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UCC27624: Bias current spec

Part Number: UCC27624
Other Parts Discussed in Thread: UCC27524

Hi team,

While go thtough our LS driver EC table bias current spec, there is some different defnition between UCC27624 and UCC27524:



I am not so clear what the definition of 'startup current', what the difference between 'start up current' and 'quiescent supply curren'?


Best regards

Mia Ma

  • Hi Mia,

    IVDDq and IDD(off) seem to be nearly equivalent. The UCC27524 doesn't specify the state of EN, and is .1V different for the IN voltages. It is basically a measure of the quiescent current when the device is below UVLO and therefore not outputting. Some of the difference between the two is that the UCC27624 has smaller pulldowns on IN (120k instead of 400k). 

    It is basically a measure of the quiescent current draw of the IC, but it could also be called the startup current as this is the current before the device starts switching. The name difference is most likely just to bring the part in line with our standards. 

    In most applications, this difference is insignificant. Once the driver starts switching, that current will be far higher than the quiescent draw. If needed, the UCC27624's power draw could be reduced by setting INx to 0V, or lowering VDD more.


    Alex M.

  • Hi  Alex,

    Thanks for your helpful explannation.


    Best regards

    Mia Ma