Part Number: BQ24040
Hi.
I am using the BQ24040 to charge a lithium-ion battery.
Figure 1 shows the circuit diagram.
An NTC thermistor (10kohm, B=3435) is connected to the TS pin.
To verify the TS function, I conducted an experiment using a temperature chamber.
Table 1 shows the results of the experiment.
Column A: Time
Column B: Temperature inside the chamber[℃]
Column C: Battery surface temperature[℃]
Column D: VOUT[V]
Column E: VTS[V]
- At 14:39:50, VOUT dropped, and I believe the charger transitioned to 4.06V charging due to high temperature.At that time, VTS was 209.4 mV. According to the datasheet, the transition should occur between 263 mV and 293 mV.Why is there a discrepancy from the datasheet?
- At 14:39:50, when VOUT dropped, VTS also appeared to drop simultaneously.Is this behavior normal?
- When charging continued, VTS dropped below 160 mV, but charging did not stop.
According to the datasheet, charging should stop when VTS is between 170 mV and 186 mV.
What could be the reason charging did not stop?
The charging status was monitored using the charging current.
Best regards,
