±15kV ESD-Prote c te d, EMC-Com plia nt, 230kbps
RS-232 Se ria l Port for Mothe rboa rds /De s ktop PCs
MAX3185
______________________________________________________________P in De s c rip t io n
PIN
NAME
FUNCTION
Supply-Voltage Input, +10.8V to +13.2V
Receiver Outputs, swing between GND and V
1
V
DD
12, 14, 17, 18, 19
R5OUT–R1OUT
T3IN, T2IN, T1IN
CC
16, 15, 13
Transmitter Inputs
10
11
V
Supply-Voltage Input, -10.8V to -13.2V
Ground. Connect system to ground.
Receiver Inputs
SS
GND
2, 3, 4, 7, 9
5, 6, 8
20
R1IN–R5IN
T1OUT, T2OUT, T3OUT Transmitter Outputs, swing between V and V
DD
SS
V
CC
Supply-Voltage Input, +4.5V to +5.5V
_______________De t a ile d De s c rip t io n
±1 5 k V ES D P ro t e c t io n
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assembly. The MAX3185 driver outputs and receiver
inputs have extra protection against static electricity
found in normal operation. Maxim’s engineers devel-
oped state-of-the-art structures to protect these pins
against ESD of ±15kV, without damage. After an ESD
event, the MAX3185 continues working without latchup.
R 50M to 100M
C
R 330Ω
D
DISCHARGE
RESISTANCE
CHARGE-CURRENT
LIMIT RESISTOR
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
C
s
150pF
STORAGE
CAPACITOR
SOURCE
ESD protection can be tested in several ways. The
transmitter outputs and the receiver inputs are charac-
terized for protection to the following:
1) ±15kV using the Human Body Model
Figure 1a. IEC1000-4-2 ESD Test Model
2) ±8kV using the Contact-Discharge Method specified
in IEC1000-4-2 (formerly IEC801-2)
3) ± 15kV us ing the Air-Ga p Me thod s p e c ifie d in
IEC1000-4-2 (formerly IEC801-2)
I
100%
90%
ES D Te s t Co n d it io n s
ESD performance depends on a number of conditions.
Contact Maxim for a reliability report that documents
test setup, methodology, and results.
10%
t = 0.7ns to 1ns
r
t
30ns
60ns
Figure 1b. IEC1000-4-2 ESD-Generator Current Waveform
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
