Learning Analog / Mixed Signal Design the Efficient Way

My secrets to self teaching complex subjects and explaining them as simply as possible

“Circuit Diagram” (xkcd #730) by Randall Munroe — https://xkcd.com/730/ — CC BY-NC 2.5: https://creativecommons.org/licenses/by-nc/2.5/

Editors Note: 6/23/26: Throughout this post, I added several links to my deep dive posts I wrote after I originally wrote this post give you a broad perspective into the way I applied this methodology to breaking down complexity in those posts, including a fully free SAR ADC post.

There is a paywall in the last two sections where I describe the process of breaking down architecture level tradeoffs and building up intuition of more complex blocks from simpler ones with a folded cascode OTA as an example.

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Most frustration in learning hard things comes from starting at the wrong zoom level.

I tried learning complicated things in analog design too early, like folded-cascode OTAs and PLLs in undergrad. I would get stuck fast — not because I wasn’t capable, but because I was being pulled into details before I had a mental frame to hang them on.

The turning point for me was realizing:

Complex topics don’t become easier when you memorize more details or view more lecture videos.
They become easier when you build better foundations and organize the details logically.

Here are the four moves I use to understand complex fields:

• Pick one foundation source (one teacher)

• Bottom-up summary (principle of operation)

• 🔒Top-down map (hierarchical outline of concepts)

• 🔒Relate advanced concepts from simpler ones (Folded Cascode OTA)

I’m going to use a few real analog design technical examples to make the method visible (because analog can get wonderfully complex).

A Survey of the Analog Design Process: From System Architecture to Transistor level Design

Choose your foundation learning sources carefully

When learning a complex field, start with one “foundation source” that’s known for clarity, then translate it into your own mental model.

• In analog design, that might be Razavis book and lecture videos.

• In machine learning, that might be Andrew Ng’s Coursera courses.

The specific source matters less than the principle: pick one clear teacher, build your base, and then other authors start becoming more clear because you finally share the same “background assumptions.”

Once you’ve identified your foundation sources, the next step is straightforward: work through the material — read the chapters or take the course.

Bottom up Summary (Principle of Operation)

Read dense sections slowly and translate the author’s explanation into a “principle of operation” summary in your own words.

Example: Understanding Switching Behavior of a single transistor in Power Electronics

This method matters especially in power electronics, because switching waveforms can look intimidating at first glance.

A switching cycle has a lot happening in a short time:

• different devices turning on/off,

• different current paths,

• different energy transfers

all across multiple time intervals. If you try to absorb the full diagram in one gulp, it becomes confusing. Take the following switching diagram for a gate driver driving a single transistor:

Source: “Power Management Integrated Circuits” by Wicht

So here’s what I do:

• I read the author’s explanation of how the circuit works. Typically this is very dense and has a lot of equations for rigor.

• As I’m reading, I break down the switching diagram into three intervals.

• In each time interval I’m writing a one line summary of what each voltage / current is doing.

  • T1: the “precharge phase” :

    • V_gs increases to V_th

  • T2: the “miller phase”:

    • V_gs increases slowly as V_ds transitions from V_bat to 0

  • T3: end of “miller phase” :

    • I_load reaches its peak

    • V_gs continues charging up to its peak value

• I bold important concepts to make them easier on the eye to reference later (like the “Miller plateau”.)

Here are my personal notes where I write the principle of operation in my own words as I went through this section the first time:

You might not explain the principle of operation the same way as me, but the point is that:

You summarize the material in a way you understand.

I have a post on the fundamentals of buck converters where I used this method to break down the principle of operations:

The Art of Power Management: Balancing Losses, Parasitics, and Tradeoffs in Buck Converters

Top down - Hierarchical Breakdown of Concepts

I break down concepts broken down in a bullet format from high level concepts to low level ones that helps quickly “cue” the concept and retrieve the information I summarized earlier. This can apply to both architecture level and complex analog blocks

Pushing the Speed Limit: Designing Transceivers for the 224 and 448Gbps Scaling Era

The Phase Locked Loop: A Primer

Here I will illustrate this with an ADC.

Example: ADC Architectures and Tradeoffs

I started reading the basics of ADCs on “Analog Integrated Circuit Design” and create a top level hierarchy of “textbook” topologies for various applications:

• ADCs

  • Low - medium speed, high accuracy

    • Integrating

    • Oversampling / ΔΣ

  • Medium speed, medium accuracy

    • SAR

    • Algorithmic

  • High speed, low to medium accuracy

    • Flash

    • Two step

    • Interpolating

    • Folding

    • Pipelined

    • Time-interleaved

One popular ADC is the SAR ADC. Check out the important design considerations in this post:

The SAR ADC Architecture: Tradeoffs for High-Speed, High Resolution, and Low-Power Design

Under each of these topologies, I expand into more detailed sub-architectures, including: