19-0410; Rev 3; 7/96
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
_______________General Description
The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E,
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 120µA 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 0.5µA. 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 MAX488E–MAX491E 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, MAX487–MAX491, and MAX1487.
____________________________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:
120µA (MAX483E/487E/488E/489E)
230µA (MAX1487E)
300µA (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/MAX487E–MAX491E/MAX1487E
______________Ordering Information
PART
MAX481ECPA
MAX481ECSA
MAX481EEPA
MAX481EESA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
________________________Applications
Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Ordering Information continued on last page.
______________________________________________________________Selection Table
PART
NUMBER
MAX481E
MAX483E
MAX485E
MAX487E
MAX488E
MAX489E
MAX490E
MAX491E
MAX1487E
HALF/FULL
DUPLEX
Half
Half
Half
Half
Full
Full
Full
Full
Half
DATA RATE
(Mbps)
2.5
0.25
2.5
0.25
0.25
0.25
2.5
2.5
2.5
SLEW-RATE
LIMITED
No
Yes
No
Yes
Yes
Yes
No
No
No
LOW-POWER
SHUTDOWN
Yes
Yes
No
Yes
No
No
No
No
No
RECEIVER/
DRIVER
ENABLE
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
QUIESCENT
CURRENT
(µA)
300
120
300
120
120
120
300
300
230
NUMBER OF
TRANSMITTERS
ON BUS
32
32
32
128
32
32
32
32
128
PIN
COUNT
8
8
8
8
8
14
8
14
8
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
) .............................................................12V
––
—
Control Input Voltage (RE , 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
= +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ....727mW
14-Pin Plastic DIP (derate 10.00mW/°C above +70°C) ..800mW
8-Pin SO (derate 5.88mW/°C above +70°C).................471mW
14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW
Operating Temperature Ranges
MAX4_ _C_ _/MAX1487EC_ A .............................0°C to +70°C
MAX4_ _E_ _/MAX1487EE_ A...........................-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.
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
Differential Driver Output (no load)
Differential Driver Output
(with load)
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
Driver Common-Mode Output
Voltage
Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States
Input High Voltage
Input Low Voltage
Input Current
SYMBOL
V
OD1
V
OD2
∆V
OD
V
OC
∆V
OD
V
IH
V
IL
I
IN1
R = 50Ω (RS-422)
R = 27Ω (RS-485), Figure 8
R = 27Ω or 50Ω, Figure 8
R = 27Ω or 50Ω, Figure 8
R = 27Ω or 50Ω, Figure 8
––
—
DE, DI, RE
––
—
DE, DI, RE
––
—
DE, DI, RE
DE = 0V;
V
CC
= 0V or 5.25V,
all devices except
MAX487E/MAX1487E
MAX487E/MAX1487E,
DE = 0V, V
CC
= 0V or 5.25V
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State (high impedance)
Output Current at Receiver
V
TH
∆V
TH
V
OH
V
OL
I
OZR
-7V
≤
V
CM
≤
12V
V
CM
= 0V
I
O
= -4mA, V
ID
= 200mV
I
O
= 4mA, V
ID
= -200mV
0.4V
≤
V
O
≤
2.4V
-7V
≤
V
CM
≤
12V, all devices except
MAX487E/MAX1487E
Receiver Input Resistance
R
IN
-7V
≤
V
CM
≤
12V, MAX487E/MAX1487E
48
kΩ
12
3.5
0.4
±1
V
IN
= 12V
V
IN
= -7V
V
IN
= 12V
V
IN
= -7V
-0.2
70
2.0
0.8
±2
1.0
mA
-0.8
0.25
-0.2
0.2
mA
V
mV
V
V
µA
kΩ
2
1.5
5
0.2
3
0.2
CONDITIONS
MIN
TYP
MAX
5
UNITS
V
V
V
V
V
V
V
µA
Input Current
(A, B)
I
IN2
2
_______________________________________________________________________________________
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MAX488E/MAX489E,
––
—
DE, DI, RE = 0V or V
CC
MAX490E/MAX491E,
––
—
DE, DI, RE = 0V or V
CC
No-Load Supply Current
(Note 3)
I
CC
MAX481E/MAX485E,
––
—
RE = 0V or V
CC
MAX1487E,
––
—
RE = 0V or V
CC
MAX483E/MAX487E,
––
—
RE = 0V or V
CC
Supply Current in Shutdown
Driver Short-Circuit Current,
V
O
= High
Driver Short-Circuit Current,
V
O
= Low
Receiver Short-Circuit Current
ESD Protection
I
SHDN
I
OSD1
I
OSD2
I
OSR
DE = V
CC
DE = 0V
DE = V
CC
DE = 0V
DE = V
CC
MAX483E
MAX487E
MIN
TYP
120
300
500
300
300
230
350
250
120
0.5
35
35
7
±15
MAX
250
500
900
500
500
400
650
400
250
10
250
250
95
µA
UNITS
MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E
DE = 0V
––
—
MAX481E/483E/487E, DE = 0V, RE = V
CC
-7V
≤
V
O
≤12V
(Note 4)
-7V
≤
V
O
≤12V
(Note 4)
0V
≤
V
O
≤
V
CC
A, B, Y and Z pins, tested using Human Body Model
µA
mA
mA
mA
kV
SWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
Driver Input to Output
Driver Output Skew to Output
Driver Rise or Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
Receiver Input to Output
t
PLH
t
PHL
t
SKEW
t
R
, t
F
t
ZH
t
ZL
t
LZ
t
HZ
Figures 10 and 12, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 10 and 12, R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
