Es la presentación del libro para placas y el diseño de las mismas

1. Printed Circuit
Board Design
Techniques for EMC
Compliance
ALAN GUSTAVO MARTINEZ VALDEZ
MINIREDES DE TRANSMISIÓN INTELIGENTE
ARTURO DOLORES VENADERO

2. Chapter 1.: Introduction
Importance of PCB Design for EMC:
The relevance of proper PCB design to ensure the
electromagnetic compatibility of electronic
products is highlighted.
It is mentioned that poor design can result in
electromagnetic emission and susceptibility
problems, which affects the performance and
safety of the devices.
Chapter Objectives:
The chapter aims to provide an overview of the
basics of PCB design for EMC.
The aim is to establish a solid foundation to
understand the techniques and methodologies that
will be addressed in subsequent chapters.

3. Chapter 1.: Introduction
PCB Design Approach:
It is mentioned that engineers must consider aspects
such as the transfer of electromagnetic fields between
circuit boards and structures, cost minimization and
regulatory compliance.
The importance of system integration in PCB design and
the need to balance functionality with EMC is
highlighted.
Chapter Content:
The importance of considering EMC from the initial stages
of PCB design is discussed.
The EMC requirements in different regions, such as North
America and international, and the need to comply with
these standards for the marketing of electronic products
are mentioned.
Emphasis is placed on the variety of design
methodologies available and the importance of selecting
the most appropriate ones to ensure EMC.

4. 1. Hidden RF and Passive Component
Characteristics : The presence of hidden
radio frequency (RF) energy in printed circuit
boards is discussed and the characteristics of
passive components are analyzed in relation to
EMC.
2. RF Energy Development on the PCB:
How and why RF energy develops within the
printed circuit board is explored, highlighting
the importance of understanding this
phenomenon for proper design.
3. Magnetic Flux and Cancellation
Requirements: Magnetic flux in printed circuit
boards and the importance of cancellation
requirements to ensure effective EMC design
are discussed.
Chapter
2.
Printed
Circuit
Board
Basics

5. Chapter
2.
Printed
Circuit
Board
Basics
4. Routin Routing Topology and
Configurations: The importance of
routing topology in printed circuit board
configurations to minimize
electromagnetic interference is
discussed.
5. Layer Stacking and Mapping: The
layer stacking technique in PCB design
and proper layer assignment to improve
signal integrity and EMC are discussed.
6. Radial Migration: It delves into the
radial migration of RF currents and its
impact on the design of printed circuit
boards to comply with EMC standards.

6. Focuses on bypass and decoupling in printed
circuit board design. Reviews resonance,
describing how at resonance, the capacitor
and inductor exchange the same stored energy
in alternating half cycles. Likewise, it explains
that at the antiresonant frequency, the tank
circuit presents a high impedance to the
current of the primary circuit, although the
current inside the tank is high. Energy is
dissipated only in the resistive part of the
network. He also mentions that the
antiresonant circuit is equivalent to a parallel
RLC circuit whose resistance is q2R.
Chapter 3: Bypassing and
Decoupling

7. .
Chapter 3: Bypassing and
Decoupling
Parallel Capacitors: The use of capacitors in
printed circuit board design is addressed to
improve electromagnetic compatibility (EMC)
compliance.
Power and Ground Planes: The chapter provides
techniques for designing the power and ground
planes on a printed circuit board, which is crucial
for proper operation and power management.
Placement: Strategic placement of components
and power/ground planes on a printed circuit
board to optimize EMC performance is discussed.

8. .
Chapter 3: Bypassing and
Decoupling
Overall, Chapter 3 delves into specific
design considerations for EMC compliance
on printed circuit boards, focusing on
aspects such as resonance, physical
characteristics, capacitors, power and
ground planes, and strategic component
placement. This chapter is valuable for
designers and professionals seeking to
understand and apply effective design
techniques for EMC compliance on printed
circuit boards.

