I'm attempting to use an INA2141 with a gain of approximately 14.4V/V using the following equation:
G = 1+ (50000/(504+R||5050))
Everything seems to be working fine but I'm seeing a significant gain error across all channels (> +/-1%).
I'm using a 0.1% resistor for the setting the gain. The maximum gain error for the INA2141 is less than +/-0.075%.
When I actually measure the resistance across the gain resistors I do see alot of variance, telling me the error is occurring in the INA stage. I would have thought the internal resistances of the INA2141 would be tightly controlled due to its small gain error spec.
Can anyone explain this?
When they actually trim the internal gain resisters of the INA2141, are they actually trimming the feedback resistors (25k) as well?
Thanks in advance for your help.
Phillip