In a world enamored with all things digital, analog just refuses to die. It seems as though analog may be old-fashioned. After all, everything we have and use today is digital. Our cameras, telephones, television, communications systems, and everything else seems to have gone digital. Doesn’t this make analog irrelevant?
The truth is, the natural world is analog. Digital is black and white, like flipping a light switch on and off, while analog is shades of grey, like the rising and setting of the sun. Every sound you utter and hear, everything you see or feel are all carried on analog waves and sensed in the analog domain.
It is true that everything analog can be digitized, but the more things turn digital, the more the world needs the analog domain. Everything we sense is analog and to digitize these analog signals we need analog circuitry. (Yes, analog-to-digital converters are considered to be analog.) Once the signals are in the digital domain, we modify them as needed, store them and/or use them to make decisions. If these signals are needed to operate upon the real world, they often need to be converted back into analog signals. Examples of this would be to play back sound and/or video. An example where the signal need not be converted back to analog would be to turn something on or off.
As it turns out, while digital processing generally yields a more consistent result, careful analog design can also have very consistent results, it is just not as easy as it is with digital processing. This is primarily because of the drifts with time and temperature, but these can be overcome through proper calibration techniques. Many drifts in digital circuits tend to be more benign, although drifts in timing can cause problems in circuits that are not properly designed.
When it comes to speed and power consumption, analog designs tend to have the edge, although this may not always be true. Generally, however, to get analog speeds with digital circuits it is necessary to work at very high clock rates, which tends to increase power consumption.
The media tends not to want to write about analog engineering, most people today do not really understand it, and students do not want to study it.
Although not true, students tend to think that analog engineering is more difficult than is digital engineering. It is a bit different than is digital engineering, but digital work today requires knowledge of analog techniques. If you think that the concept of signal integrity, power integrity, signal reflection, high speed digital signaling and the like are digital issues, I suggest that you think again. Analog engineers have always been concerned with these. It has only been since the advent of very high data rates where signal rise and fall times become a significant part of the bit time that the digital world became interested in these issues. To handle today’s high speed digital signals, then, it is imperative that the digital engineer understand some analog technique.
Analog is definitely here to stay. The biggest change for analog engineers that I see is that today is that they are required to be more in line with mixed signal engineers. They are expected to understand and be able to use processors, FPGAs, and PLDs and be able to do some programming, most notably in one of the “C” languages (C, C++, C#).
In my view, today’s world is both analog and digital. The natural world, of course is analog, resulting in the need for analog engineering. Yet, we desire to process things in the digital domain, so there is a definite need for digital engineering. We need both analog and digital engineering today. Furthermore, engineers need a familiarity with both areas, although specializing in one or the other is probably the best since it is very difficult to be all things in every area. Likewise, it makes sense that an engineer further specialize within one of these areas. For example, a digital engineer may specialize, for example, in data communications, FPGA implementation or DSP while an analog engineer may specialize in RF communications, power supply design, sensors or data conversion.
As for the educational community, our colleges and universities serve their students well when they require students to take some analog classes. Unfortunately, the student is not the best judge of what they need and may opt out of schools with this requirement. What a shame.
