How to design faster, smarter, and better for high-speed circuits

DDR3 Series part 4: Earlier DDR2 used a **T-branch** topology (signal splits to multiple DRAMs). At higher speeds, this caused reflections and timing skew. Reflections caused because of impedance mismatch between trace(controller) and load (Dram chip) **DDR3 introduced the Fly-By topology** — a daisy-chain routing where clock, command, and address signals flow sequentially across DRAMs. **Advantages:** ✅ Easier timing closure ✅ Reduced signal reflections ✅ Simplified PCB layout ✅ Enables write leveling calibration **Why it matters:** Fly-By topology made DDR3 capable of reaching higher speeds (up to 2133 MT/s) by improving signal integrity — a foundation for modern DDR design.

ESP32 based Single PCB ZX Spectrum Emulator This is a marvel of retro computing tech. In a clever fusion of retro computing and modern microcontroller design, the ESP32 Rainbow (by atomic14) implements a ZX Spectrum emulator on a single printed circuit board. What makes it stand out is that the entire system with display, storage, sound, and keyboard is consolidated onto one board, with the keyboard implemented as a capacitive touch matrix printed directly on the PCB. _________________________________________ System Design * Core Processor The heart is an ESP32-S3 microcontroller, running at up to 240 MHz, with dual cores. The emulator firmware (in C/C++ under a GPL license) emulates the Zilog Z80 CPU, ULA-like video behavior, audio, and I/O routines. Because the ESP32 is orders of magnitude faster than the original 3.5 MHz Z80, it has headroom to emulate both timing and peripheral behavior with flexibility. * Display & Audio A TFT color display is integrated on the board (320×280 resolution). For audio, a built-in speaker is used, and the firmware emulates both simple buzzer sound and optional AY-3-8912 style three-voice sound. The ESP32’s I/O or PWM outputs drive audio, optionally via simple analog filtering. * Storage & I/O A microSD card slot provides access to ROM images, tape files (TAP, TZX, etc.), snapshots, and the host firmware. USB-C is used for power and data. The board can act as a USB keyboard to a host machine. Expansion is possible via breakout headers and I²C / QWIIC connectors for peripheral experiments. * Keyboard: Capacitive Touch Matrix This is the most novel piece of the design. The board implements a capacitive touch keyboard, with each key area etched on the PCB (or at least the touch pad) and labeled with full-color silkscreen. The ESP32-S3 has built-in touch-capable channels (about 14 usable). atomic14 used 13 of these to build a keyboard matrix. A touch-matrix design rather than direct one-to-one allows more keys than touch pins. However, implementing a multiplexed or matrixed touch layout introduces challenges in reliably detecting simultaneous key presses (rollover) and avoiding ghosting. The use of full-color silkscreen lets the designer print multi-layered legends (Spectrum keywords, symbols, etc.) legibly on each “key” region — something that would be very hard with a regular monochrome silkscreen. * Technical Challenges & Tradeoffs Touch Matrix & Rollover Limitations Capacitive touch detection is sensitive to noise, and combining it in a matrix (multiplexing rows/columns) can degrade the detection margins. Users pressing multiple keys at once may experience missed inputs or ghost presses. The original build already notes “issues with detecting simultaneous keypresses, but overall it seems to work pretty well.” Enjoy #retro YouTube video here: https://lnkd.in/dZu9RuCV

Precision routing for high-speed signals, now built into DesignSpark PCB V13. The new Serpentine Routing feature enables engineers to shape traces with accuracy, ensuring signal integrity in space-constrained designs. Whether you're working on DDR, USB, or other timing-sensitive interfaces, this tool helps you meet performance requirements without compromising layout efficiency. It’s part of a broader set of enhancements in V13 designed to support modern electronics workflows. Start your free 7-day trial of DesignSpark Engineer and access the full PCB V13 feature set today. 👉 https://weare.rs/4qpjZJ2 #PCBDesign #DesignSparkPCB #SerpentineRouting #SignalIntegrity #EngineeringTools #EDAsoftware #DesignSparkEngineer #ElectronicsDesign #ProductDevelopment

Part 3 of my PCB Classification Series is here! This time, I focused on specialized function boards: HDI → essential for miniaturized devices High-frequency → critical for GHz-level communication Mixed Lamination → balancing performance and cost These specialized PCBs are the foundation of modern 5G, automotive radar, and advanced computing. #PrintedCircuitBoard #PCBDesign #HDIPCB #knownpcb #HighFrequencyPCB #MixedLaminationPCB #PCBFabrication

#Analogtober 2025 Hey analog designers, want to have a system for designing analog circuits? Let me tell you about the IIC-OSIC kit from Harald Pretl. It has 3 PDKs - all open source; sky130 from Skywater, gf180 from Globalfoundries and IHP130 from IHP. You use ngspice to simulate and develop schematics on xschem, then you do the layout, and the DRC on Magic or Klayout. Lastly, you do LVS on netgen. The best part is that it is all open-source; therefore it is not necessary to have a license that can be costly and needs renewing.

