sp485een-tr Exar Corporation, sp485een-tr Datasheet - Page 7

• Manufacturer Part Number: sp485een-tr
• Description: Sp485e -enhanced Low Emi Half-duplex Rs-485 Transceiver
• Manufacturer: Exar Corporation

May11-2007
The Human Body Model has been the generally
accepted ESD testing method for semiconductors.
This method is also specified in MIL-STD-883,
Method 3015.7 for ESD testing. The premise of
this ESD test is to simulate the human body’s
potential to store electro-static energy and
discharge it to an integrated circuit.
simulation is performed by using a test model as
shown in Figure 7. This method will test the
IC’s capability to withstand an ESD transient
during normal handling such as in manufacturing
areas where the ICs tend to be handled frequently.
The IEC-1000-4-2, formerly IEC801-2, is
generally used for testing ESD on equipment and
Figure 7. ESD Test Circuit for Human Body Model
Figure 8. ESD Test Circuit for IEC1000-4-2
DC Power
Source
DC Power
Source
R
R R
C
C C
R
R R
C
C C
SW1
SW1
SW1
SP481E Low Power Half-Duplex RS485 Transceivers
SW1
SW1
SW1
The
C
C C
S
S S
7
systems. For system manufacturers, they must
guarantee a certain amount of ESD protection
since the system itself is exposed to the outside
environment and human presence. The premise
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 8. There are
two methods within IEC1000-4-2, the Air
Discharge method and the Contact Discharge
method.
R S and R V add up to 330Ω for IEC1000-4-2.
R R S S and
C
C C
R
R R
and R R V V add up to 330
S
S S
S
S S
Contact-Discharge Module
Contact-Discharge Module
Contact-Discharge Module
add up to 330Ω Ω f f or IEC1000-4-2.
R
R R
S
S S
R
R R
V
V V
SW2
SW2
SW2
or IEC1000-4-2.
SW2
SW2
SW2
© 2007 Sipex Corporation
Device
Under
Test
Device
Under
Test