SLUSDF7A January 2020 – February 2022 BQ25616
PRODUCTION DATA
To improve the safety of charging Li-ion batteries, the JEITA guideline was released on April 20, 2007. The guideline emphasized the importance of avoiding a high charge current and high charge voltage at certain low and high temperature ranges.
To initiate a charge cycle, the voltage on TS pin, as a percentage of VREGN, must be within the VT1_FALL% to VT5_RISE% thresholds. If the TS voltage percentage exceeds the T1-T5 range, the controller suspends charging, a TS fault is reported and waits until the battery temperature is within the T1-T5 range.
At cool temperature (T1-T2), JEITA recommends the charge current to be reduced to 20% of ICHG. At warm temperature (T3-T5), JEITA recommends charge voltage less than 4.1 V.
Equation 3 through Equation 4 describe how to calculate resistor divider
values on the TS pin.
In the equations above, RNTC, T1 is the NTC thermistor resistance value at temperature T1 and RNTC, T5 is the NTC thermistor resistance value at temperature T5. Selecting a 0°C to 60°C range for a Li-ion or Li-polymer battery then: