19-0367; Rev 1; 5/06
20µA,
1
⁄
8
-Unit-Load, Slew-Rate-Limited
RS-485 Transceivers
_______________General Description
The MAX1482 and MAX1483 are low-power trans-
ceivers for RS-485 and RS-422 communication. Both
feature slew-rate-limited drivers that minimize EMI and
reduce reflections caused by improperly terminated
cables. Data rates are guaranteed up to 250kbps.
The MAX1482/MAX1483 draw only 20µA of supply cur-
rent. Additionally, they have a low-current shutdown
mode that consumes only 0.1µA. Both parts operate
from a single +5V supply.
Drivers are short-circuit current limited and are protect-
ed against excessive power dissipation by thermal
shutdown circuitry that places the driver outputs into a
high-impedance state. The receiver input has a fail-safe
feature that guarantees a logic-high output if the input
is open circuit.
The MAX1482 is full duplex and the MAX1483 is half
duplex. Both parts have a
1
⁄
8
-unit-load input impedance
that guarantees up to 256 transceivers on the bus.
____________________________Features
♦
Low 20µA Operating Current
♦
Slew-Rate Limited for Reduced EMI and
Reduced Reflections
♦
0.1µA Low-Current Shutdown Mode
♦
Designed for RS-485 and RS-422 Applications
♦
Operate from a Single +5V Supply
♦
-7V to +12V Common-Mode Input Voltage Range
♦
Allows up to 256 Transceivers on the Bus—
Guaranteed (
1
⁄
8
-unit load)
♦
Current Limiting and Thermal Shutdown for
Driver Overload Protection
MAX1482/MAX1483
Ordering Information
PART
MAX1482CPD
MAX1482CSD
MAX1482EPD
MAX1482ESD
MAX1483CPA
MAX1483CSA
MAX1483CUA
MAX1483EPA
MAX1483ESA
TEMP RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
14 PDIP
14 SO
14 PDIP
14 SO
8 PDIP
8 SO
8 µMAX
®
8 PDIP
8 SO
PKG
CODE
P14-3
S14-4
P14-3
S14-4
P8-1
S8-5
U8-1
P8-1
S8-5
________________________Applications
Low-Power RS-485/RS-422 Networks
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Large 256-Node LANs
_________Typical Operating Circuits
_________________Pin Configurations
TOP VIEW
RO
1
R
8
7
6
D
5
V
CC
B
A
GND
+5V
RE
2
DE
MAX1483
RO
1
R
RE
2
DE
3
DI
4
D
8
7
B
Rt
6
A
5
GND
A
R
RE
V
CC
B
Rt
D
DE
3
DI
DI
4
DIP/SO
RO
B
V
CC
RO
1
2
3
8
A
GND
DI
DE
MAX1483
7
6
5
NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM
DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH.
TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE.
RE
4
µMAX
MAX1482 appears at end of data sheet.
µMAX is a registered trademark of Maxim Integrated products, Inc.
MAX1482 appears 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.
