DIO2240

Version 1.2, Jan 2026

www.dioo.com

© 2026 Dioo Microcircuits Co., Ltd. Jiangsu

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10.Application Information

Important notice: Validation and testing are the most reliable ways to confirm system functionality. The

application information is not part of the specification and is for reference purposes only.

The DIO2240 measures the voltage developed as current flows across the current-sensing resistor. The

two reference pins can be used to configure either unidirectional operation or bidirectional operation. For

inline motor current sense, it is commonly configured for bidirectional operation.

10.1. Input filtering

It does not require input filters for accurate measurements using the DIO2240. It is not recommended to

use filters in this location. If filter components are used on the input of the amplifier, please refer to the

guidelines below in order to minimize the effects on performance.

External filtering of the current signal could be desired based strictly on user design requirements. Placing

the filter at the output of the current amplifier should be the first consideration. Although this location meets

the filtering requirements, it changes the low output impedance measured by any circuitry connected to the

output voltage pin. The other location for filter is at the current amplifier input pins (see Figure 18), which

also meets the filtering requirements, but the components must be carefully chosen to minimize the effects

on performance.

Figure 18. Filter at input pins

To reduce the accuracy loss, keep the value of these series resistors no more than 10 Ω as external series

resistance provide a source of additional measurement error.

To calculate the measurement error expected from the additional external filter resistors, refer to Equation

(1).

r)

Facto

Error

Gain

(100

-

100

%

Error

Gain

×

=

(1)

To calculate the gain error factor by the additional external series resistance, refer to Equation (2).

3000

R

3000

Factor

Error

Gain

S

+

=

(2)

Where:

RS is the external filter resistance value.