9. 1
Creating transmission lines within a
PCB: The importance of designing
transmission lines to control signal
impedance, minimize electromagnetic
interference and optimize circuit
performance is highlighted. Different
topology configurations are discussed,
such as microstrip, integrated
microstrip, single line and differential,
each with its own characteristics and
applications
Focuses on key aspects related to clock circuits, trace routing, and terminations in printed
circuit board design. Below is a detailed explanation of the topics covered in this chapter:
Chapter 4: Clock Circuits,
TraceRouting, and Terminations

10. 2 Propagation delay and dielectric constant: It
delves into the concept of propagation delay in
transmission lines and how the dielectric constant
of the material used can influence the speed of
signal propagation. The importance of considering
these factors is highlighted to guarantee proper
functioning of the circuit
Chapter 4: Clock Circuits,
TraceRouting, and Terminations
3 Capacitive loading of signal traces:
It analyzes how capacitive loading in
signal traces can affect circuit behavior
and offers strategies to manage this
loading effectively, avoiding potential
signal integrity problems.

11. 4
Impedance matching and reflections:
The importance of achieving proper
impedance matching to minimize signal
reflections and ensure efficient signal
transmission is explored. We discuss how
reflections can affect signal integrity
and provide guidelines for avoiding this
problem.
Chapter 4: Clock Circuits,
TraceRouting, and Terminations
5 Strategic component placement: Recommendations are
provided on the optimal placement of components on the
PCB to minimize electromagnetic interference and improve
circuit performance. The importance of placing clock
circuits near a ground bonding location is highlighted to
improve signal quality and avoid RF problems

12. Chapter 4: Clock Circuits,
TraceRouting, and Terminations
6
Calculation of trace lengths:
Guidelines are provided for calculating
trace lengths in clock circuits and high-
speed signal routing. The importance of
properly terminating traces is
highlighted to improve signal quality
and avoid RF problems.

13. Chapter 5: Interconnects and I/O
INSULATION AND PARTITIONING
(FOATING)
In this section, the isolation and
partitioning of floating circuits is
discussed. This could involve
methods such as using pits or pit
bridges to partition the design and
avoid electromagnetic interference
issues due to different ground
potentials.
1. Capacitors:
- Used to divert RF energy from the cable shield to the chassis ground.
- They can form part of an LC filter to operate at a particular frequency.
- Sensitive to high voltage levels.
2. Inductors:
- They should never be used to filter.
- They reduce the speed of transient current flow, which can alter signal
integrity.
- They can cause a voltage potential difference between devices.
3. Ferrite material (cord over cable, common mode chokes, data line
filter or equivalent):
- Absorbs high frequency RF energy.
- Allows the DC signal of interest to pass through without interruption.
- Provides high impedance at externally induced event frequencies.
- Effective at high frequencies, normally above 10 MHz.
- Protects both emissions and immunity.

14. To use a capacitor as an effective filtering device, it is
recommended that it be placed directly at the input point of the
connector, connected from line to chassis. Additionally, a data
line filter (common mode choke or differential filter) must be
placed between the driver side of the signal trace and the
connector, with the bypass capacitor between the two.
Capacitors will effectively divert common induced currents to the
chassis, so their use is important to meet regulatory regulatory
and immunity requirements.
Chapter 5: Interconnects and I/O
LOCAL AREA NETWORK I/O DESIGN
This section discusses specific aspects of input/output
design for local area networks. This may include
considerations such as signal routing, component layout,
and managing electromagnetic interference in network
environments.

15. - Main concerns when making a video design: trace impedance and power purity.
- Typical PCB has a trace impedance of 55 to 65 ohms, but video requires 75
ohms.
- For very dense multilayer PCB assemblies, trace routing should be done over an
area with no copper section directly below the 75 ohm RGB circuit.
- The absence of the copper area forces the signal traces to have an impedance
referenced to a plane at a greater distance, increasing the overall impedance.
- This lack of copper area also prevents digital power plane noise from corrupting
low voltage analog signals.
- One design technique to maintain impedance control is to alter the physical
width of the trace at each routing layer.
- Referencing a trace to a plane at a further distance within the buildup is how a
trace with a different impedance value can be routed.
VIDEO
This section focuses on the
design of printed circuit boards
with video-related components.
It can address the importance
of impedance control, filtering
techniques, and grounding
strategies specific to video
components on printed circuit
boards. This could be especially
relevant for analog monitors.
Chapter 5: Interconnects and I/O

