MAXREFDES16#: -200°C ~ 850°C, Hart Interface, RTD

Temperature is one of the most widely measured parameters in industrial process control and automation. This reference design provides a complete signal-chain solution that works with any type of RTDs, from PT100 to PT1000. The Novato PT100 2-wire, loop-powered smart temperature transmitter guarantees a low-power, easy-to-use, reliable solution of temperature measurement from -200°C to +850°C with accuracy better than 0.1% or 1.0°C, whichever is more accurate, over the entire operating range.

The signal chain contains the MAX11213 (U1), 16-bit delta-sigma ADC with programmable gain and GPIO, the RL78/G13 Renesas' microcontroller with 128kB flash memory (U2), and the 4–20mA current loop transmitter built on the MAX5216 and MAX9620 (U3 and U4). The DS8500 modem (U7) provides digital interface utilizing HART protocol over 4–20mA current loop. The MAX15006 (U6) and MAX6133 (U5) provide power and reference voltage to the entire circuitry.