Tool/software:
Hello,
we are working with the BQ25756 battery charger IC and have observed an unexpected jump in charging current when the charger is in taper charge mode.
During normal operation, the charge current follows the expected CC-CV profile. However, as the charger transitions into taper charge mode, I notice a sudden small increase (jump) in charge current instead of a smooth decrease. This behavior is visible in the chart, where I plotted the charging current in mA and the charging voltage in mV over time. I also noticed, that even if the max charge current is set to around 7.1A, the termination happens to early in my opinion at around 0.93A. I observed the same behavior on two different designs. It is also reproducible on multiple boards.
This is the plot during charging:
The device is not used in host mode. Every thresholds are set with resistors in hardware (Pictures of ILIM_HIZ, ICHG, FSW_SYNC, FB values):
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What could cause this small jump (increase) in charge current during taper mode? Are there any known issues that could explain this behavior?
I would appreciate any insights or suggestions on debugging this issue!
Best regards,
Lukas
