Because the ADS1000-Q1 has a differential input, connect the reference voltage of the INA213A-Q1 to the negative input terminal of the ADS1000-Q1. Because bidirectional current sensing is required in this application, VREF must be chosen so that:

where V_fs= 1.5 V

A 1-V reference works for this example. Because the ADS1000-Q1 is a differential input ADC, a resistive divider can be used to generate the reference voltage because of impedance effects on the INA213-Q1 are canceled out by the ADS1000-Q1. When using a single-ended ADC with the INA213A-Q1, do not use a voltage divider to generate the reference voltage.