• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 63 subscribers
  • Views 1790 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.

OTG+Charging

Abhishek Gupta4
Prodigy 90 points
Other Parts Discussed in Thread: BQ24140, BQ24045

Hello,

I have Xiaomi RedMI 1S smart phone. I want to use OTG support while charging. Going through many reference online I found that there is a resistor value for it. But i found that it only work in one way charging or OTG. If i use external battery management IC then it would be possible to use both Simultaneously?
I found resistor range 110K to 130K that i have figure out.
Please help me to do that.

  • 0
    TI__Guru**** 166626 points
    The only battery charge IC which TI makes that allows simultaneous charging and OTG is bq24140.
  • 0 in reply to Jeff F
    Prodigy 90 points
    But the phone has already a management IC. What i'm trying to do is that i need to charge phone in OTG mode. Do we have any option or any external circuit that enable both function.
  • 0 in reply to Abhishek Gupta4
    TI__Guru**** 166626 points

    The charger uses the same switching FETs when charging from input to battery and from boosting from battery back to input.  If you need an additional 5V boost rail when input power is attached, then you will need to add a boost converter IC.

  • 0 in reply to Jeff F
    Prodigy 90 points
    @jeff Sorry i didn't get it clearly. I don't need additional 5V rail, I need to charge same phone with OTG function. In OTG mode it can only draw power from battery. So after some time i need to charge my phone, But that time i'm unable to use OTG. So I found two method to do it,
    1. there is a resistor value B/W 4 and 5 pin that can enable both function simultaneously but cant get exact value but found range (OTG<110K-130K<Charging)
    2. It may be a short of Jugad what I think that By using phone in OTG mode and put an external battery charger (BQ24045) to power that phone from battery input. So in this way i can charge battery as well as OTG same time.
    But i'm not sure that it is safe to direct power from battery input.
  • 0 in reply to Abhishek Gupta4
    TI__Guru**** 166626 points
    I do not understand what you are trying to do. I know that all of TI's chargers work in either OTG boost or buck mode. They cannot work in both modes simultaneously. If you have a 5V input applied at the charger's input, you will see that voltage at PMID because there is only a FET between the input pin and PMID pin. Any current you pull from PMID while in buck charging mode will not be available to power the system output or to charge the battery.