[FAQ] BQ76940: Xready trigger reason identify.

Hi Shang,

XREADY will trigger when 5 of the 8 communications between cell groups internal to the part are corrupt in a 1 second interval.  The part considers the reported result unreliable in this condition and turns off FET outputs. Some common causes:

1. Missing power on upper groups such as droop as you indicate causing reset of the group

2. Broken or missing power connection

3. Shorted CAPn capacitor

4. TSn having trapped voltage at boot due to missing pull down

5. Pull down of TSn below its reference (abs max violation)

6. Large noise on power pins

7. Some customers have reported XREADY in high field strength environments, it is not know if the entry is through the power pins or TSn to a remote thermistor or other.  Filtering and shielding are the expected solutions.