_______________General Description
The MAX481E, MAX483E, MAX485E, MAX487EMAX491E,
and MAX1487E are low-power transceivers for RS-485 and
RS-422 communications in harsh environments. Each driver
output and receiver input is protected against 15kV electro-
static discharge (ESD) shocks, without latchup. These parts
contain one driver and one receiver. The MAX483E,
MAX487E, MAX488E, and MAX489E feature reduced slew-
rate drivers that minimize EMI and reduce reflections caused
by improperly terminated cables, thus allowing error-free
data transmission up to 250kbps. The driver slew rates of the
MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E
are not limited, allowing them to transmit up to 2.5Mbps.
These transceivers draw as little as 120A supply current
when unloaded or when fully loaded with disabled drivers
(see
Selection Table). Additionally, the MAX481E,
MAX483E, and MAX487E have a low-current shutdown
mode in which they consume only 0.5A. All parts operate
from a single +5V supply.
Drivers are short-circuit current limited, and are protected
against excessive power dissipation by thermal shutdown
circuitry that places their outputs into a high-impedance
state. The receiver input has a fail-safe feature that guaran-
tees a logic-high output if the input is open circuit.
The MAX487E and MAX1487E feature quarter-unit-load
receiver input impedance, allowing up to 128 transceivers
on the bus. The MAX488EMAX491E are designed for full-
duplex communications, while the MAX481E, MAX483E,
MAX485E, MAX487E, and MAX1487E are designed for half-
duplex applications. For applications that are not ESD sen-
sitive see the pin- and function-compatible MAX481,
MAX483, MAX485, MAX487MAX491, and MAX1487.
________________________Applications
Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
____________________________Features
o
ESD Protection: 15kV--Human Body Model
o
Slew-Rate Limited for Error-Free Data
Transmission (MAX483E/487E/488E/489E)
o
Low Quiescent Current:
120A (MAX483E/487E/488E/489E)
230A (MAX1487E)
300A (MAX481E/485E/490E/491E)
o
-7V to +12V Common-Mode Input Voltage Range
o
Three-State Outputs
o
30ns Propagation Delays, 5ns Skew
(MAX481E/485E/490E/491E/1487E)
o
Full-Duplex and Half-Duplex Versions Available
o
Allows up to 128 Transceivers on the Bus
(MAX487E/MAX1487E)
o
Current Limiting and Thermal Shutdown for
Driver Overload Protection
MAX481E/MAX483E/MAX485E/MAX487EMAX491E/MAX1487E
15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
________________________________________________________________
Maxim Integrated Products
1
MAX481E
MAX483E
MAX485E
MAX487E
MAX488E
MAX489E
MAX490E
MAX491E
MAX1487E
PART
NUMBER
HALF/FULL
DUPLEX
DATA RATE
(Mbps)
SLEW-RATE
LIMITED
LOW-POWER
SHUTDOWN
RECEIVER/
DRIVER
ENABLE
QUIESCENT
CURRENT
(
A)
NUMBER OF
TRANSMITTERS
ON BUS
PIN
COUNT
Half
Half
Half
Half
Full
Full
Full
Full
Half
2.5
0.25
2.5
0.25
0.25
0.25
2.5
2.5
2.5
No
Yes
No
Yes
Yes
Yes
No
No
No
Yes
Yes
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
300
120
300
120
120
120
300
300
230
32
32
32
128
32
32
32
32
128
8
8
8
8
8
14
8
14
8
______________________________________________________________Selection Table
19-0410; Rev 3; 7/96
______________Ordering Information
Ordering Information continued on last page.
