MAX490EESA+T [MAXIM]
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| 型号： | MAX490EESA+T |
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MAXIM INTEGRATED PRODUCTS |
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19-0122; Rev 8; 10/03
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
General Description
__Next Generation Device Features
♦ For Fault-Tolerant Applications
The MAX481, MAX483, MAX485, MAX487–MAX491, and
MAX1487 are low-power transceivers for RS-485 and RS-
422 communication. Each part contains one driver and one
receiver. The MAX483, MAX487, MAX488, and MAX489
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 MAX481, MAX485, MAX490,
MAX491, and MAX1487 are not limited, allowing them to
transmit up to 2.5Mbps.
MAX3430: ±80V Fault-Protected, Fail-Safe, 1/4
Unit Load, +3.3V, RS-485 Transceiver
MAX3440E–MAX3444E: ±15kV ESD-Protected,
±60V Fault-Protected, 10Mbps, Fail-Safe,
RS-485/J1708 Transceivers
♦ For Space-Constrained Applications
MAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,
Profibus RS-485/RS-422 Transceivers
MAX3362: +3.3V, High-Speed, RS-485/RS-422
Transceiver in a SOT23 Package
These transceivers draw between 120µA and 500µA of
supply current when unloaded or fully loaded with disabled
drivers. Additionally, the MAX481, MAX483, and MAX487
have a low-current shutdown mode in which they consume
only 0.1µA. All parts operate from a single 5V supply.
MAX3280E–MAX3284E: ±15kV ESD-Protected,
52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422,
True Fail-Safe Receivers
MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,
SOT23, RS-855/RS-422 Transmitters
Drivers are short-circuit current limited and are protected
against excessive power dissipation by thermal shutdown
circuitry that places the driver outputs into a high-imped-
ance state. The receiver input has a fail-safe feature that
guarantees a logic-high output if the input is open circuit.
♦ For Multiple Transceiver Applications
MAX3030E–MAX3033E: ±15kV ESD-Protected,
+3.3V, Quad RS-422 Transmitters
The MAX487 and MAX1487 feature quarter-unit-load
receiver input impedance, allowing up to 128 MAX487/
MAX1487 transceivers on the bus. Full-duplex communi-
cations are obtained using the MAX488–MAX491, while
the MAX481, MAX483, MAX485, MAX487, and MAX1487
are designed for half-duplex applications.
♦ For Fail-Safe Applications
MAX3080–MAX3089: Fail-Safe, High-Speed
(10Mbps), Slew-Rate-Limited RS-485/RS-422
Transceivers
________________________Applications
♦ For Low-Voltage Applications
MAX3483E/MAX3485E/MAX3486E/MAX3488E/
MAX3490E/MAX3491E: +3.3V Powered, ±15kV
ESD-Protected, 12Mbps, Slew-Rate-Limited,
True RS-485/RS-422 Transceivers
Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Ordering Information appears at end of data sheet.
______________________________________________________________Selection Table
RECEIVER/
DRIVER
ENABLE
QUIESCENT
CURRENT
(µA)
NUMBER OF
TRANSMITTERS
ON BUS
PART
NUMBER
HALF/FULL DATA RATE SLEW-RATE LOW-POWER
PIN
COUNT
DUPLEX
(Mbps)
