DIO2186

Version 1.0, Apr 2026

www.dioo.com

© 2026 Dioo Microcircuits Co., Ltd. Jiangsu

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By applying a voltage to the REF pin, the current flowing in both directions can be measured. The voltage

applied to the REF pin (VREF) sets the output state corresponding to the zero-input state. Then the output

increases above VREF in response to positive differential signals (relative to the IN– pin) and decreases

below VREF for negative differential signals. The reference voltage applied to the REF pin can be adjusted

anywhere between 0 V and VS. For bidirectional applications, VREF is commonly set to VS/2 to provide an

equal signal range for currents flowing in both directions. However, in some instances, VREF may be set to a

value other than VS/2, such as when the bidirectional current or output signal range does not require

symmetry. In this configuration, use of the amplifier output as a single-ended signal is not recommended

because the internal impedance shifts can adversely affect device performance specifications.

A less-frequently used output biasing method is to connect the REF pin to the power-supply voltage VS. In

this configuration, the output voltage saturates approximately 20 mV below the supply rail when the

differential input voltage is zero. This condition mirrors the output saturation near ground level observed

when the REF pin is tied to ground with zero differential input. Here, the output voltage only responds to

currents generating a negative differential input voltage with respect to the device’s IN- pin. As the negative

differential input signal increases, the output voltage decreases from the saturated supply voltage. It is

critical to ensure that the voltage applied to the REF pin does not exceed VS.

Figure 11. Unidirectional and bidirectional application

8.8.3. Input differential overload

When (VIN+ – VIN–) × the gain > voltage swing specifications, the DIO2186 drives its output near the positive

supply or ground rail, resulting in inaccurate measurement of the differential input voltage. To prevent this

operating condition during normal circuitry function, the shunt resistor value should be reduced or a

lower-gain variant used in combination with the selected sense resistor. In the event of a time-limited

differential overload fault, the DIO2186 output recovers to its expected level approximately 10 µs after the

fault is cleared.