LM3434 for LED application

WU YISYUAN

Expert 2165 points

Hi,

our product used an old chip LM3434.

Now have a problem.

We have a frequency flicker mode of dimming.

Frequency range from 0-20Hz.

Now the problem is, as long as I send a frequency flicker signal.
MOS Q2,Q10 was damaged, and IC LM3434 PIN14 also damaged.
What may be the cause?

Detailed parameters are as below:

Vin=12-15V, Vo=27V, Io=9A

thanks,

over 6 years ago

0 Irwin Nederbragt over 6 years ago

TI__Mastermind 28655 points

Hello,

How long has this design existed? This part is obsolete. Do you know if the failure is a timing, thermal or assembly issue? Most likely when Q2 and Q10 get damaged it damages pin 14 of the LM3434. This can be caused by shoot through, excess heat, poor thermal management.

Best Regards,

0 Irwin Nederbragt over 6 years ago in reply to Irwin Nederbragt

TI__Mastermind 28655 points

Hello,

I haven’t heard back from you, I’m assuming you were able to resolve your issue.
If not, just post a reply below (or create a new thread if the thread has locked due to time-out)

Best Regards,

Power management

Power management forum

LM3434 for LED application