19-2666; Rev 0; 10/02
±15kV ESD-Protected, ±60V Fault-Protected,
10Mbps, Fail-Safe RS-485/J1708 Transceivers
General Description
The MAX3440E–MAX3444E fault-protected RS-485 and
J1708 transceivers feature
±60V
protection from signal
faults on communication bus lines. Each device contains
one differential line driver with three-state output and one
differential line receiver with three-state input. The 1/4-unit-
load receiver input impedance allows up to 128 trans-
ceivers on a single bus. The devices operate from a 5V
supply at data rates of up to 10Mbps. True fail-safe inputs
guarantee a logic-high receiver output when the receiver
inputs are open, shorted, or connected to an idle data line.
Hot-swap circuitry eliminates false transitions on the
data bus during circuit initialization or connection to a
live backplane. Short-circuit current-limiting and ther-
mal shutdown circuitry protect the driver against exces-
sive power dissipation, and on-chip
±15kV
ESD
protection eliminates costly external protection devices.
The MAX3440E–MAX3444E are available in 8-pin SO
and PDIP packages and are specified over industrial
and automotive temperature ranges.
o
±15kV
ESD Protection
o
±60V
Fault Protection
o
Guaranteed 10Mbps Data Rate
(MAX3441E/MAX3443E)
o
Hot Swappable for Telecom Applications
o
True Fail-Safe Receiver Inputs
o
Enhanced Slew-Rate-Limiting Facilitates
Error-Free Data Transmission
(MAX3440E/MAX3442E/MAX3444E)
o
Allow Up to 128 Transceivers on the Bus
o
-7V to +12V Common-Mode Input Range
o
Automotive Temperature Range (-40°C to +125°C)
o
Industry-Standard Pinout
Features
MAX3440E–MAX3444E
Ordering Information
PART
MAX3440EESA
MAX3440EEPA
MAX3440EASA
MAX3440EAPA
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
8 SO
8 PDIP
8 SO
8 PDIP
Applications
RS-422/RS-485 Communications
Truck and Trailer Applications
Industrial Networks
Telecommunications Systems
Automotive Applications
HVAC Controls
DATA RATE
(Mbps)
0.25
2.5 to 10
0.25
2.5 to 10
0.25
LOW-POWER
SHUTDOWN
No
No
Yes
Yes
Yes
Ordering Information continued at end of data sheet.
Selector Guide
RECEIVER/DRIVER
ENABLE
Yes
Yes
Yes
Yes
Yes
TRANSCEIVERS
ON BUS
128
128
128
128
128
HOT SWAP
Yes
Yes
Yes
Yes
Yes (only
RE)
PART
MAX3440E
MAX3441E
MAX3442E
MAX3443E
MAX3444E
TYPE
RS-485
RS-485
RS-485
RS-485
J1708
Pin Configurations and Typical Operating Circuits
TOP VIEW
FAULT
1
RO
2
DE/RE
3
DI
4
D
R
8
7
6
5
V
CC
B
A
GND
FAULT 1
RO 2
DE/RE
3
D
R
8 V
CC
7 B
Rt
6
A
5 GND
DE/RE
MAX3440E
MAX3441E
B
Rt
A
R
D
DI
DI 4
RO
FAULT
DIP/SO
DIP/SO
Pin Configurations and Typical Operating Circuits continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
±15kV ESD-Protected, ±60V Fault-Protected,
10Mbps, Fail-Safe RS-485/J1708 Transceivers
MAX3440E–MAX3444E
ABSOLUTE MAXIMUM RATINGS
Voltages Referenced to GND
V
CC
........................................................................................+7V
FAULT, DE/RE,
RE,
DE,
DE,
DI, TXD..........-0.3V to (V
CC
+ 0.3V)
A, B (Note 1) ........................................................................±60V
RO ..............................................................-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration (RO, A, B) ...............................Continuous
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW
8-Pin PDIP (derate 9.09mW/°C above +70°C).............727mW
Operating Temperature Ranges
MAX344_EE_ _ ...............................................-40°C to +85°C
MAX344_EA_ _ .............................................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
A, B must be terminated with 54Ω or 100Ω to guarantee ±60V fault protection.
