We are encountering a lock problem with ADF5355 when we bypass the AUTOCAL to generate look up table for faster lock times.
We found AN-1353 application note that include bypass VCO Calibration for ADF 5355. This note is explained VCO Readback procedure in detailed. We follow this procedure to obtain VCO core band bias, but we don’t achieve lock signal output of ADF 5355.
This loop is repeated as required.
A common problem is not waiting enough time for the VCO band select to have picked the appropriate band. Approximately 3 ms should elapse before reading back the band.
Thanks for your reply.
I don’t understand exactly where to wait when apply readback procedure.
We benefit from AN-1353 Application Note page 3. In page 3, we follow VCO readback procedure steps.
Step 2 say that “Wait until MUXOUT outputs a logic high”. Should I wait this step approximately 3ms, after MUXOUT outputs a logic high?