19-2441; Rev 0; 4/02
±60V Fault-Protected, 10Mbps, Fail-Safe
RS-485 Transceiver with ±15kV ESD Protection
General Description
The MAX3443E fault-protected RS-485/RS-422 transceiv-
er features ±60V protection from signal faults on commu-
nication 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 transceivers on a sin-
gle bus. The device operates from a 5V supply at data
rates 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 cable during circuit initialization or connection to a
live backplane. Short-circuit current limiting and thermal
shutdown circuitry protect the driver against excessive
power dissipation, and integrated ±15kV ESD protec-
tion eliminates costly external protection devices.
The MAX3443E is available in 8-pin SO and PDIP pack-
ages, and is specified over commercial, industrial, and
automotive temperature ranges.
o
±60V Fault Protection
o
±15kV ESD Protection
o
Guaranteed 10Mbps Data Rate
o
Allows Up to 128 Transceivers on the Bus
o
-7V to +12V Common-Mode Input Range
o
True Fail-Safe Receiver Inputs
o
Hot-Swap Inputs for Telecom Applications
o
Automotive Temperature Range (-40°C to +125°C)
o
Industry-Standard Pinout
Features
MAX3443E
Ordering Information
PART
MAX3443ECSA
MAX3443ECPA
MAX3443EESA
MAX3443EEPA
MAX3443EASA
MAX3443EAPA
TEMP RANGE
0°C to +70°C
0°C to +70°C
-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
8 SO
8 PDIP
Applications
RS-422/RS-485 Communications
Industrial Networks
Telecommunication Systems
Automotive Applications
HVAC Controls
Pin Configuration and Typical Operating Circuit
TOP VIEW
MAX3443E
RO
1
R
8
7
6
D
5
V
CC
B
A
GND
RO
1
R
8 V
CC
7 B
Rt
6
A
5 GND
DE
D
B
Rt
A
R
RE
RO
DI
RE
2
DE
DI
3
4
RE 2
DE
DI
3
4
D
DIP/SO
________________________________________________________________
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.
±60V Fault-Protected, 10Mbps, Fail-Safe
RS-485 Transceiver with ±15kV ESD Protection
MAX3443E
ABSOLUTE MAXIMUM RATINGS
All Voltages Referenced with Respect to GND
V
CC
........................................................................................+7V
RE,
DE, DI...................................................-0.3V to (V
CC
+ 0.3V)
A, B (Note 1) ........................................................................±60V
RO ..............................................................-0.3V to (V
CC
+ 0.3V)
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
MAX3443EC_ _ ..................................................0°C to +70°C
MAX3443EE_ _ ...............................................-40°C to +85°C
MAX3443EA_ _ .............................................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Short-Circuit Duration (RO, A, B) ...............................Continuous
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 Output Fault Current
Driver Short-Circuit Output
Current
Driver Short-Circuit Foldback
Output Current
RECEIVER
DE = GND, V
CC
= GND,
V
A, B
= +12V
V
A, B
= -7V
V
A, B
=
±60V
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
V
TH
∆V
TH
-7V
≤
V
CM
≤
+12V
-200
25
250
-150
±6
-50
mA
mV
mV
µA
V
DIH
V
DIL
I
DIN
I
OFC
I
OSD
I
OSDF
V
A, B
=
±60V,
R
L
= 54Ω
-7V
≤
V
OUT
≤
+12V
(Note 3)
-7V
≤
V
OUT
≤
+12V
(Note 3)
2.0
0.8
±2
±6
±350
±25
V
V
µA
mA
mA
mA
V
OD
∆V
OD
V
OC
∆V
OC
Figure 1, R
L
= 50Ω
Figure 1, R
L
= 27Ω
Figure 1, R
L
= 50Ω or 27Ω (Note 2)
Figure 1, R
L
= 50Ω or 27Ω
Figure 1, R
L
= 50Ω or 27Ω (Note 2)
V
CC
/ 2
2.0
1.5
V
CC
V
CC
0.2
3
0.2
V
V
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Current
I
A,B
A, B
2
_______________________________________________________________________________________
±60V Fault-Protected, 10Mbps, Fail-Safe
