FAN5333BSX heat dissipation issue

Semiconductor Integrated Circuits (ICs)
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1

Dear Sir/Madam,

We use FAN5333BSX for a LCD backlight driver; it worked well before. However, the new ICs FAN5333BSX (laser mark: 33BL, ordered from digikey) used in recent product samples are very hot, and some of them burnt in a couple of days, and some ICs do not have outputs. After I changed it with an older FAN5333BSX (laser mark: 33BK), it works great, not hot at all. I think this new batch IC with laser mark 33BL has heat dissipation issue. Could you please confirm it with the IC supplier and how can we figure out this issue? We will do mass production soon and need this GOOD IC badly.

Thanks.

Bill

2

Hello @Bill

Thank you for the question. I was not able to verify the differences in the part markings you are describing. I have reached out to my rep with On-Semi to see if I can get any information on the differences or issue you are having. As soon as I hear back I will post the information here.

Thank You
-Robert

3

Thanks Robert.

Bill

4

Hello @Bill

On-Semi did not provide any informaiton on the different markings however, suggested the following.

"In such cases, when there is a quality issue, it would be the best to return the parts to the supplier for failure analysis. Please contact our quality center, for the USA it is QCenter_AMERICAS@onsemi.com email. Whole return process is described in following pdf: https://www.onsemi.com/site/pdf/CAT_Returns_FailureAnalysis.pdf