8 SO
0C to +70C
MAX481ECSA
8 Plastic DIP
0C to +70C
MAX481E
CPA
PIN-PACKAGE
TEMP. RANGE
PART
8 SO
-40C to +85C
MAX481EESA
8 Plastic DIP
-40C to +85C
MAX481EEPA
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX481E/MAX483E/MAX485E/MAX487EMAX491E/MAX1487E
15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
2
_______________________________________________________________________________________
Supply Voltage (V
CC
) .............................................................12V
Control Input Voltage (
R
--
E
, DE)...................-0.5V to (V
CC
+ 0.5V)
Driver Input Voltage (DI).............................-0.5V to (V
CC
+ 0.5V)
Driver Output Voltage (Y, Z; A, B) ..........................-8V to +12.5V
Receiver Input Voltage (A, B).................................-8V to +12.5V
Receiver Output Voltage (RO)....................-0.5V to (V
CC
+ 0.5V)
Continuous Power Dissipation (T
A
= +70C)
8-Pin Plastic DIP (derate 9.09mW/C above +70C) ....727mW
14-Pin Plastic DIP (derate 10.00mW/C above +70C) ..800mW
8-Pin SO (derate 5.88mW/C above +70C).................471mW
14-Pin SO (derate 8.33mW/C above +70C)...............667mW
Operating Temperature Ranges
MAX4_ _C_ _/MAX1487EC_ A .............................0C to +70C
MAX4_ _E_ _/MAX1487EE_ A...........................-40C to +85C
Storage Temperature Range .............................-65C to +160C
Lead Temperature (soldering, 10sec) .............................+300C
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 5V 5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
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.
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
Driver Common-Mode Output
Voltage
V
OC
3
V
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
V
OD
0.2
V
Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States
V
OD
0.2
V
Input High Voltage
V
IH
2.0
V
Input Low Voltage
V
IL
0.8
V
Input Current
I
IN1
2
A
Differential Driver Output (no load)
V
OD1
5
V
2
V
Differential Driver Output
(with load)
V
OD2
1.5
5
1.0
-0.8
mA
0.25
mA
-0.2
Receiver Differential Threshold
Voltage
-0.2
0.2
V
Receiver Input Hysteresis
V
TH
70
mV
Receiver Output High Voltage
V
OH
3.5
Receiver Output Low Voltage
V
OL
0.4
V
Three-State (high impedance)
Output Current at Receiver
I
OZR
1
A
12
k
CONDITIONS
DE = 0V;
V
CC
= 0V or 5.25V,
all devices except
MAX487E/MAX1487E
R = 27
or 50
, Figure 8
R = 27
or 50
, Figure 8
R = 27
or 50
, Figure 8
DE, DI,
R
--
E
MAX487E/MAX1487E,
DE = 0V, V
CC
= 0V or 5.25V
DE, DI,
R
--
E
DE, DI,
R
--
E
-7V
V
CM
12V
V
CM
= 0V
I
O
= -4mA, V
ID
= 200mV
I
O
= 4mA, V
ID
= -200mV
R = 50
(RS-422)
0.4V
V
O
2.4V
R = 27
(RS-485), Figure 8
-7V
V
CM
12V, all devices except
MAX487E/MAX1487E
Receiver Input Resistance
R
IN
-7V
V
CM
12V, MAX487E/MAX1487E
48
k
V
TH
I
IN2
Input Current
(A, B)
V
IN
= 12V
V
IN
= -7V
V
IN
= 12V
V
IN
= -7V
V
MAX481E/MAX483E/MAX485E/MAX487EMAX491E/MAX1487E
15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
_______________________________________________________________________________________
3
SWITCHING CHARACTERISTICS--MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E
(V
CC
= 5V 5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V 5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
mA
7
95
0V
V
O
V
CC
I
OSR
Receiver Short-Circuit Current
mA
35
250
-7V
V
O
12V (Note 4)
I
OSD2
Driver Short-Circuit Current,
V
O
= Low
mA
35
250
-7V
V
O
12V (Note 4)
I
OSD1
Driver Short-Circuit Current,
V
O
= High
MAX1487E,
R
--
E
= 0V or V
CC
250
400
350
650
