±15kV ESD-Protected, Slew-Rate-Limited,

Low-Power, RS-485/RS-422 Transceivers

10

______________________________________________________________________________________

CHARGE CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

Cs

150pF

HIGH-

VOLTAGE

DC

SOURCE

DEVICE

UNDER

TEST

Figure 6. IEC1000-4-2 ESD Test Model

tr = 0.7ns to 1ns

30ns

60ns

t

100%

90%

10%

I

R

R

Y

Z

Figure 8. Driver DC Test Load

Figure 7. IEC1000-4-2 ESD Generator Current Waveform

RECEIVER

OUTPUT

TEST POINT

1k

1k

S1

S2

15pF

Figure 9. Receiver Timing Test Load

CHARGE CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

Cs

100pF

HIGH

VOLTAGE

DC

SOURCE

DEVICE

UNDER

TEST

Figure 4. Human Body ESD Test Model

90%

36.8%

TIME

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING

(NOT DRAWN TO SCALE)

Ir

10%

0

0

AMPERES

Figure 5. Human Body Model Current Waveform