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Robust Connectivity Solutions for

Next-Generation Automotive Ethernet

2019 IEEE SA Ethernet & IP @ Automotive Technology Day

Bert Bergner, Eric DiBiaso (TE Connectivity)

© 2019 TE Connectivity. All Rights Reserved.

2

Enabling Technologies for

Autonomous Driving

SENSOR FUSION multiple

camera, radar, lidar and

ultrasonic sensors

NETWORK ARCHITECTURE

central computing,

zonal data aggregation

SAFETY redundant and

fault tolerant system design


3

Evolution of Autonomy

Increasing Data Rate

No Automation AssistedPartial

Automation

Conditional

Automation

High

Automation

Full

Automation

“Drive by Data”


Robust System Design – What does it mean?

4

Environmental

Changes

Electromagnetic

Interference

Topology

Variations

Material

Variations

Process &

Manufacturing

Tolerances

Aging

Mechanical

Stress


Transmission Channel S-Parameter

Cable models:

• Numeric models for cable types

• Parameters based on measurements

• Parameterization for:

Cable length

Impedance tolerance

Environmental changes & aging

Channel Performance Parameters

5

Transmitted Signal Received Signal

Sensor ECU

Data Transmission

Connector models:

• Based on measurements & simulations

• Connector types & pairing variants

• Mating tolerances

• Cable termination variation

• Geometric & material tolerances

Board

Connector + + + +…Board

ConnectorInline

ConnectorCable


Mating depth status #2Geometric

tolerances

Connector Parameter Impact – Example

6

Mated Connector Return Loss

Min. mating depth

Max. mating depth1

2

Min. mating depth

Max. mating depth

2

1

-dB

Environmental

effects

Topology

variationsMaterial

variations


Connector Parameter Impact – Example

7

Cable compression in crimp zone

Impedance drop

Compression

Connector Performance

No cable compression

With cable compression


tolerancesTopology

variationsMaterial

variations

Environmental

effects


Cable Parameter Impact – Example

8

Lower attenuation

Less temperature sensitivity

Larger diameter

Smaller diameter

Larger attenuation

Higher temperature sensitivity


tolerances

Topology

variationsMaterial

variations

Environmental

effects


0

-10

-20

-30

-40

-50

Retu

rn L

oss [-d

B]

f [GHz]0 1 2 3 4 5 6 7 8

Channel Analysis – Example

9

0

-10

-20

-30

-40

-50

Retu

rn L

oss [-d

B]

f [GHz]0 1 2 3 4 5 6 7 8

Preliminary Multi-Gig Ethernet Limit (NGAUTO)

Random parameter and

topology variation0.25 m 6 m 3 m 3.75 m 2 m

Single channel result


tolerances

Topology

variations

Environmental

effectsMaterial

variations

Preliminary Multi-Gig Ethernet Limit (NGAUTO)


10

Channel Analysis – Conclusion

⚫ Robust system definition considering

component tolerances and environmental changes

⚫ Robust component design with

low tolerance sensitivity of RF parameters

⚫ Processes without degradation of RF parameters

⚫ Engineered cable harnesses

allowing economic implementation


Data Capacity of Automotive Data Cabling

How fast can we go?

11

PHY PHY

ChannelIC IC

cable, connectors

complexity, chip size, power consumption

material effort, process effort, complexity

Effort

IC

Effort

channel

Optimum

Total

effort

⚫ Identify physical limits

⚫ Estimate maximum data rate

⚫ Consider robust system design

and automotive requirements

⚫ Propose possible system solutions

for data rates up to 25 Gbps


Calculation of Achievable Data Rates

12

Considerations:

⚫ Baseband signaling on

0.14 mm² STP cabling

⚫ Channel transmission parameter

Return Loss, Insertion Loss

⚫ Environmental degradation

⚫ Electromagnetic emission limits

⚫ Electromagnetic immunity

⚫ PHY dependent transmission power limits, receiver noise, etc.

Shannon-Hartley theorem:(for White Gaussian Noise)


Channel Model Including EMI

13

ConnectorConnector

Connector

PHY

PHY

Tx Rx

Txupstream

PD Tx shaped

ILInsertion Loss S

N

PD Txupstream

EMI Emission Limit

EMI Disturbance(e.g. BCI Test Power)

TFIEMI Ingress

Transfer Function

PD NOther Noise

Sources

RLReturn Loss

TFEEMI Egress Transfer

FunctionTx P

ow

er

Shap

ing

Mas

k

PD Rx

Electromagnetic Interference (EMI)


Channel Capacity – Methodology

14

Capacity

Density (

bit/s

/Hz)


Channel Data Capacity Results

15

Original STP link

(0.14 mm², 10 m)

IL w/ temperature & aging

IL w/ temperature & aging

and increased RL

IL w/ temperature & aging,

increased RL and

reduced EMI


increased RL, reduced

EMI and reduced length (6m)


increased RL, reduced

EMI, reduced length (6m)

and no duplex

Sim

ple

x (

unid

irectional)

Duple

x (

bid

irectional)

Useable Frequency

Bandwidth


16

Channel Capacity Analysis – Conclusions

⚫ Data rates > 10 Gbps possible on single shielded pair

⚫ Insertion loss is primary limiting parameter

⚫ Useable frequency bandwidth < 10 GHz

⚫ Improvements by increased return loss and shielding

→ appropriate connectors and cables


17

Channel Capacity Analysis

Options for Robust 25+ Gbps Systems

⚫ Tx and Rx on separate wire pairs

→ no single pair duplex

⚫ Decreased insertion loss

→ reduced length

→ alternative media (e.g. coax)

⚫ Multiple number of Tx/Rx pairs

→ multi lane


18

Automotive

Robustness

and Reliability

RF and

EMC Expertise

Ready for Next

Generation

Architectures

Data Connectivity forNext-GenerationMobility

High

Performance


Thank Youwww.te.com/automotive


TE Connectivity, TE connectivity (logo), and TE, are trademarks. Other logos, product and company names mentioned herein may be trademarks of their respective owners.

TE’s only obligations are those stated in TE’s General Terms and Conditions of Business (http://www.te.com/aboutus/tandc.asp). TE expressly disclaims any implied warranty regarding the information contained herein,

including, but not limited to, the implied warranties of merchantability or fitness for a particular purpose.

19 © 2019 TE Connectivity. All Rights Reserved.

http://www.te.com/aboutus/tandc.asp

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