• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 494 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS65217C switching between AC and USB at Dead Battery State

marianna zhu
Prodigy 30 points
Other Parts Discussed in Thread: TPS65217

TPS65217 technical document, Page 25:

"Dead Battery (1.5 V < V BAT < V UVLO )
Functionality is the same as for the shorted battery case. The only difference is that once AC is selected as the
input and the power-path does not switch back to USB as V AC falls below 4.1 V."


Do I understand correctly? Why does Dead Battery effect switching between AC and USB? This makes no sense.

  • 0
    TI__Expert 4005 points

    Marianna,

    That is correct. If a battery is present the limits for removal detection change:

    The device will still switch between inputs, the detection level for removal is just lower.

  • 0 in reply to Gregory Watkins
    Prodigy 30 points

    I see.

    When the battery is absent and both AC/USB are available,  power-path will switch to USB when AC drops below 4.1V. This threshold is fixed and not mentioned in Electrical Charateristics Table.

    When the battery is dead, the threshold is Vuvlo+Voffset. That means power-path will switch only when AC drops below Vuvlo+200mV, even AC is much lower than USB.

    Thanks.