Understanding Electrical Systems

IMPEDANCE INTUITION. Achieving signal integrity (SI) in high-speed PCBs requires matching the impedance of physical structures. As data rates increase, the structures we care about become smaller – even down to several mils. Here, I’ll provide a simple way to increase your impedance intuition. The secret is understanding capacitance. Memorize this capacitance approximation equation: C = ƐA/d. These parameters directly translate to items in your PCB:  A (Area) is the size of your structure, d (distance) is the distance to ground/metal, and Ɛ is the dielectric constant of the material between the metal (sometimes called Dk or Ɛr). Next, understand that capacitance is inversely related to impedance (because Impedance=Z=sqrt[L/C]). ‘Inversely related’ means if capacitance goes up, impedance goes down. When you reduce capacitance, impedance goes up. In practical terms, if you make your trace wider, then A (Area) and hence capacitance get larger causing impedance to get lower. Move your trace further from ground, and d (distance) goes up thus lowering capacitance and increasing impedance. Use lower Dk material, C goes down and impedance goes up. See how this works? While understanding impedance guides design decisions, you can also use the concepts to grasp manufacturing changes. For example, if PCB fabrication substitutes a thinner core or presses your pre-preg layers thinner than plan, d (distance) becomes smaller, and impedance gets lower. Or, if traces are imaged or etched thinner, A goes down and impedance goes up. Though fab notes try to protect against these changes, cross-section images and/or measurements may reveal these problems. And what about vias? Think of vias as traces in the Z direction, where drill size defines A (area) and via barrel distance to antipad (metal) is d. Use a smaller drill, A and C go down, so impedance goes up. Widen your antipads and d goes up making C go down, also increasing your impedance. Because we typically have to raise via impedance, both these ideas are often deployed. Keep these concepts in mind, and you can expand into SMT pads, connector styles – you name it. Failing to match the impedance of relevant PCB structures causes impedance discontinuities, the #2 reason high-speed serial links fail. Impedance matters. While your 2D/3D design and simulation tools can help you get the impedance right, per Bogatin’s Rule #9, to believe what tools are telling you it’s important to grow your impedance intuition. Are my design changes having the effect I expect? For more concepts and guidance, be sure to check out both my ‘Signal Integrity, In Practice’ book and LIVE class: Book:  https://lnkd.in/guhndNJG LIVE Class:  www.siguys.com/training #siforees (filter using my name ‘Donald Telian’) #signalintegrity

Signal Integrity Simplified: The One Concept That Unlocks High-Speed Design "It takes years to master high-speed PCB design." If you've heard this, you're not alone. This belief keeps countless engineers from pursuing advanced PCB design skills. But what if understanding ONE core concept could dramatically accelerate your path to high-speed design competence? The Transmission Line Revelation Early in my career, I avoided high-speed design. It seemed impossibly complex - filled with arcane formulas, specialized tools, and terminology I didn't understand. It was where the 'real' electrical engineers did 'black magic'. Then I had a breakthrough that changed everything: ALL signal integrity issues at their core relate to transmission line theory. Once I deeply understood how signals propagate along PCB traces as transmission lines, suddenly: - Impedance control made intuitive sense - Reflection problems became predictable - Cross-talk had clear solutions - EMI sources became obvious This single concept - viewing PCB traces as transmission lines rather than simple connections - unlocked an entire field that previously seemed impenetrable. From Concept to Competence in Weeks, Not Years Here's the step-by-step path I took to rapidly build signal integrity expertise: Master transmission line fundamentals (2 weeks) Learn to calculate and control impedance (1 week) Understand reflection mechanics and termination (1 week) Apply principles to real designs (4 weeks) Within just 8 weeks of focused learning, I was confidently handling 1Gbps+ designs that previously would have intimidated me. The Practical Application That Proves It Works Recently, one of my mentees (just 6 months into his hardware career) was tasked with designing a board with LPDDR4 memory - typically considered an advanced challenge. Rather than memorizing DDR4 design rules, he focused on understanding the transmission line characteristics of the signals. The result? His first DDR4 design passed simulation and validation on the first attempt - something his manager couldn't believe. When asked how long he'd been doing high-speed design, expecting to hear "years," his answer was simply: "About 6 weeks of focused study on the right things." Accelerate Your Own Mastery If you want to rapidly develop signal integrity expertise: Start with transmission line fundamentals - not just tools or checklists Use simple test boards to validate your understanding Focus on WHY rules exist, not just memorizing them Simplify complex problems by relating them back to basic principles You can develop professional-level signal integrity skills in MONTHS, not years - but only if you focus on the fundamental concepts that everything else builds upon. Question for hardware engineers: What's one "advanced" PCB design concept you've been avoiding because it seems too complex? #SignalIntegrity #PCBDesign #HighSpeedDesign #HardwareEngineering

