_______________General Description
The MAX3187 complete, dual DTE RS-232 serial port
meets the stringent ESD requirements of the European
Community. All transmitter outputs and receiver inputs
are protected to ±15kV using IEC 1000-4-2 Air-Gap
Discharge, ±8kV using IEC 1000-4-2 Contact
Discharge, and ±15kV using the Human Body Model.
The MAX3187’s six RS-232 transmitters and ten RS-232
receivers require no charge pump. Guaranteed to run
at data rates up to 230kbps, the MAX3187 is optimized
for desktop PC and motherboard applications, and is
compatible with popular software for PC communica-
tions. Power-supply current is less than 1mA for IDD
and ISS, and less than 3mA for ICC.
The MAX3187 is available in a space-saving 36-pin
SSOP package.
________________________Applications
Desktop PC
Motherboards
Instruments
Equipment Meeting IEC 1000-4-2
____________________________Features
♦Enhanced ESD Protection:
±15kV—Human Body Model
±8kV—IEC 1000-4-2, Contact Discharge
±15kV—IEC 1000-4-2, Air-Gap Discharge
♦Latchup Free During an ESD Event
♦36-Pin SSOP Package
♦Guaranteed 230kbps Data Rate
♦Flow-Through Pinout
♦Two Complete DTE Serial Ports
♦6 RS-232 Drivers and 10 RS-232 Receivers
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
________________________________________________________________
Maxim Integrated Products
1
35
34
33
32
31
30
29
28
27
26
25
24
23
3
4
5
6
7
8
9
10
11
12
13
14
R3IN
T1OUT
T2OUT
R4IN
T4OUT
T3OUT
R5IN
VDD
GND
R6IN
R7IN
R8IN
T4IN
R8OUT
R7OUT
R6OUT
VSS
VCC
R5OUT
T3IN
R4OUT
T2IN
T1IN
R3OUT
361 R1INR1OUT
2 R2INR2OUT
SSOP
TOP VIEW
MAX3187
22
21
15
16
T5OUT
R9IN
1918 R10INR10OUT
2017 T6OUTT6IN
R90UT
T5IN
19-1186; Rev 1; 10/98
PART
MAX3187CAX
MAX3187EAX -40°C to +85°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
36 SSOP
36 SSOP
______________Ordering Information
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
For small orders, phone 1-800-835-8769.
____________________________________________________________Pin Configuration
Typical Operating Circuit appears at end of data sheet.
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
2_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC = +4.5V to +5.5V, VDD = +10.8V to +13.2V, VSS = -10.8V to -13.2V, TA= TMIN to TMAX, unless otherwise noted. Typical values
are at TA= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
VCC...........................................................................-0.3V to +7V
VDD.........................................................................-0.3V to +14V
VSS......................................................................... +0.3V to -14V
Input Voltages
T_IN......................................................................-0.3V to +6V
R_IN.................................................................................±30V
Output Voltages
T_OUT..............................................................................±15V
R_OUT....................................................-0.3V to (VCC + 0.3V)
Short-Circuit Duration
T_OUT (one at a time)............................................Continuous
R_OUT (one at a time)............................................Continuous
Continuous Power Dissipation (TA= +70°C)
SSOP (derate 11.76mW/°C above +70°C) ..................762mW
Operating Temperature Ranges
MAX3187CAX .....................................................0°C to +70°C
MAX3187EAX ..................................................-40°C to +85°C
Storage Temperature Range ............................-65°C to +160°C
Lead Temperature (soldering, 10sec) ............................+300°C
VCC = VDD = VSS = 0, VT_OUT = ±2V
VDD = 12V, VSS = -12V, RL= 3kΩ
T_IN
VDD = 7.0V, VSS = -7.0V, RL= 3kΩ
T_IN
No load
No load
R_OUT; ISOURCE = 1mA
No load
R_OUT; ISINK = 3.2mA
CONDITIONS
V2.4RS-232 Input Threshold High V0.75RS-232 Input Threshold Low V-25 25Receiver Input Voltage Range
mA±35 ±60
RS-232 Output Short-Circuit
Current
Ω300Transmitter Output Resistance
V
±9.5
Output Voltage Swing ±5.0
VVCC - 0.6VOHR
Output Voltage High V0.4VOLR
Output Voltage Low
10.8 13.2VDD
4.5 5.5VCC
µA0.01 1Input Leakage Current V2.0VIHT
Input Logic Threshold High V0.8VILT
Input Logic Threshold Low
V
-13.2 -10.8VSS
Operating Voltage Range
750 3000ICC 370 1000IDD µA
370 1000ISS
Supply Current
UNITSMIN TYP MAXSYMBOLPARAMETER
V0.65RS-232 Input Hysteresis kΩ3 5 7RS-232 Input Resistance
mA±10
Receiver Output Short-Circuit
Current
RECEIVER INPUTS
TRANSMITTER OUTPUTS
LOGIC
DC CHARACTERISTICS
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +4.5V to +5.5V, VDD = +10.8V to +13.2V, VSS = -10.8V to -13.2V, TA= TMIN to TMAX, unless otherwise noted. Typical values
are at TA= +25°C.)
