Designing an IC is an entirely different discipline than doing a discrete circuit, as the former is not just the integrated version of the latter.
Designing, constructing, testing, and improving circuits—especially those with significant analog content—was always one of my interests. The fact that you could arrange standard active and passive components in various ways to solve problems, achieve different results, adjust operating points, balance trade-offs, overcome shortcomings, and enhance performance simply fascinated me. I suspect such circuit-design activities were a good introduction to “electronics” for many aspiring engineers.
Recently, though, I have been wondering if there’s much need for and future in this type of basic electronic-design activity. Reality is that most circuitry now is embedded within ICs, whether mostly digital, mixed signal, or even primarily analog. Of course, there are still many minimal-function ICs such as op amps or LDOs and countless discrete transistors such as the 2N2902 and 2N2222 transistors sold every year. Nonetheless, most design activity now consists of choosing the appropriate ICs and getting them to work together as intended.
Instead of trying to figure out how to get a few components or an IC to do more than they are normally expected to do, it’s about getting that IC in a real circuit to do what it should be able to do based on its datasheet and evaluation board or reference design. While there may be some adjusting of component values such as the resistance of a current-limiter in an LED circuit or setting a time contact in an RC filter, these are parameter tweaks rather than topology enhancements.
Instead of trying to figure out how to get a few components or an IC to do more than they are normally expected to do, it’s about getting that IC in a real circuit to do what it should be able to do based on its datasheet and evaluation board or reference design. While there may be some adjusting of component values such as the resistance of a current-limiter in a LED circuit or setting a time contact in an RC filter, these are parameter tweaks rather than topology enhancements.
Moving away from classical circuit design
So, do I have firm evidence for my supposition? Yes and no. Many hobbyist and maker sites are focused on showing how to use standard parts, applications notes and reference designs to achieve the project’s objectives, rather than designing from scratch. Furthermore, if you look at the well-known and popular Design Ideas section of EDN, you’ll see that there are fewer new entries. Back in the prime days of do-it-yourself (DIY) circuit design, forums devoted to clever ways to arrange, enhance, and leverage widely-used ICs such as the classic 555 timer and passives, so they could implement unique functions and solve interesting design problems.
On the other hand, I do see lots of innovative, unique, and even dangerous circuits (think Tesla coils) at discussion boards and chat sites. In many cases, these are about more than just a circuit schematic, as the physical construction of the circuit is the real challenge (Figure 1).
Figure 1 Conceptually, simple projects such as this Tesla coil are much more than their schematic diagram indicates. Key challenges are obtaining or building the components and the appropriate physical construction. Source: RIM.org
The trend away from classical circuit design using small-scale discrete components is unavoidable as ICs have become far more than basic building blocks. They are now subsystems and systems with many analog and mixed-signal blocks connected with each other. Moreover, ICs now implement functions which are hard—if not impossible—to duplicate effectively with discrete components (Figure 2).
Figure 2 The classic six-transistor AM radio receiver is a tribute to analog circuit design (upper), but has been made obsolete by the single-chip radio such as the FM receiver (lower), which embodies a more advanced RF front-end and more complicated signal-processing blocks. Sources: AngleFire.com and Electronics-DIY.com
Contrasting worlds of ICs and discrete circuits
Designing an IC is an entirely different discipline than doing a discrete circuit, as the former is not just the integrated version of the latter. The guidelines, constraints, options, rules, tools, and fundamental approaches of each are very different. While there is a loss in flexibility, ICs enable implementation of topologies, which are very difficult to do with discrete components.
There’s an interesting historical connection here. Of the eight founders of Fairchild Semiconductor—also known as the “Traitorous Eight”—who devised the all-important planar transistor fabrication technology in the 1950s, which subsequently led to the creation of ICs, only one had formal electronic engineering and circuit training or experience. The others were physicists, mechanical engineers, a chemist, and a metallurgist.
Wikipedia has an interesting piece on eight of them here, supported by credible references.
I’m not saying that the diminution of classic circuit is necessarily a bad thing. But I do wonder if the reduction in circuit design and modification skillset is fundamentally changing the role of EEs and how they position themselves with respect to design challenges.
Perhaps in the future, there will be a small, elite cadre of design experts who are called upon when needed to solve circuit problems ranging from minor (wrong component value) to serious (unsuitable topology). Then there will be the designers who can craft devices that perform basic functions and also blend multiple functional blocks into a single IC, providing assured end-to-end performance while allowing the IC user to adjust operating parameters but not change topology or basic functionality.
In the middle will be the vast majority of engineers, trying to get their products designed by combining ICs, fine-tuning performance, writing software (can’t avoid that), working through system integration issues, dealing with EMI/RFI and regulatory mandates, and similar. At the same time, DIY experimenters will do their projects using Arduino, Raspberry Pi and similar units with a minimum of external circuitry.
What’s your perspective on the changing role of classic circuit design in the engineering world? Are you concerned, or actually relieved? Do you see it as a potential problem as we lose that expertise or as an opportunity to take the discipline of circuit design to a new level?
This article was originally published on Planet Analog.
Bill Schweber is an electronics engineer who has written three textbooks on electronic communications systems, as well as hundreds of technical articles, opinion columns, and product features. In past roles, he worked as a technical website manager for multiple EE Times sites and as both Executive Editor and Analog Editor at EDN. At Analog Devices, he was in marketing communications; as a result, he has been on both sides of the technical PR function, presenting company products, stories, and messages to the media and also as the recipient of these. Prior to the marcom role at Analog, Bill was Associate Editor of its respected technical journal, and also worked in its product marketing and applications engineering groups. Before those roles, he was at Instron Corp., doing hands-on analog- and power-circuit design and systems integration for materials-testing machine controls. He has a BSEE from Columbia University and an MSEE from the University of Massachusetts, is a Registered Professional Engineer, and holds an Advanced Class amateur radio license. He has also planned, written, and presented online courses on a variety of engineering topics, including MOSFET basics, ADC selection, and driving LEDs.