𝐖𝐡𝐲 𝐜𝐨𝐧𝐭𝐫𝐨𝐥𝐥𝐞𝐝 𝐢𝐦𝐩𝐞𝐝𝐚𝐧𝐜𝐞 𝐦𝐚𝐭𝐭𝐞𝐫𝐬 "As signal speeds climb into the GHz range, #PCB traces stop behaving like simple wires, they become transmission lines. That’s why controlled #impedance is essential in high-speed designs." I'm going to share in the comments the link to the very first technical blog I wrote for Sierra back in 2017 (jeez, time flies!). My amazing team has edited it and republished it a couple of times since then. 𝐓𝐡𝐢𝐬 𝐛𝐥𝐨𝐠 𝐛𝐚𝐬𝐢𝐜𝐚𝐥𝐥𝐲 𝐛𝐫𝐞𝐚𝐤𝐬 𝐝𝐨𝐰𝐧: ► What controlled impedance really means ► When and why you need it (think DDR, HDMI, Gigabit Ethernet...) ► Key layout tactics, like length matching and diff pair routing ► Why relying on controlled dielectric alone might backfire ► How Sierra Circuits ensures impedance accuracy with in-house testing tools and calculators 𝑳𝒊𝒏𝒌𝒔 𝒊𝒏 𝒕𝒉𝒆 𝒄𝒐𝒎𝒎𝒆𝒏𝒕𝒔: • Why controlled impedance matters blog • Controlled Impedance Design Guide 😻 • Impedance Calculator 𝑾𝒉𝒂𝒕 𝒅𝒐 𝒚𝒐𝒖 𝒕𝒉𝒊𝒏𝒌? 𝑰’𝒅 𝒍𝒐𝒗𝒆 𝒕𝒐 𝒉𝒆𝒂𝒓 𝒊𝒇 𝒕𝒉𝒆𝒓𝒆’𝒔 𝒂𝒏𝒚𝒕𝒉𝒊𝒏𝒈 𝒚𝒐𝒖’𝒅 𝒕𝒘𝒆𝒂𝒌 𝒐𝒓 𝒂𝒅𝒅 𝒕𝒐 𝒎𝒂𝒌𝒆 𝒕𝒉𝒊𝒔 𝒎𝒐𝒓𝒆 𝒖𝒔𝒆𝒇𝒖𝒍 𝒇𝒐𝒓 𝒇𝒆𝒍𝒍𝒐𝒘 𝒅𝒆𝒔𝒊𝒈𝒏𝒆𝒓𝒔.

Eighteen months ago, on behalf of the Foundation for Defense of Democracies (FDD), I published "Beijing’s Power Play", a report warning that PRC-linked #battery and #energystorage firms posed long-term #nationalsecurity risks to U.S. #criticalinfrastructure. Some argued the concern was overblown. Today, Reuters reports that U.S. officials have found undocumented #communication devices embedded in Chinese-made #inverters and battery systems—components with direct access to our power grid ⚡. These rogue channels could bypass firewalls and destabilize entire energy systems. This isn’t alarmism—it’s the tip of the iceberg 🧊. As I wrote then, these risks go beyond supply chains. They’re about control, dependency, and systemic vulnerability. The fact that many of these companies—like #CATL— are listed on the Chinese military company (CMC) list makes this all the more urgent 🚨. If you’re covering this issue or tracking developments in clean tech, energy resilience, or U.S.-China strategic competition, here’s the original report: https://lnkd.in/e2Ubn6Cr Grateful to see this story gaining attention. There’s much more to uncover. #nationalsecurity #energypolicy #cleanenergy #gridsecurity #chinathreat #criticalinfrastructure #inverters #batterystorage #cybersecurity #decoupling #CATL #geopolitics #supplychainsecurity #ESG #salttyphoon #volttyphoon #internationalrelations #internationalsecurity #duediligence #zeroday https://lnkd.in/eJmWFk9J

Why the risetime (RT) of a digital signal is so important for #EMC and #signalintegrity? Rise (and fall) time are key parameters that contribute to the high-frequency spectral content of the waveform. The levels of the emissions in the regulatory frequency range are therefore strongly dependent on the risetimes and falltimes of these pulses. Here we have an analytical formula showing that the spectrum of a clock signal decays 20dB/decade until f=1/πRT, and 40dB/decade after. Simulation in #ansys #hfss #circuits show a very good agreement for this approach where a 1MHz clock signal with 20ns risetime was used. We also have measurements showing a good correlation for a 1MHz clock signal with 12.5ns risetime. The animation shows from a simulation perspective how the waveform in time domain and the spectrum changes as we change the rise/fall times from 5ns to 100ns. Note that even for a 1MHz clock signal, the spectrum content changes by several dBs at higher frequencies (+100Mhz)! Reference from measurements and analytical formula is "Introduction to Electromagnetic Compatibility" from Clayton Paul, which I'm sure most of you are very familiar with.