LIMITED
SHUTDOWN
MAX481
MAX483
MAX485
MAX487
MAX488
MAX489
MAX490
MAX491
MAX1487
Half
Half
Half
Half
Full
Full
Full
Full
Half
2.5
0.25
2.5
No
Yes
No
Yes
Yes
No
Yes
Yes
Yes
Yes
No
300
120
300
120
120
120
300
300
230
32
32
8
8
32
8
0.25
0.25
0.25
2.5
Yes
Yes
Yes
No
Yes
No
128
32
8
8
No
Yes
No
32
14
8
No
32
2.5
No
No
Yes
Yes
32
14
8
2.5
No
No
128
________________________________________________________________ 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.
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V ).............................................................12V
14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW
8-Pin µMAX (derate 4.1mW/°C above +70°C)..............830mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C).........640mW
14-Pin CERDIP (derate 9.09mW/°C above +70°C).......727mW
Operating Temperature Ranges
CC
Control Input Voltage (RE, DE)...................-0.5V to (V
Driver Input Voltage (DI).............................-0.5V to (V
Driver Output Voltage (A, B)...................................-8V to +12.5V
Receiver Input Voltage (A, B).................................-8V to +12.5V
+ 0.5V)
+ 0.5V)
CC
CC
Receiver Output Voltage (RO).....................-0.5V to (V
+0.5V)
MAX4_ _C_ _/MAX1487C_ A ...............................0°C to +70°C
MAX4_ _E_ _/MAX1487E_ A.............................-40°C to +85°C
MAX4_ _MJ_/MAX1487MJA ...........................-55°C to +125°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
CC
Continuous Power Dissipation (T = +70°C)
A
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
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 5ꢀ, T = T
to T
, unless otherwise noted.) (Notes 1, 2)
MAX
A
MIN
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Differential Driver Output (no load)
V
OD1
5
V
R = 50Ω (RS-422)
2
Differential Driver Output
(with load)
V
OD2
V
R = 27Ω (RS-485), Figure 4
1.5
5
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
∆V
R = 27Ω or 50Ω, Figure 4
R = 27Ω or 50Ω, Figure 4
R = 27Ω or 50Ω, Figure 4
0.2
V
V
V
OD
Driver Common-Mode Output
Voltage
V
3
OC
Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States
∆V
0.2
OD
Input High Voltage
Input Low Voltage
Input Current
V
2.0
V
V
DE, DI, RE
DE, DI, RE
DE, DI, RE
DE = 0V;
IH
V
0.8
2
IL
I
µA
IN1
V
V
= 12V
= -7V
1.0
IN
V
= 0V or 5.25V,
CC
mA
all devices except
MAX487/MAX1487
Input Current
(A, B)
-0.8
IN
I
IN2
V
V
= 12V
= -7V
0.25
-0.2
IN
MAX487/MAX1487,
mA
V
DE = 0V, V
= 0V or 5.25V
CC
IN
Receiver Differential Threshold
Voltage
V
TH
-7V ≤ V
≤ 12V
-0.2
3.5
0.2
CM
Receiver Input Hysteresis
∆V
V
= 0V
CM
70
mV
V
TH
Receiver Output High Voltage
Receiver Output Low Voltage
V
I
I
= -4mA, V = 200mV
ID
OH
O
O
V
= 4mA, V = -200mV
0.4
1
V
OL
ID
Three-State (high impedance)
Output Current at Receiver
I
0.4V ≤ V ≤ 2.4V
µA
kΩ
kΩ
OZR
O
-7V ≤ V
≤ 12V, all devices except
CM
12
48
MAX487/MAX1487
Receiver Input Resistance
R
IN
-7V ≤ V ≤ 12V, MAX487/MAX1487
