BQ24161 Output Current

Hi Joel,

Assuming your input source is 5V and can supply 2.5A (setting input limit to 2.5A), you can get 2.90A to SYS at 3.7V.

This can be calculated using the efficiency curve that is available on the datasheet.

Procedure:

VBATREG default is 3.600V.

If VBAT<VSYSMIN AND charge enabled, then VSYS = 3.7V

If no battery connected AND charge disabled, then VSYS = VBATREG+3% = 3.600V*1.03=3.708V

VIN*IIN*(efficiency)/3.708V=ISYS

In this case, efficiency is said to be around 86% close to 3A.

Thanks,

StevenB

Hi Steven,

Thank you very much for your answer. The BQ24161 is a fine device.

Anyway, our GSM design application specs are evolving. For cost reasons we should try to use a cheaper device tan the BQ24161. The idea is:

- Using only one Vin input of 5V.
- Supply the 2Amps. peaks that the GSM module needs using the battery connected in a BAT pin.
- In the case the battery could not be assembled, we would supply the peaks using capacitance.
- Select the charge current for the battery.
- Select the input current of the chip.

Please, could you suggest some cheaper devices wiht a Power Path integrated that could fullfill those specs?.

Best Regards,
Joel

Hi Joel,

Yes, the bq24251 can work for your solution.

Thanks,

StevenB

Hi Steven,

Thank you very much for your answer. I've been reading the datasheet and I think I'll use the BQ24250.

Best Regards,
Joel