U.S. officials and cybersecurity experts are raising alarms over the discovery of undisclosed cellular radios embedded within Chinese-manufactured power inverters. These "rogue" communication devices, found in renewable energy infrastructure, are not documented in product specifications and create covert communication channels that bypass established cybersecurity measures. This poses a significant national security risk, as these hidden functionalities could allow for unauthorized remote access, manipulation, or even disabling of critical energy grid components, potentially causing widespread power disruptions and physical damage. A prior incident in November 2024, where solar power inverters were reportedly disabled remotely from China, underscores the tangible threat. Read more here: https://lnkd.in/gB-e42Xd #HatTip: Matt Johansen #Cybersecurity #NationalSecurity #EnergyGrid

⚠️ Expert Insights and Safety Reminder We recently encountered a significant issue with an electrical circuit. Here are insights from two experienced engineers: 🔆 Engineer A: Believes the problem is due to poor contact. Immediate action is required to replace the switch and terminal. Issues identified include: 1) One-phase overcurrent due to a breaker not operating in full phase, 2) Unbalanced load, 3) Poor contact. 🔆 Engineer B: Suggests that the three-phase imbalance is the core issue, with the middle phase bearing a heavy load. A high demand for 220V power can lead to unbalanced loads. Recommends redistributing the 220V power supply to balance the load, such as using one phase for the eastern section and another for the western section. If you have any insights, please share your thoughts below. This serves as an important reminder to always use quality, reliable #fuses and #circuitbreakers to protect your #electricalsystems. Ensuring safety and reliability in electrical installations is crucial for preventing such issues. If you have any questions about fuses and circuit breakers, please feel free to contact me. #ElectricalSafety #CircuitBreaker #Fuse #ElectricalEngineering #SafetyFirst #EngineeringSolutions #LinkedInCommunity

Imagine a device designed to harness the sun's energy for your home—only to discover it might be transmitting data back to a foreign power. Recent investigations have uncovered undocumented communication modules in Chinese-manufactured solar inverters and batteries, raising alarms about potential cybersecurity threats to the U.S. power grid. While these inverters are essential for integrating renewable energy into our grids, their dominance by Chinese manufacturers like Huawei and Sungrow poses a significant risk. The presence of rogue communication devices suggests a vulnerability that could be exploited to bypass firewalls, potentially allowing remote manipulation of our energy infrastructure. With the increasing integration of foreign-made technology into our critical infrastructure, how can we ensure the security and resilience of our energy systems against potential cyber threats? https://lnkd.in/e9xsn7j5

Power factor correction (PFC) refers to the process of improving the power factor in electrical systems, which is the ratio of real power (measured in kilowatts, kW) to apparent power (measured in kilovolt-amperes, kVA). Power factor is a measure of how efficiently electrical power is being used. A power factor of 1 (or 100%) is ideal, meaning all the power is being effectively used for productive work. However, many electrical systems have a power factor below 1, which indicates inefficiencies and can lead to higher electricity costs, increased wear on equipment, and potential penalties from utility companies. Causes of Poor Power Factor: Inductive Loads: Common in motors, transformers, and HVAC equipment, where current lags behind voltage. Capacitive Loads: Rare, but can cause the opposite, where current leads voltage. Harmonics: Distortion in electrical systems due to non-linear loads, which can further degrade power factor. Power Factor Correction Methods: Installing Capacitors: Capacitors counteract the effects of inductive loads by supplying reactive power. This reduces the phase difference between current and voltage, improving power factor. Using Power Factor Correction Controllers: These automatically adjust the level of reactive power compensation by controlling capacitor banks based on real-time demand. Synchronous Condensers: These are rotating machines that operate like capacitors and adjust power factor by injecting reactive power into the system. What a Controls Tech Can Do to Improve Power Factor: Monitor and Diagnose Power Factor: Use power meters or building automation systems (BAS) to measure the power factor in real time. Controls techs can program alarms or dashboards to show when power factor drops below a desired level. Optimize Equipment Operation: Review motor and HVAC system operation to ensure that motors are not running at partial load for extended periods. Controls techs can use variable frequency drives (VFDs) to adjust motor speed and load, reducing reactive power consumption. Implement Power Factor Correction Devices: Recommend and configure capacitor banks or power factor correction controllers in electrical systems to automatically correct for low power factor. Harmonic Mitigation: If harmonics are degrading the power factor, a controls tech can work with electrical engineers to install harmonic filters. BAS or power quality analyzers can detect harmonic distortion. Perform System Audits: Regularly audit the electrical and HVAC systems, identifying underloaded motors or improperly tuned VFDs. Tuning control systems to prevent equipment from running unnecessarily can improve the power factor. In summary, a controls technician can play a critical role in identifying and addressing poor power factor by leveraging monitoring tools, optimizing equipment operation, and implementing corrective measures such as capacitors or VFDs. This helps ensure energy efficiency, cost savings, and better overall system performance.

