AnsweredAssumed Answered

Problem with LT3999 start up

Question asked by payam@vpg on Apr 23, 2018
Latest reply on Apr 24, 2018 by DONGW

I have an issue with LT3999 in one of our products. Basically the Soft Start functionality is not working as it is described in the datasheet. Based on datasheet a 6.8uF capacitor on pin 9 (Ilimi/ss) should make startup time around 544ms. But I can see that it starts working right after Vin reaches to UVLO threshold.

Any suggestion regarding why this doesn't work properly and/or how we can suspend safely start up for about 500ms?

 

Thanks,

Outcomes