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LM5069: deactivation of power limit?

Expert 5720 points
Part Number: LM5069
Other Parts Discussed in Thread: TPS2663,

hi, my question is similar to what is discussed in following thread:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1166241/lm5069-how-to-disable-current-limit-and-power-limit 

They want to turn off the power limt of LM5069MM-2 because they have problems when testing for EMC - that is not needed then.

Can you confirm that it can be deactivated with RPWR of 470kOhm?

Regards

Andreas

  • Hi Andreas,

    What is happening during EMC test ? with large RPWR values, we are basically removing the FET protection. Is that ok for the customer ?

    What is the application use case, system rating? Can you show them TPS2663 eFuse

    Best Regards,

    Rakesh

  • Because of  the EMC problem theydecided to use only the OV and UV feature of the LM5069. The current limit is disabled  by a “zero” ohm resistor, to eliminate the switch off of the LM5069. So there shouldn’t be an analog current limiting feature active by the LM5069 which would damage the FET because auf being too long in the SOA region. The system supply is 24V +/-20% and a maximum load current of 2A.

    They are in the end-phase of the project, where a change of the part isn’t possible. Just want to pass EMC requrirements.

  • Hi Andreas,

    Understood. They can use “zero” ohm resistor to avoid nuisance trips and high RPWR (470kOhm) to disable to power limit function. 

    Best Regards,

    Rakesh