CM
2
_______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V 5ꢀ, T = T
to T
, unless otherwise noted.) (Notes 1, 2)
MAX
A
MIN
PARAMETER
SYMBOL
CONDITIONS
MAX488/MAX489,
MIN
TYP
MAX
UNITS
120
250
DE, DI, RE = 0V or V
CC
MAX490/MAX491,
DE, DI, RE = 0V or V
300
500
CC
DE = V
500
300
300
230
350
250
120
0.1
900
500
500
400
650
400
250
10
CC
MAX481/MAX485,
No-Load Supply Current
(Note 3)
RE = 0V or V
I
µA
CC
DE = 0V
DE = V
CC
CC
MAX1487,
RE = 0V or V
CC
DE = 0V
DE = 5V
DE = 0V
MAX483
MAX487
MAX483/MAX487,
RE = 0V or V
CC
Supply Current in Shutdown
Driver Short-Circuit Current,
I
µA
MAX481/483/487, DE = 0V, RE = V
SHDN
CC
I
I
-7V ≤ V ≤12V (Note 4)
35
250
mA
OSD1
OSD2
O
V
= High
O
Driver Short-Circuit Current,
= Low
-7V ≤ V ≤12V (Note 4)
35
7
250
95
mA
mA
O
V
O
Receiver Short-Circuit Current
I
0V ≤ V ≤ V
O CC
OSR
SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487
(V
CC
= 5V 5ꢀ, T = T
to T
, unless otherwise noted.) (Notes 1, 2)
MAX
A
MIN
PARAMETER
Driver Input to Output
SYMBOL
CONDITIONS
Figures 6 and 8, R = 54Ω,
MIN
10
10
TYP
30
30
5
MAX
60
60
UNITS
ns
t
t
PLH
DIFF
C
L1
= C = 100pF
L2
PHL
Driver Output Skew to Output
Driver Rise or Fall Time
t
Figures 6 and 8, R
= 54Ω, C = C = 100pF
10
ns
SKEW
DIFF
L1
L2
MAX481, MAX485, MAX1487
MAX490C/E, MAX491C/E
= C = 100pF
L2
MAX490M, MAX491M
3
5
3
15
15
15
40
40
40
40
90
90
90
40
Figures 6 and 8,
R = 54Ω,
DIFF
t , t
R
25
ns
F
C
L1
40
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
t
Figures 7 and 9, C = 100pF, S2 closed
70
70
70
70
200
150
200
ns
ns
ns
ns
ZH
L
t
Figures 7 and 9, C = 100pF, S1 closed
ZL
LZ
HZ
L
t
t
Figures 7 and 9, C = 15pF, S1 closed
L
Driver Disable Time from High
Figures 7 and 9, C = 15pF, S2 closed
L
MAX481, MAX485, MAX1487
20
20
20
Figures 6 and 10,
= 54Ω,
Receiver Input to Output
t
, t
R
MAX490C/E, MAX491C/E
= C = 100pF
L2
MAX490M, MAX491M
ns
PLH PHL
DIFF
C
L1
Figures 6 and 10, R
= 54Ω,
| t
- tPHL | Differential
DIFF
PLH
t
13
ns
SKD
C
L1
= C = 100pF
L2
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
t
Figures 5 and 11, C = 15pF, S1 closed
20
20
20
20
50
50
50
50
ns
ns
ns
ns
Mbps
ns
ZL
RL
t
Figures 5 and 11, C = 15pF, S2 closed
RL
ZH
t
LZ
Figures 5 and 11, C = 15pF, S1 closed
RL
t
Figures 5 and 11, C = 15pF, S2 closed
RL
HZ
f
2.5
50
MAX
Time to Shutdown
t
MAX481 (Note 5)
200
600
SHDN
_______________________________________________________________________________________
3
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)
(V
CC
= 5V 5ꢀ, T = T
to T
, unless otherwise noted.) (Notes 1, 2)
MAX
A
MIN
PARAMETER
SYMBOL
CONDITIONS
Figures 7 and 9, C = 100pF, S2 closed
MIN
TYP
MAX
UNITS
Driver Enable from Shutdown to
Output High (MAX481)
t
t
t
t
40
100
ns
ZH(SHDN)
ZL(SHDN)
ZH(SHDN)
ZL(SHDN)
L
Driver Enable from Shutdown to
Output Low (MAX481)
Figures 7 and 9, C = 100pF, S1 closed
40
100
1000
1000
ns
ns
ns
L
Receiver Enable from Shutdown
to Output High (MAX481)
Figures 5 and 11, C = 15pF, S2 closed,
