DIO2240

Version 1.2, Jan 2026

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© 2026 Dioo Microcircuits Co., Ltd. Jiangsu

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

connected to an internal gain network. The two reference pins are same for operation.

9.3.2. Reference pin connections for unidirectional current measurements

For unidirectional operation, the current measurements is conducted through a resistive shunt in one

direction. In this operation, connect the device reference pins together and then to the negative rail (ground

referenced output) or the positive rail (VS referenced output). The required differential input polarity is

determined by the output voltage setting. The amount of current flowing through the external shunt resistor

determines how much the amplifier output deviates from the referenced rail. When 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). When the amplifier reference pins are connected at ground, then the input polarity

must be positive to move the amplifier output up (towards supply).

To configure the output for unidirectional operation, please refer to the content below.

In a unidirectional mode with a ground referenced output, both reference pins are connected to ground.

When there is a 0 V differential at the input, this configuration takes the output to ground (see Figure 12).

Figure 12. Ground referenced output

In a unidirectional mode with a VS referenced output, both reference pins are connected to the positive

supply. Before power is applied to the load, use this configuration for circuits requiring power-up and

stabilization of the amplifier output signal and other control circuitry (see Figure 13).

Figure 13. VS referenced output