MAXIM MAX3185CWP

19-1076; Rev 0; 9/96
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
________________________Applications
Desktop PC
Motherboards
____________________________Features
♦ Enhanced ESD Protection:
±15kV—Human Body Model
±8kV—IEC1000-4-2, Contact Discharge
±15kV—IEC1000-4-2, Air-Gap Discharge
♦ Latchup Free During an ESD Event
♦ 20-Pin SSOP and SO Packages
♦ Guaranteed 230kbps Data Rate
♦ Flow-Through Pinout
♦ Pin Compatible with SN75C185
♦ Complete DTE Serial Port
______________Ordering Information
PART
TEMP. RANGE
MAX3185CWP
0°C to +70°C
MAX3185CAP
MAX3185EWP
MAX3185EAP
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
20 SO
20 SSOP
20 SO
20 SSOP
Instruments
Equipment Meeting IEC1000-4-2
__________Typical Operating Circuit
MAX3186
MAX3185
T1
R1
T2
TTL/CMOS
LOGIC
I/O
RS-232
R3
INTERCONNECTING
T4
R4
CABLE
T5
TOP VIEW
R2
T3
R5
__________________Pin Configuration
TTL/CMOS
LOGIC
I/O
VDD 1
20 VCC
R1IN 2
19 R1OUT
R2IN 3
18 R2OUT
R3IN 4
17 R3OUT
16 T1IN
T1OUT 5
15 T2IN
T2OUT 6
14 R4OUT
R4IN 7
13 T3IN
T3OUT 8
R1
T1
12 R5OUT
R5IN 9
R2
T2
R3
T3
VSS 10
MAX3185
11 GND
SO/SSOP
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX3185
_______________General Description
The MAX3185 is a complete DTE RS-232 serial port
designed to meet 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 MAX3185 has three RS-232 transmitters, five RS232 receivers, and no charge pump, optimizing it for
operation in desktop PC and motherboard applications.
It is guaranteed to run at data rates up to 230kbps, providing compatibility with popular software for communicating with personal computers. Power-supply current
is less than 300µA for IDD and ISS, and less than 1mA
for ICC.
The MAX3185 is pin and functionally compatible with
the industry-standard 75185, so existing designs can
instantly become EMC compliant. The MAX3185 is
available in an SO package and in the tiny SSOP that
further reduces board space.
MAX3185
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
ABSOLUTE MAXIMUM RATINGS
VCC ...........................................................................-0.3V to +7V
VDD .........................................................................-0.3V to +14V
VSS......................................................................... +0.3V to -14V
Input Voltages
TIN ........................................................................-0.3V to +6V
RIN ...................................................................................±30V
Output Voltages
TOUT .................................................................................±15V
ROUT .......................................................-0.3V to (VCC + 0.3V)
Short-Circuit Duration
TOUT (one at a time)...............................................Continuous
ROUT (one at a time) ..............................................Continuous
Continuous Power Dissipation (TA = +70°C)
Wide SO (derate 10.00mW/°C above +70°C)..............800mW
SSOP (derate 8.00mW/°C above +70°C) ....................640mW
Operating Temperature Ranges
MAX3185C_ P .....................................................0°C to +70°C
MAX3185E_ P ..................................................-40°C to +85°C
Storage Temperature Range ............................-65°C to +160°C
Lead Temperature (soldering, 10sec) ............................+300°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.