20µA,
1
⁄
8
-Unit-Load, Slew-Rate-Limited
RS-485 Transceivers
MAX1482/MAX1483
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
) ...............................................................7V
Control Input Voltages (RE, DE) .................-0.5V to (V
CC
+ 0.5V)
Driver Input Voltage (DI).............................-0.5V to (V
CC
+ 0.5V)
Driver Output Voltages ..........................................-7.5V to 12.5V
Receiver Input Voltages (A, B) ..............................-7.5V 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
8-Pin µMAX (derate 4.10mW/°C above +70°C) .............330mW
Operating Temperature Ranges
MAX148_C_ _ .......................................................0°C to +70°C
MAX148_E_ _.....................................................-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. Typical values are at T
A
= +25°C.) (Note 1)
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
Three-State (high impedance)
Output Current at Driver
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
Input Current
(A, B)
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State (high impedance)
Output Current at Receiver
Receiver Input Resistance
SYMBOL
V
OD1
V
OD2
∆V
OD
V
OC
∆V
OD
I
OZD
V
IH
V
IL
I
IN1
R = 50Ω (RS-422), Figure 1
R = 27Ω (RS-485), Figure 1
R = 27Ω or 50Ω, Figure 1
R = 27Ω or 50Ω, Figure 1
R = 27Ω or 50Ω, Figure 1
MAX1482 only,
-7V < V
Y and
V
Z
< 12V
––
—
DE, DI, RE
––
—
DE, DI, RE
––
—
DE, DI, RE
MAX1482,
DE = 0V, V
CC
= 0V or 5.25V
MAX1483,
DE = 0V, V
CC
= 0V or 5.25V
-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
96
3.5
0.4
±1
V
IN
= 12V
V
IN
= -7V
V
IN
= 12V
V
IN
= -7V
-0.2
75
2
1.5
CONDITIONS
MIN
TYP
MAX
5
5
5
0.2
3
0.2
UNITS
V
V
V
V
V
±50
2.0
0.8
±2
150
-100
200
-150
0.2
µA
V
V
µA
I
IN2
µA
V
TH
∆V
TH
V
OH
V
OL
I
OZR
R
IN
V
mV
V
V
µA
kΩ
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.
2
_______________________________________________________________________________________
20µA,
1
⁄
8
-Unit-Load, Slew-Rate-Limited
RS-485 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
MAX1482,
RE = 0V or V
CC
MAX1483,
RE = 0V or V
CC
DE = 0V, RE = V
CC
DI = high or low, -7V
≤
V
O
≤
12V (Note 2)
0V
≤
V
O
≤
V
CC
35
±7
CONDITIONS
DE = V
CC
DE = 0V
DE = V
CC
DE = 0V
MIN
TYP
25
20
55
20
0.1
MAX
45
35
85
35
10
250
±95
µA
mA
mA
µA
UNITS
MAX1482/MAX1483
No-Load Supply Current
I
CC
Supply Current in Shutdown
Driver Short-Circuit Current
Receiver Short-Circuit Current
I
SHDN
I
OSD
I
OSR
SWITCHING CHARACTERISTICS
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
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
(Note 3)
CONDITIONS
Figures 3 and 5, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 3 and 5, R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
Figures 3 and 5, R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
Figures 4 and 6, C
L
= 100pF, S2 closed
Figures 4 and 6, C
L
= 100pF, S1 closed
Figures 4 and 6, C
L
= 15pF, S1 closed
Figures 4 and 6, C
L
= 15pF, S2 closed
Figures 3 and 7, R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
Figures 3 and 7, R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
Figures 2 and 8, C
RL
= 15pF, S1 closed
Figures 2 and 8, C
RL
= 15pF, S2 closed
Figures 2 and 8, C
RL
= 15pF, S1 closed
Figures 2 and 8, C
RL
= 15pF, S2 closed
250
50
200
0.25
0.2
0.1
0.3
0.3
0.25
160
90
90
90
90
600
2
2
3
3
MIN
TYP
MAX
2
2
800
2
2
2
3.0
3.0
2.25
UNITS
µs
ns
µs
µs
µs
µs
µs
µs
ns
ns
ns
ns
ns
kbps
ns
µs
µs
µs
µs
|
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
Driver Enable from Shutdown to
t
ZH(SHDN)
Figures 4 and 6, C
L
= 100pF, S2 closed
Output High
Driver Enable from Shutdown to
t
ZL(SHDN)
Output Low
Figures 4 and 6, C
L
= 100pF, S1 closed
Receiver Enable from Shutdown
Figures 2 and 8, C
L
= 15pF, S2 closed,
t
ZH(SHDN)
to Output High
A - B = 2V
Receiver Enable from Shutdown
t
ZL(SHDN)
to Output Low
Figures 2 and 8, C
L
= 15pF, S1 closed,
B - A = 2V
Note 2:
Applies to peak current. See
Typical Operating Characteristics.
