SP3243E EXAR [Exar Corporation], SP3243E Datasheet - Page 17

• Manufacturer Part Number: SP3243E
• Description: 3 Driver/5 Receiver Intelligent +3.0V to +5.5V RS-232 Transceivers
• Manufacturer: EXAR [Exar Corporation]

Figure 24. ESD Test Circuit for IEC1000-4-2
The circuit models in Figures 23 and 24 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
pacitor (C
The higher C
IEC1000-4-2 model are more stringent than the
Human Body Model. The larger storage capaci-
tor 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.
Table 4. Transceiver ESD Tolerance Levels
Driver Outputs
Receiver Inputs
DEVICE PIN
TESTED
S
S
, the current limiting resistor, onto the
S
) are 330Ω an 150pF, respectively.
DC Power
) and the source capacitor (C
Source
S
value and lower R
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
S
is initially charged with the DC
R
HUMAN BODY
C
MODEL
+15kV
+15kV
S
) and the source ca-
SW1
S
value in the
S
) are
Air Discharge
C
17
S
+15kV
+15kV
R S and R V add up to 330Ω for IEC1000-4-2.
Figure 25. ESD Test Waveform for IEC1000-4-2
R
S
30A
15A
0A
Contact-Discharge Model
R
t = 0ns
Direct Contact
V
IEC1000-4-2
+8kV
+8kV
SW2
t →
Device
Under
Test
t = 30ns
SP3243E_100_072309
Level
4
4