📞 𝗪𝗵𝗮𝘁 𝗰𝗮𝗻 𝗛𝗲𝗮𝘃𝗶𝘀𝗶𝗱𝗲 𝘁𝗲𝗮𝗰𝗵 𝘂𝘀 𝗮𝗯𝗼𝘂𝘁 𝗥𝗙 𝗱𝗲𝘀𝗶𝗴𝗻 𝘁𝗼𝗱𝗮𝘆? In the 1880s, Oliver Heaviside fixed long-distance telephone distortion by 𝗯𝗮𝗹𝗮𝗻𝗰𝗶𝗻𝗴 𝘁𝗵𝗲 𝗲𝗹𝗲𝗰𝘁𝗿𝗶𝗰𝗮𝗹 𝘁𝗶𝗺𝗲 𝗰𝗼𝗻𝘀𝘁𝗮𝗻𝘁𝘀 in the transmission line—specifically by 𝗮𝗱𝗱𝗶𝗻𝗴 𝗶𝗻𝗱𝘂𝗰𝘁𝗮𝗻𝗰𝗲 to match the effects of resistance and capacitance, satisfying the condition 𝗥𝗖 = 𝗟𝗚. Today, the same principles still apply to RF and high-speed digital design. 🔍 𝗧𝗶𝗺𝗲 𝗖𝗼𝗻𝘀𝘁𝗮𝗻𝘁 𝗕𝗮𝗹𝗮𝗻𝗰𝗶𝗻𝗴 𝗦𝘁𝗶𝗹𝗹 𝗠𝗮𝘁𝘁𝗲𝗿𝘀 In RF PCBs and interconnects, mismatched time constants, 𝗥𝗖 and 𝗟𝗚, still cause:  • Dispersion  • Pulse smearing  • Eye diagram collapse 🛠️ 𝗗𝗼𝗻’𝘁 𝗝𝘂𝘀𝘁 𝗠𝗶𝗻𝗶𝗺𝗶𝘇𝗲—𝗕𝗮𝗹𝗮𝗻𝗰𝗲 Modern designers often focus on reducing parasitics. But Heaviside reminds us: 📏 𝗜𝘁’𝘀 𝗻𝗼𝘁 𝗮𝗹𝘄𝗮𝘆𝘀 𝗮𝗯𝗼𝘂𝘁 𝗺𝗮𝗸𝗶𝗻𝗴 𝘁𝗵𝗶𝗻𝗴𝘀 𝘀𝗺𝗮𝗹𝗹𝗲𝗿—𝗶𝘁’𝘀 𝗮𝗯𝗼𝘂𝘁 𝗸𝗲𝗲𝗽𝗶𝗻𝗴 𝘁𝗵𝗲𝗺 𝗶𝗻 𝗽𝗿𝗼𝗽𝗼𝗿𝘁𝗶𝗼𝗻. Don’t just shrink capacitance—sometimes you need to increase inductance to preserve waveform integrity. Don’t just buy exotic materials and components—𝗼𝗽𝘁𝗶𝗺𝗶𝘇𝗲 𝗴𝗲𝗼𝗺𝗲𝘁𝗿𝘆 and 𝗶𝗺𝗽𝗲𝗱𝗮𝗻𝗰𝗲 𝗰𝗼𝗻𝘁𝗿𝗼𝗹. The goal remains the same: faithful signal transmission. 💡 Takeaway for RF Designers Today ✅ Don’t just fight parasitics—design with them ✅ Think in terms of electromagnetic fields, not just in circuits ✅ The past solved the same problems—we just do it at gigahertz and terahertz now What other timeless lessons from history do you still use in your RF or high-speed design work? 👇 Let’s discuss in the comments. 🧮 𝗪𝗮𝗻𝘁 𝘁𝗼 𝗲𝘅𝗽𝗹𝗼𝗿𝗲 𝗥𝗙 𝗱𝗲𝘀𝗶𝗴𝗻 𝗰𝗼𝗻𝗰𝗲𝗽𝘁𝘀 𝗵𝗮𝗻𝗱𝘀-𝗼𝗻? Try the free 𝗥𝗙 𝗱𝗲𝘀𝗶𝗴𝗻 𝗰𝗮𝗹𝗰𝘂𝗹𝗮𝘁𝗼𝗿𝘀 from 𝗤𝘂𝗮𝘅𝘆𝘀. https://quaxys.com/tools #RFDesign #SignalIntegrity #Heaviside #TransmissionLines #PCBDesign #Electromagnetics #EngineeringHistory #Quaxys #MicrowaveEngineering