I am looking at SLUA511B "Configuring the bq20z40/bq20z45 Data Flash". On page 7 it explains how the AFE OC Dsg register works and the values it will take.
I set the value to 0x00. According to the table on page 7, that means the OC protection will trigger when the AFE sees 50mV. On my system, with a 0.011 Ohm sense resistor, that's 4.54A I think (50mV / 11mOhm).
I set my electronic load for 5A, but the OC protection does not trigger. AFE OC Dsg Time Configuration is set for 0x0f (31mS). In 2 seconds, the 1st level protection triggers (it is set for 2A).
If I read the voltage across the sense resistor with a DMM. I see the expected 55mV, which should trigger the AFE. (Actually I see -55mV, positive lead on ASRP, negative lead on ASRN. Does that matter?)
I set the OC Dsg register to 0x01, adjusted values and tried again - same result.
What am I missing?
Thanks
Ed K