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.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS
Operating Voltage Range
VCC
4.5
5.5
VDD
10.8
13.2
VSS
-13.2
-10.8
ICC
No load
380
1500
IDD
No load
185
500
ISS
No load
185
500
Input Logic Threshold Low
VILT
TIN
Input Logic Threshold High
VIHT
TIN
Supply Current
V
µA
LOGIC
Input Leakage Current
VOLR
ROUT; ISINK = 3.2mA
Output Voltage High
VOHR
ROUT; ISOURCE = 1mA
V
1
µA
0.4
V
V
0.01
Output Voltage Low
0.8
2.0
VCC - 0.6
V
TRANSMITTER OUTPUTS
Output Voltage Swing
Transmitter Output Resistance
VDD = 7.0V, VSS = -7.0V, RL = 3kΩ
±5.0
VDD = 12V, VSS = -12V, RL = 3kΩ
±9.5
VCC = VDD = VSS = 0V, VT_OUT = ±2V
300
RS-232 Output Short-Circuit
Current
V
Ω
±35
±60
mA
25
V
RECEIVER INPUTS
Receiver Input Voltage
Operating Range
-25
RS-232 Input Threshold Low
0.75
V
RS-232 Input Threshold High
RS-232 Input Hysteresis
RS-232 Input Resistance
Receiver Output Short-Circuit
Current
2
2.4
V
7
kΩ
0.65
3
5
±10
_______________________________________________________________________________________
V
mA
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
(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.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ESD CHARACTERISTICS
Human Body Model
ESD Protection
±15
IEC1000-4-2 (Contact Discharge)
±8
IEC1000-4-2 (Air-Gap Discharge)
±15
kV
TIMING CHARACTERISTICS
Transmitter Output
Propagation Delay, Low to High
tPLHT
VDD = 12V, VSS = -12V, RL = 3kΩ,
CL = 1000pF, TA = +25°C
4
µs
Transmitter Output
Propagation Delay, High to Low
tPHLT
VDD = 12V, VSS = -12V, RL = 3kΩ,
CL = 1000pF, TA = +25°C
4
µs
Transmitter Propagation Delay
Skew, | tPLHT - tPHLT |
tSKT
VDD = 12V, VSS = -12V, RL = 3kΩ,
CL = 1000pF, TA = +25°C
0.4
µs
SR
VDD = 12V, VSS = -12V,
RL = 3kΩ to 7kΩ,
measured from +3V to -3V
or -3V to +3V, Figure 3,
TA = +25°C
Transition Output Slew Rate
CL = 150pF to
2500pF
4
30
CL = 50pF to
1000pF
8
30
V/µs
Receiver Output
Propagation Delay, Low to High
tPLHR
VCC = 5V, CL = 50pF, TA = +25°C
4.0
µs
Receiver Output
Propagation Delay, High to Low
tPHLR
VCC = 5V, CL = 50pF, TA = +25°C
4.0
µs
Receiver Propagation Delay
Skew, | tPLHR - tPHLR |
tSKR
VCC = 5V, CL = 50pF, TA = +25°C
0.4
µs
DR
VCC = 5V, VDD = 12V,
VSS = -12V,
RL = 3kΩ to 7kΩ,
TA = +25°C
Guaranteed Data Rate
Mouse Driveability
CL = 50pF to
2500pF
120
CL = 50pF to
1000pF
230
kbps
T3OUT = -5mA, T1OUT = T2OUT = +5mA
±7.5
V
_______________________________________________________________________________________
3
MAX3185
ELECTRICAL CHARACTERISTICS (continued)
__________________________________________Typical Operating Characteristics
(VCC = +5.0V, VDD = +12.0V, VSS = -12.0V, TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SUPPLY CURRENT
vs. LOAD CAPACITANCE
2 TRANSMITTERS AT DATA RATE / 16
0
3kΩ + 2500pF LOAD
ISS, 20kbps
ISS, 120kbps
ISS, 240kbps
-20
10.8
12.5
12.0
12.6
-7.5
120kbps
3kΩ + CL LOAD
0
1000
2000
3000
4000
LOAD CAPACITANCE (pF)
5000
MAX3185-TOC03
FALL
10
RISE
8
6
1 TRANSMITTER 240kbps
2 TRANSMITTERS 15kbps
3kΩ + CL LOAD
4
2
0
0
0
5000
15
10
T1
VOUT+
T2
-5
VCC
VOUTVOUT-
T3
2000
3000
4000
5000
SLEW RATE
vs. TEMPERATURE
25
20
VOUT+
5
0
1000
