applied to the device. The output voltage can range from as low as 20 mV to as high as 200 mV below the

supply voltage.

8.4 Device Functional Modes

8.4.1 Adjusting the Output With the Reference Pins

Figure 8-2 shows a test circuit for reference-divider accuracy. The INA241x output is configurable to allow for

unidirectional or bidirectional operation.

+

±

REF2

REF1

VS

GND

OUT

VS

IN+

IN±

Figure 8-2. Test Circuit For Reference Divider Accuracy

The output voltage is set by applying a voltage or voltages to the reference voltage inputs, REF1 and REF2. The

reference inputs are connected to an internal gain network. There is no operational difference between the two

reference pins. The resistor network connected to the two reference pins are designed with ultra-precision and

matching. Output is set accurately at the mid-point voltage between the voltages applied to reference voltage

inputs, when current-sense input voltage is 0 V as shown in Equation 1 . In most bidirectional applications, one

reference input is connected to the positive supply and the other reference input is connected to the negative

supply (GND pin) to set the output voltage to mid-supply.

VOUT=G× VIN+− VIN− +VREF1+ VREF2

2

(1)

8.4.2 Reference Pin Connections for Unidirectional Current Measurements

Unidirectional operation allows current measurements through a resistive shunt in one direction. For

unidirectional operation, connect the device reference pins together and then to the negative rail (see the

Ground Referenced Output section) or the positive rail (see the VS Referenced Output section). The required

differential input polarity depends on the reference input setting. The amplifier output moves away from the

referenced rail proportional to the current passing through the external shunt resistor. If the amplifier reference

pins are connected to the positive rail, then the input polarity must be negative to move the amplifier output down

(towards ground). If the amplifier reference pins are connected to 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 INA241x 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

(see Figure 8-3).

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INA241A, INA241B

SBOSA30A – MARCH 2022 – REVISED AUGUST 2022

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