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HMC704 using external VCO with Eval Software

Question asked by tewasch on Dec 27, 2017
Latest reply on Jan 12, 2018 by tewasch

I'm trying to use an evaluation board for the HMC704 to experiment with the HMC733 VCO (10-20GHz).  I have div-by-4 in the feedback path of the RF.  I modified the board to support a larger VTUNE analog swing (up to 22V).  This all works with my own custom software controlling the evaluation board; however, I'd like to use the evaluation software provided (it has more features).


I have downloaded the software and USB driver.  I load the register file provided, but this is for an on-board VCO.  I never get a "lock detect" status.  Instead, it always reads "UNLOCKED" in red.  I have tried to simply lock with an R=1 (50Mhz), and N=55 which should lock to 11GHz but nada.


Are there ways to get or create a default register set appropriate for this test case?  I have tested that USB turns on and off the chip enable; however, is there a better way to test USB communications?


Thanks,   Tom.