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Efficient & compact isolated digital inputs

Replace your optocoupler and simplify your PLC, grid or motor drive design

Isolated digital inputs provide galvanic isolation between a sensor input, or other input type, and a logic output for a host controller interface. Compared to traditional optocoupler solutions, our isolated digital input devices provide a simple, low-power alternative with an accurate current limit. This alternative to optocouplers enables the design of compact and high-density I/O modules for PLC, AC and servo drives, and protection relay or substation automation grid applications.

View our isolated digital input products

The ISO1211 and ISO1212 devices are isolated, 24-V to 60-V digital input receivers that improve on traditional optocoupler designs for high-density I/O modules.

What are isolated digital inputs?

Find out how isolated digital inputs differ from digital isolators and why they are designed specifically for programmable logic control (PLC), motor control and grid applications.

Evaluate our isolated digital inputs

Each of our isolated digital inputs has an evaluation module (EVM) that you can use the test the performance of our devices.

Learn more about isolated digital inputs

How To Simplify Isolated 24-V PLC Digital Input Module Designs (Rev. B)

Are you designing a PLC digital input module? Learn how isolated digital inputs can simplify your design for IEC61131-2 Type 1, Type 2 and Type 3 standards.

How to Improve Speed and Reliability of Isolated Digital Inputs in Motor Drives

Learn how to improve the speed, noise immunity and reliability of isolated digital inputs in motor drive applications.

Reference designs featuring our isolated digital inputs

Broken Wire Detection Using An Optical Switch Reference Design

This reference design features two groups of eight isolated digital input channels. Broken wire detection can be executed using only one additional optical switch per channel or two optical switches and one additional capacitor for each group, with no secondary side supply needed.

Sub 1-W, 16-Channel, Isolated Digital Input Module Reference Design

This reference design shows a compact implementation of 16 isolated digital input channels where all channels consume less than 1 W of input power combined, enabling a compact layout with minimal heat dissipation.

96-Channel Bidirectional Digital Input Module Reference Design for PLC

This reference design features 96 isolated digital input channels with better thermal performance than traditional optocoupler solutions. This design makes a digital input board with multiple channels more compact and decreases board temperature (less than 50°C).