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BQ25887: Audible noise can be heard near the IC when taper charging.

kuro
Prodigy 90 points
Part Number: BQ25887

Audible noise can be heard near the IC when taper charging.
Is there a cause and solution?

The frequency of the audible noise is about 6.7 kHz.

The schematics and constants are basically created by referring to datasheets and EVMs.

When it shifts to tapered charge, the I2C control squeezes the charge current to make it inaudible.

If this problem can be solved by replacing the value or variety of the parts, I would prefer that.

File attached.

Thank you very much.

schematic_bq25887.pdf

  • 0
    TI__Mastermind 34325 points

    Can you provide me with the register setting of REG02? I am worried that Out of Audio PFM is disabled.

    Can you provide waveforms of the  BAT current, BAT voltage, SW node, and VBUS when this is occurring?

    Also, I am having trouble understanding your issue. You say there is audible noise, but that the "I2C control squeezes the charge current to make it inaudible." What conditions result in audible situations and what conditions result in inaudible situations? Can you please provide the above waveforms for each case?

    Thanks,

    Mike Emanuel

    Please click "This resolved my issue" button if this post answers your question.