Digital input/output (I/O) modules

Digital input and output modules (I/O modules) are key elements of any PLC (programmable logic controller) system. They take control via the CPU unit of the PLC and form the industrial automation power interface to and from the shopfloor. Embedded controllers can communicate with each other and with the central unit via fieldbus system. Action commands, incoming signals from the factory floor, component and system status data are exchanged. As a result, digital I/O modules face an ever-increasing list of challenges. They result from a growing demand for flexibility and scalability, while their system robustness and reliability determine the downtime of automation systems.

Changing customer needs also play a role. The IP protection and access restriction of a solution play a decisive role from the customer's point of view, as do power consumption and the longevity of the system. Likewise, safety aspects, especially in the control of drives, are gaining in importance. In competition, long-term experience is of fundamental importance, as are features such as simple and cost-effective maintenance and security in data access.

One of the most important components of a digital I/O module is the switch. In general, two types of configurations are possible: high-side or low-side. Regardless of the configuration, Infineon offers dedicated solutions for a wide range of load currents to be switched to advance your project. Our high-side ISOFACE™ output switches are known for their high level of integration and robustness. They come with galvanic isolation, protection and diagnostic feedback integrated into a single device. Infineon's Industrial PROFET™ (PROtected FET) products include protection and diagnosis functions to ensure safe system operation of I/O modules. The OptiMOS™ 5 40V and 60V families are Infineon’s discrete solutions for I/O modules for typical 24V applications. In case AC currents need to be switched the CoolMOS™ family, which is also thermally optimized and has the lowest R _DS (on) is the right choice. Corresponding gate drivers complement Infineon’s portfolio for a discrete approach. Not to forget, the ISOFACE™ input devices, which enable I/O system providers to “translate” incoming digital signals up to 24V, e.g. from isolated sensors to microcontroller processable level, including diagnostics.
The HITFET™ family is Infineon’s answer to all lowside configurations. Integrated protection and intelligence functions make these components ideal for use in PLCs and I/O modules.

Infineon provides a one-stop-shop product and design portfolio where you can find all the components for your designs from a trusted source:

• Various options for microcontrollers, including Infineon’s AURIX™ family that is best suited for demanding safety applications
• Memory ICs such as SRAM or NOR Flash Memories, e.g. for DATA logging
• Embedded security controllers that enable secure connectivity, cloud identification and over-the-air updates, protecting the IoT from cloud-to-end nodes
• Power management ICs that supply power to all components on the I/O modules, keeping losses and system heating at the lowest possible level
• Communication devices, wired as fieldbus or wireless (WiFi, BT, 5G), that establish a communication network
• Protective devices to prevent ESD or overvoltage damage to components transmitted over the communication lines.