BQ21061: Why is there an upper limit on IN capacitance?

Scott Brenneman

Part Number: BQ21061

The datasheet for the BQ21061, in Table 39, gives 10 uF as the upper limit for capacitance on the IN pin. Why is there an upper limit? In our design the power rail feeding this pin has more than 10 uF capacitance on it. What will happen, if anything, if the capacitance on IN is >10 uF?

Thanks,

Scott

over 5 years ago

0 Gautham over 5 years ago

TI__Genius 12485 points

Hi Scott,

This comes off from an inrush limit on certain USB products. What capacitance on the powersupply are you using?

I don't see any issues with having >10uF but would like to know what value we are dealing with to not have other side effects with the VINDPM or ILIM loops.

Regards,

Gautham

0 Scott Brenneman over 5 years ago in reply to Gautham

Genius 3295 points

Hi Gautham,

It's nothing crazy, probably something like 15 or 20 uF instead of 10 uF.

Thanks,

Scott

0 Gautham over 5 years ago in reply to Scott Brenneman

TI__Genius 12485 points

Hi Scott,

This is pretty common so I don't see any issues with this. Let me know if you have any questions!

Regards,

Gautham

0 Scott Brenneman over 5 years ago in reply to Gautham

Genius 3295 points

Okay, thank you!

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BQ21061: Why is there an upper limit on IN capacitance?