DRV8813 / about parasitic diode of internal FET

K.Yaita

Hi Team,

My customer put Zenor Diode on VM to prevent VM rising because the phase current could be charging back the supply(VM) when the motor is running along with huge mechincal vibration.

In this case, I recognize it is possible that the current flow through following route.

Is my understanding correct?

If answer is yes, I'd like to know how much current is acceptable to flow through the parasitic diode of internal FET.

Is there any absolute maximum current value?

Best Regards,

Yaita / Japan disty

over 9 years ago

0 RE over 9 years ago

TI__Mastermind 20985 points

That is the correct current path. For more info on this, see the blog at: http://e2e.ti.com/blogs_/b/motordrivecontrol/archive/2013/12/13/art-of-stopping-the-motor-vm-pumping.aspx

It is common practice to use a TVS diode for this purpose. I'm not sure about the max possible current through the internal body diodes.

Best regards,
RE

0 K.Yaita over 9 years ago in reply to RE

Guru 29690 points

Hi RE-san,

Thank you for your precious advice.

Could you ask the value of max possible current to your motor driver team?

My customer concerns if device could be damaged in the case of VM pumping.

Best Regards,

Yaita

0 RE over 9 years ago in reply to K.Yaita

TI__Mastermind 20985 points

The body diodes of the integrated FETs can handle the max current the design is specified to, which is 2.5A in this case.

Best regards,
RE

0 K.Yaita over 9 years ago in reply to RE

Guru 29690 points

RE-san,

Thank you for your support.

I understood.

Best Regards,

Yaita

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DRV8813 / about parasitic diode of internal FET