🌟 A4988 Stepper Motor Driver Schematic for KiCAD 🌟 We’ve added a new A4988 Stepper Motor Driver schematic module to our collection at Proto Circuit Labs. This KiCAD 8-9-compatible module includes all essential signal connections and an STM32F0 microcontroller example, making it easier to integrate stepper motor control into your designs. At Proto Circuit Labs, we provide modular, reusable KiCAD schematic blocks — including MCU interfaces, sensor modules, power circuits, and driver schematics — to help developers design faster and with greater consistency. You can also try out free modules available on our website to test and evaluate before committing to full designs. 🔗 Explore the new module here: https://lnkd.in/dVVnMWan 🔗 Browse the full library: https://lnkd.in/dnbcGtQB #KiCAD #PCBDesign #HardwareDesign #EmbeddedSystems #ElectronicsDesign #MotionControl #ProtoCircuitLabs

Why are multi-layer boards indispensable in modern electronic products? ✔️High-density wiring: Incorporating tens of thousands of connections within a limited area, it serves as the physical foundation for chips (such as high-speed CPUs/GPUs/BGA) to achieve their powerful functions. ✔️Signal integrity: By using dedicated signal layers and ground plane layers, a complete and clean return path is provided for high-speed signals, reducing crosstalk and electromagnetic interference (EMI). ✔️Power integrity: Utilize an independent power layer to provide stable and low-noise power supply to the chip, preventing system instability caused by voltage drops. ✔️Efficient heat dissipation: By using thermal vias, the heat generated by key components is conducted to the inner layer or the backside, thereby enhancing product reliability. ✔️Miniaturization and lightweighting: "Moving upwards" is an important approach to achieving the thin and lightweight design of devices. Gain a thorough understanding of its core structure: A typical multilayer board is like a "precise sandwich", consisting of: 1. Core board, semi-cured sheet 2. Signal layer, power layer, ground layer 3. Blind holes, embedded holes, mechanical through holes The alignment accuracy of each layer and the dielectric constant of the materials directly affect the performance and yield of the final product. The challenges and pursuits we face: From the layered design, impedance control, to thermal stress management, every decision is crucial to success. We are committed to transforming the invisible layers into visible excellence and ultimate reliability for our customers. What challenges have you encountered in the design or manufacturing of multi-layer boards? Were they related to signal integrity issues, or the balance between cost and the number of layers? Please feel free to share your insights in the comment section! 👇 #PCBDesign #HardwareEngineering #HighSpeedCircuit #ElectronicManufacturing #SignalIntegrity #PowerIntegrity #PCBMultilayerBoard #HighDensityInterconnection Frank Wu PCBAStore

Designing at the speed of tomorrow ⚙️ With DDR5, every picosecond matters. High-speed designs no longer forgive approximation — routing, constraints, and timing must work in perfect harmony. That’s where Xpedition by Siemens EDA comes in: 💡 Constraint Manager turns rules into guarantees. ⚡ Sketch Routing accelerates layout without sacrificing precision. Fewer errors, fewer iterations, greater reliability. 👉 Learn more in the full French article by Adrian Piticco: Reinventing High-Speed Signal Design https://lnkd.in/djq8kb9z #DDR5 #HighSpeedDesign #Xpedition #SiemensEDA #SignalIntegrity #ElectronicInnovation #VarIndustries

Giving the Rocket a Brain — The Avionics PCB Design In a rocket, the avionics subsystem acts as its brain — and the PCB (Printed Circuit Board) is what keeps that brain thinking clearly. A PCB connects discrete electronic components, such as resistors, capacitors, and ICs, through precisely designed copper traces. You can think of it as a map of electrical pathways: once each component is soldered according to the design, they form a stable and complete circuit system. In our rocket, the microcontroller (such as the STM32) and its surrounding components are all integrated onto the PCB. The same board also handles power supply management — linking transformers, grounding, and voltage regulation. Most importantly, the PCB ensures stability and safety under intense vibration, acceleration, and impact — preventing short circuits or disconnections that could compromise the rocket’s avionics performance. ⚡ 📸 Image: Preliminary design of the STM32 control board. The large central IC is the STM32 MCU, surrounded by headers, capacitors, resistors, and other components. This board is responsible for controlling the MTV motor. #RocketEngineering #Avionics #PCBDesign #STM32 #AerospaceEngineering #SystemIntegration #StudentRocket #Starocketry

Kicad can export layout and individual nets as STL files, which can then be imported in Blender with the new Import STL node. You can either import the entire geometry or selected specific nets by typing their name. The imported geometry can then be scaled up to view a net of interest in more details like this pcb planar transformer design. Featuring Texas Instruments PMP41163 65W low-profile AC/DC USB PD charger reference design with integrated GaN #kicad #b3d #blender3d #gan #altium #pcbdesign #electronics #usbc