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.
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +4.75V to +5.25V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
DRIVER
Differential Driver Output
Change in Magnitude of
Differential Output Voltage
Driver Common-Mode
Output Voltage
Change in Magnitude of
Common-Mode Voltage
DRIVER LOGIC
Driver Input High Voltage
Driver Input Low Voltage
Driver Input Current
Driver Short-Circuit Output Current
(Note 3)
Driver Short-Circuit Foldback
Output Current
RECEIVER
V
CC
= GND, V
A, B
= 12V
Input Current
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
I
A,B
A, B
V
A, B
= -7V
V
A, B
=
±60V
V
TH
∆
V
TH
-7V
≤
V
CM
≤
+12V
-200
25
250
-150
±6
-50
µA
mA
mV
mV
V
DIH
V
DIL
I
DIN
I
OSD
I
OSDF
0
≤
V
OUT
≤
+12V
-7V
≤
V
OUT
≤
V
CC
(V
CC
- 1V)
≤
V
OUT
≤
+12V (Note 3)
-7V
≤
V
OUT
≤
+1V (Note 3)
-350
+25
-25
2
0.8
±2
+350
V
V
µA
mA
mA
V
OD
∆V
OD
V
OC
∆V
OC
Figure 1, R
L
= 100Ω
Figure 1, R
L
= 54Ω
Figure 1, R
L
= 100Ω or 54Ω (Note 2)
Figure 1, R
L
= 100Ω or 54Ω
Figure 1, R
L
= 100Ω or 54Ω (Note 2)
V
CC
/ 2
2
1.5
V
CC
V
CC
0.2
3
0.2
V
V
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
±15kV ESD-Protected, ±60V Fault-Protected,
10Mbps, Fail-Safe RS-485/J1708 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +4.75V to +5.25V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
RECEIVER LOGIC
Output High Voltage
Output Low Voltage
Three-State Output Current at
Receiver
Receiver Input Resistance
Receiver Output Short-Circuit
Current
CONTROL
Control Input High Voltage
Input Current Latch During First
Rising Edge
SUPPLY CURRENT
MAX3440E (DE/RE = V
CC
),
MAX3442E (DE = V
CC
,
RE
= GND),
MAX3444E (DE =
RE
= GND)
MAX3441E (DE/RE = V
CC
),
MAX3443E (DE = V
CC
,
RE
= GND)
V
CIH
I
IN
DE,
DE, RE,
DE/RE
DE, DE/RE,
RE
2
90
V
µA
V
OH
V
OL
I
OZR
R
IN
I
OSR
Figure 2, I
OH
= -1.6mA
Figure 2, I
OL
= 1mA
0
≤
V
A, B
≤
V
CC
-7V
≤
V
CM
≤
+12V
0
≤
V
RO
≤
V
CC
48
±95
V
CC
- 0.6
0.4
±1
V
V
µA
kΩ
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX3440E–MAX3444E
30
mA
10
Normal Operation
I
Q
No load,
DI = V
CC
or GND
DE = GND,
RE
= V
CC
(MAX3442E/
MAX3443E)
Supply Current in Shutdown Mode
I
SHDN
DE = GND,
RE
= V
CC
, T
A
= +25°C
(MAX3442E/MAX3443E)
DE
=
RE
= V
CC
(MAX3444E)
DE
=
RE
= V
CC
, T
A
= +25°C (MAX3444E)
Supply Current with Output
Shorted to
±60V
I
SHRT
DE = GND,
RE
= GND, no load
output in three-state (MAX3443E)
20
µA
10
100
10
±15
mA
PROTECTION SPECIFICATIONS
(V
CC
= +4.75V to +5.25V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
Overvoltage Protection
ESD Protection
FAULT DETECTION