RS-485 Transceiver with ±15kV ESD Protection
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 DE Current Latch
During First DE Rising Edge
Input Current
RE
Current Latch
During First
RE
Falling Edge
V
CIH
DE,
RE
2.0
90
90
V
µA
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
MAX3443E
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
SYMBOL
CONDITIONS
A, B
R
SOURCE
= 0, R
L
= 54Ω
IEC 1000-4-2 Air-Gap
Discharge
ESD Protection
A, B
IEC 1000-4-2 Contact
Discharge
Human Body Model
SUPPLY CURRENT
Normal Operation
Supply Current in Shutdown
Mode
Supply Current with Output
Shorted with
±60V
I
Q
I
SHDN
I
SHRT
No load, DI = V
CC
or GND,
RE
= GND,
DE = V
CC
DE = GND,
RE
= V
CC
DE = GND,
RE
= GND, output in three-state
10
10
±15
mA
µA
mA
MIN
±60
±2
±8
±15
kV
TYP
MAX
UNITS
V
_______________________________________________________________________________________
3
±60V Fault-Protected, 10Mbps, Fail-Safe
RS-485 Transceiver with ±15kV ESD Protection
MAX3443E
SWITCHING CHARACTERISTICS (DRIVER)
(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
Figure 5, R
L
= 500Ω, C
L
= 50pF
Figure 5, R
L
= 500Ω, C
L
= 50pF
Figure 5, R
L
= 500Ω, C
L
= 50pF
Figure 6, R
L
= 500Ω, C
L
= 50pF
Figure 6, R
L
= 500Ω, C
L
= 50pF
Figure 6, R
L
= 500Ω, C
L
= 50pF
R
L
= 500Ω, C
L
= 50pF
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
MIN
TYP
MAX
60
60
25
UNITS
ns
ns
ns
10
ns
Differential Driver Output Skew
Maximum Data Rate
Driver Enable Time to Output
High
Driver Disable Time from Output
High
Driver Wake Time from Shutdown
to Output High
Driver Enable Time to
Output Low
Driver Disable Time from Output
Low
Driver Wake Time from Shutdown
to Output Low
Time to Shutdown
10
ns
Mbps
ns
ns
µs
ns
ns
µs
ns
4
_______________________________________________________________________________________
±60V Fault-Protected, 10Mbps, Fail-Safe
RS-485 Transceiver with ±15kV ESD Protection
SWITCHING CHARACTERISTICS (RECEIVER)
(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 Propagation Delay
Receiver Output Skew
Receiver Enable Time to Output
High
Receiver Disable Time from
Output High
Receiver Wake Time from
Shutdown to Output High
Receiver Enable Time to Output
Low
Receiver Disable Time from
Output Low
Receiver Wake Time from
Shutdown to Output Low
Time to Shutdown
SYMBOL
t
RPLH
,
t
RPHL
t
RSKEW
t
RPZH
t
RPHZ
t
RPSH
t
RPZL
t
RPLZ
t
RPSL
CONDITIONS
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
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF
Figure 8, R
L
= 1kΩ, C
L
= 20pF
MIN
TYP
MAX
75
15
400
400
4.2
400
400
4.2
800
UNITS
ns
ns
ns
ns
µs
ns
ns
µs
ns
MAX3443E
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 prior to foldback current limiting; the short-circuit foldback out-
put current applies during current limiting to allow a recovery from bus contention.
Typical Operating Characteristics
(V
CC
= +5V, T
A
= +25°C, unless otherwise noted.)
NO-LOAD SUPPLY CURRENT
vs. TEMPERATURE
MAX3443E toc01
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX3443E toc02
RECEIVER OUTPUT CURRENT
vs. OUTPUT LOW VOLTAGE
35
30
25
20
15
10
5
MAX3443E toc03
6
DE = V
CC
, RE = GND
5
SUPPLY CURRENT (mA)
4
DE = RE = GND
3
2
1
0
10
DE = GND, RE = V
CC
SUPPLY CURRENT (nA)
40
RECEIVER OUTPUT CURRENT (mA)
1
0.1
0.01
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
0
0 0.5
1.0
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
OUTPUT LOW VOLTAGE (V)
_______________________________________________________________________________________
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
