Reducing Component Count in Factory Automation Applications

December 13, 2016

Christine Young By: Christine Young
Blogger, Maxim Integrated 


With plans to increase its output to 500,000 cars per year by 2018, it’s no wonder that Tesla is making moves to rev up its manufacturing capabilities. In November, Tesla announced its acquisition of Grohmann Engineering, a German engineering group that will be folded into Tesla Advanced Automation Germany. The company noted in a statement:

“As the machine that builds the machine, our factories are so important that we believe they will ultimately deserve an order of magnitude more attention in engineering than what they produce. At very high production volumes, the factory becomes more of a product than the product itself.”

It’s a fitting move in this era of Industry 4.0, when technologies like robotics and machine learning come together to automate manufacturing processes. For companies increasing their focus on factory automation, underlying technologies that can enhance speed and accuracy—while overcoming emerging challenges—are in demand.

For example, high-resolution systems are moving to higher bit counts. To function with a higher bit count, these systems require attention, to prevent susceptibility to noise. Having a 24-bit signal chain in a universal input means the system is both high performance and flexible, with the ability to accurately measure current, voltage, RTD, and thermocouple signals.

Greater Accuracy and Flexibility

Maxim’s MAXREFDES67# reference design addresses the challenges of higher bit counts. It reduces component count on boards to simplify designs and save costs because the signal chain is designed entirely with Beyond-the-Rails parts—meaning the parts can accept industrial current or voltage signals that are of greater or lesser value than the voltage used to bias the part. With this flexibility, the MAXREFDES67# can take in bipolar signals without generating a negative rail on the board.

The MAXREFDES67# 24-bit front-end accepts bipolar voltage and current, RTD, and TC inputs.

At the heart of this reference design is a 24-bit analog-to-digital converter (ADC) providing a highly accurate signal chain with more than 22 effective number of bits (ENOB). The design is entirely software configurable, so no jumpers are needed on input. You can go from current input to two-wire RTD input to change the wires sending in the signals. This makes it easier to configure and reconfigure. On-board analog switches on the electronic side of the board handle all of the signal switching.

Board calibration is fairly easy, too. Firmware on the board supports a calibration process—you’ll need to the calibrate the board the first time you use it, then again after a couple of years, since the resistance and capacitance on the board will change over time.

Maxim worked with Wurth Electronics Midcom to build a customized, energy-efficient power isolation transformer for industrial applications using the reference design. Watch this video that shows the MAXREFDES67 in action