MAX222
5 V DUAL RS 232 LINE DRIVER/RECEIVER
WITH
±15
kV ESD PROTECTION
SLLS590D − SEPTEMBER 2003 − REVISED AUGUST 2004
APPLICATION INFORMATION
1.5
VHBM = 2 kV
DUT = 10-V, 1-Ω Zener Diode
1
I DUT − A
0.5
0
0
50
100
Time − ns
150
200
Figure 6. Typical HBM Current Waveform
Machine Model
The Machine Model (MM) ESD test applies to all pins using a 200-pF capacitor with no discharge resistance.
The purpose of the MM test is to simulate possible ESD conditions that can occur during the handling and
assembly processes of manufacturing. In this case, ESD protection is required for all pins, not just RS-232 pins.
However, after PC board assembly, the MM test no longer is as pertinent to the RS-232 pins.
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
9