Hi,
A problem that was discovered about 4 months ago doesn't seem to have been resolved with the BQ78350 R1 firmware..
The BQ76940 detects a short circuit which the BQ78350 reads through the I2C bus, but the fault never clears.
We used a logic analyzer to look at the I2C line (between the BQ78350 and BQ76940) and determine whether the command was sent to clear the SCD bit, but it never does. Attached is the csv file (renamed txt because this forum doesn't allow csv files apparently) of the data stream (we recorded a minute after the short circuit was detected; the short circuit is detected at 4.5 seconds). The BQ78350 is set with a 5 sec recovery, 10 secs counter dec delay and 15 seconds reset, threshold and delay bits have all been set to 0 to reduce the impact of causing short circuits).
Through BQ Studio, we see the ASCD bit (Safety Status) toggling in the interface, but it keeps coming back.
The datasheet specifies that the host (in this case the BQ78350) must clear the bit by writing a 1 to that bit. To see whether clearing the bit solved the problem, we connected an I2C host debugger and sent the command manually over the I2C bus. The SCD bit was then cleared. We confirmed through BQ Studio that the ASCD bit was indeed cleared and the problem was gone. The XDSG bit was also cleared.
We have two boards that exhibit the same behaviour.
Please advise.
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