Hi everyone,
I am using INA129 to sense the current from a sensor. The potential is scan from -1.2V to 1.2V (linear form from DAC) to the sensor and it produces the current in range of uA. The current is sense via a 100k resistor and then the INA will detect it with bias 2.5V. Here I set the gain = 1.
I test this part with a resistor at the place of the sensor so the current go through the resistor should be proportional to the potential, which means the output of INA should have the same form as the scan potential, a linear ramp (am I right?)
However, the output voltage read by ADC is not like that, it slightly changes above 0V (2.7V after biased).
I test ADC and it works fine. What could be causing the problem?
Thank you!
Quan