These are the presentation slides that are linked to the 96Boards OpenHours episode #36. This episode can be found on YouTube here: https://youtu.be/pgK_JRJtBzY Please join us every week: www.96Boards.org/OpenHours

1. System level ESD protection overview
STMicroelectronics
Mathieu ROUVIERE
System & Application Engineering
Mohamed SAADNA
Product Marketing
January, 19th 2017

2. What is ESD (Electro Static Discharge) ?
• ESD is an everyday, every everywhere concern
2
Source: https://www.esda.org/about-esd/esd-fundamentals/part-1-an-introduction-to-esd/

3. Why should I care about ESD ?
• Example of physical degradations induced by ESD on integrated circuit :
3
• Oxide punch-through • Junction damage • Metallization damage

4. Any electronics board must be protected
STMicroelectronics 3D-printer board protection example
• Protections on STEVAL-3DP001V1 :
• Power lines → surge protection : IEC 61000-4-5
• Connector
• Button
• SD card
• Integrated on all IC’s → ESD protection for manufacturing : JEDEC HBM
4
SMAJ12A
SMBJ24A
EMIF06-MSD02N16
3x USBLC6-2SC6
ESDA5V3L
http://www.st.com/content/st_com/en/products/evaluation-tools/solution-evaluation-tools/computer-and-
peripherals-solution-eval-boards/steval-3dp001v1.html
ESD protection for system : IEC 61000-4-2

5. ESD protection
STMicroelectronics 3D-printer board protection example
• Layout recommendations on application note AN1751:
• ESD protections must be placed closest to the ESD source
• Tracks design must minimize residual inductive effects
5
0
0
0
x3

6. Why ESD external protection ?
• IEC 61000-4-2 is not HBM (and both responses are not correlated)
6
Human Body Model for IC IEC 61000-4-2 for system
IC most of the time : +/- 2 kV
Complete system :
+/- 8 kV Contact discharge
+/- 15 kV Air discharge
8kV

7. ESD protections are mandatory
to comply with regulations
• EN 55024 : Specification Title: Information technology equipment -
Immunity characteristics - Limits and methods of measurement.
• ISO 10605 : Road vehicles — Test methods for electrical disturbances
from electrostatic discharge
• EUROCAE ED-14 /RTCA DO-160 : Environmental Conditions and
Test Procedure for Airborne Equipment. Section 25: Electrostatic
Discharge.
7

8. System-level ESD protection standard
IEC 61000-4-2 test bench
8
Contact
discharge
Air
discharge
Stress Level Test Voltage
(kV)
Test Voltage
(kV)
Number of
discharge
1 2 4
At least 10
single
discharges
in the most
sensitive
polarity
2 4 6
3 6 8
4 8 15
System state as a result of system–level ESD stress
A Normal performance
B
Temporary loss of function or degradation of performance which cease after
the disturbance ceases. The DUT recover its normal performance , without
operator intervention
C Temporary loss of function or degradation of performance , the correction of
which requires operator intervention
D loss of function or degradation of performance, no recovery possible
Self-restored
Require a system
reset

9. Video 9

10. ESDA7P60-1U1M 8kV ESD response 10
Peak voltage = 25.4V
30ns voltage = 7.7V

11. Basic of ESD protection choice

12. Basic of protection choice: question related to
1. Is signal positive and negative?
• Yes  bidirectional protection
• No  unidirectional protection
2. Maximum signal voltage < protection stand-off voltage
3. Signal frequency / rise time < protection cut-off frequency
12
1. Protection robustness
2. Package in line with assembly PCB rules
SIGNAL TO BE PROTECTED
BOARD TO BE PROTECTED

13. Basics of ESD / EOS protection choice:
voltage polarity
• Two kind of characteristics: Unidirectional and Bidirectional
13
VCL VCL
-VCL
-VF
• Mandatory for audio signals
• Limit harmonics generation if RF coupling on the protected line
• Better reverse protection

14. Basics of ESD / EOS protection choice:
working voltage
14
Example of HSP061-4NY8:
3V
100nA
6V
1mA

15. Basics of ESD / EOS protection choice:
Capacitance value, cut-off frequency
• Over frequency, a protection can be basically
modeled by a capacitor
• Analog signal :
• S21 attenuation in accordance with system output power
• Digital signal :
• Fc =
1
π tr
with Fc : cutoff frequency and tr : rise time
• And keep in mind that protection must be
transparent
15
ESDALC6V1-1U2 (C=12pF) S21

16. Basics of ESD / EOS protection choice:
Package
16
• Various package are available
• They must be chosen in accordance with PCB rules
SOD323
SOD523
WLCSP
0201 - 01005
QFN
Single line
µQFN-16L
µQFN-10L
µQFN-6L
µQFN-4L
Multi line
Example with µQFN

17. ESD protection matching with IC

18. Transmission Line Pulse:
System-Efficient ESD Design
• Transmission Line Pulse: dynamic ESD response to match external ESD
protection to internal ESD protection of IC to protect
• 3 theoretical cases:
• External ESD protection protects the IC (1)
• External ESD protection protects the IC and
shares the current with internal ESD protection of IC to protect (2)
• External ESD protection is not efficient alone (3)
18
Current (A)
Voltage (V)
Failure

19. Transmission Line Pulse:
System-Efficient ESD Design with an external resistor
19
• Co-design of protection + IC protection is sometimes mandatory to optimize the overall
system robustness
• Resistor between IC and protection is also a degree of freedom
(if allowed by application)
Co-development of protection for ASIC example
TLP responses

20. For ESD protection selection, go to :
http://www.st.com/tvs-smartselector

21. ESD PROTECTION FOR
ESDA15P60-1U1M
EMIF06-MSD02N16 EMIF08-LCD04M16
ECMF04-4HSWM10
EMIF02-SPK03F2
ESDALC6V1-1U2
ECMF2-0730V12M12

22. Thanks !