16. - Audio printed circuit boards require separate areas for digital, analog and audio.
- Multi-level partition is applicable only for a stack of four or more layers.
- The analog section must be isolated from the digital zone by means of a bridge or pit.
- When designing a pit structure for analog power and ground, route traces between the digital
and analog section in the immediately adjacent area.
- Use a ferrite bead between the analog/digital power and ground.
- Depending on how the audio driver is divided, the analog ground and digital ground can be
interconnected.
- All interconnect tracks not associated with the audio controller must traverse a bridge located
directly below the audio controller and physically adjacent to a solid reference plane.
- The audio interface requires complete isolation of the digital power and ground planes to
avoid switching noise.
AUDIO
This section can
discuss specific
design strategies
for audio signal
integrity, routing
techniques, and
electromagnetic
interference
considerations.
Chapter 5: Interconnects and I/O

17. Audio cables must be made up of a pair of wires, signal and return for each channel, and the audio interface
connector must be isolated from the rest of the PCB.
- Data line filters should be used to eliminate common mode currents and provide isolation from ESD events or
RF induced energy.
- A ground coil or inductor should not be incorporated into the ground circuit to refer to "audio".
- Analog tracks and components must be located within the isolated analog section to avoid coupling
between digital and analog sections.
- If a cable with RF braid is used, it should be connected directly to chassis ground with a bypass capacitor to
eliminate RF energy that corrupts audio quality.
- Different peripheral device vendors must not terminate the braid of the interconnection cable.
AUDIO
Chapter 5: Interconnects and I/O
It is worth mentioning that this explanation is based on the information
provided in the document "Printed Circuit Board Design Techniques for EMC
Compliance: A Designer's Manual, Second Edition" and does not include
specific details about the sections that do not have detailed information in
the document provided.

18. Chapter 6: Electrostatic Discharge Protection
1. What are the key considerations for implementing
effective ESD protection techniques in PCB design?
Route power and ground traces adjacent to each other with a minimum
distance between them.
- Connect multiple power and ground traces together forming a network to
provide a smaller loop area, resulting in lower induced currents and magnetic
field coupling.
- Route parallel signal traces close together to minimize RF return current loop
area.
- Route signal traces as close as possible to a ground trace and use a ground
network to help implement this requirement.
- Use high frequency bypass capacitors between power and ground that
contain a low impedance value at ESD frequencies.
- Incorporate components not sensitive to ESD, such as CMOS or TTL
protected by diodes, in circuits susceptible to ESD disturbances.
- Use bypass capacitors with a high self-resonance frequency between power
and ground, with an equivalent series inductance (ESL) and an equivalent
series resistance (ESR) that are as low as possible.
Key considerations for
implementing effective ESD
protection techniques in
PCB design include:

19. 2. How does the triboelectric series guide charge
accumulation and its potential impact on ESD events?
The triboelectric series guides the accumulation of charges by friction between two different materials,
which can generate a static charge. This accumulation of charges can lead to an ESD event when the
charges are abruptly discharged. When an ESD event occurs, this sudden release of energy can cause
damage to electronic components and circuit operability, making it necessary to understand and apply
design techniques to prevent ESD damage.
3. What are the implications of ESD damage to components and operational
disruption, and how can they be mitigated in practical PCB design?
The implications of ESD damage to components and operational disruption can result in significant costs and
unplanned downtime. To mitigate these effects in practical PCB design, various techniques can be implemented,
such as the use of avalanche diodes (Tranzorbs) to dissipate power in a short period of time, the employment of LC
filters to prevent high ESD energy frequency enters the system, and the use of bypass capacitors with low
inductance in series to reduce the loop area between the power and ground planes. Additionally, the use of non-
ESD sensitive components, such as diode-protected CMOS or TTL, in circuits susceptible to ESD disturbances can
help mitigate the effects of ESD damage in PCB design.
Chapter 6: Electrostatic Discharge Protection

20. I
4.What would be the price for the system?
1. Avoid charge injection into PCB circuits to prevent their destruction or interruption.
2. Provide complete shielding around components and circuits susceptible to radiated
ESD corruption.
3. Connect the shield to chassis ground at multiple points, providing a low impedance
path for ESD currents absorbed by the shield.
4. Consider effective isolation if shielding is not practical, functioning effectively for
"direct discharge", not radiated ESD coupling.
5. Capture the energy before it enters the system to avoid re-radiation of the pulse into
the product.
6. Ensure that filters have a high quality RF impedance path to ground, choosing filters
for a particular application and which may consist of various topologies.
Protection for the system
against electrostatic
discharge (ESD) includes
the following general
measures according to the
design rules presented in
the document:
IMPORTANT: These measures provide comprehensive protection for
the system against the damaging effects of electrostatic discharge.
Chapter 6: Electrostatic Discharge Protection

