• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 63 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

BQ25895M: Design clarification

NIKHITHA ANTONY
Intellectual 340 points
Part Number: BQ25895M

I was added 261R resistor near the ILIM pin of the BQ25895M. So according to the equation  IINMAX = KILIM/RILIM, the maximum input current to the VBUS pin of the charging IC is 1.36A(ie, IINMAX = KILIM/RILIM = 355/261 = 1.36A) .

 Please confirm my assumption is correct or not.

  • 0
    Intellectual 340 points

    I have one more confusion. When we are connecting battery with 3.7 V, then voltage output at SYS pin of charging IC will be 3.7 V. And when there is no charge for the battery, power at the VBUS pin will charge the battery. Suppose I am supplying 5V at the VUS pin for charging the battery, and Voltage of battery is 3.7 V, Then also voltage output at SYS pin will be 3.7V.

    Please confirm my assumptions are correct or not.

  • 0 in reply to NIKHITHA ANTONY
    TI__Mastermind 46551 points

    Hi,

    1. Please use KILIM = 390 max. Referring to 8.2.12 Input Current Limit on ILIM  on the d/s, For example, if the register setting is 111111 for 3.25 A, and ILIM has a 260-Ω resistor (KILIM = 390 max.) to ground for 1.5 A, the input current limit is 1.5 A.

    2. When valid VBUS is present, 8.2.6.1 Narrow VDC Architecture applies. Figure 10. V(SYS) vs V(BAT) gives the relationship between VSYS and VBAT. When battery only, 8.2.6.3 Supplement Mode applies. When the system voltage falls below the battery voltage, the BATFET turns on to connect VSYS to VBAT.   Figure 12 shows the V-I curve of the BATFET gate regulation operation.

    Thanks,

    Ning.