JAJSCL0B July 2016 – February 2018 INA240
For this application, the INA240 measures current in the driver circuit of a 24-V, 500-mA water valve.
To demonstrate the performance of the device, the INA240A4 with a gain of 200 V/V was selected for this design and powered from a 5-V supply.
Using the information in the Adjusting the Output Midpoint With the Reference Pins section, the reference point is set to midscale by splitting the supply with REF1 connected to ground and REF2 connected to supply. Alternatively, the reference pins can be tied together and driven with an external precision reference.
A value of 10 mΩ was selected to maintain the analog input within the device limits.