ISO1211

The ISO1211 and ISO1212 devices are isolated 24V to 60V digital input receivers, compliant to IEC 61131-2 Type 1, 2, and 3 characteristics. These devices enable 9V to 300V DC and AC digital input modules in programmable logic controllers (PLCs), motor-control, grid infrastructure, and other industrial applications. Unlike traditional optocoupler designs with discrete, imprecise current limiting circuitry, the ISO121x devices provide a simple, low-power design with an accurate current limit to enable the design of compact and high-density I/O modules. These devices do not require field-side power supply and are configurable as sourcing or sinking inputs.

The ISO121x devices operate over the supply range of 2.25V to 5.5V, supporting 2.5V, 3.3V, and 5V controllers. A ±60V input tolerance with reverse polarity protection helps provide the input pins are protected in case of faults with negligible reverse current. These devices support up to 4Mbps data rates passing a minimum pulse width of 150ns for high-speed operation. The ISO1211 device is designed for applications that require channel-to-channel isolation and the ISO1212 device is designed for multichannel space-constrained designs.

The ISO121x devices reduce component count, simplify system design, improve performance, and reduce board temperatures compared to traditional designs. For details, refer to the How To Simplify Isolated 24V PLC Digital Input Module Designs TI TechNote, How To Improve Speed and Reliability of Isolated Digital Inputs in Motor Drives TI TechNote, and How to Design Isolated Comparators for ±48V, 110V and 240V DC and AC Detection TI TechNote.