21. Chapter 7:Backplanes, Ribbon Cables, and
Daughter Cards
What are the main concerns when designing interconnects
on backplanes, ribbon cables, and daughter cards?
Impedance of trace paths: It is crucial to maintain a constant impedance along the
signal paths to avoid reflection problems and signal distortion.
a.
Purity of power distribution system: Ensure that power distribution is stable and
noise-free to avoid electromagnetic interference.
b.
Assembly Construction: The physical layout of components and the structure of the
assembly must be designed to minimize crosstalk and maintain signal integrity.
c.
Trace Termination: It is important to apply proper termination techniques to
eliminate harmful effects and improve signal quality, especially on long trace paths.
d.
Signal routing topology: Signal routing design must be carefully planned to minimize
crosstalk and ensure optimal performance.
e.
Trace length: Controlling the length of the traces is essential to avoid timing
problems and ensure proper functioning of the system.
f.
When designing
interconnects on
backplanes, ribbon cables,
and daughter cards, key
concerns include:
IMPORTANT: These concerns are essential to achieving
effective and reliable interconnect design on backplanes, ribbon
cables, and daughter cards.

22. What design rules and techniques applicable to PCB
design are presented in this chapter?
Keep all trace path discontinuities as short as possible.
a.
Use as many ground connections as possible within the allotted space.
b.
Establish a common ground reference within the connector.
c.
Use board materials with low dielectric constant for greater signal integrity.
d.
Keep the RF return path as close to the signal path as possible.
e.
Match impedance between PCB assemblies to ensure optimal performance.
f.
Minimize impedance discrepancy at the connector boundary.
g.
Provide enough power and ground pins on the connector to maintain a
constant impedance throughout the assembly.
h.
The aforementioned
chapter presents various
design rules and
techniques applicable to
PCB design, especially in
the context of backplanes,
ribbon cables, and
daughter cards. Some of
the notable rules and
techniques are:
IMPORTANT: These rules and techniques are critical to ensuring
efficient and reliable PCB design, especially in the context of
interconnects on backplanes, ribbon cables, and daughter cards.
Chapter 7:Backplanes, Ribbon Cables, and
Daughter Cards

23. How can the purity of the power distribution system be
ensured in a PCB design?
Impedance and capacitive load control: Ensure each trace path has proper impedance
and controlled capacitive loading to maintain signal integrity and minimize interference.
a.
Maintain power plane purity: Avoid contamination of the power and ground plane by
preventing switching noise, externally induced RF fields, surge events, among others.
b.
Use materials with low dielectric constant: Employ low dielectric constant board materials
for faster signal propagation speed and reduced capacitance in trace paths.
c.
Minimize crosstalk and interference: Design signal and power paths to minimize crosstalk
and avoid unwanted interference between components.
d.
Apply proper termination techniques: Use appropriate trace terminations to eliminate
harmful effects and improve signal quality, especially on long routes.
e.
Maintain a common ground reference: Establish a common ground reference within the
connector to ensure proper signal return and minimize interference problems.
f.
To ensure the
purity of the power
distribution system
in a PCB design,
the following
practices and
techniques can be
followed:
IMPORTANT: By following these practices and techniques, the purity of the power distribution system in a
PCB design can be ensured, which will contribute to optimal and reliable operation of the electronic system.
Chapter 7:Backplanes, Ribbon Cables, and
Daughter Cards

24. What is the importance of placing components such as oscillators and crystals on a
localized plane?
The importance of placing components such as oscillators and crystals on a localized plane lies in several key aspects for
the design of printed circuit boards:
Chapter 8
1. **Reduction of electromagnetic interference (EMI):** By placing these
components on a localized plane, the radiation of radio frequency (RF)
energy generated internally in the circuit is minimized, helping to reduce
radiated RF emissions and to improve signal integrity .
2. **Additional decoupling:** The localized plane provides the
opportunity to add additional decoupling for specific components,
contributing to better power distribution and more stable circuit
operation .
3. **Improved system performance:** By placing the oscillators and
crystals on a localized plane, proper grounding is facilitated and
interference that could affect optimal system performance is minimized .