VDD = 12V, VSS = -12V, RL= 3kΩ,
CL= 1000pF, TA= +25°C
VDD = 12V, VSS = -12V,
RL= 3kΩto 7kΩ,
measured from +3V to -3V
or -3V to +3V,
Figure 1, TA= +25°C
IEC 1000-4-2 (Contact Discharge)
4
Human Body Model
tPHLT
830
µs
SR
Transmitter Output
Propagation Delay, High to Low
V/µsTransition Output Slew Rate
IEC 1000-4-2 (Air-Gap Discharge)
VCC = 5V, CL= 50pF, TA= +25°C
VCC = 5V, CL= 50pF, TA= +25°C
CL= 50pF to
1000pF
4.0
4.0
CONDITIONS
tPHLR
CL= 50pF to
2500pF
µs
VDD = 12V, VSS = -12V, RL= 3kΩ,
CL= 1000pF, TA= +25°C
Receiver Output
Propagation Delay, High to Low
tPLHR
4
µs
tPLHT
Receiver Output
Propagation Delay, Low to High
µs
Transmitter Output
Propagation Delay, Low to High
T3OUT = -5mA, T1OUT = T2OUT = 5mA
120
±7.5 VMouse Driveability
VCC = 5V, CL= 50pF, TA= +25°C 0.4tSKR µs
Receiver Propagation Delay
Skew, |tPLHR - tPHLR |VCC = 5V, VDD = 12V,
VSS = -12V,
RL= 3kΩto 7kΩ,
TA= +25°C, any two
transmitters switching 230 kbpsDRGuaranteed Data Rate
±8
±15
VDD = 12V, VSS = -12V, RL= 3kΩ,
CL= 1000pF, TA= +25°C 0.4tSKT µs
Transmitter Propagation Delay
Skew, |tPLHT - tPHLT |
CL= 50pF to
1000pF
430
CL= 150pF to
2500pF
kV
±15
ESD Protection
UNITSMIN TYP MAXSYMBOLPARAMETER
ESD CHARACTERISTICS
TIMING CHARACTERISTICS
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
4_______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(VCC = +5V, VDD = +12V, VSS = -12V, TA = +25°C, unless otherwise noted.)
40
-40
SUPPLY CURRENT
vs. LOAD CAPACITANCE
20
MAX3187/TOC-01
SUPPLY CURRENT (mA)
0 1000 3000
LOAD CAPACITANCE (pF)
2000 4000 5000
0
-20
30
10
-10
-30
IDD, 240kbps
IDD, 20kbps
ISS, 20kbps
ISS, 120kbps
ISS, 240kbps
ICC
IDD, 120kbps
2 TRANSMITTERS AT DATA RATE
4 TRANSMITTERS AT DATA RATE/16
3kΩ + CLOAD
40
-40 10.8
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
20
MAX3187/TOC-02
SUPPLY VOLTAGE (±V)
SUPPLY CURRENT (mA)
12.011.4 12.6 13.2
0
-20
30
10
-10
-30
IDD, 240kbps
IDD, 20kbps
ISS, 20kbps
ISS, 120kbps
ISS, 240kbps
ICC
IDD, 120kbps
4 TRANSMITTERS AT DATA RATE/16
3kΩ + CLOAD
VCC = 5V
2 TRANSMITTERS AT DATA RATE
16
00 1000 3000
SLEW RATE
vs. LOAD CAPACITANCE
12
MAX3187/TOC-03
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
2000 4000 5000
8
4
14
10
6
22 TRANSMITTERS AT DATA RATE
4 TRANSMITTERS AT DATA RATE/16
3kΩ + CLOAD
RISE
FALL
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3187/TOC-04
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
12.5
10.0
7.5
5.0
2.5
0
-2.5
-5.0
-7.5
-10.0
-12.5 4000 50003000200010000
240kbps
120kbps
120kbps
240kbps
2 TRANSMITTER, 240kbps
4 TRANSMITTERS, 15kbps
3kΩ + CLOAD
TRANSMITTER OUTPUT VOLTAGE vs.
LOAD CURRENT PER TRANSMITTER
MAX3187/TOC-05
LOAD CURRENT PER TRANSMITTER (mA)
TRANSMITTER OUTPUT VOLTAGE (V)
15
10
5
0
-5
-10
-15 10 12 14 16 186 82 4
0
VOUT+
VOUT-
T1
VCC
VOUT+
VOUT-
T2
T3
SLEW RATE
vs. TEMPERATURE
MAX3187/TOC-06
TEMPERATURE (°C)
SLEW RATE (V/ms)
25
20
15
10
5
085 105 12545 655 25-35 -15-55
RISE, 500pF
FALL, 500pF
RISE, 2000pF FALL, 2000pF
_______________Detailed Description
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges (ESD) encountered during handling
and assembly. The MAX3187 driver outputs and receiv-
er 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 ±15kV ESD, without damage. After an ESD
event, the MAX3187 continues working without latchup.
