Hi,
We have designed a battery charger based on BQ24072T .Currently we have provided only the resistor divider input to "TS" pin(10K thermistor from battery is not connected) of charger and is working fine.
As recommended in the datasheet , we have used the resistor values as 200K-ohms and 49.9K-ohms ,to hold the TS pin at an appropriate voltage.
We would like to use the thermistor function of the battery and hence we changed the resistor divider values as 20K(R63 in schematics) and 10K (R68 in sch) respectively, for our thermistor.
As suggested in Pg20 of datasheet, if the value of the resistor is less than 100K ,a series resistor need to be connected.Please find the image below for reference.
Can you please clarify the below doubts regarding the series resistor(R8 in the image above).
Also please find the attached battery charger schematic for reference.
1. We are using a USB 5V for charging.Do we still need the series resistor to limit current.
2. If series resistor is still required,can you please let me know why we need to use 100K resistor value .
Your help is highly appreciated.
Thanks,
Uma.