Signal integrity

Goals

formation-objectifs-seointro Signal integrity :

- Take into account design difficulties related to increased transmission speeds (losses, crosstalk, mode conversion, non-linearity, etc.)
- Understand the dynamic and frequency limitations of signals and their propagation, and use design tools to assist with board layout and routing, as well as wired transmissions

The aim of this training course is to:
- Identify the causes and effects of noise superimposed on signals
- Master power noise and its decoupling (power integrity, ground bounce)
- Be able to simulate line effects and model signal integrity (SI)
- Identify the main pitfalls in electronic board design, including component selection and implementation
- Be able to analyse the effects of filters (linear or otherwise) and calculate a surge protection circuit

Program

1/ Signal-to-noise ratio

Reminders and definitions

FFT and inverse FFT

Thermal and quantisation noise

Peak, average and median values

Amplitude probability density (APD)

Excess noise and 1/F – Choice of technology

SINAD and effective number of bits (ENOB)

Signal-to-noise ratio (SNR)

Relationships between THD, SNR and SINAD

Integral and differential non-linearity (INL, DNL)

Bit error rate (BER, BEP)

2/ Noise margin

Confusion between the concepts of earth, ground and 0 V

Static and dynamic noise margins

« Ground bounce: cause, measurement and effects

Front slopes, simultaneous switching

Jitter, case inductance, maximum throughput

Choice of layers and stacking stacking »

Thermal drift and non-linearity

Envelope detection: example

3/ Power supply noise (PI) Power converter noise Power bus impedance Current return - Layer change

Modelling a power supply by planes

Spectrum of current consumption and simulation

Cavity effect between planes, distance between vias

Power supply noise and induced ‘jitter’ induced jitter

Routing errors – Effects of slots

Structural resonances – Edge effect

“ Power integrity, PSRR and decoupling

4/ Line effects

Electromagnetism, permeability and permittivity

Current flow, propagation speed

Characteristic impedance / line parameters

Near and far fields - Propagation

Transition and delay time measurements

Simulation of skin effect and roughness

Inductance of finite and imperfect planes

The two types of resonance - Measurements in 50 Ω

Effects of line losses - Simulation

Dielectric losses and choice of dielectric

« HDI », high-density integration and microvias

Pre-emphasis, peaking, active equalisation

« TDR » Reflectometry: Measurements and simulation

« Overshoot », « Ringing », waveforms

Effects and risks of serpentine delay

Capacitor pads, vias and stub effect

Risk of double toggling - Adaptation

S parameters: definition and simulation

Embedding and de-embedding

OSM/OSTM calibration - Smith chart

Connectors for HF signals - Simulation

Fast clock routing

Distributed adaptation simulation

5/ Active components

Dual sources / data sheets

Crossover distortion and effects

References and voltage regulators

Amplifier output filtering

Schematic analysis and validation

SerDes (Serialiser/deserialiser)

QFP, BGA, ‘wire bond’, " flip chip »

RLC and SIP / LVDS drivers

High-density interconnections (HDI)

Metastability / Dual synchronisation

O’ diagramand histogram

Concept of mask – Error rate

Amplitude and phase modulation

OFDM modulation / Constellation

Jitter measurements, Jitter / analysis

Phase noise – Effect on ADC / DAC

Spectrum spreading clocks (SSC)

6/ Crosstalk and near fields

Capacitive and inductive crosstalk

Parasitic crosstalk / telediaphony / modelling

« Glitch » due to crosstalk: pull-in and push-out

Crosstalk between lines – load effects

« NEXT », « FEXT » and « Alien »

Crosstalk/attenuation ratio (ACR)

Connectors and near-field probes

7/ Differential links

Magnetic components and symmetrisation

Longitudinal conversion loss (LCL, TCL)

BER and common mode rejection (CMRR)

Connection asymmetries: layout routing

Skew effect and other asymmetries

Even Z, odd Z (Zodd and Zeven), routing

Microstrip or stripline / Radiated emission

8/ Protective components

Latch-up phenomenon

Absolute maximum values / risks

Power supply input protection

Clamping diodes (" clamping »)

Resistor overload resistance

F and t simulation of low-pass filters

Problems and choice of capacitor

Surge arresters - Choice of Transzorb

Linear or non-linear filters – Examples

Zt of shielded cable and reducing effect

Choice of shielded cable and connector