SBOSA75B July 2021 – November 2021 INA823
The stability and temperature drift of the external gain setting resistor (RG) also affects gain. The contribution of RG 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 RG 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 (RG.) 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.