Datasheet

_______________Detailed Description
±15kV ESD Protection
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.
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
2) ±8kV using the Contact-Discharge Method specified
in IEC1000-4-2 (formerly IEC801-2)
3) ±15kV using the Air-Gap Method specified in
IEC1000-4-2 (formerly IEC801-2)
ESD Test Conditions
ESD performance depends on a number of conditions.
Contact Maxim for a reliability report that documents
test setup, methodology, and results.
MAX3185
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
_______________________________________________________________________________________ 5
______________________________________________________________Pin Description
PIN NAME FUNCTION
1 V
DD
Supply-Voltage Input, +10.8V to +13.2V
12, 14, 17, 18, 19 R5OUT–R1OUT Receiver Outputs, swing between GND and V
CC
16, 15, 13 T3IN, T2IN, T1IN Transmitter Inputs
10 V
SS
Supply-Voltage Input, -10.8V to -13.2V
11 GND Ground. Connect system to ground.
2, 3, 4, 7, 9 R1IN–R5IN Receiver Inputs
5, 6, 8 T1OUT, T2OUT, T3OUT Transmitter Outputs, swing between V
DD
and V
SS
20 V
CC
Supply-Voltage Input, +4.5V to +5.5V
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
C
s

150pF
R
C
50M to 100M R
D
330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
t
r
= 0.7ns to 1ns
30ns
60ns
t
100%
90%
10%
I
PEAK
I
Figure 1a. IEC1000-4-2 ESD Test Model
Figure 1b. IEC1000-4-2 ESD-Generator Current Waveform