Scott Witcher on Power Integrity, Systems Thinking, and Humble Leadership

Scott Witcher didn’t set out to become one of the sharpest voices in power integrity. In fact, he thought he’d be doing Fourier transforms (FFTs) and signal processing for the rest of his life. But somewhere between designing PCBs for satellites and sitting in on his first DesignCon tutorial, he caught a different rhythm.

“When I attended a power integrity presentation for the first time, something about the topic immediately spoke to me. I wouldn’t go so far as to say I heard the music, but I certainly caught a few notes right off the bat.”

That music is power integrity (PI) — a discipline that, while invisible on a schematic, determines whether the world’s fastest chips compute reliably or collapse into chaos. For Witcher, PI is more than just stable voltage rails, it’s a way of thinking about hardware design.

“Power integrity is a big topic nowadays and so it keeps me busy,” he says. “What probably sounded like science fiction a decade ago is now normal, so it keeps you on your toes. There’s never a dull day.”

In our conversation, Witcher mapped out not just the technical contours of PI, but a philosophy of engineering that blends rigor with curiosity — an ethos at the heart of Hardware Rich Development.

Baptism by Fire: A Satellite and 1500 Pins

Witcher’s initiation into hardware was anything but gentle. Fresh at Northrop Grumman, he was handed responsibility for a mixed-signal PCB destined for space.

“The pressure was on instantly. My first design involved two 1500-pin FPGAs, digital-to-analog converters, and high-speed SerDes – and there I was, barely knowing how to navigate a component datasheet and completely unfamiliar with what a stackup even was. The risk of face planting was incredibly high.”

Most new engineers would have faked their way through, but Witcher did the opposite. “I had to learn really quick that it was okay to admit you don’t know and to find good help.”

That humility became a superpower. He cultivated mentors, built relationships with subject matter experts, and realized that hardware design punishes posturing. “The lab is going to expose you anyway. Admitting you don’t know can be the cheapest insurance there is.”

This mindset — curiosity mixed with rigor — would carry him through his career.

The Drive of the Impossible

Every engineer eventually faces a design that seems impossible. The spec sheet contradicts itself. The thermal envelope suffocates every option. The stackup cannot satisfy both signal and power constraints. These moments are not distractions from engineering; they are where the discipline is proven. Scott Witcher remembers it clearly. His first PCB design demanded more than skill. It required humility, mentors, and the ability to ask questions before failure became too expensive.

Impossible problems act as crucibles. They strip away the notion that engineering is just formulas applied to tidy constraints. Witcher’s own description fits: “Power integrity is Maxwell’s Equations meets Murphy’s Law.” A model that looks clean could break under measurement. A rail that looks flat on a schematic could ripple under load. Resonances appear where no specification mentioned them. Engineers are forced back to fundamentals and forced to confront the limits of their own assumptions.

These challenges also summon creativity. Wrestling with constraints clarifies priorities. Negotiating tradeoffs between cost, copper thickness, ripple, and EMI teaches what really matters for a system to survive. As Witcher puts it, “Not perfection — balance. If you think you’ve found the flawless solution, you probably haven’t considered all the tradeoffs.”

The “impossible” does more than refine technical skill. It shapes character. Teams learn humility when the bench exposes their errors. Leaders learn patience when progress comes only through repeated iteration. Organizations gain resilience when difficult projects force disciplines to work together rather than apart.

In this sense, the impossible is not an obstacle to engineering progress but the engine of it. Advances in hardware, from spacecraft avionics to gigawatt data centers, come from engineers who faced contradictions head-on, who accepted that failure is part of the process, and who found in those failures the path to better understanding.

The Wild West of PI

At first glance, PI might seem like just another checkbox on a long design to-do list. But Witcher insists it’s uniquely unruly.

“Inductance is the enemy. Everything that I work on is touched by that. But I would say what makes power integrity fun and challenging is that it’s sort of the Wild West… Power integrity usually lacks the precise requirements seen in signal integrity, so it forces you to lean a lot more on intuition and sound engineering judgment.”

Unlike signal transmission lines, which often have well-defined 50 or 100 ohm standards, PI engineers operate without universal specifications. Every chip, every stackup, every package changes the equation.

“You have to impose your own PI requirements a lot of the time,” Witcher explains. Target impedance, often treated like gospel, is at best an approximation. “If you ask 10 power integrity engineers to calculate the target impedance, you’ll likely get 10 different answers.”

