Industrial I/O Isn’t a Drive-Thru—Keep the Chips Cool
Finally, Friday! On the way home, I stop by a local fast food and order some French fries, which locals indeed simply call “chips”. The server accepts my order, walks a couple of steps, and throws a portion of chips into the scorching oil.
Suddenly, cracking and sizzling, a strong burn-like smell hit me in the face, reminding me of the trouble I had faced last week. A fried chip, or a fried industrial I/O chip, is surely not a desirable control solution.
Hot Chips Are Delicious—Unless They’re in Your Module
What is it that reminded me of the industrial control module I am currently working on? Perhaps the subtle cracking coming from the electronic controller board next to me caught my attention. Curious, I touched the I/O chip. Ouch!
I burned my finger. A plastic-burning smell and a wisp of smoke followed. I quickly unplugged the power supply, relieved that the smoke alarm hadn’t gone off, and evacuated the building. But the question remains, what went wrong?
Save the Frying for Fries: Keep Your I/O Cool
All channels sourcing the maximum control current cannot be a problem, as the chip is designed for such operation, or is it? It took a while, perhaps putting numbers together, to realize that there is nothing wrong with the circuit, the board, or the chip itself. Simply put, the chip was generating too much heat when all channels were enabled.
It’s easy to have chip functionality, but now I am facing a real problem: How to manage thermals in such a tiny space? I can reduce power by lowering the primary chip voltage, allowing it to be cool enough; however, in such a case, the module will not operate correctly under all specified loading conditions.
Fried Chips Belong in Takeaways, Not in Control Cabinets
Analog control chip with enough intelligence would resolve the problem by regulating the voltage dynamically as per loading conditions. Such functionalities can be found under the terminology of Adaptive Power Switching or Dynamic Power Control.
While Dynamic Power Control (DPC) regulates the voltage and improves power efficiency by up to 90%, it must be implemented on a per-channel basis. This results in an increase in the component count and the space it occupies within the module. DPC finds its application in channel-to-channel isolated control modules, where physical isolation of power supplies per-channel basis are required anyway.
Adaptive Power Switching (APS) employs a more area-efficient approach, by using only two voltage power rails, which can be shared across multiple channels. Switching between voltage rails is done automatically on a per-channel basis, increasing power efficiency by up to 40%. The APS feature is possible to utilise using chips as AD74416H and AD5460.
Figure 1: Temperature difference of the AD74416H Software Configurable I/O chip with APS disabled vs enabled
Fried Chips Are for Fridays, Not for Factory Floors
With intelligent Analog chips and power managing features in place, there is no need for overheating on factory floors or restricting the use of power-demanding channel functions in simultaneous operation. As the industry embarks on the journey of intelligence, having reduced power dissipation allows for smaller form factors and increased reliability.
Adaptive power switching helps devices and systems be more intelligent about their power consumption, driving the future of industry and process control applications, and creating modules more compact and chips less “fried”.
Read all the blogs in the Configurable Industrial I/O series.