Hi,
I've been using INA199A2 to measure current flowing from my 12V battery to a load. It worked fine.
Later I started designing a boost converter (from 12V to 20V) with a INA199A2 sensors. For my first experiments I controlled only voltage, so I assembled INA199A2 sensors but I didn't even apply any voltage to Voltage Supply port. They are on my PCB for further experiments.
First couple of tests run okay. Later I started having problems as voltage in the circuit just collapsed. I started removing different parts of the circuit and I couldn't find where the problem was. Finally, I saw that whenever I energize the circuit my V+ port of INA199A2 shows the same voltage as the batterym which is 12V. The current is clearly "leaking" through my INA199 sensors.
Can someone tell me what is wrong with the circuit and why suddenly 12V is being generated at the V+ terminal of INA199A2?
Best Regards,
Bartosz