BQ25306: Is the 3A the total current when using the external power path topology?

Lauren Mayfield

Part Number: BQ25306

When using the external power path topology circuit, is the 3A the total current including charge and system power? Or does it just represent the charge current only?

Thanks!
Lauren

over 3 years ago

0 Kedar Manishankar over 3 years ago

TI__Mastermind 24075 points

Hi Lauren,

3A represents charge current out of ISW only. As in the external powerpath configuration, it shows the external load on PMID, you are restricted by the IINPDM current limit.

0 Lauren Mayfield over 3 years ago in reply to Kedar Manishankar

TI__Expert 6910 points

Hey Kedar,

Just to clarify, the input current regulation(I INDPM) is 3A min. So in a topology where I am powering the load through PMID and charging the battery simultaneously I am limited to a total of 3A between the load and the battery charging current, correct?

Also is there a specific reason there is a diode on the gate of Q4 for the external power path?

Thanks,
Lauren

0 Kedar Manishankar over 3 years ago in reply to Lauren Mayfield

TI__Mastermind 24075 points

Hi Lauren,

IINDPM is measuring the total input current, so it will sense the load current out of PMID + input current of the buck stage required to charge the battery at your specified charge current. Not the actual charge current at the output of the converter.

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BQ25306: Is the 3A the total current when using the external power path topology?