Receiver Differential Threshold
Receiver Differential Threshold
Fault-Detection Common-Mode
Input Voltage Positive
Fault-Detection Common-Mode
Input Voltage Negative
F
DIPH
F
DIPL
V
CM
= 0, high limit
V
CM
= 0, low limit
270
-450
12
-7
450
-270
mV
mV
V
V
SYMBOL
A, B
CONDITIONS
A, B; R
SOURCE
= 0, R
L
= 54Ω
Human Body Model
MIN
±60
±15
TYP
MAX
UNITS
V
kV
_______________________________________________________________________________________
3
±15kV ESD-Protected, ±60V Fault-Protected,
10Mbps, Fail-Safe RS-485/J1708 Transceivers
MAX3440E–MAX3444E
SWITCHING CHARACTERISTICS (MAX3440E/MAX3442E/MAX3444E)
(V
CC
= +4.75V to +5.25V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
Driver Propagation Delay
SYMBOL
t
PLHA,
t
PLHB
t
DPLH
,
t
DPHL
t
LH
,t
HL
t
SKEWAB
,
t
SKEWBA
t
DSKEW
f
MAX
t
PDZH
t
PDHZ
t
PDHS
t
PDZL
t
PDLZ
t
PDLS
t
SHDN
t
RPLH
,
t
RPHL
t
RSKEW
t
RPZH
t
RPHZ
t
RPWAKE
t
RPZL
t
RPLZ
t
SHDN
Figure 5, R
L
= 500Ω, C
L
= 50pF
Figure 5, RL = 500Ω, C
L
= 50pF
Figure 5, RL = 500Ω, C
L
= 50pF
(MAX3442E/MAX3444E)
Figure 6, R
L
= 500Ω, C
L
= 50pF
Figure 6, R
L
= 500Ω, C
L
= 50pF
Figure 6, R
L
= 500Ω, C
L
= 50pF
(MAX3442E/MAX3444E)
R
L
= 500Ω, C
L
= 50pF (MAX3442E/MAX3444E)
Figure 7, C
L
= 20pF, V
ID
= 2V, V
CM
= 0
C
L
= 20pF, t
RSKEW
= |t
RPLH
- t
RPHL
|
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF
(MAX3442E/MAX3444E)
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF
R
L
= 500Ω, C
L
= 50pF
(MAX3442E/MAX3444E)
CONDITIONS
MAX3440E/MAX3442E,
Figure 3, R
L
= 54Ω, C
L
= 50pF
MAX3444E, R
DIFF
= 60Ω, C
DIFF
= 100pF
Figure 4, R
L
= 54Ω, C
L
= 50pF
Figure 4, R
L
= 54Ω, C
L
= 50pF
R
L
= 54Ω, C
L
= 50pF,
t
SKEWAB
= |t
PLHA
- t
PHLB
|,
t
SKEWBA
= |t
PLHB
- t
PHLA
|
R
L
= 54Ω, C
L
= 50pF,
t
DSKEW
= |t
DPLH
- t
DPHL
|
250
2000
2000
4.2
2000
2000
4.2
800
2000
200
2000
2000
4.2
2000
2000
800
200
2000
2000
ns
ns
MIN
TYP
MAX
2000
UNITS
ns
Driver Differential Propagation Delay
Driver Differential Output
Transition Time
Driver Output Skew
350
ns
Differential Driver Output Skew
Maximum Data Rate
Driver Enable Time to Output High
Driver Disable Time from Output High
Driver Enable Time from Shutdown to
Output High
Driver Enable Time to Output Low
Driver Disable Time from Output Low
Driver Enable Time from Shutdown to
Output Low
Driver Time to Shutdown
Receiver Propagation Delay
Receiver Output Skew
Receiver Enable Time to Output High
Receiver Disable Time from Output High
Receiver Wake Time from Shutdown
Receiver Enable Time to Output Low
Receiver Disable Time from Output Low
Receiver Time to Shutdown
200
ns
kbps
ns
ns
µs
ns
ns
µs
ns
ns
ns
ns
ns
µs
ns
ns
ns
4
