max221e Maxim Integrated Products, Inc., max221e Datasheet - Page 8

• Manufacturer Part Number: max221e
• Description: Max221e ?15kv Esd-protected, +5v, 1?a, Single Rs-232 Transceiver With Autoshutdown
• Manufacturer: Maxim Integrated Products, Inc.

the ESD that withstands voltage measured to IEC 1000-
4-2 is generally lower than that measured using the
Human Body Model. Figure 6a shows the IEEE 1000-4-
2 model and Figure 6b shows the current waveform for
the ±8kV IEC 1000-4-2 Level 4 ESD Contact-Discharge
test.
The Air-Gap Method involves approaching the device
with a charged probe. The Contact-Discharge Method
connects the probe to the device before the probe is
energized.
±15kV ESD-Protected, +5V, 1µA, Single RS-232
Transceiver with AutoShutdown
Figure 5a. Human Body ESD Test Model
Figure 5b. Human Body Model Current Waveform
8
VOLTAGE
AMPERES
SOURCE
HIGH-
_______________________________________________________________________________________
DC
I
P
36.8%
100%
90%
10%
CHARGE-CURRENT
LIMIT RESISTOR
0
0
R
C
1M
t
100pF
RL
C s
STORAGE
CAPACITOR
R
CURRENT WAVEFORM
RESISTANCE
TIME
D
DISCHARGE
1500
t
DL
I r
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
DEVICE
UNDER
TEST
The Machine Model for ESD tests all pins, using a
200pF storage capacitor and zero discharge resis-
tance. Its objective is to emulate the stress caused not
only by RS-232 inputs and outputs, but also by contact
that occurs due to handling and assembling during
manufacturing. Therefore, after PC board assembly, the
Machine Model is less relevant to I/O ports.
Figure 6a. IEC 1000-4-2 ESD Test Model
Figure 6b. IEC 1000-4-2 ESD Generator Current Waveform
VOLTAGE
SOURCE
HIGH-
t r = 0.7ns to 1ns
DC
R
CHARGE-CURRENT
C
LIMIT RESISTOR
100%
50M to 100M
90%
10%
I
150pF
C s
30ns
STORAGE
CAPACITOR
R
RESISTANCE
DISCHARGE
D
330
60ns
Machine Model
DEVICE
UNDER
TEST
t