The lack of clarity isn’t a flaw — it’s the defining feature. PI forces engineers to fall back on first principles, to embrace intuition, and to accept that there won’t always be crystal-clear constraints.

Resonance, Q-Factor, and the Physics of Stability

Where many engineers chase rules of thumb, Witcher found grounding in resonance and Q-factor.

He became fascinated with Q as a ubiquitous concept. “Q is a remarkable parameter. Chemists use it for spectral lines of atoms, physicists use it to describe simple harmonic motion, and PI engineers use it to quantify impedance flatness. PI is at the nexus of several hardware disciplines, and Q seamlessly bridges the silos between them.”

The lesson? Low-Q systems are stable and well-damped, while high-Q systems oscillate like bridges collapsing under resonance.

“Power distribution networks are the exact opposite of oscillators. We do not want them oscillating… we want them to be like the shock absorbers in the suspension of your car. Handle those nasty potholes and quickly return to steady state.”

It’s an elegant translation: physics as metaphor, and Q-factor as a unifying concept.

Measurement and the Hard Truth about Simulations

Every engineer has cursed a simulation at some point. Witcher has a more systemic critique.

“Most power integrity simulations that I’ve seen in my career model voltage regulators as passive linear circuits even though they’re active nonlinear devices. Capacitor models are also notoriously inaccurate.”

These deficiencies can lead to false conclusions. Models can be incomplete, capacitor libraries can lack real bias data, and VRM behavior rarely fits neat assumptions. That’s why he champions measurement-based models. “I heard a saying a while ago that nobody trusts a simulation except the person who did it, but everybody trusts a measurement except the person who did it. To avoid adding to the garbage in, garbage out stigma of simulations, model hygiene via measurement correlation is non-negotiable.”

For Witcher, oscilloscopes and vector network analyzers are not optional. They’re the final court of appeal. Even “messy” probing under dynamic load is better than “blind assumptions.”

Mentorship and Passing the Baton

Throughout his career, Witcher has leaned heavily on mentors — and now pays that forward.

“Nothing is worse than your design not working properly after it’s been manufactured. Re-spins are extremely expensive, so inviting early critique is your best bet.”

The key is approaching mentorship with respect for the wisdom of experience. “If you find someone that’s willing to teach, respect the relationship by showing effort and enthusiasm. Don’t just come up and say, ‘Can you give me the answer?’ because that cheapens the time they’ve invested in their craft. But if you say, ‘Here’s what I tried, it’s not working, what am I missing?’ I’ve never seen an experienced engineer respond negatively to that.”

This curiosity compounds. Sitting with seasoned engineers, watching how PI failures manifest in the field, learning how constraints ripple through designs — these broadened perspectives make better system thinkers.

“Being able to break a problem down into small digestible pieces and communicate in first principles, that’s a primary differentiator in engineering careers.”

Witcher admits he’s learned that lesson the hard way. At Northrop Grumman, he once pitched management on more resources for PI analysis, armed with highly technical slides. It fell flat.

“Managers think in terms of cost and schedule… I didn’t know my audience. That was a big mistake. I really had to reflect and ask myself whether I wanted to be in the business of persuasion or pontification.”

He learned to translate engineering principles into terms leaders could act on.

Sustainability and the Future of Hardware

Power integrity isn’t just about bit errors anymore. In an era of gigawatt AI data centers, it’s also about sustainability.

“When you look at modern data centers, there are legitimate concerns in the coming years about how local power grids are going to be distributed.”

For Witcher, PI is conservation at the microscopic scale. “Saving money and not wasting power are synonymous. I absolutely view clean power delivery as falling under the umbrella of sustainability.”

The future he imagines is both pragmatic and hopeful: better tools, global collaboration, and a new generation of engineers who respect fundamentals while pushing boundaries.

Closing: Respect the Invisible

At the end of our conversation, Witcher circles back to where he began: constraints.

“Power delivery is getting squeezed from every possible direction. Current demands are increasing exponentially while rail voltages decrease. Noise margins have no choice but to become incredibly tight.”

Within those tight constraints lies the art of engineering. Building systems that hold under stress, and leading with curiosity and humility — that is the hidden backbone of hardware progress.

Witcher’s message is simple but profound: respect the invisible. Because in hardware, the things you can’t see are usually the ones that matter most.