Common Electrical Engineering Interview Topics

Luke Metro
Jan 29 · 5 min read

Over the past few years, a software engineer interview prep industry has emerged, from Cracking the Coding Interview to Leetcode. Sadly, no similar resource currently exists for electrical engineers.

But in my experience interviewing for jobs, most interviewers ask questions about a common set of subjects. This is a quick study guide of common interview topics that I encountered while interviewing for jobs recently.

Disclaimer: this list was mostly acquired by interviewing for generalist, PCB-level EE positions at Bay Area tech companies. Sorry, IC designers! I tried to add links to useful resources where I could find them.

SPI and I2C

Explaining SPI and I2C seems to be our industry’s version of fizzbuzz. Since these interfaces are so ubiquitous, it’s a common filter question on phone screens to check for basic experience with digital electronics. In addition, comparing the interfaces is a good way to see if someone can discuss engineering trade-offs.

SPI

I2C

  • Sparkfun Overview

Both: Compare and Contrast

  • Speed

Both: Potential Implementation Problems

  • Clock Skew

Other Host Interfaces

  • Differential vs. Single-Ended Signaling

Power Converters

Again, these questions are common because they are both very important and a good way to see how a candidate discusses design trade-offs.

Interview Topics

  • Big 3 switching topologies: buck converters, boost converters, and buck-boost converters. Know how each uses an inductor to efficiently increase or reduce the input voltage. Also know how to choose a frequency, and how that affects conversion losses and inductor size.

Basic PCB CAD

Most systems-level electrical engineering jobs involve making printed circuit boards in some form. These jobs will require knowledge of at least one major PCB CAD software package. Altium, Cadence, and Eagle are the most popular, though they all have a similar workflow.

At smaller companies, engineers typically do the whole process, from schematic capture to PCB layout and routing. Large companies often have separate engineers doing board layout and routing, though the process is supervised by the engineer who designed the schematic.

PCB CAD Interview Topics

  • Basic trace and plane sizing for current loads.

Amplifiers

Most systems-level EE jobs don’t involve making transistor amps, so questions tend to focus on op-amp based designs.

Amplifier Interview Topics

  • Op-Amp topologies: Inverting, non-inverting, and differential amplifiers.

Analog-to-Digital Converters (ADCs)

  • Common topologies: pipeline, sigma-delta, successive approximation

Miscellaneous

These are the less-common questions that I’ve seen, and they tend to vary more greatly from job-to-job. My interviewers at Apple did not ask about motor control, but be prepared if you’re interviewing at the hot new scooter startup.

Miscellaneous Interview Topics

  • Microcontroller selection: How to go about picking an appropriate microcontroller for a certain problem. Common criteria are I/O, footprint, low power modes, and performance (clock rate and instruction set).

And Lastly …

Each of these topics has a ton of depth, far more than can be appreciated in a quick blog post. Last-minute prep can only take you so far.

If there’s anything I missed, DM me on Twitter and I’ll add it to the list! I’m also interested in putting together a list of sample circuit and system design problems, so also send me those!