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DRV8323: seperate supply for DRV8323

Olrik Maier
Expert 5020 points
Part Number: DRV8323

DRV8323 cannot drive normal Level FETs in case the DC link has gone down to e.g. 7V

 

What would happen in case we would build in a step-up Converter to Supply the IC with minimum 13V?

 

In that case we would have enough Voltage to allow operation of the normal Level FETs.

 

But then we have the problem that the PIN VM of the IC is higher than the PIN VDRAIN.

 

è  Will it cause some issue e.g diodes conducting in the Chip

è  Will VDC monitoring work?

DRV8323_extDC.pdf

Best wishes,

Olrik

  • 0
    TI__Guru 65390 points

    Olrik,

    This will work in theory.

    Assuming 13V on VM, the internal charge pump will give us 11V with respect to SHx which makes it ~18V. The High Side VGS clamp diode will limit the VGS to ~16V which will fully enhance the FET. As long as the selected FET has an ABS MAX VGS of higher than 16V, we should be fine.

    Regards,

    -Adam

    EDIT: 11/30/18, we discussed this more among the team and will be doing some lab testing to confirm a few things. I will post back here once we have our findings.

  • 0 in reply to Adam Sidelsky
    TI__Guru 65390 points
    Post above Edited.