CONDITIONS
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
230
400
300
500
MAX481E/MAX485E,
R
--
E
= 0V or V
CC
500
900
MAX490E/MAX491E,
DE, DI,
R
--
E
= 0V or V
CC
300
500
MAX488E/MAX489E,
DE, DI,
R
--
E
= 0V or V
CC
120
250
DE = V
CC
300
500
DE = 0V
DE = V
CC
DE = 0V
A
MAX481E/483E/487E, DE = 0V,
R
--
E
= V
CC
0.5
10
I
SHDN
Supply Current in Shutdown
120
250
I
CC
No-Load Supply Current
(Note 3)
DE = V
CC
DE = 0V
MAX483E
MAX487E
MAX483E/MAX487E,
R
--
E
= 0V or V
CC
A
5
20
25
MAX490EC/E, MAX491EC/E
MAX481E, MAX485E, MAX1487E
Driver Rise or Fall Time
t
R
, t
F
3
20
40
Figures 10 and 12,
R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
MAX490EC/E, MAX491EC/E
Figures 11 and 13, C
L
= 15pF, S2 closed
Figures 11 and 13, C
L
= 15pF, S1 closed
Figures 11 and 13, C
L
= 100pF, S1 closed
Figures 11 and 13, C
L
= 100pF, S2 closed
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
Driver Enable to Output High
t
ZH
45
70
Receiver Input to Output
t
PLH
, t
PHL
Driver Output Skew to Output
ns
Driver Enable to Output Low
t
ZL
45
70
ns
Driver Disable Time from Low
t
LZ
45
70
ns
|
t
PLH
- t
PHL
|
Differential
Receiver Skew
Driver Disable Time from High
t
SKD
t
HZ
45
70
5
ns
20
60
200
Receiver Enable to Output Low
t
ZL
20
50
ns
Receiver Enable to Output High
Driver Input to Output
t
ZH
20
50
ns
Receiver Disable Time from Low
t
LZ
20
50
t
PLH
10
40
60
ns
Receiver Disable Time from High
t
HZ
20
50
Mbps
Maximum Data Rate
f
MAX
2.5
ns
Time to Shutdown
t
SHDN
50
200
600
t
SKEW
5
10
ns
CONDITIONS
Figures 10 and 14,
R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
Figures 10 and 14, R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
Figures 9 and 15, C
RL
= 15pF, S1 closed
Figures 9 and 15, C
RL
= 15pF, S2 closed
Figures 9 and 15, C
RL
= 15pF, S1 closed
Figures 9 and 15, C
RL
= 15pF, S2 closed
MAX481E (Note 5)
Figures 10 and 12, R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
MAX481E, MAX485E, MAX1487E
ns
Figures 10 and 12, R
DIFF
= 54
, C
L1
= C
L2
= 100pF
t
PHL
10
40
60
ns
ns
ns
20
60
150
ns
kV
15
A, B, Y and Z pins, tested using Human Body Model
ESD Protection
MAX481E/MAX483E/MAX485E/MAX487EMAX491E/MAX1487E
15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
4
_______________________________________________________________________________________
SWITCHING CHARACTERISTICS--MAX483E, MAX487E/MAX488E/MAX489E
(V
CC
= 5V 5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
SWITCHING CHARACTERISTICS--MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E
(continued)
(V
CC
= 5V 5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
225
1000
Figures 11 and 13, C
L
= 100pF, S2 closed
Figures 11 and 13, C
L
= 100pF, S1 closed
Figures 9 and 15, C
L
= 15pF, S2 closed,
A - B = 2V
CONDITIONS
ns
45
100
t
ZH(SHDN)
Driver Enable from Shutdown to
Output High (MAX481E)
ns
Figures 9 and 15, C
L
= 15pF, S1 closed,
B - A = 2V
t
ZL(SHDN)
Receiver Enable from Shutdown
to Output Low (MAX481E)
ns
45
100
t
ZL(SHDN)
Driver Enable from Shutdown to
Output Low (MAX481E)
ns
225
1000
t
ZH(SHDN)
Receiver Enable from Shutdown
to Output High (MAX481E)
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
t
PLH
t
SKEW
Figures 10 and 12, R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
t
PHL
Figures 10 and 12, R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
Driver Input to Output
Driver Output Skew to Output
ns
20
800
ns
ns
2000
MAX483E/MAX487E, Figures 11 and 13,
C
L
= 100pF, S2 closed
t
ZH(SHDN)
Driver Enable from Shutdown to
Output High
250
2000
ns
2500
