Spice & CEM

Goals

formation-objectifs-seointro Spice & CEM :

- Master the basic analytical approach to understand orders of magnitude
- Know and master the correct tool settings for EMC
- Understand the libraries of active and passive components
- Be able to understand and model EMC couplings and non-linear effects
- Understand the modelling technique for sensors, couplers, EMC generators, shielded cables, filters, varistors, TVS, etc.

Program

1/ EMC: reminders

EMC characterisation of equipment

EMC analysis method

Common mode / Differential mode

Use of decibels

Time/frequency relationship



2/ History of Spice - LT Spice

The LT Spice interface and functions

Toolbars, diagrams, libraries, post-processing

No calculations

Adding a component to a library

Modelling by directive

Time simulations and AC sweep

Time and frequency principles of an FFT

Minimum and maximum spectral leakage

Ripple (" Ripple") of an FFT

Effect of compression on a calculated spectrum

FFT spectrum of a centred and off-centre pulse

Hann, Nutall, Blackmann windowing Harris, Tukey

Flat top filters with normalised bandwidths

Generation of centred bursts in the window

Simulation of a wideband generator

Narrowband to wideband correction

Simulation of an asymmetric pulse generator

Pulses in a 111 µs time window

Broadband pulse spectra in 9 kHz

Effect of compression on a calculated spectrum

Automatic calculation of THD

Simulation of intermodulation distortion

Creation of standardised templates



3/ Modelling of passive components

Modelling of a resistor, capacitor, inductance

Ladder network

Modelling of an electrochemical capacitor

Modelling of a frequency-variable inductance

Comparison of MC inductance measurement and simulation

Modelling of a pulse transformer

Magnetic components and ferrite absorbers

Modelling of varistors/transzorb/transil/Éclateur

Quartz model (Crystal)



4/ Modelling of active components

Modelling of an OP amplifier

Slew Rate according to model

PSRR, CMRR modelling

Envelope detection simulation

JFET input stage detection

Output impedance effect

Simulation and effect of crossover distortion

Caution regarding active filter structure

Stability on capacitive load

Simulation of dropout voltages

Simulation of incoherent noise spectral density

IBIS model

Modelling and diode recovery

Parametric simulation of transconductance amplifiers



5/ Signal integrity

Linear parameters

Use of QUCS for line calculations

Stub effect of a via in frequency and frequency

Diagram of the

Modelling line losses



6/ Crosstalk

Capacitive and inductive crosstalk on CIP

Definition of characteristic impedances

Capacitance/mutual extraction from connector pins

Reduction of the edge effect of a connector

Effects of good pin distribution

Line simulation to model crosstalk

Crosstalk between natural lines and adapted microstrips

Effects of increased transition times

Crosstalk as a function of Zc

Resonant, cumulative crosstalk



7/ &Conducted emission

Principle and modelling of MD disturbances

Schematic and modelling of an RSIL

Simulation of Differential Mode in FFT and AC

SPICE simulation of an MD converter

Principle of disturbances in CM

Modelling in primary CM on chassis

Limitation of Common Mode models

Theoretical filtering principle in DM and CM

Modelling and insertion lossinsertion of a filter in MD and MC

Simulation of radiation coupling of a filter

Spectrum spreading (SCC): triangular modulation

Synthesis of a cusp function generator



8/ Modelling of couplings

Radiated emission problems

Evaluation of MC currents on blanksConversion (dissymmetry)

Simple model of a coaxial cable in MC + MD

Reducing effect of a coaxial cable in F and T

Effect of a pigtail in F and T

Impedance of a mesh (reinforcing bars)

Calculation and simulation of a lightning surge



9/ Conducted immunity

Difficulty in modelling common mode tests

WF4 + WF5 generator according to MIL-STD 461G/DO-160

Simulation of WF4/WF5 injection on a beam

61000-4-5 shock wave generator in MD and MC

BCI injection clamp modelling

PI attenuator

Synthesis of a filter using QUCS

Definition of the S parameters of a filter

Tuning a filter with S parameters