• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 366 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.

BQ25890: Help for Device selection

AnBer
Mastermind 30110 points
Part Number: BQ25890
Other Parts Discussed in Thread: BQ25895, BQ25898

Team,

a) I am looking for a charge with the following specification. Do we have something that could fit?

The system will be mostly power from the Vin source. The battery (Li-Ion 3,8V 800mA) will only provide power when the Vin is not present (ie for emergency in case of main power failure).
The electrical specs would be:

Vin (4.5Vmin/ 10Vmax)
Vout 3.8V
I out : 3A min / 6A max when power providing from the Vin
I out:  2A max when power provided from Battery (no power coming from Vin).

Do we have a device that will has a BUCK to regulate the output to 3.8V in both scenario (with Vin present or from battery)?

The ideal solution would be like BQ25890 but with an Output that could be regulated to 3.8V instead of 5V. Is it possible with some of our BQ2xxx devices?

b) What is the closest/cheapest equivalent to LTC4040 (http://www.analog.com/en/products/ltc4040.html ) we have?

Thanks in advance,

Anthony

  • 0
    TI__Guru**** 165886 points
    Hi AnBer,

    Unfortunately, we do not have an exact match for LTC4040. All of our 1S LiIon chargers the SYS voltage to a minimum system value (up to 3.7V) until the battery voltage reaches that voltage and then SYS follows the battery up to 4.2V. Is a two chip solution not option?
  • 0 in reply to Jeff F
    TI__Mastermind 30110 points

    The goal was to use one DCDC less by having the regulated rails at 3.8V at the outpout of the charger.

    Now I am looking at an USB OTG compatible charger (to have a regulated 5V at the output).
    The requirement would be to have minimum 2A out of the BOOST when the Vin is not present.
    So far I found bq25890/2, BQ25898 that can support 2.4A and BQ25895 that can support 3.1A.
    -What other 1S LiOn charger do we have that can support 2A minimum from the BOOST?

    Thanks in advance,
    Anthony

  • 0 in reply to AnBer
    TI__Guru**** 165886 points
    Anthony,

    The bq2589x family is the best choice for 2A in OTG boost mode. Keep in mind that the 890/2 and 898 boost back to VBUS pin while 895 boost back to PMID pin.