Hello Sudheena,
Thanks for posting this question to the forum.
Both the INA381 and INA190 would work at measuring these currents; however, the best one for you depends upon your system, error, and price requirements.
The INA381 is functionally different in that it has an internal comparator. Do you need a comparator?
The INA190 and INA381 differ on quiescent current, input bias current, input voltage offset, bandwidth, and output drive capabilities among other things.
When measuring current you need to establish what is maximum allowable error at the minimum current and use this to define an appropriate shunt resistor value. Please watch our training video and view the circuit publications below to get an idea on how to understand out devices and error analysis.
http://www.ti.com/lit/an/sboa336/sboa336.pdf
http://www.ti.com/lit/an/sboa297/sboa297.pdf
Please keep in mind you need to determine what the maximum possible voltage can be on your 24V rail. If this voltage can exceed 26V, even momentarily, then this will break the INA381 as its VCM Absolute Maximum rating in 26V. See section 6.1 of datasheet.
Sincerely,
Peter Iliya
Current Sensing Applications
