Control of Noise, Signal Integrity & EMI in High Speed Circuits & PCBs

Synopsis

When time-varying (AC) signals travel in the transmission lines of a PC board, state changing electric and magnetic fields are present. Left unconstrained, these fields are the energy source for Noise, EMI and Signal Integrity issues.

We classically define ‘Noise’ as ‘Intentional Energy’ which we fail to control and contain.  Unharnessed energy can, and will, generate many forms of interference.  What this statement fails to address is ‘Why’ this happens… why are some circuits noisy, while others are not?

Compounding the problem are today’s extremely fast ICs.  Output edge rate (rise/fall time) of devices, more than the rate at which they are clocked, is a leading factor with regard to SI, EMI and Noise issues in PC Boards.  A circuit with 200 ps rise time devices can generate serious problems whether clocked at 2 MHz, 200 MHz or 2 GHz.

 

Training that works

Having the opportunity to gain a comprehensive understanding of critical design issues in specific technology areas can be rare. This workshop provides easy access to practical design solutions delivered by experts proven to be successful in their field.

Knowing how to design circuit boards to contain and control energy (fields) and knowing how to mitigate and control the effects of high speed devices is the key to successful design of low noise circuits.  This 2-day workshop is a crisp focus of the issues PCB Designers and Engineers need to know to prevent signal integrity, EMI, crosstalk and grounding problems in high speed digital and mixed signal designs.

 

Workshop Highlights

  • Impact of Frequency on Board Layout
  • What Drives Frequency - Analogue vs Digital
  • Basic essentials of Grounding
  • What is Energy...where is the Energy in a Circuit
  • Transmission Lines and Return Current Paths in PC Boards
  • Importance of Proper Plane Assignment
  • Common misuse of Planes
  • Noise and Signal Attenuation Factors
  • Routing and Reflections
  • Propagation Time and Velocity
  • Lumped vs Distributed Length Lines
  • Transmission Line Impedance Control
  • How to get Impedance Control at NO COST
  • Impact of Nearby Traces on Impedance
  • Importance of Reflection Mode Switching
  • Routing and Termination Styles
  • Impact of Long Ts in transmission lines
  • Vcc and Ground Bounce
  • Jitter and Inter-Symbol Interference
  • Skin Effect and Loss Tangent
  • PCB Material Choices to Reduce Losses
  • Alternative to Higher Cost PCB Materials
  • Impact of Trace Corners and Vias
  • Crosstalk...what is it...exactly
  • Differential Pair Basics
  • Differential Impedance...What Really Matters
  • Differential Pair Cross Talk
  • Differential Pair Length Matching and Skew Issues
  • Differential Line Termination
  • Basic Types of EMI
  • Antenna Basics and PC Board Radiators
  • Keys to Controlling Common Mode Currents
  • Power Distribution and Decoupling
  • IC Impact on Power System Noise
  • Decoupling Boards without Power Planes
  • Decoupling Conventional 4 Layer Boards
  • Decoupling High Layer Count Boards
  • Impact of Via and Plane Inductance
  • Analogue IC Decoupling
  • Ferrites in the Power Bus
  • Basic Component Placement issues
  • Extreme Importance of I/O Connector Placement
  • Routing to Control EMI and Noise
  • Impact of Connector Pin Assignments
  • Extreme Importance of PC Board Stack-Up
  • PC Board Stack-Ups that work for SI and EMI control
  • Setup of the I/O Structure

 

About the Instructor

Rick Hartley was until recently a Senior Principal Engineer at L-3 Communication, Avionics Systems. Now he concentrates his time as the principal of RHartley Enterprises, through which he consults and teaches internationally. Rick’s focus is on correct design of PC boards to prevent & solve problems. He has consulted with major corporations in the US, Australia, Canada, Mexico, Brazil, China, Japan, England, France, Spain and Germany. His design career has focused on circuits and PC boards for computers, aircraft avionics and telecommunications. Rick has a degree in engineering and 49 years of experience in electronics. He has dedicated the past 36 years to PC board and circuit development with emphasis on control of noise, in both Digital and RF circuits. He is a past member of the Editorial Review Board of Printed Circuit Design Magazine and has written numerous technical papers on methods to control EMI and signal integrity. He is currently on the IPC Designers Council Executive Board and is a past international chairman of the IPC Designers Council.


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