• ADF4157 and ADIsimPLL

    I just downloaded the REV A specification for the ADF4157. I see it has a fast  lock mode along with the CSR. It does not appear that ADIsimPLL 3.1 supports the  ADF4157 in fast lock mode. Is this true or am I missing something  here?

  • ADF4157 problem


    I used ADF4157(fractional mode) with OP27 to control the VCO(DCMO190410)

    I found that some noise were running on the Fout(desired frequency) its like modulated signal.

    my design rule  as below

    loop bandwidth=40KHz

    phase margin =45 degree


  • ADF4157 Phase Issue

    Dear Sir,

    I had a question for ADF4157 and please see the attachment.

    While I had write all registers and why the phase seems shift the 90 degree??

    Thank you.

  • Using ADF4157 at 6.3 GHz

    Noted that the ADF4157 datasheet is specified only to 6GHz.  I would like to use this chip with an external 6.3GHz VCO for a room temperature application.   Is there any reason this chip will not fucntion in this application?  If so, what are they besides…

  • User Guide of ADF4157 EVB

    Hi there,

    Good day!

    Is there any user guide of ADF4157 EVB available, which is similar to ADF4158’s UG-123?

    Moreover, I also wonder whether ADF4157 EVB is using USB interface to PC.

    Thanks in advance for your great help!



  • ADF4157 Channel Spacing


    From what I can  see, the channel spacing can’t be set at desired increments as the denominator is fixed at 33554432. As stated in the data sheet, the resolution is REF/33554432. So, for 62.5KHz channel spacing I guess I have to work out the codes…

  • ADF4157 Digital Lock Detect problem


    I have a ADF4157 with the configuration shown in this screenshot

    when I probe the output signal with the spectrum analyzer I can see a clean spectrum, however the Digital Lock Detect is not asserted at the MAXOUT pin. Any idea what config has been…

  • Query about ADF4157 Sweeping Frequency

    Hi, there

    I have a question on ADF4157 when sweeping frequency. PLL output frequency band is 5.8GHz ~ 6GHz. Sweeping step is 1MHz or 2MHz with fPFD of 10MHz. When measuring the output of sweeping, there are glitches available at every 10MHz when sweeping…

  • Digital lock detect problem on ADF4157.

    I am using the ADF4157 fractional N PLL chip and have observed some strange behavior in the digital lock detect.

    First, the operating conditions:

    1) Frf = 1.68GHz

    2) Fref = 12MHz

    3) Fcp = 12 MHz (phase detector freq is the same as the reference clock…

  • ADF4153, ADF4153A, ADF4154, ADF4156 and ADF4157 Software

    The latest ADF4153, ADF4153A, ADF4154, ADF4156 and ADF4157 evaluation board software is attached.

    Windows XP, Vista, 7 compatible.

    • v4.5.0: added improved prescaler warning.