LOAD CAPACITANCE (pF)
FALL, 500pF
15
RISE, 500pF
10
RISE, 2000pF
5
-10
FALL, 2000pF
0
-15
-12.5
4
ISS, 240kbps
MAX3185 TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CURRENT PER TRANSMITTER
240kbps
-10.0
ISS, 120kbps
-15
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
-2.5
-5.0
-10
SUPPLY VOLTAGE (V)
1 TRANSMITTER AT DATA RATE
2 TRANSMITTERS AT DATA RATE / 16
3kΩ + CL LOAD
0
ISS,
20kbps 2 TRANSMITTERS AT DATA RATE / 16
1000
2000
3000
4000
LOAD CAPACITANCE (pF)
240kbps
2.5
0
-5
13.2
120kbps
5.0
1 TRANSMITTER AT DATA RATE
ICC
-25
11.4
10.0
7.5
5
-20
TRANSMITTER OUTPUT VOLTAGE (V)
-15
12
IDD, 20kbps
SLEW RATE (V/µs)
-10
10
MAX3185-TOC05
-5
14
IDD, 120kbps
MAX3185-TOC06
ICC
16
SLEW RATE (V/µs)
1 TRANSMITTER AT DATA RATE
IDD, 240kbps
15
SUPPLY CUREENT (mA)
IDD, 20kbps
5
MAX3185-TOC04
SUPPLY CUREENT (mA)
IDD, 120kbps
10
20
MAX3185-TOC02
IDD, 240kbps
15
SLEW RATE
vs. LOAD CAPACITANCE
25
MAX3185-TOC01
20
TRANSMITTER OUTPUT VOLTAGE (V)
MAX3185
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
0
2
4
6
8
10
12
14
16
18
LOAD CURRENT PER TRANSMITTER (mA)
-55 -35 -15
5
25 45
65 85 105 125
TEMPERATURE (°C)
_______________________________________________________________________________________
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
PIN
NAME
FUNCTION
1
VDD
12, 14, 17, 18, 19
R5OUT–R1OUT
Supply-Voltage Input, +10.8V to +13.2V
Receiver Outputs, swing between GND and VCC
16, 15, 13
T3IN, T2IN, T1IN
Transmitter Inputs
10
VSS
Supply-Voltage Input, -10.8V to -13.2V
11
GND
Ground. Connect system to ground.
2, 3, 4, 7, 9
R1IN–R5IN
5, 6, 8
T1OUT, T2OUT, T3OUT
20
VCC
Receiver Inputs
Transmitter Outputs, swing between VDD and VSS
Supply-Voltage Input, +4.5V to +5.5V
_______________Detailed Description
RC 50M to 100M
CHARGE-CURRENT
LIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
Cs
150pF
±15kV ESD Protection
RD 330Ω
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 1a. IEC1000-4-2 ESD Test Model
I
100%
90%
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electrostatic 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 developed 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 characterized 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
IPEAK
ESD performance depends on a number of conditions.
Contact Maxim for a reliability report that documents
test setup, methodology, and results.
10%
tr = 0.7ns to 1ns
t
30ns
60ns
Figure 1b. IEC1000-4-2 ESD-Generator Current Waveform
_______________________________________________________________________________________
5
MAX3185
______________________________________________________________Pin Description
MAX3185
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
Human Body Model
Figure 2a shows the Human Body Model, and Figure
2b shows the current waveform it generates when discharged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the device through a
1.5kΩ resistor.
IEC1000-4-2
The IEC1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifically
refer to integrated circuits. The MAX3185 helps you
design equipment that meets Level 4 (the highest level)
of IEC1000-4-2, without additional ESD-protection components.
