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229 Threads found on Frequency Synthesizer
Hi all I have a question about spread spectrum and its use with PLL synthesizer Let's say I have a clock source that is generating 100 MHz clock with 5000 ppm down spread with 33 kHz frequency modulation profile. Thus, the minimum and maximum frequency from this source is 99.5 MHz and 100 MHz, respectively. Then let's say I have a (...)
The coil and the 0.22uF capacitor to ground block high frequencies but pass low frequencies. If you know the cutoff frequency then the value of the coil can be calculated but instead maybe you should simply try different values and select the one that does what you want.
Hello, I am trying to design a frequency synthesizer with the use of the CD4046B IC which is a PLL. Based on some research I have done I see that this is possible with the addition of a divide by N counter in the feedback loop between the VCO and phase comparator input. Before doing this there are resistors and capacitors that have to be designed
Here is datasheet and it says "The TSA5512 is a single chip PLL frequency synthesizer designed for TV tuning systems." But from what I can see it's just PLL, and requires external crystal and puts out voltage according to phase difference between crystal oscillator and RF in. If I understood correctly, TSA551
Hi all, Just a general question of my knowledge of dividers. So far, I know that a "divider-by-2" (when the VCO freq is high, the divider by 2 is analog) is needed because its output signal gives 50% duty cycle and also the programmable digital divider (prescaler) can functions better with lower frequencies. Are there any other benefits in
I would like to generate fully differential quadrature signals of 950MHz using PLL frequency synthesizer from 1900MHz differential VCO with low power. Currently, I realize this by D-FF based on master-slave latch structure using CML. However current consumptions are fairly large. Alternate idea I have is using two D-FFs based on TSPC where o
I am using a Max2900 transmitter. This includes a frequency synthesizer that can be tuned in the 902-928 ISM band. It has 3 digital inputs to select the divide by ratio. How does this determine which frequency the transmitter is tuned at and what frequencies can this transmitter tune to based upon this?
Please help me out in resolving the issue with sine wave generation using DDS. How to generate 4 different sinusoidal signals with phase angles 0,90,180 and 270. How phase increment values are related to frequency. am designing my QPSK modulator for a clock frequency of 100 MHz. IP core has been generated for DDS, hw to make it work efficiently for
You can design a frequency synthesizer (which just multiplies frequency) .. Or you can design AM or FM detectors via PLL ..
i am using adf4153 in that for single frequency 1800MHz my code is locking.whereas if i change the frequency to 1810MHz i have program R0 register and restore the new values to how i have to store the new R0 value to the old one
Dear everybody, I am wonder to know whether some frequency synthesizer IC are available in market to be able to dynamically reconfigure (change) their operating frequency)? For instance, Suppose that I have a digital design operating at 600MHz frequency that has 1.67 nsec clock frequency. I wan to (...)
hiz to all can anyone tell me about the DDS interfaced with microcontroller? i just need a system which can change its frequency based on control word generated by the Microntroller on DDS. Hop count per sec is not finalized yet. the frequency band will be VHF/UHF and 2.4ISM. Waiting for help
Hello, What is Input Channel and Output channel of PLL frequency synthesizer (ADF4112BRUZ), how can i get it from PIN DIAGRAM.
Hi, I want to design a frequency synthesizer circuit, freq_center=4900MHz I recommend using ADF4108 IC Could you help me design schematic of this circuit. Thanks in advance :-D
I want to design a frequency synthesizer using DDS Output frequency should be variable between 45KHz - 55KHz. with minimum frequency step of ~10Hz or less. Is it possible to design such system using DDS ? Or what else can I use? Please reply ASAP. :-| Thank you in advance !:-)
Hi, I implemented a integer-N pll based frequency synthesizer but it takes 2m second to lock at desired frequency. But my adviser didn't accept it. Now I want to use DDFS but my project's details are as below: 1- output frequency between 880 MHz and 912 MHz 2- reference frequency 880 MHz or 900 MHz (...)
I need a sine wave signal for my circuit, and frequency is in the 100Hz to 5kHz range. I don't need very high output voltage/power, but the phase noise should be low. I check the frequency synthesizer ICs from the major manufacturers, but their frequency is always too high for me (hundreds of MHz to GHz). Can anyone (...)
Hi, I'm simulating a PLL based frequency synthesizer using dual modulus prescaler. I know I should divide output with MP+A while A is programmable down counter. The theory is "N=A(P+1)+(M-A)P=MP+A". I found a control logic as below to realize this. My question is how to implement "+A" in divider? I mean I can divide by MP but what about MP+A? [A
As far as I know. Lock time only applies if you are using a PLL. The DDS by design does not have a lock time. The time it needs to change the frequency is just the time to update the phase increment register. Which is added to the phase accumulator on each clock pulse. frequency changes immediately . Some DDSs update this register on the overflow o
That LT part requires you to program your divider using the SPI interface. Is that fast enough to meet your 500 uS requirement? That's in addition to the lock-time of the PLL, which depends on your filter, frequency step size, etc.