Engineering Blog

Notes from the bench

What we learn designing power electronics, embedded firmware and connected products, written by the engineers who build them.

Block diagram of the LibreVNA source: MAX2871 synthesizer, two SP4T RF switches and three low-pass filters
RF LibreVNA

Inside LibreVNA, part 1: the source filter bank

Why the MAX2871 output needs three low-pass filters, and why it takes RF switches, not ordinary ones, to select them.

10 min read
Read article →
Filter output impedance plotted against converter input impedance in EngineeringPaper.xyz
Power Tools

How we design power supply input filters with EngineeringPaper.xyz

Following TI's SNVA538 step by step: model the converter, size the LC filter, check Middlebrook's criterion and add damping.

10 min read
Read article →
Non-inverting op amp circuit with feedback resistors and modern op amp spec highlights
Analog PCB Layout

Op amps on real PCBs: specs, new features and layout

The specs that limit your circuit, what modern op amps bring, and the layout rules that keep them precise and stable.

11 min read
Read article →
MCUboot and application RAM maps with the SEGGER RTT control block at the same address
Firmware Debugging

SEGGER RTT across MCUboot and your Zephyr app

Keep J-Link RTT logs flowing from the bootloader into your application by pinning the control block to one RAM address.

7 min read
Read article →
MCUboot flash layout: bootloader, primary slot, secondary slot and scratch area
Firmware Zephyr

Secure firmware updates with MCUboot on Zephyr

Flash slot layout, image signing, swap vs. overwrite upgrades and safe rollback for fielded devices.

8 min read
Read article →