• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 477 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.

BQ24079: BQ2407x what if ILIM > 8kOhm

Karoly Pados
Prodigy 45 points
Part Number: BQ24079

BQ2407x chargers specify that the maximum R_ILIM resistor value must not be larger than 8kOhm, which essentially sets a 200mA input current limit.

The charger though can obviously handle a smaller input limit (100mA) in USB mode (EN1=EN2=0). My question is, what are the consequences of exceeding the 8kOhm R_ILIM limit? Say, I set (EN2,EN1)=(1,0) and then I use 10.16kOhm (for 150mA) or 21,8kOhm (for 70mA) for the ILIM resistor. Would these configurations really not work or what negative consequences should I expect?

Thank you,

Karoly P.

  • 0
    TI__Guru 67476 points
    Hello
    For the condition R_ILIM 8k ohms, input current limit of 200mA and EN1 & EN2=0, input current limit 100mA (USB100). The EN1 & EN2 will limit input current to 100mA.

    Input current will support both charging current(BAT) and output current (OUT). Priority will be given OUT and BAT will be reduced as needed to support out.

    Low input current limit values make it difficult to charge and support output current.
  • 0 in reply to Bill Johns
    Prodigy 45 points
    Thank you, but these are already stated in the datasheet, and mostly in my question above.

    "Low input current limit values make it difficult to charge and support output current." - this doesn't really answer the question either because the bq24079 CAN charge at low currents like 100mA, assuming it is in USB mode. The question is, what are the consequences if I set the same limit (or even higher, say, 150mA) using the Rilim resistor.