ESD Simulator
DUT or System
Power and Ground Connection
Horizontal Coupling
Plane (HCP)
To the Wall
Ground
Non-conducting Table
Insulation
470 K
470 K
Ground Reference Plane
Typical Position for
Direct Discharge
Setup
3
SLVUBE1A – February 2018 – Revised April 2018
Copyright © 2018, Texas Instruments Incorporated
ESD224 Evaluation Module User's Guide
•
S
41
: Far end cross talk
3.2
U2 - ESD Clamping waveforms
One ESD224 (U2) also has two SMB (J5, J6) connectors for capturing clamping waveforms with an
oscilloscope during an ESD strike. Caution must be taken when capturing clamping waveforms during an
ESD event so as not to damage the oscilloscope
3.2.1
ESD Tests
The ESD224 device provides an ultra-low clamping voltage during an ESD event. The pass-through
capabilities of this board allow it to be connected to a system and then do the system level ESD testing.
3.2.1.1
Test Method and Set-Up
An example test setup is shown in
. Details of the testing table and ground planes can be found in
the IEC 61000-4-2 test procedure. Contact and air-gap discharge are tested using the same simulator with
the same discharge waveform. While the simulator is in direct contact with the test point during contact, it
is not during air-gap.
Figure 2. System Level ESD Test Setup
3.2.1.2
Oscilloscope setup
Without a proper procedure, capturing ESD clamping waveforms exposes the oscilloscope to potential
voltages higher than the rating of the equipment. Proper methodology can mitigate any risk in this
operation.
Recommended equipment:
•
Minimum of 1GHz bandwidth oscilloscope.
•
1 10X 50
Ω
attenuator and one 150
Ω
resistor (the resistor is already factory installed at R1 and R2).
•
50
Ω
shielded SMB cables.
Procedure
In order to protect the oscilloscope, attenuation of the measured signal is required. Here is the procedure
for testing channel 1 of U2:
1. Using one 10X attenuator:
•
Attach two 10X attenuator to the oscilloscope.
•
Attach the 50
Ω
shielded SMB cable between J5 and the attenuator.
