R
C
R
C
SW1
SW1
DC Power
Source
R
S
R
S
SW2
SW2
C
S
C
S
Device
Under
Test
Figure 9. ESD Test Circuit for Human Body Model
with IEC1000-4-2 is that the system is required
to withstand an amount of static electricity when
ESD is applied to points and surfaces of the
equipment that are accessible to personnel during
normal usage. The transceiver IC receives most
of the ESD current when the ESD source is
applied to the connector pins. The test circuit for
IEC1000-4-2 is shown on
Figure 10.
There are
two methods within IEC1000-4-2, the Air
Discharge method and the Contact Discharge
method.
With the Air Discharge Method, an ESD voltage
is applied to the equipment under test (EUT)
through air. This simulates an electrically charged
person ready to connect a cable onto the rear of
the system only to find an unpleasant zap just
before the person touches the back panel. The
high energy potential on the person discharges
through an arcing path to the rear panel of the
system before he or she even touches the system.
This energy, whether discharged directly or
through air, is predominantly a function of the
Contact-Discharge Module
R
C
R
C
SW1
SW1
DC Power
Source
R
S
R
S
R
V
SW2
SW2
C
S
C
S
Device
Under
Test
RS and RV add up to 330Ω for IEC1000-4-2.
Figure 10. ESD Test Circuit for IEC1000-4-2
Rev. 06/20/02
SP202E Series High Performance RS232 Transceivers
© Copyright 2002 Sipex Corporation
9
SIPEX [ SIPEX CORPORATION ]
