BQ24171: USE of Q1,Q2 & Q3 in the charging Circuit?

Hi Kalariya,

Q1 provides reverse blocking so that the battery voltage isn't seen at the input when no input power is provided. It can be replaced with a Schottky diode. Q2 and Q3 are needed if your application needs power path so that input is provided at SYSTEM or the battery is connected at system but not both at the same time.  If your SYSTEM is connected directly to the battery, you don't need those.

Regards,

Jeff

Hi Kalariya,

If not used, Q2 can be shorted but Q3 must be open, i.e. no 0 ohm resistor.  The system then connects directly to the battery.  The charger will be unable to distinguish between system current and charge current so the charger may never report charge termination.

Regards,

Jeff

Hi Kalariya,

Yes.

Regards,

Jeff

Hi  Parth,

No.  All our chargers regulate the output to the final battery regulation voltage, i.e. the output is eventually the battery voltage.

Regards,

Jeff

Hi Parth, 

Our switching chargers does not have a dedicated regulated 5V output.

Hi Parth, 

For the fixed output, you will need to use a separate DC/DC converter or LDO based on your design requirement. If you need part recommendation on DC/DC converter or LDO, I suggest to post a new thread so that our corresponding product team can help suggest a best fit for your need.

Hi Jing,

Thanks for your reply. i will do it seperately.