25. What considerations should be taken into account when selecting components for printed circuit board
design?
When selecting components for printed circuit board design, it is essential to take into account various considerations
to ensure optimal circuit performance and compliance with EMC standards. Some of the key considerations include:
Chapter 8
1. **Electromagnetic Compatibility (EMC):** It is crucial to select components
that meet EMC requirements to avoid electromagnetic interference that may
affect circuit performance .
2. **RF Current:** When choosing components such as oscillators and clock
drivers, it is important to consider the RF currents generated and ensure the
design can handle them effectively to avoid signal integrity issues and comply
with EMC standards .
3. **Decoupling:** Consideration should be given to the need to add additional
decoupling for specific components, which can be achieved through the
strategic placement of localized planes and the inclusion of decoupling
capacitors

26. Chapter 8
4. **Grounding:** It is essential to select components
that facilitate proper grounding, especially for critical
components such as oscillators and crystals, to minimize
interference and ensure stable system operation.
5. **Signal integrity:** When choosing components for
printed circuit board design, consider signal integrity
and ensure that the selected components are
compatible with the system's signal specifications .
In summary:when selecting components for printed circuit board design, it is essential to consider aspects such as electromagnetic compatibility, RF
currents, decoupling, grounding, and signal integrity to ensure an efficient and reliable design that Comply with EMC standards.

27. How can corner routing on a printed circuit board be optimized to improve EMC performance?
TTo optimize corner routing on a printed circuit board and improve Electromagnetic Compatibility (EMC) performance, some best practices
can be followed:
Chapter 8
1. **Avoid right-angled corners:** Right-angled corners can cause
radiated emissions problems due to the generation of stray
electromagnetic fields. It is recommended to soften the corners using
soft curves to minimize this effect .
2. **Strategic component placement:** Placing critical components
such as oscillators and crystals on a localized plane can help reduce
electromagnetic interference and improve signal integrity .
3. **Consider power distribution:** Ensure that power distribution on
the printed circuit board is adequate, avoiding current concentrations
that could generate unwanted electromagnetic fields .

28. Chapter 8
4. **Use ferrites for unwanted signal suppression:** Proper
selection of ferrite devices can help attenuate RF energy and
minimize electromagnetic interference on the printed circuit
board.
5. **Optimize trace routing:** Avoid traces routed exactly on
the physical edge of a reference plane and ensure that the RF
return flow is uniform to reduce radiated emissions.
6. **Implement proper terminators:** Correct placement of
terminators on transmission lines is crucial to ensure good
EMC performance and avoid signal integrity issues.
Al seguir estas recomendaciones y consideraciones al diseñar el trazado de ruta para esquinas en un circuito impreso, se puede mejorar
significativamente el rendimiento de EMC y reducir las posibles interferencias electromagnéticas que puedan afectar el funcionamiento del sistema.

29. Conclusions
**Understanding EMC**: EMC is crucial for the proper functioning of electronic
devices that utilize PCBs. By comprehending and implementing EMC principles,
manufacturers can avoid costly product recalls, ensure regulatory compliance, and
deliver reliable products to customers².
**Mitigating RF Energy**: The book emphasizes techniques to prevent the emission
or reception of unwanted radio frequency (RF) energy generated by components and
interconnects on PCBs. Achieving acceptable levels of EMC for electrical equipment
is essential¹³.
**Simplified Approach**: Rather than relying on rigorous mathematical analysis, the
book simplifies EMC concepts using real-life experience, training, and knowledge. It
covers topics such as interconnects, bypassing, decoupling, clock circuits, and more¹.
**Rules-Driven Format**: The user-friendly format allows quick access and cross-
referencing, making it suitable for electrical engineers, EMC consultants, technicians,
and PCB designers regardless of their experience or educational background¹.

30. Montrose, M. I. (2000). Printed Circuit
Board Design Techniques for EMC
Compliance: A Handbook for Designers.
Wiley-IEEE Press.
Montrose, Mark I. Printed circuit board design
techniques for EMC compliance: a handbook
for designers / Mark I. Montrose.--2nd ed. p.
cm.--(IEEE Press series on electronics
technology) "IEEE Electromagnetic
Compatibility Society, sponsor."
Bibliographic
reference