This region of operation is the least accurate for the INA19xA-Q1 family. To achieve the wide input common mode voltage range, these devices use two operational amplifier front ends in parallel. One operational amplifier front end operates in the positive input common mode voltage range, and the other in the negative input region. For this case, neither of these two internal amplifiers dominates and overall loop gain is very low. Within this region, V_OUT approaches voltages close to linear operation levels for Normal Case 2. This deviation from linear operation becomes greatest the closer V_SENSE approaches 0 V. Within this region, as V_SENSE approaches 20 mV, device operation is closer to that described by Normal Case 2. Figure 7-8 illustrates this behavior for the INA195A. The V_OUT maximum peak for this case is tested by maintaining a constant V_S, setting V_SENSE = 0 mV and sweeping V_CM from 0 V to V_S. The exact V_CM at which V_OUT peaks during this test varies from part to part, but the V_OUT maximum peak is tested to be less than the specified V_OUT tested limit.

A. INA193, INA196 V_OUT Tested Limit = 0.4 V

INA194, INA197 V_OUT Tested Limit = 1 V

V_OUT tested limit at V_SENSE = 0 mV, 0 ≤ V_CM1 ≤ VS.

V_CM2, V_CM3, and V_CM4 illustrate the variance from part to part of the V_CM that can cause maximum V_OUT with V_SENSE < 20 mV.

Figure 7-8 Example for Low V_SENSE Case 2 (INA195A, INA198A: Gain = 100)