SLUSCC5A September 2016 – May 2018 BQ25890H
PRODUCTION DATA.
For high current charging system, resistance between charger output and battery cell terminal such as board routing, connector, MOSFETs and sense resistor can force the charging process to move from constant current to constant voltage too early and increase charge time. To speed up the charging cycle, the device provides resistance compensation (IRCOMP) feature which can extend the constant current charge time to delivery maximum power to battery.
The device allows the host to compensate for the resistance by increasing the voltage regulation set point based on actual charge current and the resistance as shown below. For safe operation, the host should set the maximum allowed regulation voltage register (VCLAMP) and the minimum resistance compensation (BATCOMP).