(towards ground). If the amplifier reference pins are connected at ground, then the input polarity must be positive

to move the amplifier output up (towards supply).

The following sections describe how to configure the output for unidirectional operation cases.

8.4.2.1 Ground Referenced Output

When using the INA240 in a unidirectional mode with a ground referenced output, both reference inputs are

connected to ground; this configuration takes the output to ground when there is a 0-V differential at the input (as

Figure 8-3 shows).

+

±

REF2

REF1

VS

GND

OUT

VS

IN+

IN±

Figure 8-3. Ground Referenced Output

8.4.2.2 VS Referenced Output

Unidirectional mode with a VS referenced output is configured by connecting both reference pins to the positive

supply. Use this configuration for circuits that require power-up and stabilization of the amplifier output signal and

other control circuitry before power is applied to the load (as shown in Figure 8-4).

+

±

REF2

REF1

VS

GND

OUT

VS

IN+

IN±

Figure 8-4. VS Referenced Output

8.4.3 Reference Pin Connections for Bidirectional Current Measurements

Bidirectional operation allows the INA240 to measure currents through a resistive shunt in two directions.

For this operation case, the output voltage can be set anywhere within the reference input limits. A common

configuration is to set the reference inputs at half-scale for equal range in both directions. However, the

reference inputs can be set to a voltage other than half-scale when the bidirectional current is non-symmetrical.

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INA240

SBOS662C – JULY 2016 – REVISED DECEMBER 2021

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