Power Mistakes Beginners Make Before Routing
WHAT THIS VIDEO COVERS
Power delivery problems are among the most common reasons beginner PCB designs fail after assembly. This video identifies the top power-related mistakes made before routing even begins and shows how to avoid them for stable, reliable boards.
The guide stresses accurately calculating total current requirements — including MCU, sensors, LEDs, and startup spikes — before selecting regulators. It explains the distinct roles of bulk capacitors versus decoupling capacitors and why a deliberate strategy is essential to prevent voltage drops under load.
Viewers learn why using a single via or thin trace for power pins creates high current density and inductance issues, and why simply pouring a power plane does not automatically solve return path, placement, or loop area problems.
These concepts apply directly to 4-layer PCB, multilayer PCB, and high-reliability designs used in IoT devices, industrial control systems, and automotive electronics. Proper power design before routing significantly improves signal integrity, thermal management, and overall product reliability.
Get an instant PCB quote or explore turnkey PCB assembly services and 4-layer PCB manufacturing for your next project.
KEY HIGHLIGHTS
- Current Calculation: Always calculate total current draw including peak loads before selecting regulators — guessing leads to unstable power delivery.
- Capacitor Strategy: Bulk and decoupling capacitors serve different purposes; a deliberate placement strategy is required to maintain stable voltage under varying loads.
- Power Delivery Details: Multiple vias, proper return paths, and careful placement matter far more than simply adding a power plane.
FAQ
Q1: Why does my PCB reset under load even when powered on?
A1: This is often caused by inadequate power design — insufficient current capacity, poor decoupling, or high inductance from single vias rather than firmware issues.
Q2: How many vias should I use for power pins on a PCB?
A2: Multiple vias are recommended for power pins to reduce current density and inductance. A single via frequently creates voltage drops and instability under load.
Q3: Does adding a power plane solve all PCB power problems?
A3: No. While helpful, a power plane requires proper component placement, short return paths, and controlled loop areas to be effective. It is not a complete solution by itself.
Board powers on. Then it resets under load.
You blame firmware.It's your power design.
1. Not knowing current requirements
You picked a regulator without checking the actual current.
MCU, sensors, LEDs, startup spikes, it all adds up.
If you don't know the numbers,you're designing blind.
2. No bulk and decoupling strategy
You added a few capacitors because the reference design had them.
But bulk caps and decoupling caps do different jobs.
Without a strategy, voltage drops are guaranteed.
3. Single via for power pins
One thin trace.
One via to the plane. Looks clean.
But current density and inductance don't care about clean.
4. Assuming one power plane fixes everything
"Just pour a plane. Problem solved."
No. Return paths, placement, and loop size still matter.
A plane is not magic.
Stable power is designed before routing begins.
