Figure 7-1 illustrates a test circuit for reference divider accuracy. The output of the INA28x-Q1 can be connected for unidirectional or bidirectional operation. Neither the REF1 pin nor the REF2 pin may be connected to any voltage source lower than GND or higher than V+, and that the effective reference voltage (REF1 + REF2)/2 must be 9 V or less. This parameter means that the V+ reference output connection shown in Figure 7-3 is not allowed for V+ greater than 9 V. However, the split-supply reference connection shown in Figure 7-5 is allowed for all values of V+ up to 18 V.

A. Reference divider accuracy is determined by measuring the output with the reference voltage applied to alternate reference resistors, and calculating a result such that the amplifier offset is cancelled in the final measurement.

Figure 7-1 Test Circuit for Reference Divider Accuracy