ul component failure tests on LNK 409

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We have applied for UL certification for our LED drivers based on Link Switch devices using the reference designs RDR195, RDR 193 and DER286.  UL Engineer insisted the following component failure tests on the LNK 409 , LNK407 and LNK405 ICs .  Kindly let me know whether the below tests are suggested or recommended. If these tests are not recommended please explain so that we can convince UL people.


1.       1. Short the pins 7 and 5 during normal operation of the driver.

2.       2. Short the pins 2 and 3 during normal operation of the driver.

3.       3. Short the pins 1 and 4 during normal operation of the driver.


Please let me know what will happen if the above SC tests be conducted. Whether IC will survive the above tests?

Is it possible to measure the voltages between pin 1 and pin 3 of the LNK IC? Waiting for your prompt reply.



Stalin DM 





Kindly contact your local FAE for immediate support and faster response. Let me know if you unable to do so.

Trying to get support from Local FAE. Please let me know your comments on the issue  so that I can go back to UL people immediately.

Shorting adjacent pins of the driver IC is a common and standard safety test. However, I don't expect any IC failure from the tests you described. The unit may turn-off, the fuse may blow (which is the case for shorting Drain-Source-pin 7 and 5).

Can you describe the failure mode? What is happening to the units and why it is failing UL certification?