BQ25606: Whether Ilim has influence on Ichg

Amelie Zheng

Part Number: BQ25606

Hi Team,

If I set Ilim is 0.5-1A, will it have influence on Ichg?

As my understanding, ILIM and ICHG are independent...

ICHG depends on KICHG and RICHG;ILIM depends on KILIM and RILIM, right? So even I set limitation on ILIM, it won't influence ICHG...

over 5 years ago

0 Jeff F over 5 years ago

TI__Guru**** 167196 points

Hi Amelie,

That is incorrect. ILIM resistor sets the buck converter input current limit if D+/D- detects unknown adapter; otherwise, D+/D- detection sets the input current limit. If the charger doesn't have enough input current for ICHG+ISYS, ICHG is reduced. You can use the datasheet efficiency curves and the power balance equation below to estimate the maximum buck converter output for a given input voltage and current:

efficiency = Pout/Pin = VSYS*(ICHRG+ISYS) / VBUS*IBUS where IBUS is limited by ILIM or D+/D-. Just use VSYS~=VBAT, which isn't exactly correct but close enough.

Regards,

Jeff