Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com

SP3243E_100_072309

17

DEVICE PIN

HUMAN BODY

IEC1000-4-2

TESTED

MODEL

Air Discharge

Direct Contact

Level

Driver Outputs

+15kV

+15kV

+8kV

4

Receiver Inputs

+15kV

+15kV

+8kV

4

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,

thecurrentlimitingresistor(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.

Figure 25. ESD Test Waveform for IEC1000-4-2

Figure 24. ESD Test Circuit for IEC1000-4-2

Table 4. Transceiver ESD Tolerance Levels

RS and RV add up to 330Ω for IEC1000-4-2.

Device

Under

Test

DC Power

Source

SW1

SW2

Contact-Discharge Model

t = 0ns

t = 30ns

0A

15A

30A

t →