Date: 03/30/05

SP3203E, 3V RS232 Serial Transceiver with Logic Selector and 15kV ESD

© Copyright 2005 Sipex Corporation

14

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

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

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

1.5kW an 100pF, respectively. For IEC-1000-4-

2, the current limiting resistor (R

capacitor (C

The higher C

lower R

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.

Figure 20. ESD Test Waveform for IEC1000-4-2

t=0ns

t=30ns

0A

15A

30A

t ➙

Figure 19. ESD Test Circuit for IEC1000-4-2

Table 2. Transceiver ESD Tolerance Levels

R

RS

S and

and R

RV

V add up to 330

add up to 330Ω

Ω ffor IEC1000-4-2.

or IEC1000-4-2.

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

Contact-Discharge Module

Contact-Discharge Module

R

R

C

C

R

SW1

SW1

SW2

SW2

Device

Under

Test

DC Power

Source

SW1

SW2

Contact-Discharge Module