ESD protection can be tested in several ways. The
transmitter outputs and receiver inputs are character-
ized for protection to the following:
1) ±15kV using the Human Body Model
2) ±8kV using the Contact-Discharge Method specified
in IEC 1000-4-2 (formerly IEC 801-2)
3) ±15kV using the Air-Gap Method specified in
IEC 1000-4-2 (formerly IEC 801-2)
ESD Test Conditions
ESD performance depends on a number of conditions.
Contact Maxim for a reliability report that documents
test setup, methodology, and results.
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
_______________________________________________________________________________________ 5
______________________________________________________________Pin Description
PIN NAME FUNCTION
4, 5, 7, 14, 15, 17 T1IN–T6IN Transmitter Inputs
9 VCC Supply-Voltage Input, 4.5V to 5.5V
27 GND Ground. Connect system to ground.
1, 2, 3, 6, 8, 11,
12, 13, 16, 18 R1OUT–R10OUT Receiver Outputs, swing between GND and VCC
10 VSS Supply-Voltage Input, -10.8V to -13.2V
28 VDD Supply-Voltage Input, 10.8V to 13.2V
19, 21, 24, 25, 26,
29, 31, 34, 35, 36 R10IN–R1IN Receiver Inputs
20, 22, 23, 30, 32, 33 T6OUT–T1OUT Transmitter Outputs, swing between VDD and VSS
tF2
tF1
tPHL tPLH
tR1
tR2
1.5V
3.0V
0V
0V
DRIVER
INPUT
VOUT
VOH
VOL
3.3V
3.0V
-3.0V
-3.3V
RLCL
SIGNAL
GENERATOR
Figure 1. Slew-Rate Test Circuit and Timing Diagram
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
6_______________________________________________________________________________________
Human Body Model
Figure 2a shows the Human Body Model, and Figure
2b 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 device through a
1.5kΩresistor.
IEC 1000-4-2
Since January 1996, all equipment manufactured
and/or sold in the European community has been
required to meet the stringent IEC 1000-4-2 specifica-
tion. The IEC 1000-4-2 standard covers ESD testing
and performance of finished equipment; it does not
specifically refer to integrated circuits. The MAX3187
helps you design equipment that meets Level 4 (the
highest level) of IEC 1000-4-2, without additional ESD-
protection components.
The main 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 ESD test model (Figure 3a), the
ESD withstand voltage measured to this standard is gen-
erally lower than that measured using the Human Body
Model. Figure 3b shows the current waveform for the
±8kV IEC 1000-4-2 Level 4 ESD Contact-Discharge test.
The Air-Gap test involves approaching the device with a
charge probe. The Contact-Discharge method connects
the probe to the device before the probe is energized.
CHARGE-CURRENT
LIMIT RESISTOR DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RC
1M RD
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
IP 100%
90%
36.8%
tRL TIMEtDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
00
AMPERES
CHARGE-CURRENT
LIMIT RESISTOR DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
150pF
RC
50M to 100M RD
330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
tr = 0.7ns to 1ns 30ns 60ns
t
100%
90%
10%
IPEAK
I
Figure 3a. IEC 1000-4-2 ESD Test Model Figure 3b. IEC 1000-4-2 ESD-Generator Current Waveform
Figure 2b. Human Body Model Current Waveform
Figure 2a. Human Body ESD Test Model
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
_______________________________________________________________________________________ 7
TRANSISTOR COUNT: 419
___________________Chip Information
Machine Model
The Machine Model for ESD testing uses a 200pF stor-
age capacitor and zero-discharge resistance. It mimics
the stress caused by handling during manufacturing
and assembly. Of course, all pins (not just RS-232
inputs and outputs) require this protection during man-
ufacturing. Therefore, the Machine Model is less rele-
vant to the I/O ports than are the Human Body Model
and IEC 1000-4-2.
Applications Information
Use proper layout to ensure other devices on your
board are not damaged in an ESD strike. Currents as
high as 60A can instantaneously pass into ground, so
be sure to minimize the ground-lead return path to the
power supply. A separate return path to the power sup-
ply is recommend. Trace widths should be greater than
40 mils. Bypass VCC, VDD, and VSS with 0.1µF capaci-
tors as close to the part as possible to ensure maxi-
mum ESD protection.
Connect any unused transmitter inputs to GND or VCC.
The MAX3187 is not sensitive to power-supply
sequencing, and therefore requires no external protec-
tion diodes.
RS-232
INTERCONNECTING
CABLE
T1
T2
T3
T4
T5
R1
R2
T3
T4
T5
R3
R4
R5
R8
R9
R10
R2
R1
R3
T1
T2
TTL/CMOS
LOGIC
I/O
TTL/CMOS
LOGIC
I/O
MOUSE
V+ GND VSS
GND VSS
0.1µF
0.1µF
-12V
V+
V-
TX
T6
R6
-12V
0.1µF
0.1µF0.1µF
+5V
VCC VDD
MAX3186MAX3187
VCC VDD
+12V +5V +12V
0.1µF
R7
__________Typical Operating Circuit
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
8
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
MAX3187
±15kV ESD-Pr otected, EMC-Compliant, 230kbps,
Dual RS-232 Serial Port for Motherboards/Desktops
________________________________________________________Package Information
SSOP.EPS
