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118 Threads found on Pll And Chip
You would have to route the source clock from the pad to the center of the chip, and that is not desirable. Think about the net delay. If you can place your design near the pll and that would reduce clock net delay significantly. Whereas if your pll is somewhere at the center of the (...)
Its the reference frequency for a pll - - - Updated - - - I want a Colpitts oscillator which uses an external off-chip crystal. I think your pll needs a stable VCO. What are the design specs?
hi I am trying to design a Fm transmitter with LMX2322 pll chip. Kindly explain the working principle of pll. How Phase and frequency is compared? How N and R counters values are selected in LMX2322 for VCO at 100MHZ and Local Oscillator at 12MHz? Regards
I want to use a pll IC with the minicircuits POS-150 VCO for an FM broadcast transmitter. All the schematics I find use very old chips that are only on ebay from china and maybe fake (TSA5511, MC145170, etc.) I want a new chip that I might be able to get from a reliable source like digikey or mouser that would work for (...)
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 (...)
Usually there is driver chip under the pcb. Often it is member of LB18XX family from Sanyo. It needs clock signal so pll (part of the driver ic)can lock onto it. First step is to carefully remove rotor then loose pcb screws and try to read driver ic part number. In datasheet you will find clock signal range and (...)
if a periodic pulse has a known width and repetition rate and you wish to synchronize a clock to this pulse rate, a pll chip such as CD4046 using Type I XOR mixer if VCO is close to required frequency and filter bandwidth allows capture range required. If working to 1ns pulses, then special (...)
Your problem indicates the pll is not stable. I think you should look for these possible reasons: 1. Injection pulling, due to high power matching frequency source nearby. 2. Unregulated power source with noise. 3. Defective chip. 4. Defective crystal. 5. Improper antenna size. 6. Error in register settings. 7. EM interference.
As a beginner you can try to assemble some simple FM pll radio. It would not drift of your station. Such radios has one chip for stereo receiver, microcontroller to control pll and pll chip. Radio modules with TEA5767 chip are available on ebay. One of such projects just (...)
only a ham would consider a "bang bang" pll. How about just getting a modern pll chip and using it properly?
I have been having trouble getting a Maxim MAX2769B chip to work on a protoboard. I'm hoping someone here has worked with one of these before. Basically I have tried mounting several to proto-advantage boards. The latest one I took extra care to mount all mount all of the decoupling, AC coupling, DC blocking capacitors and the pll CRC filter (...)
I think of MC1496+pll Feedback form could produce FM signal, due to pll chip lack some compensation .
hi, everyone i got a few questions about a pll datasheet.The image is part of datasheet 1.what's the difference between average period and absolute min period 2.what's the difference between rise time and rise time variation 100931 Thanks any help in advance
it probably varies for individual types of pll chips what is the pll chip you want to use, I would assume that info would be in the datasheet for the said chip Dave
anyone have experience with this chip. Programming the registers is pretty wonky... have to go much slower than data sheet, double and triple load the 5 registers, etc. sometimes program R1 alone, the reprogram all 5 registers before they "take". wondering if I have a bad batch of boards, or it is just a non-standard SPI implementation? (...)
If you only need it for ADC clock would be better to include a pll to boost freq. Putting a single ended 500 MHz into a chip from outside will likely have jitter degradation. Also would have poor duty cycle predictability. Jitter performance for ADC is usually strick and poor jitter means poor ADC noise floor. I doubt, that an on
I wanted to start designing some polar feedback systems using a pll for phase correction, but I really want to avoid using a digitally programmable pll. I'm able to use microcontrollers and such, but I really don't want to put one on a PCB for the soul purpose of programming a pll once on power up. So I was hoping to (...)
Dear all, I need a signal near 100MHz,the general method is to design with pll.But, my requirement of frequency stability is not strict,20ppm or 50ppm is accepted,also my requirement of PCB size is strict. 1)my first choice is to find a fully integrated IC including pll and VCO, and N/R divider is also (...)
