LM5021: LM5021 sync function application problem

Hi, Clyde:

Thanks for interested in LM5021.  For the connection of LM5021's sync function. You may refer the connection as the previous E2E thread like below and hope it is helpful to you. 

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/391767/external-clock-synchronization-of-lm5021-pwm/1410280?tisearch=e2e-sitesearch&keymatch=LM5021%252525252520Sync#1410280

Regards, 

Wesley

I see the information in the link you are provided, the sync problem from 7 years ago is still not been solved. and his problem is the same as mine.

I used TINA-TI for simulating external clock inject to RT pin of LM5021, then I find the same problem occurs. that is the external clock can not synchronize the RT (original free-running frequency). I just wondering if the model of LM5021 of TINA-TI is real enough to show the real function. because I inject 5V, 100ns pulse clock into RT pin, the voltage of RT pin is still DC 2V, with no deviations on RT.

any suggestion?

OK, I'll try it by real testing. Thanks for your reply.