BQ25887: BQ25887 Valid USB power detection

user6372292

Part Number: BQ25887

Hi,

I am using in a prototype a BQ25887 and willing to use it with the default settings (no host). When starting the chip, having a USB voltage set with a power supply delivering 5.5V @ at max current 3.5A, I cannot get the charger to charge the batteries.

When debugging a bit more my pins PG and stat are at 1 seems to mean that the USB voltage does not meet requirements but i am sure it does at 5.5V & 3.5A.

Do you foresee something wrong in my design below?

Thanks for helping.

Best regards

José

over 3 years ago

0 Ricardo over 3 years ago

TI__Genius 10385 points

Jose,

I cannot see your attachment. Please re upload and reply.

Thanks,

Ricardo

0 user6372292 over 3 years ago in reply to Ricardo

Prodigy 70 points

I hope it is better this way.

Thanks

Best regards

José

0 Ricardo over 3 years ago in reply to user6372292

TI__Genius 10385 points

José,

I see your PSEL pin is pulled up to VCC. HIGH indicates USB host source (500mA) and LOW indicates adapter source (3.0A). Please pull PSEL LOW by shorting to GND.

I hope this resolves your issue,

Ricardo

0 user6372292 over 3 years ago in reply to Ricardo

Prodigy 70 points

Hi Ricardo,

Thanks for helping, i have changed to put PSEL to GND but there is no change.

PG is still high, i have no current drained from USB.

Thanks

Best regards

José

0 user6372292 over 3 years ago in reply to user6372292

Prodigy 70 points

Hi,

Does any TI's application engineer have any feedback on this post to help me out?

Thanks

Best regards

José

0 Ricardo over 3 years ago in reply to user6372292

TI__Genius 10385 points

Jose,

It is really difficult to read your component values. Here are the following factors that can affect your input current limit:

PSEL: (we have checked this, PSEL should be LOW for your application)
ILIM: this is set by R_ILIM and behaves as I_INMAX (the maximum input current) = K_ILIM (1110 A / ohm) / R_ILIM. I think I see 10k but that is not a valid value. Please short this pin to GND or disable the EN_ILIM bit to rule this out.
ICO routine: This occurs upon start up. Please check the ICO_ILIM register to see what value the routine has set
IINDPM: Please report what value the IINDPM register is showing.

Upon boot, the BQ25887 will use the lowest value as the input current limit.

Thanks,

Ricardo

0 user6372292 over 3 years ago in reply to Ricardo

Prodigy 70 points

Hi Ricardo,

I have just tried point 2 above (Grounding pin ilim) but still same result.

I am trying to use the chip with default config without writing and reading the chip.

Is there a way to reset to factory setup in case something is wrong?

Thanks

Best regards

José

0 Ricardo over 3 years ago in reply to user6372292

TI__Genius 10385 points

Jose,

Could you describe your TS connection? I see 30.1k from TS to GND and 5.23k from TS to REGN. I see other components between TS and GND but I cannot see what they are clearly.

Thanks,

Ricardo

0 user6372292 over 3 years ago in reply to Ricardo

Prodigy 70 points

Hi Ricardo,

I have on the schematics multiple CTN's 10K but only one is connected the other is for flexibility in the layout but not fitted. So basically it is the 30K from TS to GND with 10K CTN in parallel. and Correct 5.2K from TS to REGN.

Is it correct?

Is there a way without connection in I²C to reset to default factory parameters?

Thanks

Best regards

José

0 Ricardo over 3 years ago in reply to user6372292

TI__Genius 10385 points

Jose,

Power cycling (remove battery and VBUS) will reset the device to factory default. Could you measure the voltage at CD and VBAT?

Thanks,

Ricardo

0 user6372292 over 3 years ago in reply to Ricardo

Prodigy 70 points

HI Ricardo,

still the problem, CD=0V and VBATT = 7.54V and still no current to charge Vbatt is going down, PG and Stat still at 5V.

Thanks

Best regards

José

0 Ricardo over 3 years ago in reply to user6372292

TI__Genius 10385 points

Jose,

Would it be possible for you to send a register dump? The status bits might tell us what is going on.

Thanks,

Ricardo

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BQ25887: BQ25887 Valid USB power detection