Measurements and limits of conducted EMI

We will stick to the conventional descriptions and definitions, before we talk about the differences that arise when applying these concepts to power conversion. Conducted emissions fall into two basic categories: Differential mode (DM), also called symmetric mode or normal mode Common mode (CM), also called asymmetric mode or ground leakage mode. Looking at Figure … Read more

Electromagnetic design software uses parallel processing to accelerate simulations

Cobham Technical Services has released a new version of its Opera electromagnetics and multiphysics design software that enables design engineers to considerably accelerate analysis time. By harnessing the parallel processing capabilities of multicore processors, computational time can be significantly reduced using Opera-3d version 16. Designed for use on standard office-grade PCs, Opera-3d version 16 contains … Read more

EM simulation tools only go so far

Tight schedules, budgets, and faster devices have made EMC software tools more attractive than ever. Radiated emissions are always a challenge, and the lower voltage levels of very fast devices have made immunity (ESD, radiated, conducted) even more important than in the past. Certainly there will be no shortage of work for EMC engineers in … Read more

Using requirements planning in embedded systems design: Part 1 – Dissecting the requirements document

To begin any embedded system-level design, the developer needs a clear understanding of what the final software design must accomplish. The source of this information is the system requirements document, or simply the requirements document. The requirements document should contain the functions required, their timing, their communications needs, and their priorities. At this level, the … Read more

Overcoming FPGA board design challenges

If your board design experience with FPGAs is limited or nil, the prospect of putting one in your next project can be daunting – especially if it's a 1,000-pin monster. Continue reading to get a feel for the selection and design process, and for lots of gotchas you'll need to avoid. Pick a vendor, any … Read more

DC/DC converter PCB layout, Part 1

Fundamental to careful system design of any DC/DC power converter is a well-planned and carefully executed printed circuit board (PCB) layout. An optimized layout leads to better performance, lower cost and faster time-to-market. Additionally, it can constitute a competitive advantage for the end equipment user owing to higher reliability (lower component temperature), easier regulatory compliance … Read more

LTC Design Note: Active bridge rectifiers reduce heat dissipation within PoE security cameras

Download Design Note 519 (PDF) Introduction Power over Ethernet (PoE) has been embraced by the video surveillance industry as a solution to an age-old problem: complicated cabling. For instance, a basic, traditional fixed-view security camera requires two cables: one for power (10W to 15W from a 24V AC or 12V DC), and a separate, coax … Read more