• AD9551 question

    Hello,

    I am trying to program AD9551. Our instrument board has a AD9551 on it and the board design around AD9551 is as below;

    external crystal feeds 25 Mhz signal to external crystal input, RefA has 100 Mhz signal from board, RefB is not connected…

  • RE: Fractional N clocks

    PLLs typically fall into either fractional or integer types.  This type refers to the ratio of the input reference frequency to the output frequency.  If the PLL is capable of non-integer division then it is a fractional PLL.  Example of integer PLL is…

  • RE: Hardware configured PLL or Synthesisers

    AD9552 and AD9551 also is pin configurable in integer value.

  • Comment on AD9551_基准输入规格

    用单端源驱动AD9551的REFA或REFB输入时,有两个选择(推荐选择#1)。

    选择#1:通过一个0.1uF电容将未使用的输入去耦至地。

    选择#2:让未使用的输入悬空(不推荐使用,因为这会降低抖动性能)

    此外,建议让输入电压摆幅始终低于1.8Vpp,否则内部ESD二极管将开启,导致抖动性能降低。对于超过1.8Vpp的输入信号,应利用电阻分压器将信号电平降至1.8Vpp,并通过一个0.1uF电容将降低后的信号交流耦合到输入(AD9551的REF输入为直流自偏置)。

  • About the output of AD9951

    Dear Forum

       I refer the official manual to design AD9551 ,and my output filter is refer AN-837 as follow,

     now my problem is when my output frequency is 100KHZ,it output normally,but when my output frequency below 30KHZ,it  hadn't output,the signal

    at…

  • Looking for USBEvBdProgrammerSetup.zip

    I'm trying to get an old AD9551 Dev board to working on a win 7, 64 bit PC. However, it doesn't seem to recognise the device when it is plugged in. I have seen some online sources suggest that this is due to driver compatibility issues with win 7 64 bit…

  • RE: AD9552 cannot lock with 2 reference inputs

    Dear rocqip,

    The AD9552 was never intended to have two input references in this manner.

    I have a few alternatives:

    1. The AD9553 has dual inputs, but is an integer-N PLL.

    2. The AD9551 has dual inputs, but Fin should be at least 104 MHz for it to…

  • RE: fine frequency tunning for high speed ADC clock

    I think there is a typo in your question, but assuming you meant "We need to lock THE clock signal", then this could be a challenge do to without affecting SNR. 

    The devices we have that are capable of locking to such a low frequency are not…

  • TAGS LIST: Clock and Timing

    LTC6953
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    LTC6957-1
    HMC6832
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    HMC987
    AD9576
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    ADN4670
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  • RE: How to use AD9557 for Synchronous Ethernet?

    Hi Wojtek,

         Typical ethernet applications use a +/- 100 ppm frequency source to generate their local timing, usually an XTAL. Each ethernet node which generates its local timing from a local source is asynchronous with other ethernet nodes. The idea…