MAX3241E MAXIM [Maxim Integrated Products], MAX3241E Datasheet - Page 10

• Manufacturer Part Number: MAX3241E
• Manufacturer: MAXIM [Maxim Integrated Products]

The IEC 1000-4-2 standard covers ESD testing and per-
formance of finished equipment; it does not specifically
refer to integrated circuits. The MAX3222E/MAX3232E/
MAX3237E/MAX3241E help you design equipment that
meets Level 4 (the highest level) of IEC 1000-4-2, without
the need for additional ESD-protection components.
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2 because series resistance is
lower in the IEC 1000-4-2 model. Hence, the ESD with-
stand voltage measured to IEC 1000-4-2 is generally
lower than that measured using the Human Body
Model. Figure 5a shows the IEC 1000-4-2 model, and
Figure 5b shows the current waveform for the ±8kV IEC
1000-4-2 Level 4 ESD Contact Discharge test.
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
Figure 4a. Human Body ESD Test Model
Figure 5a. IEC 1000-4-2 ESD Test Model
10
VOLTAGE
VOLTAGE
SOURCE
SOURCE
HIGH-
HIGH-
DC
DC
______________________________________________________________________________________
CHARGE-CURRENT
CHARGE-CURRENT
LIMIT RESISTOR
LIMIT RESISTOR
50MΩ to 100MΩ
1MΩ
R
R
C
150pF
C
100pF
C s
C s
STORAGE
CAPACITOR
STORAGE
CAPACITOR
RESISTANCE
RESISTANCE
DISCHARGE
1500Ω
DISCHARGE
330Ω
R
R
D
D
IEC 1000-4-2
DEVICE
DEVICE
UNDER
UNDER
TEST
TEST
The Air-Gap Discharge test involves approaching the
device with a charged probe. The Contact Discharge
method connects the probe to the device before the
probe is energized.
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 by
contact that occurs with handling and assembly during
manufacturing. All pins require this protection during
manufacturing, not just RS-232 inputs and outputs.
Therefore, after PC board assembly, the Machine
Model is less relevant to I/O ports.
Figure 4b. Human Body Model Current Waveform
Figure 5b. IEC 1000-4-2 ESD Generator Current Waveform
AMPERES
t r = 0.7ns to 1ns
I
P
36.8%
100%
90%
10%
0
100%
90%
10%
0
I
t
RL
30ns
CURRENT WAVEFORM
TIME
t
60ns
DL
I r
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Machine Model
t