MAXREFDES42#: RTD Temperature Sensing, IO-Link

The MAXREFDES42# is a high-accuracy IO-Link® resistance temperature detector (RTD) temperature sensor reference design for use with a 2-wire, 3-wire, or 4-wire PT100 RTD over a wide temperature range. Built in an industrial form factor, the design makes use of Maxim Integrated’s highly integrated MAX31865 RTD-to-digital converter.

A rugged, on-board female M12 connector allows off-the-shelf RTDs to be connected to the board using a standard M12 extension cable. The temp sensor performs accurate temperature conversions to 15-bit resolution with multiple fault detection features.

A display shows coarse temperatures rounded to the nearest °C, while the IO-Link communication tracks and provides fine temperature values. This sensor utilizes IQ2 Development’s IO-Link device stack to communicate to any IO-Link version 1.1-compliant master.

By utilizing an industrial DC-DC step-down converter, this reference design consumes minimal power.

The board also contains a male M12 connector for connection to a compliant IO-Link master using a standard M12 cable. Connecting the MAXREFDES42# to a USB IO-link master such as the IQ2 Development iqInterface® IO-Link master, using their iqTool® software, allows for evaluation with a PC.