To avoid pulling I select offset pll structure. But at fractional frequency the on-chip PA deteriorates pll IPN so much, larger power out worse IPN. At integer frequency it's OK. In open loop test the VCO performance doesn't change. If does PA affect N-divider, PFD or CP's linearity? What's the path and mechanism? Thank you.
maybe you could rephrase your question, as it does not make any sense to me. If you have a vco that has a tuning range of 0 to 3 volts, and you connect it to a modern pll chip with a charge pump output, with that pll chip running off of say 3.3 V DC, then the pll phase detector will (...)
Hello~ I'm doing sth on pcie with the chip of altera cyclone IV (EP4CGX22F14C7 actually). The pcie core uses transceivers for the RX and the TX differential signals, and the 3rd couple of differential signal ,refclk, is used to clock the transceiver partially. Inside the FPGA, the refclk should be routed to a Multipurpose (...)
dude! the internal pll for the PIC18F4550 ONLY generates 96/2 MHz from an 4 MHz input!!!! but you can divide your actual oscilator to get this 4MHz so you can use a 4,8,16,20,24 MHz crystal, divide it (with CPUDIV) and get the 96/2 MHz i don't recommend to put a 10MHZ and pll...
What Shaiko said, and also btw the device on the right is a pll chip, and only the prescaler portion of it is being used. It was described in another thread that I noticed a while back : However, that i.c. is quite hard to find now. I'm planning to do something similar, but plan to use a different device,
Hello, I have seen several broadcast FM pll designs on the internet. I have seen two basic types. One that uses a microcontroller and LCD and another one which uses DIP switches and a pll chip like the MC145151 to set the frequency. I have red somwhere in the past that DIP switched (...)
Hello, I want to design a pll based oscillator. I am using ADF4157 as synthesizer and AD797A as active filter OPAMP. Schematic of the structure is as given in the attachment. I operate the opamp by supplying Vs+: 15V and Vs-: GND ; Vin+: GND I am sure that ADF4157 is working correctly but I see 14V at the tuning port of (...)
Hi Guys, I got a design(without pll), which includes a "clock generator" driving the whole chip. The "clock generator" has one clock root and generate many clocks by using different logic circuits, especially there is no divider circuit! In other words, only logic gates in this subblock, but the combinational circuits look not simple!!! (...)
You are going to have a hard time making a pll without using a pll "chip"! If you could use a pll chip, you would choose one with an onboard charge pump. Then you could set up a passive loop filter with a narrow loop bandwidth (perhaps 2 KHz bandwidth) (...)
Technically speaking, a clipped sine wave output is capable of better phase noise than a cmos or "TTL" output. So if you are buying a very expensive TCXO and trying to make the best pll possible, that would be the way to go. In most cases, though, it will not make a difference. If you are using a modern pll chip, the (...)
Hi I have 2 board with same configration except first uses SPI1 of STM32F103 and second uses SPI2 and I also use USART3, I connect first board to a pll circut (ADM4106) and it configures it and pll is locked and so well. But with second one Nothing happen what so ever (...)
You can't use just one pll for making a PSK modulator. There is a possibility to use two synchronized pll's (working as phase/frequency modulators) with summed outputs, and a phase shifter.
Hello, You don't have to use specific pins for SDR SDRAM (except for the memory clock where you'll use a pll output pin).
give some ideas about the diffrences bettween fpga and asic : : the resource -> (especially to the fpga realization), u need to consider the resources that the fpga chip can use(eg: FFS/Memory bits/adder/multiplier/pll), so u need to be carefull of the number of the above resources your coding will occupy when after mapping to the fpga (...)
Hi, What is the frequency of your square wave ?. What you can do is make a pll with an NE567 chip that is tuned to this squarewave frequency and if you put the output IR signal into the NE567 input you will get a stable and nice signal on pin 8 ONLY when there is a sqware wave frequency on the input of the sensor due to (...)
Probably it will work, but loading the initial loop filter and CP output definitely some performances as phase noise and spurious emissions will degrade. Actually the first combo chip pll/VCO appears about 35 years ago (CD4046), which is still in production.
