Heat is the sworn enemy of the efficient factory floor. Against this foe designers of control systems in manufacturing environments as diverse as beverage bottlers to petrochemical plants battle constantly. They seek efficiency improvements and continue to press for smaller and smaller industrial control systems with more and more channels. Squeezing more performance into less space creates the problem of removing excess heat. Compact industrial control modules on the market today run so hot they are designed to derate, or drop a channel or two (depending on usage) to keep from burning up. Meaning that customers were not getting all the channels of the control they were paying for.
How did Analog Devices win this Battle of the Heat? The story begins with our long-standing partnership with a Fortune 500 manufacturer. Their systems designers would meet often with our semiconductor designers to share their requirements for next-generation control systems. Then, one day, they came to us with a challenge. Build an eight-channel analog output module that wouldn’t need to derate in order to lower its temperature to survive. Along with being low power it also had to be small, to allow the manufacturer to pack more of them into a space-limited factory floor.
The core functionality of an analog output module is a Digital-to-Analog converter (DAC), which takes its commands from a processor in the digital language of ones and zeros. The controller converts those ones and zeros into a voltage or current to perform some physical task, like opening a valve or moving an actuator. Our designers quickly came to the conclusion that building the controller with just DACs would solve neither the heat nor space problem.
In addition to the channel density request, the requirements also included channel-to-channel isolation. Simply put, factories are very noisy places. Every swivel, crank, twist and turn generates noise which can affect the performance of semiconductors. Additionally, the control systems have long cabling, which leads to greater chances of voltage imbalances damaging channels. By isolating each channel those faults do not destroy the output module and reliability increases. But this also increases the size and power (meaning more heat is produced) compounding the problem faced by our engineers.
That’s when two more partnerships kicked in. Only these were inside ADI; one with our power management design team and the other with our isolation group. Leveraging their expertise with that of our DAC designers provided a clear path to the solution so desperately needed by our customer. The result is a system solution that enables the world’s first eight-channel Analog Output that runs on less than two watts – and does so with no derating. What makes this solution even more valuable to today’s manufacturer is that it is no bigger than a deck of cards.
With multiple modules often needed to manage critical and complex machinery, our groundbreaking system solution provides an immediate boost in efficiency and reduction in operating cost. These provide the opportunity for manufacturers to expand, should they need to do so in the future. Expansion is also made easier because the module is software configurable, eliminating the cost, time, and effort of rewiring the factory’s hardware, something required in previous solutions.
Designers who wish to learn more about ADI’s low-power, eight-channel, EMI-protected, non-derating I/O module, are encouraged to visit www.analog.com/AD5758. Datasheets and reference designs are available, as is an evaluation board.
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