AnsweredAssumed Answered

HMC703 can't be locked

Question asked by lgq1225 on Nov 1, 2017
Latest reply on Nov 15, 2017 by lgq1225

Hello,

I am using HMC703 for a design.After powering up the board,I use Hittite USB Interface to make the HMC703 locked first.Then i pull out the SCK,SDI and SEN and connect them to FPGA board.Then I can control the HMC703 by FPGA board,such as changing the frenquency and turning to sweep mode.However,when I use FPGA board to control the HMC703 first after powering up the board rather than using USB Interface first,I can't lock the HMC703.By the way ,CEN is always connected to 3.3V.

Now that I can write HMC703 REG after it has be locked,why can't i write it when it has't be locked ? And how can i make it lock after powering up?

The REG i write are as below:

01000002

02000001

05DEADBE

06003D1E

07104845

08036FFF

0935FEFD

0A000076

0B01E071

0C000019

0D8444C0

0E000000

0F000001

03000016

04000000

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