# Simple Circuits and Complex Circuits that Perform the same Function

#### NathanielZhu

Joined Dec 5, 2011
50
I've been intrigued by how you can have a whole lot of circuits that all do the same thing.

I'm a beginner....not sure how I will know when I am not since I am learning on my own.
But for example (but this applies to anything not just sine waves) given three circuits that all produce sine waves, where one circuit is hugely more complex than other circuits, then what are the benefits of a complex circuit?

Are complex circuits always better than simpler circuits? Are there examples where a simple circuit is better than a complex circuit?

Are complex circuits just a lot of little simpler circuits combined together?

Are there circuits that can't be made more fancy? Like for example, I see the 555 timer used the way it is and between people, their circuits look similar. But something like the sine wave, there's so many different circuits.

Or Is this a meaningless question? Do circuit designers build circuits bottom up where they just start building and at the end the circuit just HAPPENS to be complex as if it's like an unplanned journey or so designers see an end goal of how complex it should be?   And so on.

#### ISB123

Joined May 21, 2014
1,236
Simpler circuit that does the same job with same quality as the complex one is always better.

#### WBahn

Joined Mar 31, 2012
27,863
Most of it comes down to what your metric is for "better".

You mention sine wave generators. Yes, there are lots of different ways to do this. So let's say that you have a "simple" circuit A and a "complex" circuit B (the quotes are because the very notion of what constitutes "simple" vs. "complex" needs to be spelled out, though if the difference is significant enough, it because reasonably obvious). If you look at the output waveforms and can't tell the difference, the usually the "simple" circuit is preferred. But what if you change the power supply voltage by 10% and the waveform from A changes frequency 2% while the waveform from B changes by 0.02%. If frequency stability as a function of supply voltage is important to you, then maybe circuit B is starting to look more attractive. You could probably name a half dozen or more variables that might be of interest, such as frequency stability as a function of temperature or age, or amplitude stability, or noise, or jitter. Then the "simple" circuit might be simple only because it is built around a very expensive part while the "complex" circuit is complex because it uses much cheaper parts and the complexity is to overcome the limitations of the parts used. So the simple circuit might perform better than the complex circuit, but be sufficiently more expensive that people would use the complex circuit instead.

• absf