Why Analog Electronics is beautiful

Analog Electronics is beautiful? Huh? What are you smoking? Surely not! How could it be? In University we spend years gazing at simple circuits with a couple of resistors maybe a capacitor or two, transistors connected in various ways and op-amps for both the DC scenario and AC to calculate voltages and currents in the circuit and never have to use any of this in the real world right??

Well it turns out in the real world we spend most of our time doing these things:

  1. Creating a basic circuit concept from requirements
  2. Selecting parts to realise the circuit by reading datasheets and considering cost, lead times etc
  3. Drawing the circuit in a CAD tool
  4. Drawing the PCB in a CAD tool
  5. Get the PCB manufactured
  6. Open a box to take out your PCB which will 100% work the first time (Note: Not necessarily ;) )
  7. Slap the board on your desk, apply power and cross your fingers (Fire/Smoke may be observed during this time)
  8. Perform various measurements and then pass it over to the Software Engineers (If they think there are hardware problems, just ask them to fix it with Software and proceed to slowly walk away ;))

So where in the above do we sit down and crunch numbers for the circuit? The only spot you may perform some back of the envelope calculations is when you create the basic circuit concept but even then you can let the simulator do it for you!

Okay so I've spent years at uni crunching numbers only to be served a dish of reality which consists of mainly designing and testing circuits as well as reading datasheets? Whaa? Yep, that's right, and the good news is that all of those steps are a lot of fun (okay the datasheets are a harder sell, but one of the great things with datasheets is I guarantee you will always learn something new with each one you read). Now that I've hopefully wet your appetite, let's take a closer look at what a Hardware Engineer would actually typically do during steps 1 and 8.

Circuit Design/Testing

It is week 1 of your internship/cadetship and you've been assigned to a buddy/mentor to give you tasks as well as be your first point of contact for help, great that's all well and good and then he gives you your first task which is to measure the performance of one of the Switch Mode Power Supply, SMPS, circuits on a PCB (Step 8). It's at this point you may start to go white in the face wondering what all of the words mean but if you're lucky you may have heard of a Switch Mode Power Supply but never had to measure the performance of one. The circuit might look something like below...

ADP2118 SMPS circuit

Yep, that's right, as an intern you'll be wondering where on earth do I start?! Well if you've been assigned the right mentor he'll show you what he means by measure the performance by turning the scope on at your desk and probing where Vout is shown in the above circuit for example. You see a waveform on the scope which looks more or less like a straight line hovering around 3.3V with this jittery stuff riding on the flat line, cool you think, job done it looks good. Not quite, you see in the real world that jittery stuff can literally ruin your day or even worse cause failures in your product when used "in the field" (More on this in the course and other blog posts). But the good news is that this is where the art and beauty comes into play, the reality is that you will ask questions such as is this noise acceptable? And if yes, great, if not, time to go back to the drawing board and typically either tweak component values, such as that inductor and cap next to Vout or even change the SMPS part or even change the circuit topology completely. This can be a very creative process and it brings engineers a lot of satisfaction seeing it iteratively get better until the point you can all say yep that'll do the job, onto the next part of the circuit.

As you acquire more experience you will start getting involved with the initial circuit concept (Steps 1-5), perform more advanced testing (Step 8 again), (Yep there is even a fine art to this, trust me or ask any HW Engineer!!!) draw the circuit and potentially PCB (Steps 6-7) too and help the S/W guys with hardware bring up which can be the most enjoyable part of it all as you never quite know how it will go and when/if it works it is truly delightful to everyone who played their part.

So this is why Analog Electronics is beautiful. As you spend more time doing it you develop so much more of an appreciation for things like transistors, that part that does so much heavy lifting and never complains (unless you didn't protect the poor guy from heat properly or shorted him out) or even capacitors which get charged/discharged all day by FPGA's/Micro's when I/O's change, and so much more. Every single day you will learn something new.

Stay tuned in the Analog Electronics course for additional material on all of this great stuff!