JAJSCJ2 October 2016
PRODUCTION DATA.
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
A typical application consists of the device configured as an I2C controlled device and another switch mode charger for Li-Ion and Li-polymer batteries used in a wide range of smart phones and other portable devices. A host controls which charger is enabled during the charging process.
PARAMETER | VALUE |
---|---|
Input voltage range | 3 V to 6 V |
Input current limit | 0.1 A to 7.5 A |
Output voltage range | 3 V to 4.975 V |
The bq25872 continuously monitors battery and adaptor connector temperature by measuring the voltage between TS_BAT pin and TS_BUS pins and ground, typically determined by a negative temperature coefficient thermistor and an external voltage divider. The device compares this voltage against its internal thresholds to determine if charging is allowed. To initiate a charging cycle, both battery and connector temperatures must be lower than the temperature threshold, else the device suspends charging and waits until both temperatures are blow the threshold.
Assuming a 103 AT NTC thermistor is used on the battery pack, the values RT1 (connected between TS_X pin to VREF) and RT2 (connected between TS_X and ground) can be determined by using the following equations.
where