SP3221ECA SIPEX [Sipex Corporation], SP3221ECA Datasheet - Page 15

• Manufacturer Part Number: SP3221ECA
• Description: Intelligent +3.0V to +5.5V RS-232 Transceiver
• Manufacturer: SIPEX [Sipex Corporation]

Figure 18. ESD Test Circuit for IEC1000-4-2
The circuit model in Figures 17 and 18 represent
the typical ESD testing circuit used for all three
methods. The C
power supply when the first switch (SW1) is on.
Now that the capacitor is charged, the second
switch (SW2) is on while SW1 switches off. The
voltage stored in the capacitor is then applied
through R
device under test (DUT). In ESD tests, the SW2
switch is pulsed so that the device under test
receives a duration of voltage.
For the Human Body Model, the current limiting
resistor (R
1.5kΩ an 100pF, respectively. For IEC-1000-4-
2, the current limiting resistor (R
capacitor (C
The higher C
IEC1000-4-2 model are more stringent than the
Human Body Model. The larger storage capacitor
injects a higher voltage to the test point when
SW2 is switched on. The lower current limiting
resistor increases the current charge onto the test
point.
Date: 7/21/04
Table 4. Transceiver ESD Tolerance Levels
Driver Outputs
Receiver Inputs
DEVICE PIN
TESTED
DC Power
Source
S
, the current limiting resistor, onto the
S
) and the source capacitor (C
S
) are 330Ω an 150pF, respectively.
S
value and lower R
S
is initially charged with the DC
R
R
HUMAN BODY
C
C
MODEL
±15kV
±15kV
S
) and the source
SW1
SW1
S
value in the
SP3221E +3.0V to +5.5V RS-232 Transceiver
S
) are
Air Discharge
C
C
15
S
S
±15kV
±15kV
R S and R V add up to 330Ω for IEC1000-4-2.
R S and R V add up to 330Ω for IEC1000-4-2.
Figure 19. ESD Test Waveform for IEC1000-4-2
15A
30A
R
0A
R
S
S
Contact-Discharge Module
Contact-Discharge Module
t=0ns
R
R
V
V
Direct Contact
IEC1000-4-2
±8kV
±8kV
SW2
SW2
t
© Copyright 2004 Sipex Corporation
Device
Under
Test
t=30ns
Level
4
4