EMC in automobiles

Goals

The objectives of the training EMC in automobiles :

At the end of this training course, trainees will be able to design and integrate electronic modules in automobiles, taking into account coupling modes and limiting the effects of various sources, including radio interference.
• 06 to 08.10.2026 - Trappes

The aim of this training course is to:

• Know how to assess the EMC environment inside and outside the vehicle


• Be able to identify the EMC risks of ESAEs based on the source of disturbance inside or outside the vehicle


• Know how to choose the EMC shielding and filtering solutions to be implemented


• Be familiar with the regulations in force for a vehicle and an SEEE

Program

1/ Introduction:
• Introduction: EMC in automobiles
• EMC characterisation of automotive equipment
• Internal EMC in vehicles: permanent sources/victims
• Internal EMC and vehicles: confrontation between sources and victims
• The two modes: common/differential
• Reminder: EMC units and terminology
• Narrowband/broadband spectrum
• Time-frequency conversion


2/ EMI environment
• Typical values of fields radiated by common transmitters
• Radio environment on roads (France)
• Strong radio fields generated in a vehicle
• Signatures of disturbers on vehicles
• Static charges in motor vehicles
• Disturbances in the automotive electrical system


3/ Susceptibilities of logic and analogue circuits
• Response of circuits to HF interference
• Static margins of common logic circuits
• Equivalent frequency of common logic circuits
• Transition power consumption
• Binary error rates with/without coding
• Sensors and transducers in automobiles
• Signal-to-noise ratio
• Envelope detection
• Characterisation of OP amplifier inputs and outputs


4/ Interference from ground planes
• Coupling through common impedance (C.I.C.)
• Impedance of a ground plane
• Impedance of copper and steel planes
• HF impedance of printed circuit tracks
• Impedance of circular conductors
• Critical grounding points on vehicles
• Exercise: interference through common impedance
• Analogue/digital comparison
• Calculating power supply noise
• Reducing power supply impedance
• Mesh power supply networks
• Analogue/digital mixing/high currents in ground planes


5/ Ground loops: solutions
• MC-MD conversion
• Capacitive coupling between board and chassis
• Total capacitance between board and ground plane
• Mechanical ground / electrical ground
• Edge effects


6/ Crosstalk
• Capacitive and magnetic crosstalk: analysis
• Track-to-track capacitance
• Wire-to-wire capacitive coupling
• Wire-to-wire inductive coupling
• Crosstalk reduction using ground planes
• Wiring rules for vehicle harnesses


7/ Field-loop coupling / field-wire coupling
• Field propagation
• Loop voltage
• Approximation of induced field-loop voltage
• Twisting of conductors
• Whip and dipole antennas
• Electric field to cable’ coupling
• Field reduction by ground plane


8/ Radiation from electronic devices
• The two types of radiation from electronic devices
• Spectrum of a trapezoidal train
• Radiation from a small loop
• Radiated spectrum in differential mode
• Why be wary of clocks?
• Radiation from a small whip
• Origins of common mode current
• Radiated spectrum in common mode
• Disturbances in an injection system


9/ Shielding
• How does shielding work?
• Near field/far field
• Losses due to reflection/absorption
• Choice of shielding material
• Shielding of conductive treatments
• Attenuation of an opening in a thin wall
• Steps in developing shielding


10/ Conduction protection
• The three methods of MC BF protection
• The three methods of HF common mode protection
• Immunity of vehicle digital connections
• Immunity of the CAN bus
• Envelope detection of optocouplers
• EMC filters in automotive electronics
• Filter circuits and impedances
• Capacitors and filters for printed circuit boards
• Attenuation due to battery impedance
• 12 V filtering problem
• Input/output filtering and protection
• Performance of different EMC ferrites
• Main surge arresters
• Coil interference suppression
• Shielded and coaxial cables
• Connection of shielded cable screens
• Importance of grounding base plates
• Car radios: interference from antenna coaxial cables


11/ Standardisation
• Automotive Directive: references and application
• R10 03 regulation
• Manufacturer specifications
• ISO 7637-X standard
• ISO 11452-X standard