––
—
Note 3:
The MAX1482/MAX1483 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.
_______________________________________________________________________________________
3
20µA,
1
⁄
8
-Unit-Load, Slew-Rate-Limited
RS-485 Transceivers
MAX1482/MAX1483
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
RECEIVER PROPAGATION DELAY
vs. TEMPERATURE
MAX1482-01
DRIVER PROPAGATION DELAY
vs. TEMPERATURE
MAX1482-02
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
80
OUTPUT CURRENT (mA)
70
60
50
40
30
20
10
0
MAX1482-03
1400
RECEIVER PROPAGATION DELAY (ns)
1300
1200
1100
1000
900
800
-40
-20
0
20
40
60
80
1200
DRIVER PROPAGATION DELAY (ns)
1100
1000
900
800
700
600
500
400
-40
-20
0
20
40
60
80
90
100
100
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
OUTPUT VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
DIFFERENTIAL OUTPUT VOLTAGE (V)
R = 54Ω
3.0
MAX1482-04
OUTPUT CURRENT vs.
DRIVER OUTPUT LOW VOLTAGE
MAX1482-05
OUTPUT CURRENT vs.
DRIVER OUTPUT HIGH VOLTAGE
MAX1482-06
3.5
140
120
OUTPUT CURRENT (mA)
100
80
60
40
20
120
100
OUTPUT CURRENT (mA)
80
60
40
20
0
2.5
2.0
1.5
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
0
0
2
4
6
8
10
12
OUTPUT LOW VOLTAGE (V)
-7 -6 -5 -4 -3 -2 -1 0
1 2
3 4
5
OUTPUT LOW VOLTAGE (V)
MAX1482
SUPPLY CURRENT
vs. TEMPERATURE
MAX1482-07
MAX1483
SUPPLY CURRENT
vs. TEMPERATURE
70
SUPPLY CURRENT (µA)
60
50
40
30
20
10
0
DE = GND
DE = V
CC
MAX1482-08
80
70
SUPPLY CURRENT (µA)
60
50
40
30
20
10
0
-40
-20
0
20
40
60
80
DE = V
CC
DE = 0V
80
100
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
20µA,
1
⁄
8
-Unit-Load, Slew-Rate-Limited
RS-485 Transceivers
______________________________________________________________Pin Description
PIN
MAX1482
DIP/SO
2
MAX1483
DIP/SO
µMAX
1
3
NAME
FUNCTION
Receiver Output. With the receiver output enabled (RE low), RO is high if
A > B by 200mV or when A and B are not connected, and RO is low if A < B
by 200mV.
Receiver Output Enable. When RE is low, RO is enabled. When RE is high, RO
is high impedance. If RE is high and DE is low, the MAX1482/MAX1483 enter
a low-power (0.1µA) shutdown state.
Driver Output Enable. The driver outputs, A and B, (Y and Z for the MAX1482)
are enabled by bringing DE high. When DE is low, the driver outputs are high
impedance, and the devices can function as line receivers if RE is low. If RE is
high and DE is low, the parts will enter a low-power (0.1µA) shutdown state. If
the driver outputs are enabled, the devices function as line drivers.
Driver Input. With DE high, a low on DI forces output Y low and output Z high,
and a high on DI forces output Y high and output Z low.
Ground
Noninverting Driver Output
Inverting Driver Output
Noninverting Receiver Input and Noninverting Driver Output
Noninverting Receiver Input
Inverting Receiver Input and Inverting Driver Output
Inverting Receiver Input
Positive Supply: 4.75V to 5.25V
No Connect—not internally connected
MAX1482/MAX1483
RO
3
2
4
RE
4
3
5
DE
5
6, 7
9
10
—
12
—
11
14
1, 8, 13
4
5
—
—
6
—
7
—
8
—
6
7
—
—
8
—
1
—
2
—
DI
GND
Y
Z
A
A
B
B
V
CC
N.C.
_______________________________________________________________________________________
5
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