Texas Instruments | ESD Protection for Automotive Infotainment | Application notes | Texas Instruments ESD Protection for Automotive Infotainment Application notes

Texas Instruments ESD Protection for Automotive Infotainment Application notes
____________________________________________________
ESD Protection for Automotive Infotainment
Dajah Edwards
Recently there has been an increase in demand for
connectivity in vehicles. Most infotainment systems
today are composed of a head unit and media
interface system.
Universal Serial Bus (USB)
Media interface refers to the system that connects
external or internal media (from a cellphone, media
player, etc.) to the vehicles infotainment system, while
head unit refers to the hardware interface of an
automotive infotainment system.
The media interface can receive inputs from USB,
HDMI, SD Cards, or Audio Jacks. The most common
found in today’s vehicles are USB, as Audio Jacks are
experiencing a decline in use.
These interfaces cause the internal system circuitry to
be at risk of electrostatic discharge (ESD) strikes.
During an ESD strike thousands of volts are being
discharged which can cause harm to internal
components.
To simulate real world ESD even in vehicles the ISO
10605 is used. To simulate a discharge directly from a
human body the ISO 10605 uses a 2kΩ resistor, but to
simulate a human body discharging through a metal
object a 330Ω resistor is used. A 150 pF capacitor is
used to simulate a person inside the vehicle and a
330pF capacitor is used to simulate a person outside
of the vehicle. The graph below shows the contact
discharge waveforms of a person inside and outside of
a vehicle discharging through a metal object.
SLVAE27 – December 2018 – Revised 08 2018
Submit Documentation Feedback
A Universal Serial Bus (USB) is an interface used to
connect a variety of electronic devices together. Within
the automotive industry USB is typically used to
connect the occupants’ mobile devices to the
infotainment system in the vehicle. As of late there has
been an increase in USB 2.0 and USB 3.0 ports in
vehicles.
Four pins make up the USB 2.0 connector: VBUS, D+,
D-, and ground. The VBUS line and the data lines will
require ESD protection. The output voltage on a USB
connector is ≤5V, so the working voltage of an ESD
protection device should be 5V for the VBUS line. USB
2.0 has a data speed of 480Mbps so the ESD
protection device for the data lines should have a low
capacitance.
In addition to the four pins that a USB 2.0 connector
has, USB 3.0 has an additional five pins. The five
additional pins are two super-speed transmitter
differential pairs and a ground for signal return. USB
3.0 has a data speed of 5Gbps so a low capacitance is
necessary to maintain signal integrity.
TI offers several protection devices for USB 2.0 and
USB 3.0 such as the TPD1E05U06-Q1, TPD4E05U06Q1, and the TPD4E02B04-Q1.
High-Definition Multimedia Interface (HDMI)
ESD Protection for Automotive Infotainment Dajah Edwards
Copyright © 2018, Texas Instruments Incorporated
1
Related Documentation
www.ti.com
A High-Definition Multimedia Interface connector
transmits audio and video data. Within the automotive
industry HDMI is typically used in rear-seat
entertainment systems, or used internally to transmit
data back to the head unit from the media hub. An
HDMI connector has nineteen pins.
L Audio IN
Audio Amplifier
Class AB
(ESD Sensitive)
L Audio
L
GND
R Audio IN
Speaker
Connector
(Source of ESD)
1
1
Audio Amplifier
Class AB
(ESD Sensitive)
R Audio
R
GND
2
GND
2
TI offers the TPD1E10B06-Q1 and the TPD1E10B09Q1 for audio jack protection.
For the non-TMDS channels ESD protection is needed
but capacitance is not a concern due to the passing of
low speed data. The TMDS lines can transmit data at
≤18Gbps for HDMI 2.0 at an operating voltage of 3.6
so a device with low capacitance is desired. The
TPD1E05U06-Q1, TPD4E05U06-Q1, and the
TPD4E02B04-Q1 are also options for protecting HDMI
connections.
SD/Memory Cards
Table 1. Alternative Device Recommendations
Device
Channels, VRWM,
Cap
Interface
TPD1E05U06-Q1
1, +5.5V, 0.5pF
Ethernet, HDMI 1.3/1.4,
HDMI 2.0, LVDS, USB
2.0, USB 3.0
TPD1E10B06-Q1
1, ±5.5V 10pF
Audio, General Purpose
TPD1E10B09-Q1
1, ±9V 12pF
Audio, General Purpose
2, +5.5V, 1.5pF
Ethernet, General
Purpose, LVDS,
Memory/SIM Care, USB
2.0
2, +5.5V, 1.5pF
Ethernet, General
Purpose, LVDS,
Memory/SIM Care, USB
2.0
TPD4E001-Q1
4, +5.5V, 1.5pF
Ethernet, General
Purpose, LVDS,
Memory/SIM Care, USB
2.0
TPD4E05U06-Q1
4, +5.5V, 0.5pF
Ethernet, HDMI 1.3/1.4,
HDMI 2.0, LVDS, USB
2.0, USB 3.0
TPD4E02B04-Q1
4, ±3.6V, 0.25pF
Ethernet, HDMI 1.3/1.4,
HDMI 2.0, LVDS, USB
2.0, USB 3.0
An SD port transfers data (typically pictures or system
updates) from an SD card. Seven pins of an SD card
need ESD protection. There are four data lines, a
clock pin, an input and output command, and a 2.6V to
3.3V power pin. Capacitance does not need to be
minimized due to the highest write speed of an SD
card being 90Mbps.
PIN 1
PIN 2
PIN 3
PIN 4
PIN 5
PIN 6
PIN 7
PIN 8
PIN 9
DAT2
DAT3
CMD
GND
VDD
CLK
GND
DAT0
DAT1
For protecting these ports TI offers the TPD2E001-Q1
and the TPD4E001-Q1.
TPD2E001-Q1
TPD2E2U06-Q1
Audio Jacks
An audio jack connects only audio to the head unit of a
vehicle through an auxiliary port. These audio jacks
are seeing a decline in application and eventually will
no longer exist within automotive systems.
1
Typically audio signals remain within ±5V before they
are amplified, but can rise after the amplifier. Due to
the low frequency of 30kHz capacitance is not a
concern when choosing ESD protection, however it
should be bi-directional because analog audio
operates in both positive and negative directions.
1.1
Related Documentation
System Level ESD Selection Guide
ESD Essentials Video Series
ISO 10605 Tech Note
Trademarks
All trademarks are the property of their respective owners.
2
ESD Protection for Automotive Infotainment Dajah Edwards
Copyright © 2018, Texas Instruments Incorporated
SLVAE27 – December 2018 – Revised 08 2018
Submit Documentation Feedback
IMPORTANT NOTICE AND DISCLAIMER
TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE
DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”
AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY
IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD
PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate
TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable
standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you
permission to use these resources only for development of an application that uses the TI products described in the resource. Other
reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third
party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims,
damages, costs, losses, and liabilities arising out of your use of these resources.
TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on
ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable
warranties or warranty disclaimers for TI products.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2018, Texas Instruments Incorporated
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Related manuals

Download PDF

advertising