Figures 10 and 12, MAX481E, MAX485E, MAX1487E
R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF MAX490EC/E, MAX491EC/E
Figures 11 and 13, C
L
= 100pF, S2 closed
Figures 11 and 13, C
L
= 100pF, S1 closed
Figures 11 and 13, C
L
= 15pF, S1 closed
Figures 11 and 13, C
L
= 15pF, S2 closed
20
20
3
5
MIN
10
10
TYP
40
40
5
20
20
45
45
45
45
60
60
5
20
20
20
20
2.5
50
200
50
50
50
50
600
MAX
60
60
10
40
ns
25
70
70
70
70
200
ns
150
ns
ns
ns
ns
ns
Mbps
ns
ns
ns
ns
ns
UNITS
ns
ns
Figures 10 and 14, MAX481E, MAX485E, MAX1487E
t
PLH
, t
PHL
R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF MAX490EC/E, MAX491EC/E
t
SKD
t
ZL
t
ZH
t
LZ
t
HZ
f
MAX
t
SHDN
Figures 10 and 14, R
DIFF
= 54Ω,
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)
|
t
PLH
- t
PHL
|
Differential
Receiver Skew
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable Time from Low
Receiver Disable Time from High
Maximum Data Rate
Time to Shutdown
_______________________________________________________________________________________
3
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E
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)
PARAMETER
SYMBOL
CONDITIONS
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
Figures 9 and 15, C
L
= 15pF, S1 closed,
B - A = 2V
MIN
TYP
45
45
225
225
MAX
100
100
1000
1000
UNITS
ns
ns
ns
ns
Driver Enable from Shutdown to
t
ZH(SHDN)
Output High (MAX481E)
Driver Enable from Shutdown to
t
ZL(SHDN)
Output Low (MAX481E)
Receiver Enable from Shutdown
t
ZH(SHDN)
to Output High (MAX481E)
Receiver Enable from Shutdown
t
ZL(SHDN)
to Output Low (MAX481E)
SWITCHING CHARACTERISTICS—MAX483E, MAX487E/MAX488E/MAX489E
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
Driver Input to Output
Driver Output Skew to Output
Driver Rise or Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
Receiver Input to Output
SYMBOL
t
PLH
t
PHL
t
SKEW
t
R
, t
F
t
ZH
t
ZL
t
LZ
t
HZ
t
PLH
t
PHL
t
SKD
t
ZL
t
ZH
t
LZ
t
HZ
f
MAX
t
SHDN
t
ZH(SHDN)
t
ZL(SHDN)
t
ZH(SHDN)
t
ZL(SHDN)
CONDITIONS
Figures 10 and 12, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 10 and 12, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 10 and 12, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 11 and 13, C
L
= 100pF, S2 closed
Figures 11 and 13, C
L
= 100pF, S1 closed
Figures 11 and 13, C
L
= 15pF, S1 closed
Figures 11 and 13, C
L
= 15pF, S2 closed
Figures 10 and 14, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 10 and 14, R
DIFF
= 54Ω,
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
t
PLH
, t
PHL
< 50% of data period
MAX483E/MAX487E (Note 5)
MAX483E/MAX487E, Figures 11 and 13,
C
L
= 100pF, S2 closed
MAX483E/MAX487E, Figures 11 and 13,
C
L
= 100pF, S1 closed
MAX483E/MAX487E, Figures 9 and 15,
C
L
= 15pF, S2 closed
MAX483E/MAX487E, Figures 9 and 15,
C
L
= 15pF, S1 closed
250
50
200
600
2000
2000
2500
2500
250
250
250
300
300
250
250
100
25
25
25
25
50
50
50
50
MIN
250
250
TYP
800
800
20
MAX
2000
2000
800
2000
2000
2000
3000
3000
2000
2000
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
kbps
ns
ns
ns
ns
ns
I
t
PLH
- t
PHL
I
Differential
Receiver Skew
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable Time from Low
Receiver Disable Time from High
Maximum Data Rate
Time to Shutdown
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
4
_______________________________________________________________________________________
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
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
= +25°C.
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 RE 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.
MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E
__________________________________________Typical Operating Characteristics
(V
CC
= 5V, T
A
= +25°C, unless otherwise noted.)
OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
MAX481E-01
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
MAX481E-02
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
4.6
OUTPUT HIGH VOLTAGE (V)
4.4
4.2
4.0
3.8
3.6
3.4
3.2
MAX481E-03
50
45
OUTPUT CURRENT (mA)
40
35
30
25
20
15
10
5
0
0
0.5
1.0
1.5
2.0
-25
4.8
I
RO
= 8mA
OUTPUT CURRENT (mA)
-20
-15
-10
-5
0
2.5
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
OUTPUT LOW VOLTAGE (V)
OUTPUT HIGH VOLTAGE (V)
3.0
-60 -40 -20
0
20
40
60
80 100
TEMPERATURE (°C)
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
MAX481E-04
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
80
OUTPUT CURRENT (mA)
70
60
50
40
30
20
10
0
MAX481E-05
0.9
0.8
OUTPUT LOW VOLTAGE (V)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-60 -40 -20
0
20
40
60
I
RO
= 8mA
90
80 100
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
DIFFERENTIAL OUTPUT VOLTAGE (V)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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