FR4 is a very poor choice for 7 GHz! To have a prayer of working, I would make the microwave traces as short as possible. I would eliminate R15, R16, and R17, for instance, as they do very little. You can make R13 a larger value to act like an attenuator. I would lay it out to put the VCO output very close the the pll chip input. Keep (...)
Hi, I am working on a prototype pll, and before implementing it in ASIC CMOS technology I would like to build one using off-the-shlef components. A VCO can easily be found in analog plls, with tuning voltage input. I also need a classical Charge pump with up, down inputs. Do you know any commercial chips providing such a (...)
You probably want this divider: You MIGHT be able to find a single chip cmos divider somewhere, like using a UHF pll chip from analog devices, ignoring the pll part, and just using the test pins to get at the programmable counter part. Unfortunately, these "dual modulus" counters ty
hello programmers, i am in need of some code for a 16f84. i am trying to control a pll chip. I need a 7 bit up / down counter that is stepped by rotary encoder on porta input pins. and displayed in binary (led's) on portb output pins . i need it to start at 0 and count to 127 (0000000-1111111) then reset back to 0. i also (...)
I have a question on the reference frequency crystal that is used for the pll and baseband logics. In integrated transeivers with both RF and baseband modem circuits on the same chip, do they use a single crystal? For instance, pll uses a crystal for the reference clock. Is (...)
hi is there a way to phase lock the pll input to its output when using the pll for frequency multiplication? can we guarante the input and output edges to be in a fixed relationship in the aspect of static timing? does it depend on the pll or FPGA chip, or we never can lock it? I am asking this to (...)
What package are you using? Have you tried to get a model from the package house and simulate your output driver with it? Moreover, your power supply pins are as important as your signal pins, their inductance might affect the performance of your pll and should be included in the simulations as well!
Hi guys, I have a on-chip pll runing at open loop configuration,i.e., I broke the loop filter from the loop. and I just let the input of vco be connected to the board via a pin so that I can adjust the vco output frequency from the board. If I plug the vco output to a scope and see its eye, I found in the open loop (...)
You will need to look at the datasheet for the configuration settings. Every device is different. The 18F4550 has a pll and therefore has lots of possible oscillator configurations. r.b.
Hi,I am using this chip Cdcs502 from Ti.I am running a 27Mhz crystal and connecting Capacitor load of 35pF ,with FS=0,the output is a clock pulse with 0.8 low and 2.1 high,i think this is fine.But the problem is when i do FS=1,the frequency gets 108Mhz but the amplitude becomes very low , the peak to peak amplitube is 800mV having a DC (...)
after tape out, one chip's pll is 'out of work' sometimes. for eg. fin=35M/s, fout=280M/s,my pll is simple with pd,chp,vco,and 1/8 devider for comparation with fin, even without lock check circuit. I can test ck_out by 1/4 divider. that is 70M/s, sometimes it is well meet, sometimes it will go to 60M/s. each times i power (...)
Please help identifying this Tuner IC. It is a single chip pll TV tuner IC with SDA/SCL. Xtal is 4.0MHz.
Hi Looking for TV Tuners having Difgital pll control. Can you help providing TV current make and models which have those tuners? and also of which pll IC programming details are available. Thanks.
I am using Si3050 DAA with Si3019 Line Interface Unit. Si3050 takes a 2 Mhz and an 8 Khz clock for pll to start working. The problem i am experiencing is, Si3050 wont lock pll except when we touch Oscilloscope probe to the clock (8Khz). The moment we touch the probe to the 8Khz clock it gets locked and the (...)
Hey, I'm looking for a programmable pll chip for clock generation. I need two clocks running at "fc" and "fc+50kHz", in which "fc" need to be programmable in the range of 1~10MHz. I found LMK04000 from National Semiconductor, which gives great clock performance but the minimum programmable step is about 500kHz. Thus I need external (...)
Simulate a pll and then you will only learn it, there are so many details that you will learn in the process. You will be surprised.