find the only way to implement this is by using a SRD comb generator and a phase detector to phase lock the Vt-DRO,it requires a sweep circuit too(sampling phase locked (...)
TSA5512 don't have an internal VCO, and needs an external one. The external VCO is controlled by the phase detector (PD output of the chip). The 4MHz internal oscillator is the Reference oscillator.
The low input impedance will affect the pll loop gain, but the minimal phase detector output current of 100 ?A should still give full output swing. Are you sure that the VXCO has the same frequency and control voltage range? You can add a voltage buffer after the loop filter and check if it changes the behavior.
I can't follow equation 4 either. How about this paper, which describes a better equation and better 3 phase over-sampling detector.
Hi, This question is about digital pll design. I post my question here because I do not find another appropriate forum on digital pll. The Dpll is in fact a software pll according to some pll's definition. It calculates the phase error with hardware. This (...)
Is there any relation between delay and blind zone in phase frequency detector? can we decrease the dead zone or blind zone by decreasing the delay of the overall circuit for phase frequecy detector?
use a mixer as a phase detector (u need on with a DC coupled IF output). Line length L2 is much longer than L1, so it forms a delay line frequency discriminator. You might need to trim L2 or L1 slightly to get the mixer into quadrature. Drive the power splitter with >14 dBm. The oscilloscope shows the voltage out of the mixer, which (...)
I think, you can answer the question yourself by looking at slope of the transfer characteristic of the phase detector and assume different start phases for the lock process. I don't have the book, but the answer sounds very visual.
YOu can use a type II phase freq detector for this with a VCO. and /N counter but VCO must be variable from 100 to 500Hz with a loop filter around 1Hz. This wont work very well as the mixer frequency is too close to the loop filter BW and so even with S&H and integrators, it will still be noisy. But if your goal is to improve stability (...)
You can use one of several types of phase detector. They are used, for example, in pll's. One of the simplest is to limit the signals (assuming they are "clean") in order to obtain square waves and apply them to an EXOR gate. Regards Z
Hi all I am writing matlab code for pll component. Below is my code: function = pllcom(ipump,vco_gain,fref,fout,bandwidth,phase_margin) Kpd = ipump/2/pi; % phase detector gain Kvco = vco_gain*2*pi; % vco gain omega = 2*pi* bandwidth; % open loop bandwidth in radians/sec N = (...)
iam looking for analog pll matlab code. i have written code for phase detector and filter, could anyone tell me how to write the vco code in pll,, and how to integrate the whole pll..
The phase detector is usually actually a phase/frequency detector. It has the capability to determine if the frequency of the VCO is higher or lower than the input reference frequency. It also, once they are at the same frequency, to output a voltage proportional (+/-) to the phase difference between the (...)
Hello all, Can someone help me with implementation of PFD, not by CMOS, rather than by CML (current mode logic) or ECL (emitter coupled logic)? This PFD will be used in pll. all I've seen was designs using 2 DFF's, but all were designed for CMOS... Thank you
Better check the PFD (phase-Frequency-detector), which accepts reference clock as its input, in the pll to see if it uses sine wave or TTL/CMOS square wave.
Hi All, I am new to the analog/RF IC design. I am desiging the phase frequency detector for pll. I need to design a D flip flop for the phase frequency detector. Could someone please provide me a simple CMOS D flip flop circuit to start with ? Thanks in advance.
It is output of phase detector, i think. Btw, what do you meant by "I did not use any fitler"
for FM demodulation: If modulation index is low (max. phase deviation less than 1 radian), you could use a narrow-band pll as a phase demodulator. The output is the ouput of the phase detector, that after derivation gives the frequency. This can work for low-index FM but (...)
Only to the extent that the loop is responsible for the spurs. From fluttering about the edges, I see some components of phase noise that are internally generated (esp. supply rail activity and phase detector signal risetimes, these create small jitters and close-in phase noise that the loop can only (...)
Most pll literatures seems to spend a great deal on the behavioral level analysis to determine best behavioral level parameters, for example, Kvco for VCO gain, Kpd for phase detector gain, etc., but say very little about the connections between behavioral level parameters and the ckt level (...)
Hello, all. I am thinking of using Analog devices AD9901 phase frequency detector for a multiloop pll design. This device shall be used in the coarse loop, stepping in 60MHz steps. I would appreciate if someone out there could share with me the following: What is the residual phase noise of AD9901, (...)
