Datasheet

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
these pins against ESD of ±15kV without damage. The
ESD structures withstand high ESD in all states: normal
operation, shutdown, and powered down. After an ESD
event, Maxim’s E versions keep working without
latchup, whereas competing RS-232 products can
latch and must be powered down to remove latchup.
ESD protection can be tested in various ways; the
transmitter outputs and receiver inputs of this product
family are characterized for protection to the following
limits:
1) ±15kV using the Human Body Model
2) ±8kV using the Contact-Discharge Method specified
in IEC 1000-4-2
3) ±15kV using IEC 1000-4-2’s Air-Gap Method.
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 6a shows the Human Body Model and Figure 6b
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5kΩ resistor.
I
P
100%
90%
36.8%
t
RL
TIME
t
DL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I
r
10%
0
0
AMPERES
Figure 6b. Human Body Current Waveform
t
r
= 0.7ns to 1ns
30ns
60ns
t
100%
90%
10%
I
PEAK
I
Figure 7b. IEC 1000-4-2 ESD Generator Current Waveform
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
C
s
100pF
R
C
1MΩ R
D
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 6a. Human Body ESD Test Model Figure 7a. IEC 1000-4-2 ESD Test Model
CHARGE CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
C
s
150pF
R
C
50MΩ to 100MΩ R
D
330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Maxim Integrated
13
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E