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Elementary, Mr. Watson: Why Your PCB Looks Like a Studio Apartment

In November 2022, I wrote a column called "Is Your Bathroom in the Kitchen?" This piece related a bizarre real estate listing that emerged out of St. Louis that had architects scratching their heads and interior designers cringing. Nestled in the historic Central West End sat a 200-square-foot apartment that completely defied logic. It wasn't the size that raised eyebrows, it was the layout.

Right in the heart of the kitchen was a fully plumbed bathroom: a toilet, tub, and sink sat smack in the middle of the culinary workspace. My first thought was, “How does this work?” Imagine sautéing onions while someone was taking a shower three feet away, or preparing dinner while someone was seated on the toilet. This wasn't an open-air plan. There was no floor plan at all.

I chuckled when I first saw this, assuming it was a joke or some creative Photoshop prank. No, it was real. The longer I examined the photos, the more "conveniences" came to light. Need to reach the top cabinets? The toilet doubles as a stepstool. Doing dishes? Skip the sink and use the tub. Need a soak while your lasagna bakes? Go right ahead. This truly was efficiency taken to absurd extremes.

Functionality? Check (but barely). Sanitation? Questionable. Logic? Completely missing.

Was this designed as an act of desperation or maybe a misguided attempt at minimalism? Perhaps this was the work of an architect who had never lived in a small space before and thought, "Why not put everything in one room?"

One thing was clear: This wasn't just quirky. It was a textbook case of what happens when floor planning goes off the rails and a cautionary tale for anyone designing with limited space. When form doesn't follow function, you don't get innovation; you get a bathtub next to your blender.

Here's the kicker: While that's rare in real estate, it's shockingly common in PCB design. Instead of placing a tub next to the stove, it's an RF front end snuggled up next to a buck converter or a high-speed digital line doing a tango across an analog ground plane. It's the engineering equivalent of brushing your teeth while frying an egg, and it's just as messy.

Getting in the Zone
PCB floor planning is very similar to architectural zoning. Just as your city’s code enforcement wouldn't allow a nightclub to open next to a nursery, a well-planned board separates functional "rooms" like RF, analog, digital, and power into clearly defined, isolated zones. Each area has its own crucial behavioral personality: RF requires quiet, analog needs stability, digital is noisy and fast, and power is often downright messy. When these zones are properly organized, signals flow logically, return paths are clean, and the board performs like a well-coordinated machine.

But in practice, some PCB layouts look like they were pieced together at 2 a.m. after three energy drinks and a long night of denial, with components scattered without rhyme or reason. You might see a sensitive RF front end wedged between a buck converter and a high-speed microcontroller, as if nobody told the designer that noise leaks. Power regulators hum and buzz like a karaoke machine cranked up in the middle of a library, blasting EMI into fragile RF traces that were trying to do their job and pass a clean signal. Digital clocks glitch away within millimeters of an op-amp desperately trying to hold onto a millivolt-level of accuracy. All of this is done in the name of convenience or creative engineering gone wrong.

The bottom line is that functional zones aren't just suggestions—they're non-negotiable. Treat your board like a miniature city and give each zone the space and shielding it deserves. Otherwise, you're not designing a PCB but rather an electrical mosh pit, and everyone is invited and won't play nicely together.

The problem with the PCB floor plan is that it is often totally out of the designer’s control. The component placement is often treated as a mechanical process rather than an electronic one. Designers typically constrain themselves by the physical requirements of the product enclosure. Connectors must align with external ports, mounting holes must match standoffs, and components like buttons, LEDs, or displays are fixed in location by the industrial design. These mechanical requirements often dictate where components must be placed before any consideration is given to electrical performance. As a result, large portions of the board are laid out based on fit and form rather than function.

There’s a tendency to prioritize space efficiency and routing convenience over signal integrity. Components are arranged to minimize board size or make routing easier, without fully considering how signals flow between them or where return paths will travel. That leads to noise infiltrating the entire design, finding every possible path to interfere with its neighboring circuit. When component placement is driven by the mechanical team instead of the electronic team, the result may be a compact, visually clean board, but one that fails to perform as expected.

The apartment design didn't happen because someone hated logical design. It probably happened because they were trying to make things fit. They crammed it all into one room and called it a day. It's a failure of planning driven by mechanical convenience, not functional flow. Sound familiar?

I’ve also observed that once the schematic is pushed into the PCB and the mechanical team takes over component placement, designers often overlook revisiting and understanding the functional relationships established in the schematic.

In that schematic, components like an op-amp and its filter, or a processor and its decoupling capacitors, are logically grouped and connected. But during layout, especially when driven by those pesky mechanical concerns, those groupings often begin to fall apart faster than a ’90s boy band after their first album. The op-amp is placed on one side, with its filter components elsewhere, and the decoupling caps end up far from the IC they're supposed to support. But don't worry, they're all still connected by the warm, fuzzy interference radiating from that ever-helpful buck converter humming away in the middle of your PCB.

The floor plan isn't just about layout; it starts with truly understanding your schematic. Placing parts without understanding their role is like building a house without knowing which walls are load-bearing, or worse, like putting the bathroom in the middle of the kitchen. Good PCB design doesn't just ask what goes where, it demands that you understand why.

This column originally appeared in the August 2025 issue of Design007 Magazine.