The INA190-EP devices are bidirectional current-sense amplifiers capable of measuring currents through a resistive shunt in two directions. This bidirectional monitoring is common in applications that include charging and discharging operations where the current flowing through the resistor can change directions.

The user can apply a voltage to the REF pin to measure this current flowing in both directions (see Figure 7-4). The voltage applied to REF (V_REF) sets the output state that corresponds to the zero-input level state. The output then responds by increasing above V_REF for positive differential signals (relative to the IN– pin) and responds by decreasing below V_REF for negative differential signals. This reference voltage applied to the REF pin can be set anywhere between 0 V to V_S. For bidirectional applications, V_REF is typically set at V_S/2 for equal signal range in both current directions. In some cases, V_REF is set at a voltage other than V_S/2; for example, when the bidirectional current and corresponding output signal do not need to be symmetrical.