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Which Is Better – Analog or Digital?

When I was a student intern in 1985, I worked for Loral in Pasadena. I had a great time that summer, learning from actual problem-solving engineers.

At the end of the summer, my supervisor told me, “Stay in analog. Digital design is a dime-a-dozen and will be very popular. But staying in analog will always lead to a job — it's an analog world and people will have to convert the signal out of the wall to something the digital people can use.” This statement has stayed with me even though now people say today's world is digital. Is it really? Several conditions cannot be directly processed digitally.

All of our senses result in an analog processing for our brains. We hear multiple octaves of tones and at many levels of volume. We see a myriad of colors, not black and white. We feel different levels of pressure, not just one level or none. We feel various degrees of temperature, and not necessarily hot or cold. Taste and smell are even more analog than what I have presented thus far.

We can take the analog world to non-human applications as well. Take the nearby wall outlet. I say that a digital person sees the output as high or low. The analog engineer in me responds, “What do you want from it?”

As I go about in life, other things become quite interesting to the digital realm. Watch closely to the other drivers around you. Or feel carefully how the driver of the car you are in is controlling the speed. There are the analog drivers that accelerate up the hill in order to maintain speed and back off the accelerator on the downhill to let the engine slow the car. The digital driver will hold the pedal at a set value up the hill and the car will slow down, yet go faster on the downhill. Even on the level road, I see the digital drivers in action — brake or gas — stop and go. The analog driver will get better mileage than the digital driver in these instances.

The current electronic trend is digital power supplies. Look carefully at the overall frequency response of the digital power supply versus the old analog power supply. Where the change in power demand is slow, the digital supply can be a better performer since it can adjust the power supply parameters to be more efficient at low-power levels as compared to high power. But when the change in power demand is rapid, such as a computer's processor power, analog still dominates with the MHz switch-mode supply.

So, is digital really better than analog? What stories do you have that can prove or disprove that analog is more important than digital?

8 comments on “Which Is Better – Analog or Digital?

  1. eafpres
    March 8, 2013

    Frequently during my many trips to China over the years, I have had to take taxis to get around.  Traffic in China is an “experience”; your comment on digital drivers reminded me of a phenomenon I've observed over and over with Shanghai, Beijing, and other Chinese-city taxi drivers.  On a relatively open road, with lots of space behind and in front of the taxi, they will mash the accelerator and speed up, say, 5 km/h; then they lift their foot, and slow down -5 km/h, and repeat.  Some of them can get into a kind of resonance that is pretty tough if you are seasick prone.  So I vote for more analog taxi drivers, please!

  2. RedDerek
    March 8, 2013

    Riding in a Chinese taxi is more than a thrill ride. I remember them well when I visited Shanghai and Hong Kong. Though Shanghai has much more room to have them show their capabilities. Traffic lights seemed to be an option in a few cases as well. They drive digitally since that is the age they are in. haha

  3. jkvasan
    March 11, 2013

    @Derek,

    Quite an interesting post, this one. Simple yet kindles some old memories of heated debates between the hard-working analog engineer and the easy-going digital one.

    Digital is at best an approximation of analog, can never get to the exact analog level. Better the digital resolution, closer is the output to the input. I still relish listening to music in my father's old AM valve radio. 

    When it comes to processing, digital scores more, I guess.

  4. SunitaT
    March 11, 2013

    As far as music and film are concerned, digital is quickly taking over
    because of its convenience. I think that On Demand digital television
    will replace scheduled programming in the very near future. It makes
    sense to let the viewer have more power over their television
    experience, and offering the customer the ability to watch whatever
    shows they want whenever they want seems like the next logical step in
    the evolution of television. Some On Demand service offers this to
    some degree. This freedom simply isn't possible with analog
    technology.

  5. Netcrawl
    March 11, 2013

    Interesting article @derek, thansk for the share! about what is better-Analog or Digital? I would go for digital-first, we are now entering into a new world, a post-PC era- its a digital world where almost everything are web connected. From smartphone to PC. And digital are fast becoming the next trend and backbone- our future depend on it, it far more convinient and much more cost-effective than analog. And last its has huge potentials.  

  6. David Maciel Silva
    March 11, 2013

    We're really going through a time of change, and increasingly digital circuits …

    But I still believe that we can not say that digital systems are better than analog, one depending on the other end …

    Right now we have large digital resources, but it would have no understanding of analogue signals?

  7. Kufman01
    March 20, 2013

    In the world of high power systems, analog is still the way to go.  Digital is nice for sending signals over long distances but analog is the best for calculating error signals.  The world is analog and digital is just a sampled approximation. 

  8. Brad Albing
    March 20, 2013

    My 2 cents on the how power consideration, from 2 separate product perspectives (but leading to similar conclusions):

    Power supplies – I'm starting to favor digital power supplies in applications where the power draw is high and a sophisticated supply is needed – status and error reporting, current sharing, hot-swap capability, etc.

    Audio – For high-power amplifiers, I'll go with a class-D.

    Watch for a blog on these topics soon.

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