MAX483E/MAX487E, Figures 9 and 15,
C
L
= 15pF, S1 closed
t
ZL(SHDN)
Receiver Enable from Shutdown
to Output Low
ns
2500
MAX483E/MAX487E, Figures 9 and 15,
C
L
= 15pF, S2 closed
t
ZH(SHDN)
Receiver Enable from Shutdown
to Output High
ns
2000
MAX483E/MAX487E, Figures 11 and 13,
C
L
= 100pF, S1 closed
t
ZL(SHDN)
Driver Enable from Shutdown to
Output Low
ns
50
200
600
MAX483E/MAX487E (Note 5)
t
SHDN
Time to Shutdown
t
PHL
t
PLH
, t
PHL
< 50% of data period
Figures 9 and 15, C
RL
= 15pF, S2 closed
Figures 9 and 15, C
RL
= 15pF, S1 closed
Figures 9 and 15, C
RL
= 15pF, S2 closed
Figures 9 and 15, C
RL
= 15pF, S1 closed
Figures 11 and 13, C
L
= 15pF, S2 closed
Figures 10 and 14, R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
Figures 11 and 13, C
L
= 15pF, S1 closed
Figures 11 and 13, C
L
= 100pF, S1 closed
Figures 11 and 13, C
L
= 100pF, S2 closed
CONDITIONS
kbps
250
f
MAX
250
800
2000
Maximum Data Rate
ns
25
50
t
HZ
Receiver Disable Time from High
ns
250
800
2000
25
50
t
LZ
Receiver Disable Time from Low
ns
25
50
t
ZH
Receiver Enable to Output High
ns
25
50
t
ZL
Receiver Enable to Output Low
ns
ns
100
300
3000
t
HZ
t
SKD
Driver Disable Time from High
I
t
PLH
- t
PHL
I
Differential
Receiver Skew
Figures 10 and 14, R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
ns
300
3000
t
LZ
Driver Disable Time from Low
ns
250
2000
t
ZL
Driver Enable to Output Low
ns
Figures 10 and 12, R
DIFF
= 54
,
C
L1
= C
L2
= 100pF
ns
250
2000
t
R
, t
F
250
2000
Driver Rise or Fall Time
ns
t
PLH
Receiver Input to Output
250
2000
t
ZH
Driver Enable to Output High
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
MAX481E/MAX483E/MAX485E/MAX487EMAX491E/MAX1487E
15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
_______________________________________________________________________________________
5
0
5
10
15
20
25
30
35
40
45
50
OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
MAX481E-01
OUTPUT LOW VOLTAGE (V)
OUTPUT CURRENT (mA)
1.5
2.0
2.5
1.0
0.5
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
-60
-20
60
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
MAX481E-04
TEMPERATURE (C)
OUTPUT LOW VOLTAGE (V)
20
100
-40
40
0
80
I
RO
= 8mA
0
-5
-10
-15
-20
-25
1.5
3.0
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
MAX481E-02
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
5.0
4.5
4.0
2.0
2.5
3.5
3.0
3.2
3.4
3.6
3.8
4.0
4.2
4.4
4.6
4.8
-60
-20
60
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
MAX481E-03
TEMPERATURE (C)
OUTPUT HIGH VOLTAGE (V)
20
100
-40
40
0
80
I
RO
= 8mA
0
10
20
30
40
50
60
70
80
90
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
MAX481E-05
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
1.5 2.0 2.5 3.0 3.5 4.0 4.5
1.0
0.5
0
__________________________________________Typical Operating Characteristics
(V
CC
= 5V, T
A
= +25C, unless otherwise noted.)
NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICS
Note 1:
All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device
ground unless otherwise specified.
Note 2:
All typical specifications are given for V
CC
= 5V and T
A
= +25C.
Note 3:
Supply current specification is valid for loaded transmitters when DE = 0V.
Note 4:
Applies to peak current. See
Typical Operating Characteristics.
Note 5:
The MAX481E/MAX483E/MAX487E are put into shutdown by bringing
R
--
E
high and DE low. If the inputs are in this state for
less than 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are
guaranteed to have entered shutdown. See
Low-Power Shutdown Mode section.
PDF 
ZIP