Hi,
I am using a couple of INA219s in a dual independent 12V charger but, due to placement space, I have had to connect the sense resistor to the part reversed - i.e. the high side of the resistor to Vin- and the low side to Vin+.
This requires that I complement the current and power outputs but the bus voltage remains much the same as the sense resistor is only 0.033R.
The sense resistor is between the charger output and the battery so senses the battery current and voltage.
The question is will this arrangement affect anything else or can I continue with this layout with no issues?
There is one thing I have noticed and that is that when there is no current output by the charger (but a voltage at pin Vin+ due to the battery that's permanently connected) I get a current flow of around 1.2mA from the battery an a current output of -127 from the IN219. This is above the published input leakage for the device and well above the published leakage for the diode that's in-line with the charger output.
The IN219 is set to PG Gain /2, ADC 128 sample, Continuous Shunt and Bus, and Calibration 12412 to set 100uA/count.
Thanks
John