_______________________________________________________________________________________
±15kV ESD-Protected, ±60V Fault-Protected,
10Mbps, Fail-Safe RS-485/J1708 Transceivers
SWITCHING CHARACTERISTICS (MAX3441E/MAX3443E)
(V
CC
= +4.75V to +5.25V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
Driver Propagation Delay
Driver Differential Propagation Delay
Driver Differential Output
Transition Time
Driver Output Skew
SYMBOL
t
PLHA,
t
PLHB
t
DPLH
,
t
DPHL
t
LH
,t
HL
t
SKEWAB
,
t
SKEWBA
t
DSKEW
f
MAX
t
PDZH
t
PDHZ
t
PDHS
t
PDZL
t
PDLZ
t
PDLS
t
SHDN
t
RPLH
,
t
RPHL
t
RSKEW
t
RPZH
t
RPHZ
t
RPWAKE
t
RPSH
t
RPLZ
t
SHDN
Figure 5, R
L
= 500Ω, C
L
= 50pF
Figure 5, R
L
= 500Ω, C
L
= 50pF
Figure 5, R
L
= 500Ω, C
L
= 50pF (MAX3443E)
Figure 6, R
L
= 500Ω, C
L
= 50pF
Figure 6, R
L
= 500Ω, C
L
= 50pF
Figure 6, R
L
= 500Ω, C
L
= 50pF (MAX3443E)
Figure 6, R
L
= 500Ω, C
L
= 50pF (MAX3443E)
Figure 7, C
L
= 20pF, V
ID
= 2V, V
CM
= 0
C
L
= 20pF, t
RSKEW
= |t
RPLH
- t
RPHL
|
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF (MAX3443E)
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF
R
L
= 500Ω, C
L
= 50pF (MAX3443E)
CONDITIONS
Figure 3, R
L
= 27Ω, C
L
= 50pF
Figure 4, R
L
= 54Ω, C
L
= 50pF
Figure 4, R
L
= 54Ω, C
L
= 50pF
R
L
= 54Ω, C
L
= 50pF,
t
SKEWAB
= |t
PLHA
- t
PHLB
|,
t
SKEWBA
= |t
PLHB
- t
PHLA
|
R
L
= 54Ω, C
L
= 50pF,
t
DSKEW
= |t
DPLH
- t
DPHL
|
10
1200
1200
4.2
1200
1200
4.2
800
85
15
400
400
4.2
400
400
800
MIN
TYP
MAX
60
60
25
UNITS
ns
ns
ns
MAX3440E–MAX3444E
10
ns
Differential Driver Output Skew
Maximum Data Rate
Driver Enable Time to Output High
Driver Disable Time from Output High
Driver Enable Time from Shutdown to
Output High
Driver Enable Time to Output Low
Driver Disable Time from Output Low
Driver Enable Time from Shutdown to
Output Low
Driver Time to Shutdown
Receiver Propagation Delay
Receiver Output Skew
Receiver Enable Time to Output High
Receiver Disable Time from Output High
Receiver Wake Time from Shutdown
Receiver Enable Wake Time from
Shutdown
Receiver Disable Time from Output Low
Receiver Time to Shutdown
10
ns
Mbps
ns
ns
µs
ns
ns
µs
ns
ns
ns
ns
ns
µs
ns
ns
ns
Note 2:
∆V
OD
and
∆V
OC
are the changes in V
OD
and V
OC
, respectively, when the DI input changes state.
Note 3:
The short-circuit output current applies to peak current just before foldback current limiting; the short-circuit foldback output
current applies during current limiting to allow a recovery from bus contention.
_______________________________________________________________________________________
5
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