To improve the safety of charging Li-ion batteries, 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 must be within the VT1 to VT5 thresholds. If TS voltage exceeds the T1-T5 range, the controller suspends charging and waits until the battery temperature is within the T1 to T5 range.

At cool temperature (T1-T2), the charge current is reduced to 20% of programmed fast charge current. At warm temperature (T3-T5), the charge voltage is reduced to 4.1 V. Charge termination is disabled for cool and warm conditions.

Figure 9-2 JEITA Profile: Charging Current

Figure 9-3 JEITA Profile: Charging Voltage

Equation 1 through Equation 2 describe updates to the resistor bias network.

Figure 9-4 TS Pin Resistor Network

Equation 1.

Equation 2.

Select 0°C to 60°C range for Li-ion or Li-polymer battery:

• RTH_COLD = 27.28 kΩ
• RTH_HOT = 3.02 kΩ
• RT1 = 5.23 kΩ
• RT2 = 30.9 kΩ