Part Number: BQ25060
Hello,
I am working with the BQ25060 charger IC and using the TS pin with a 10 kΩ NTC (B3435). My goal is:
- Cold stop: around −20 °C chamber temperature (≈ −17.3 °C at the NTC)
- Cold restart: around −18 °C chamber temperature (≈ −15.8 °C at the NTC)
- Hot stop: around +50 °C (to be tested later)
My current TS network is:
- R1 = 15 kΩ (TS → VLDO)
- R2 = 5.36 kΩ (TS → GND)
- NTC = 10 kΩ, B3435 (in the battery pack)
With this configuration, charging correctly stops at approximately −20 °C chamber (−17.3 °C at the NTC). However, when I warm the system back up, charging does not restart near −18 °C. Instead, it restarts much warmer (around −6 °C chamber or higher).
My questions:
- Does the BQ25060 use the same VCOLD threshold for both cold-stop and cold-restart, with only minimal hysteresis?
- Is it possible to achieve a cold-stop at −20 °C and a cold-restart at −18 °C using only the TS resistor network?
- Is the large restart gap I am observing expected due to internal hysteresis, or is it more likely caused by thermal lag between the chamber, battery, and NTC?
- If independent stop and restart temperatures are required, is the recommended approach to control charging via EN using a system microcontroller, with TS acting only as a safety limit?
I have repeated the tests multiple times with long soak periods, and the cold-stop point is very consistent. The restart point, however, is significantly warmer than expected based on the TS equations in the datasheet.
Any guidance on whether the BQ25060 can support a narrower cold hysteresis window using only the TS network would be greatly appreciated.
Thank you.
