MAXREFDES1161#: Small size, high accuracy, 2-wire, 4mA to 20mA current loop transmitter

Overview

The MAXREFDES1161# is a small form factor, high accuracy, 2-wire 4mA to 20mA transmitter which integrates all functional and protection blocks in a small 1.0in x 0.6in dual-row header footprint that is compatible with breadboards and off-the-shelf peripheral expansion boards.

The MAXREFDES1161# uses the MAX12900 to achieve a total solution for industrial loop-powered current transmitters which convert the microcontroller 16-bit pulse-width modulated (PWM) signal to current without using a DAC, greatly reducing total system cost without degrading the accuracy. The 4mA to 20mA current loop transmitter can achieve a 1μA resolution and 0.1% FS accuracy. The MAX12900 also provides diagnostic functionality, such as loop power monitoring and current readback. The reference design integrates protection functions, such as loop power reverse protection and overvoltage protection, and can support up to 36V loop power input at 4mA current output.

The MAXREFDES1161# can be used to evaluate the performance of the MAX12900 and can be directly used in final products to simplify the current loop transmitter design and shorten development cycles.

Design files, firmware, and software can be found on the Design Resources tab. The board is also available for purchase.

Features

• Loop Compliance Voltage up to 36V
• 4mA to 20mA Output with 0.1% FSR Accuracy
• Robust Industrial Design with Reverse Voltage Protection, and Overcurrent Protection

• IEC 61000-4 Transient Immunity Protection
• Industrial Standard Form Factor
• Complete solution with Proven Layout