The main difference between tests done using the
Human Body Model and IEC1000-4-2 is higher peak
current in IEC1000-4-2. Because series resistance is
lower in the IEC1000-4-2 ESD test model (Figure 1a),
the ESD withstand voltage measured to this standard is
generally lower than that measured using the Human
Body Model. Figure 1b shows the current waveform for
the ±8kV IEC1000-4-2 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.
RC 1M
CHARGE-CURRENT
LIMIT RESISTOR
Machine Model
The Machine Model for ESD testing uses a 200pF storage 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 manufacturing. Therefore, the Machine Model is less relevant to the I/O ports than are the Human Body Model
and IEC1000-4-2.
__________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 supply is recommend. Trace widths should be greater than
40 mils. Bypass VCC, VDD, and VSS with 0.1µF capacitors as close to the part as possible to ensure maximum ESD protection.
Tie any unused transmitter inputs to GND or VCC. No
external protection diodes are needed because the
MAX3185 is not sensitive to power-supply sequencing.
RD 1500Ω
IP 100%
90%
DISCHARGE
RESISTANCE
Ir
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
AMPERES
HIGHVOLTAGE
DC
SOURCE
Cs
100pF
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
36.8%
10%
0
0
Figure 2a. Human Body ESD Test Model
6
tRL
TIME
tDL
CURRENT WAVEFORM
Figure 2b. Human Body Model Current Waveform
_______________________________________________________________________________________
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
TRANSISTOR COUNT: 217
3.0V
DRIVER
INPUT
0V
1.5V
TPHL
TPLH
VOH
3.3V
3.0V
VOUT
0V
-3.0V
-3.3V
tF2
tR2
tF1
tR1
VOL
SIGNAL
GENERATOR
RL
CL
Figure 3. Slew-Rate Test Circuit and Timing Diagram
_______________________________________________________________________________________
7
MAX3185
___________________Chip Information
MAX3185
±15kV ESD-Protected, EMC-Compliant, 230kbps
RS-232 Serial Port for Motherboards/Desktop PCs
________________________________________________________Package Information
DIM
D
0°- 8°
A
e
B
0.101mm
0.004in.
A1
C
L
A
A1
B
C
E
e
H
L
INCHES
MAX
MIN
0.104
0.093
0.012
0.004
0.019
0.014
0.013
0.009
0.299
0.291
0.050
0.419
0.394
0.050
0.016
DIM PINS
E
Wide SO
SMALL-OUTLINE
PACKAGE
(0.300 in.)
H
D
D
D
D
D
16
18
20
24
28
INCHES
MIN MAX
0.398 0.413
0.447 0.463
0.496 0.512
0.598 0.614
0.697 0.713
MILLIMETERS
MIN
MAX
2.35
2.65
0.10
0.30
0.35
0.49
0.23
0.32
7.40
7.60
1.27
10.00
10.65
0.40
1.27
MILLIMETERS
MIN
MAX
10.10 10.50
11.35 11.75
12.60 13.00
15.20 15.60
17.70 18.10
21-0042A
DIM
α
E
H
C
L
A
A1
B
C
D
E
e
H
L
α
INCHES
MILLIMETERS
MAX
MIN
MIN
MAX
0.078
1.73
0.068
1.99
0.008
0.05
0.002
0.21
0.015
0.25
0.010
0.38
0.008
0.09
0.004
0.20
SEE VARIATIONS
0.209
5.20
0.205
5.38
0.0256 BSC
0.65 BSC
0.311
7.65
0.301
7.90
0.037
0.63
0.025
0.95
8˚
0˚
0˚
8˚
DIM PINS
e
SSOP
SHRINK
SMALL-OUTLINE
PACKAGE
A
B
A1
D
D
D
D
D
14
16
20
24
28
INCHES
MILLIMETERS
MAX
MIN MAX MIN
6.33
0.239 0.249 6.07
6.33
0.239 0.249 6.07
7.33
0.278 0.289 7.07
8.33
0.317 0.328 8.07
0.397 0.407 10.07 10.33
21-0056A
D
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
© 1996 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.