Hi Danilo,
I would recommend Vout >= GND + 50mV in order to remain in spec for gain error as shown here:
You may also determine the lowest Vin required for linear output using the 'Swing to ground' spec. As highlighted above:
Swing to GND (Vout min) = 0.025 V
(example) Gain = 20 V/V
Vin min = 0.025V / 20V/V = 0.00125V
However, as mentioned above, the gain error is not specified for this range and error may be higher than desired.
Cierra
Hi Danilo,
Yes, the higher gain devices will allow a lower Vsense while still remaining in gain error spec. If gain = 200V/V for example, Vsense(min) = 50mV / 200V/V = .00025 V or 250uV to keep gain error <= 0.5%.
However, as you decrease Vsense, keep in mind offset error while have a greater impact. For INA280, voltage offset max referred to input is 150uV. This means for Vsense = 250uV, there will be 60% error due to offset alone (150uV/250uV). This will be in addition to other error sources explained here: https://www.ti.com/video/series/ti-precision-labs-current-sense-amplifiers.html
If a very low Vsense is desired, you may consider some other devices with lower offset to help decrease the offset error. INA290 is a drop-in replacement for INA280 and has a lower max offset of 25uV.
Cierra
