The stability and temperature drift of the external gain setting resistor (R_G) also affects gain. The contribution of R_G to gain accuracy and drift is determined from Equation 2.

The best gain drift of 5 ppm/℃ (maximum) is achieved when the INA823 uses G = 1 V/V without R_G connected. In this case, gain drift is limited by the slight mismatch of the temperature coefficient of the integrated 50-kΩ resistors in the differential amplifier (A₃).

At gains greater than 1 V/V, gain drift increases as a result of the individual drift of the 50-kΩ resistors in the feedback of A₁ and A₂ relative to the drift of the external gain resistor (R_G.) The low temperature coefficient of the internal feedback resistors significantly improves the overall temperature stability of applications using gains greater than 1 V/V over alternate options.