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

SP3222EB/SP3232EB_103_081414

13

DEVICE PIN

HUMAN BODY

IEC61000-4-2

TESTED

MODEL

Air Discharge

Direct Contact

Level

Driver Outputs

+15kV

+15kV

+8kV

4

Receiver Inputs

+15kV

+15kV

+8kV

4

equipment from a person already holding

the equipment. The current is transferred

on to the keypad or the serial port of the

equipment directly and then travels through

the PCB and finally to the IC.

The circuit models in Figures 18 and 19 rep-

resent the typical ESD testing circuit used for

all three methods. The C

with the DC 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

the current limiting resistor, onto the 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

(C

IEC-61000-4-2, the current limiting resistor

(R

Figure 20. ESD Test Waveform for IEC61000-4-2

Figure 19. ESD Test Circuit for IEC61000-4-2

Table 3. 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 →

The higher C

lower R

the IEC61000-4-2 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.

DESCRIPTION