Some chips have a lock detector pin on them already, others you have to design one yourself. for the standard discrete phase frequency detector chip, you get pulses of random frequency out of the phase detector when it is not locked. You AC couple that to a shottky diode, and store the (...)
hi, CMOS current sterved VCO is giving 333khz at 0.5V input bias and 1.2GHz at 1.4V input bias. Due to this nonlinear behavior i am not getting stable output at the input of VCO that is the filter output has ripples and if the ripples is are upto 5mv then also the frequency changes very much. if i want to remove the ripples then ver
I designed a phase-Frequency-detector and an Charge-Pump, as blocks of a pll. And what parameters I should measure of this two blocks? The mismatch of Iup and Idn and the stability of the CP? And anymore? About the current mismatch, what method I should use? The method I used is to connect a dc voltage source with the CP ou
So far I used 4046, and there are a few tutorials for design with steps: calculating the loop gain and evaluating stability etc. for a charge pump phase detector like in 74hc9046 what are the differences in design? Could you please recommend a tutorial/ design method? [I need to know to calculate by hand, so I won't (...)
thanks for the help. I am using Hogge's linear phase detector for CDR. so I will need a charge pump as well.
V_e =out put voltage of phase detector(P.D.)θ_e=output pahe o PD.K_a=gain of amplifier.K_o=gain of vco & k_V=k_a×K_o×K_d & k_d =gain of PD
A Simple Precharged CMOS phase Frequency detector
I think you can use an LC VCO and include it in a pll. You need to adapt the pll, to lock to the input signal with a phase difference of 90deg. However, the majority of phase detectors have good linearity only for small phase difference. A pll using a type (...)
first , when most of the new pll use PFD or phase detector based on logic circuits like flip flops and so these components are discrete time not continues and for main stream design we use the S domain for the design and model the pll near lock state so we always make the refernce (...)
hi everyone, I am designing a phase detector for a pll. I use CMOS for my Gilbert cell. The problem is I cannot derive the expression of Vout as a function of the product of the 2 inputs (Vout = K Vi x Vo ). Anyone could guide me how to get the above equation? (all the documents I found are (...)
Hi, What is the differnce between Analog pll and a Digital pll. Is this only regarding the use of XOR gate as phase/frequecy detector in Digital pll and we use Charge Pumped PFD in Analog pll Thanks Shaikh Sarfraz
close loop response in pll is low pass filter with 3db cuttoff frequency, let BW be loop bandwidth so for the frequecy offsets at the output less than BW, the dominent phase noise here are beacuse of refrence noise, N counter noise, and charge pump noise, keeping large Kd phase detector gain and N small (...)
MSSN and safwatonline, thank u for ur reply. The lock detector will be used in a fractional pll. That means the phase difference between ref_clk and div_out_clk will be large some times due to the changing div_ratio. I want to have a solution which can detect locking with a certern accuracy. allow maybe 1/4 or 1/8 (...)
what type of phase detectors should be used for pll design at 6 GHz? pls mention the relative advantages of analog & digital type of phase detectors at this freq?
How to implement the time-tagging circuit and firmware, which has a gain of Kdet = 1bit/ns. This phase detector is for the Dpll, using the digital loop filter. Could someone kindly provide some materals about the time tagging circuit? Thanks in advance!
The lock range is determined by the tuning range of the VCO over which the VCO is linearly tunable and the output of your phase detector, whether it can tune the VCO over that tuning range. So ideally the lock range would be the smaller of the 2 ranges.
Synthesizer designers will find this tool useful for selecting the best HMC Divider, Counter, phase Frequency detector and VCO to simulate & achieve optimal pll phase noise.
for safety reasons you will have to use very low power. Here is one thing to try. Put a resistor between the source and the wire. Measure the voltage on the wire. Another thing to measure is the phase shift between the source and the wire. A phase detector as used in pll circuits can be used. If the (...)
Analog Devices has a free version that only works with its divider and phase detector ICs. This should give you some practice to decide before spending the funds for the general purpose program.
Hittite has made many excellent VCOs and phase detectors.
To amplify the previous post, have the pll operate at a multiple of the input clock. Use a counter in the feedback to the phase detector. Decode the counter states to get your clock phases.
You have two options. One is to use a pll with a VCO at the final frequency and a divide by five counter in the feedback loop to the phase detector. Ther other method is to use a nonlinear circuit to produce harmonics and then a band pass filter to get the one you want. for these higher harmonics, a step recovery diode (...)
use matlab for system simulation (S-Domain) to check stability of the loop first, then u can use matlab for transient sim. of the loop with swiching nature of phase-detector considered. NOTE: do not simulate pll with spice before system simulation or u will waste your time! BEST!
XAPP028 - Frequency/phase Comparator for phase-Locked Loops (12/96) XAPP Note
want to design a phase detector for 10G pll. is there any reference circuit i can learn?
What do you mean by PFD (phase-Frequency detector ...???) ? Anyways, there are many types of PD (phase detectors: 2-state, 3-state, etc. And each type works a little bit dirrerent for the type of data fed into the pll: RZ, NRZ , NRZ Square, etc. I've attached (scanned just now (...)