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UCC2813-4-Q1: Specification Question on Startup Current

Part Number: UCC2813-4-Q1

Question from customer:


The data sheet contains the following information:



The typical value for the start-up current is 0.1mA, maximum is 0.23mA.


Does this mean that the controller can be guaranteed to turn on from 0.1mA to 0.23mA, or that a maximum start-up current of 0.23mA is required, worst case, to turn on the controller?


I would interpret this spec that worst case the IC will draw 0.23mA while below the UVLO threshold/start threshold for q current but if the device is actually going to startup then I would reason that the worst case current to do this would be 1.2mA based on the "Operating Supply Current" spec parameter.

Please confirm or correct.

Kind Regards,


  • Marc,

    Thanks for the interest here.

    0.23mA is the maximum the IC will draw over temperature when below UVLO start threshold under the conditions specified. You need to go above UVLO start threshold to turn-on. To actually startup yes it will require more than this startup current specification. Note though that 1.2mA max operating current is not switching. Switching frequency and cap load at output will dominate the operating current. But those are variables different from use case to use case. 

    Let me know if this answers the question.



  • Thanks John,

    That should be sufficient.  I will run by the customer first before closing out the case.