LM3478 / DR voltage if Vin is open

K.Yaita

Guru 29690 points

Hi Team,

Could you tell me DR voltage if Vin is open?
Is it Hi-Z?
My customer concerned about open failure mode of Vin.

Best Regards,
Yaita / Japan disty

over 9 years ago

0 Doyel Ghosh over 9 years ago

TI__Intellectual 770 points

Hello,

Yes, if Vin is open, DR will be high-Z.

Regards,
Doyel

0 K.Yaita over 9 years ago in reply to Doyel Ghosh

Guru 29690 points

Hello Doyel-san,

I understood.
I appreciate for your support.

Best Regards,
Yaita

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

Guru 29690 points

Hi Doyel-san,

I would like to ask an additional question.
Could you tell me DR voltage if Vin<2.97V(etc.Vin=0V)?
Is it indefinite output state?

Best Regards,
Yaita

0 Doyel Ghosh over 9 years ago in reply to K.Yaita

TI__Intellectual 770 points

Hi Yaita-san

If we reduce the Vin below UVLO (2.97Vmax/2.85Vtyp), the device will turn off. The DR pin will be pulled low to zero. However, if we keep going lower, after a particular threshold output state becomes undefined. We cannot guarantee the value of that particular threshold, as it will vary from part to part. Hope this helps.

Regards,
Doyel

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LM3478 / DR voltage if Vin is open