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Engineering journal

Field Notes for Hardware Teams

Long-form guidance on power, signal integrity, PCB constraints, and component strategy. New entries are published as they are finalized.

Published Articles

All published articles are available here.

May 12, 20268 min read

Power over Ethernet Cable Length: How Far Can You Really Go?

# Power over Ethernet Cable Length: How Far Can You Really Go?

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May 12, 20268 min read

Embedded Systems Design Checklist: 25 Things to Verify Before PCB Fabrication

# Embedded Systems Design Checklist: 25 Things to Verify Before PCB Fabrication You just finished your PCB layout.

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May 12, 20268 min read

Understanding FPGA Logic Elements, ALMs, and LUTs: Architecture Explained

# Understanding FPGA Logic Elements, ALMs, and LUTs: Architecture Explained You're comparing two FPGAs for your next project.

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May 12, 20267 min read

PoE Voltage Drop Calculator: Cable Gauge, Distance, and Power Loss

# PoE Voltage Drop Calculator: Cable Gauge, Distance, and Power Loss You're planning a PoE deployment.

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May 12, 20268 min read

I2C Bus Capacitance: Why Your Bus Fails at Long Distances (And How to Fix It)

# I2C Bus Capacitance: Why Your Bus Fails at Long Distances (And How to Fix It) Your I2C bus works perfectly on the breadboard.

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May 12, 20269 min read

PCB Thermal Management: Trace Sizing for High-Current Designs

# PCB Thermal Management: Trace Sizing for High-Current Designs You just finished a board layout.

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May 12, 20269 min read

PoE IEEE 802.3bt Type 3 vs Type 4: What's New and What Changed

# PoE IEEE 802.3bt Type 3 vs Type 4: What's New and What Changed If you've been working with Power over Ethernet for a while, you probably know the old standards by heart — 802.3af gives you up to 12.95W at the powered device, 802.3af/at uses 2-pair delivery, and that covers most access points and IP cameras.

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May 12, 20268 min read

FPGA Power Consumption Estimation: How to Compare Devices Before You Buy

# FPGA Power Consumption Estimation: How to Compare Devices Before You Buy You're evaluating three FPGAs for your next design.

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May 12, 20267 min read

The Complete PCB Design Toolkit: Free Online Calculators Every Engineer Should Bookmark

# The Complete PCB Design Toolkit: Free Online Calculators Every Engineer Should Bookmark Every PCB designer has a folder of bookmarks, a desktop full of spreadsheets, and a post-it note with formulas scratched on it.

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May 10, 202610 min read

How to Design a PCB from Scratch: A Step-by-Step Beginner's Guide

# How to Design a PCB from Scratch: A Step-by-Step Beginner's Guide You've got an idea for an electronic project.

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May 8, 20268 min read

Lattice vs Xilinx vs Altera FPGAs: 2026 Comparison for Embedded Designs

# Lattice vs Xilinx vs Altera FPGAs: 2026 Comparison for Embedded Designs Three companies dominate the FPGA market for embedded systems: Lattice, AMD (formerly Xilinx), and Intel (formerly Altera).

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May 6, 20267 min read

Differential Pair PCB Design: Impedance, Length Matching, and Skew

# Differential Pair PCB Design: Impedance, Length Matching, and Skew If you're routing USB 2.0, HDMI, PCIe, or really any high-speed interface on a PCB, you're working with differential pairs.

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May 4, 20268 min read

I2C at 400 kHz: Fast Mode Design Considerations and Pull-Up Sizing

# I2C at 400 kHz: Fast Mode Design Considerations and Pull-Up Sizing Running I2C at the standard 100 kHz is forgiving.

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May 2, 20268 min read

6-Band Resistor Color Code: How to Read Temperature Coefficient

# 6-Band Resistor Color Code: How to Read Temperature Coefficient Most engineers learn 4-band resistor color codes in school and never think about it again.

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April 30, 20268 min read

How to Calculate PCB Trace Resistance for Voltage Drop Analysis

# How to Calculate PCB Trace Resistance for Voltage Drop Analysis You just routed a 2-amp power trace on your PCB.

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April 28, 20269 min read

FPGA Selection Guide for Hardware Startups: Balancing Cost, Performance, and Speed

# FPGA Selection Guide for Hardware Startups: Balancing Cost, Performance, and Speed You're a hardware startup.

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April 26, 20269 min read

PoE for IoT Devices: A Complete Design Guide for Smart Home and Industrial Sensors

# PoE for IoT Devices: A Complete Design Guide for Smart Home and Industrial Sensors Running power and data over a single Ethernet cable sounds simple enough.

