Preparing Circuits Online: Modeling and Simulation for IoT Devices

Many folks are referring to the fast-growing IoT industry as the fourth industrial revolution. The first industrial revolution being steam power, the second as electricity, and the third as information technology, it makes sense that the internet of things would be the fourth.

Unlike some of the more bumbling turnovers in previous revolutions, the IoT is using fully the technology available to make creating IoT devices and electronics easier than ever. With the ability to make your doorbell sync with your phone, your car communicate with your watch, or chips embedded in your body giving data to monitors and sensors, the revolution is constantly innovating ways to make these devices more useful. 

The core of this revolution is in making these IoT devices more approachable, affordable, and ubiquitous than ever before. We have the technology, why not use it to make any facet of our lives easier? Before you jump into making your own device, keep in mind these few principles. 

Simulation, Modeling, and IoT Devices

While IoT devices aren’t particularly new these days, and therefore their design challenges can be mostly accounted for, SPICE tools can still be of great service in bringing the circuits online. Even the most basic of SPICE tools should be able to help with signal interactivity, thermal considerations, and impedance matching for your IoT devices. 

What makes IoT difficult from a design standpoint, typically, is the longevity and unique use-scenarios involving the electronic. Thankfully, strong SPICE tools should also be around to provide you accurate analysis of component tolerances based on your power supply network, calculate board modifications based on target manufacturing yield, and yield likelihoods for failure and sensitivity analysis to determine where, if at all, your device might be at risk. 

Utilizing a smart SPICE engine can help with your designs at every step of the cycle; however, there are other layout and design considerations you might take to bring circuits online in a smart fashion. 

Modular Design Approaches Step by Interactive Step

With all the new and, quite frankly, amazing circuit designs emerging from companies far and wide, it will become increasingly trivial to simply add ‘plug and play’ circuits into your online devices in order to achieve an otherwise complex request. Largely, you will not have to do the grunt work of knowing all there is to know about designing circuits when you can find them online. 

A personal example of this is achieving IoT communication protocols in a simple speaker design. After taking the time to design the power amps and crossover networks, it was time to bring my circuit online. The learning curve that I found was far steeper than I cared to climb. Instead, I scoured the web and found a few pre-designed boards that got me close to what I needed. This process could have taken lightyears longer if I started a wifi board on my own.

Incorporating out-of-house modular designs can easily get you where you need to go with whatever IoT device you have in mind. After you’ve nailed down the functionality, you can then consider working backward and look to reverse engineer the modular boards to integrate them properly. There is plenty of potential content that falls under this topic, but we’ll keep it simple and leave it at this for now.

Work With New Packaging Technology

Chip packaging is getting smaller, thinner, and more efficient. This momentum will certainly be carrying us far and away from traditional tech and allowing us to place our boards in smaller, thinner, and more efficient chassis. Although manufacturers will require the necessary capabilities to implement, the benefits may outweigh the costs.

Here are just a few examples of new chip tech:

• SiP (System in Package) is as it sounds; a system level design encased in a single module (package) which usually can perform the necessary functions of a full electronic system. This allows easier integration digital, analog, and RF into a single chip.

• MCM (Multi Chip Modules) allow form factors to remain thin while integrating multiple chips onto a single substrate so that we can treat it as a single IC.

• 3DICs (3-Dimensional IC’s) allow us to vertically stack IC’s (say what?!) while keeping profiles thin, and power consumption to a minimum.

Not a bad start to new chip tech. I am personally very eager to see what future chip endeavors hold as they are the cornerstone of any form and function of our devices and will change the way boards are developed and manufactured.

Integrating modular board designs can help you achieve short-term success on an otherwise steep learning curve.

Lack of Real Estate

As you’ve likely heard a hundred times before, the age of having ample amounts of board room to work with is all but gone. Smaller, faster, more efficient - these are the pillars that will form IoT devices.

The other day, I took apart an old (big) stereo amplifier and saw an unbelievable amount of space between components. The PCB must have been a full 8.5” x 11” with only a few dozen components. Nothing will exist like this in the upcoming design era.

Stereo systems nowadays are very sleek and efficient with their space. Most speakers have amps already included in them making the need for peripheral equipment non-existent. This trend of ‘less is more’ is extending far beyond the audio realm. TV’s having the cable box, video game console, and any extras integrated into them is a fast approaching practice.

Planning out power budgets on battery-powered IoT devices will put power budgets on the top of your priorities list.

Power Budget Priorities

With many IoT devices being powered by battery sources instead of a seemingly unlimited amount of AC, keeping in mind your device’s power distribution and power budget is crucial. When thinking about your device and the needs that your device has, one question you should always have in mind is how actively you will be using it. 

AC-DC simulation with SPICE simulators is not only possible but easily accessible. In fact, any kind of power supply management can be managed efficiently with SPICE simulation. Showing voltage flow, heat dissipation, and power necessities on your board can be accounted for and modified quickly between layout and simulation. 

There are options for keeping your device’s power consumption managed. You might consider software options like device sleep-cycles, and low-power modes that can make it so when you’re not heavily using the device, it will reduce its power necessities. Alternatively, you could work through more circuit-oriented approaches such as low-voltage Bluetooth designs, or choosing the proper microcontroller for your device to keep your circuit online. 

Remember, while it is certainly possible to make your device communicate with a network of other electronics, the more frequencies and transmissions active will tend to make your electronic’s power necessities rise too. 

Cadence's PCB design and analysis tools are not only capable but exceedingly potent for working through consumer electronics and IoT devices. Especially OrCAD PSpice Simulator, which is capable of modeling heat, voltage, current, temperature variations, component sensitivity, and impedance amongst others with ease.  

If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.