• RE: LTC6948-2 ,I can read from LTC6948-2,but I cant write in LTC6948-2 register.


    Are you using the LTC6948 eval board, FracNWizard, and DC2026 (USB to SPI board)?  Or are you trying to write to the part using your own software and hardware?  Can you send a plot of your SCLK, SDI and !CS signals, so I can look at the timing?

    To write…

  • How to Set LTC6948 Integrated Circuit Integer Mode

    Have a good day.


    I am developing a project on stm32f407 with LTC6948 integration.

    I generate frequency between 2000-2500 Mhz with 5 Mhz difference. 

    I am using LTC6948 fractional mode

    LTC6948 Register Values

    LTC6948.h01.TLO = 0;                   //CP Clamp Low Flag

  • LTC6948 non-simultaneous 3.3V and 5V


    Is it mandatory to power up the PLL LTC6948 with 3V3 and 5V at the same time?

    In other words, can we reset one of the supply while the other is still on?



  • RE: LTC6948 issue detection using Demo circuit DC590B

    Hi Claudio,

    Is this on the DC1959 eval board?  Or on your own custom hardware?

    It looks like the FracNWizard is reading back a high state for all SPI registers (i.e. all 1s).  The way the FracNWizard detects the LTC694x is by reading the PART field in register…

  • LTC6948 vco output frequency offset in Fractional-N mode ?

    Hi all,

    It is the question about the output frequency offset of the LTC6948.

    Integer-N and Fractional-N PLL Synthesizers

    In Fractional-N PLL Synthesizers,
    We think due to the architecture of the Σ-Δ modulator, there is a fixed +(fPFD/2**18) offset on the…

  • LTC6948 - impedance of the RF+/- differential lines?


    We plan to use the LTC6948-3 with a 5GHz output, using a balun to produce a single-ended output.

    I have a few questions regarding this:

    - The HHM1570B1 is out of stock and we have decided to go for the HHM1595A1 which has a wider band at the price…

  • LTC6948's SDO Pin


    If the LTC6948 is not used in a multi-drop configuration, the datasheet recommends a high-value resistor of greater than 200 kOhm between the SDO and GND.

    However, since Ioh = -19.5mA (max), I think that there is no problem if the resistance value…

  • ltc6948能实现FSK控制嘛?


  • LTC6948-2 unlock

     i use register as follow,but it does not lock , the ref is 40M,pfd is 20M  output frequency is 985M,integer mode , how can slove this problem