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April 24, 20268 min read

I2C vs SPI vs UART: Which Serial Protocol Is Right for Your Design?

# I2C vs SPI vs UART: Which Serial Protocol Is Right for Your Design?

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April 22, 20267 min read

PCB Via Current Capacity: How to Calculate and When to Worry

# PCB Via Current Capacity: How to Calculate and When to Worry Vias don't get enough respect.

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April 20, 20267 min read

Resistor Tolerance Explained: What ±1% vs ±5% Actually Means for Your Circuit

# Resistor Tolerance Explained: What ±1% vs ±5% Actually Means for Your Circuit Every resistor datasheet lists a tolerance — usually ±1%, ±5%, or ±10%.

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April 18, 20267 min read

How to Choose the Right FPGA for Your Embedded Project: A Selection Framework

# How to Choose the Right FPGA for Your Embedded Project: A Selection Framework Choosing an FPGA isn't like picking a microcontroller.

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April 16, 20267 min read

PoE Power Budget Calculator: How to Plan Power for Multi-Device Networks

# PoE Power Budget Calculator: How to Plan Power for Multi-Device Networks Power over Ethernet is one of those technologies that sounds simple until you start planning a real deployment.

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April 14, 20267 min read

I2C Bus Design Mistakes: 7 Errors That Cause Communication Failures

# I2C Bus Design Mistakes: 7 Errors That Cause Communication Failures I2C is supposed to be simple.

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April 12, 20266 min read

IPC-2221 vs IPC-2152: Which PCB Trace Standard Should You Use?

# IPC-2221 vs IPC-2152: Which PCB Trace Standard Should You Use?

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April 10, 20268 min read

10 Common PCB Design Mistakes That Fail EMC Testing (And How to Fix Them)

# 10 Common PCB Design Mistakes That Fail EMC Testing (And How to Fix Them) You just got your board back from the EMC lab and it failed.

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April 10, 20261 min read

FPGA Selection Playbook for Edge Products

A concise framework for choosing FPGA families when power budgets, lifecycle availability, and integration complexity all compete.

FPGAedge computecomponent selection
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April 8, 20267 min read

FPGA vs ASIC vs MCU: When to Choose Each for Your Design

# FPGA vs ASIC vs MCU: When to Choose Each for Your Design You're starting a new hardware project and the first big architectural decision is staring you in the face: FPGA, ASIC, or MCU?

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April 8, 20261 min read

SOM vs SBC Decisions Through a Lifecycle Risk Matrix

A structured way to compare module and board options when long-term support, cost stability, and redesign risk matter most.

SOMSBCproduct strategy
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April 6, 20268 min read

Power over Ethernet (PoE) Explained: IEEE 802.3af/at/bt Standards Compared

# Power over Ethernet (PoE) Explained: IEEE 802.3af/at/bt Standards Compared Running both data and power over a single Ethernet cable sounds simple — and it is, once you understand the standards.

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April 6, 20261 min read

Differential-Pair Skew Planning with Real Stackups

A disciplined approach to skew budgeting when dielectric variation, layer changes, and connectors are all part of the path.

differential pairshigh-speed designPCB routing
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April 4, 20267 min read

PCB Trace Width Calculator: How to Use IPC-2221 Standards

# PCB Trace Width Calculator: How to Use IPC-2221 Standards You're laying out a PCB and need to run 3 amps through a power trace.

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April 4, 20262 min read

IPC Trace Current Derating Inside Hot Enclosures

How to convert IPC-based trace calculations into robust derating decisions for sealed or high-ambient product enclosures.

PCBthermal designIPC-2221
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April 2, 20267 min read

I2C Pull-Up Resistor Calculation: A Complete Guide with Formulas

# I2C Pull-Up Resistor Calculation: A Complete Guide with Formulas You've got your I2C bus wired up, but the signals look terrible on the scope — slow rise times, rounded edges, maybe even communication failures.

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April 2, 20262 min read

I²C Bus Margins to Lock Before Prototype Freeze

The highest-impact I²C checks to complete before your first prototype run to avoid late debugging cycles.

I2Csignal integrityhardware validation
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March 31, 20268 min read

How to Read Resistor Color Codes: 4-Band, 5-Band, and 6-Band Explained

# How to Read Resistor Color Codes: 4-Band, 5-Band, and 6-Band Explained You've probably been there — staring at a tiny cylindrical component with colored stripes, trying to figure out if that's a 4.7kΩ or a 47kΩ resistor.

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March 31, 20262 min read

Avoiding Hidden Power Budget Failures in PoE Deployments

A practical pre-deployment checklist for preventing undervoltage and startup instability in long-run PoE systems.

PoEpower integrityfield reliability
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