DIO2186

Version 1.0, Apr 2026

www.dioo.com

© 2026 Dioo Microcircuits Co., Ltd. Jiangsu

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8. Function Description

The DIO2186 is a bidirectional and high-precision voltage output current sense amplifier. It can be used as

high side or low side current monitor in automotive electronics. The DIO2186 sense drops across RShunt

independent of the supply voltage. This device supports common-mode inputs from -2 V to 40 V, making it

ideal for current sensing of inductive loads in automotive applications.

8.1. High-precision current measurement

The DIO2186 enables precise current measurements across an extensive dynamic range. Its high

measurement accuracy stems from its excellent low gain error and offset performance. The low offset

feature of DIO2186 is beneficial for enhancing accuracy under light-load conditions—scenarios where

when VIN+ approaches VIN–. Additionally, the low offset voltage offers another advantage: it allows a lower

RShunt. These smaller RShunt reduce power dissipation within the current-sense circuit, in turn boosting the

overall power efficiency of the end application.

In the current-sense measurement, the gain error becomes the dominant source of error as the sensed

voltage becomes much larger than the offset voltage. If the device monitors currents near the full-scale

output range, the total measurement error approaches the value of the gain error.

8.2. Low input bias current

Compared with conventional current-sense amplifiers, the DIO2186 features very low input bias current,

which bring three advantages.

It can have lower current consumption. Traditional architectures draw tens of microamps at the inputs; this

current is required to bias the input stage and to drive the internal gain-setting network. The DIO2186

eliminates this burden through a capacitively coupled input stage followed by a precision difference

amplifier, reducing the bias current to near zero.

It can support input filtering without sacrificing measurement accuracy. Traditional current-sense amplifiers

lose accuracy when adding such filters. However, the DIO2186’s measurement accuracy is barely affected

by input filters because of its low bias currents.

It can use a larger current-sense resistor. Therefore, it is able to accurately monitor currents.

8.3. Low quiescent current

The DIO2186 features low quiescent current (IQ), and at the same time, it can still provide small-signal

bandwidth in most applications. Therefore, there is no need for excessive drain on the battery for its

application in many portable electronic systems.

8.4. Bidirectional current monitoring

For bidirectional operation, the current measurement is conducted through a RShunt in two directions. For

bidirectional current-sensing, apply a voltage at the REF pin to offset the voltage.

When a positive differential voltage is detected at the input terminals, the output voltage will be higher than

the applied reference voltage. Similarly, when a negative differential voltage is detected at the input

terminals, the output voltage will be lower than the applied reference voltage. The output voltage of the

current-sense amplifier can be calculated with the equation: