BQ25606: Determining max charge current with K_ICHG and K_ICHG_ACC

user4725373

Expert 1645 points

Part Number: BQ25606

Hi,

I'm trying to determine the range of the max charging current of my circuit. I'm using a 604 Ohm ±1% as my R_ICHG.

By using 639 <= K_ICHG <= 715, I get:

Ichg_max = 715 / (604 * 0.99) = 1.196A

Ichg_min = 639 / (604 * 1.01) = 1.047A

Where does K_ICHG_ACC come into play? As its value is ±6%, should I add an additional 6% to Ichg_max and remove 6% from Ichg_min? What does it represent?

Thanks,

Fred

over 5 years ago

0 ezhao over 5 years ago

TI__Genius 10240 points

Hi,

You don't need to add additional 6%. K_ICHG_ACC in (A x ohm) reflects the same information of ICHG_REG in A.

0 user4725373 over 5 years ago in reply to ezhao

Expert 1645 points

Hi Eric, thanks for the answer.

So the min max of K_ICHG is basically K_ICHG ± K_ICHG_ACC. However, they aren't exactly the same, as using K_ICHG ±6% gives:

636.38 <= K_ICHG <= 717.62

while the datasheet says

639 <= K_ICHG <= 715

Which one should I trust more?

0 Ning T over 5 years ago in reply to user4725373

TI__Guru 57541 points

Hi,

K_ICHG and K_ICHG_ACC are equivalent specs. You may just use 639<=K_ICHG<=715 to do ICHG calculation.

Thanks,

Ning.

0 user4725373 over 5 years ago in reply to Ning T

Expert 1645 points

How are they equivalent if they do not give the same values?

0 Ning T over 5 years ago in reply to user4725373

TI__Guru 57541 points

Hi,

Both specs are round up to integers. +/-6% spec is more conservative.

Thanks,

Ning.

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BQ25606: Determining max charge current with K_ICHG and K_ICHG_ACC