L
A - B = 2V
300
300
Receiver Enable from Shutdown
to Output Low (MAX481)
Figures 5 and 11, C = 15pF, S1 closed,
L
B - A = 2V
SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489
(V
CC
= 5V 5ꢀ, T = T
to T
, unless otherwise noted.) (Notes 1, 2)
MAX
A
MIN
PARAMETER
Driver Input to Output
SYMBOL
CONDITIONS
MIN
250
250
TYP
800
800
MAX
2000
2000
UNITS
t
t
PLH
PHL
Figures 6 and 8, R
= 54Ω,
= 54Ω,
= 54Ω,
DIFF
ns
C
= C = 100pF
L1
L2
Figures 6 and 8, R
DIFF
Driver Output Skew to Output
Driver Rise or Fall Time
t
100
800
ns
ns
SKEW
C
= C = 100pF
L1
L2
Figures 6 and 8, R
DIFF
t , t
R
250
2000
F
C
= C = 100pF
L1
L2
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
t
Figures 7 and 9, C = 100pF, S2 closed
250
250
300
300
250
250
2000
2000
3000
3000
2000
2000
ns
ns
ns
ns
ZH
L
t
Figures 7 and 9, C = 100pF, S1 closed
L
ZL
LZ
HZ
t
Figures 7 and 9, C = 15pF, S1 closed
L
Driver Disable Time from High
t
Figures 7 and 9, C = 15pF, S2 closed
L
t
t
PLH
PHL
Figures 6 and 10, R
= 54Ω,
DIFF
Receiver Input to Output
ns
ns
C
= C = 100pF
L1
L2
Figures 6 and 10, R
= C = 100pF
= 54Ω,
I t
- tPHL I Differential
DIFF
PLH
t
100
SKD
C
L1
L2
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
t
Figures 5 and 11, C = 15pF, S1 closed
20
20
20
20
50
50
50
50
ns
ns
ZL
RL
t
Figures 5 and 11, C = 15pF, S2 closed
RL
ZH
t
LZ
Figures 5 and 11, C = 15pF, S1 closed
ns
RL
t
Figures 5 and 11, C = 15pF, S2 closed
ns
HZ
RL
f
t
, t < 50ꢀ of data period
PLH PHL
250
50
kbps
ns
MAX
Time to Shutdown
t
MAX483/MAX487 (Note 5)
200
600
SHDN
Driver Enable from Shutdown to
Output High
MAX483/MAX487, Figures 7 and 9,
C = 100pF, S2 closed
L
t
t
2000
ns
ns
ns
ns
ZH(SHDN)
Driver Enable from Shutdown to
Output Low
MAX483/MAX487, Figures 7 and 9,
C = 100pF, S1 closed
L
t
2000
2500
2500
ZL(SHDN)
Receiver Enable from Shutdown
to Output High
MAX483/MAX487, Figures 5 and 11,
C = 15pF, S2 closed
L
ZH(SHDN)
Receiver Enable from Shutdown
to Output Low
MAX483/MAX487, Figures 5 and 11,
C = 15pF, S1 closed
L
t
ZL(SHDN)
4
_______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
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
= 5V and T = +25°C.
A
CC
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 MAX481/MAX483/MAX487 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.
__________________________________________Typical Operating Characteristics
(V
CC
= 5V, T = +25°C, unless otherwise noted.)
A
OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
RECEIVER OUTPUT HIGH VOLTAGE vs.
TEMPERATURE
-20
-18
-16
-14
-12
-10
4.8
4.6
45
I
RO
= 8mA
40
35
4.4
4.2
30
25
20
15
10
5
4.0
3.8
-8
3.6
3.4
3.2
3.0
-6
-4
-2
0
0
0
0.5
1.0
1.5
2.0
2.5
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
OUTPUT HIGH VOLTAGE (V)
-50 -25
0
25
50
75 100 125
OUTPUT LOW VOLTAGE (V)
TEMPERATURE (°C)
RECEIVER OUTPUT LOW VOLTAGE vs.
TEMPERATURE
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
0.9
0.8
2.4
2.3
90
80
70
R = 54Ω
I
= 8mA
RO
0.7
0.6
2.2
2.1
2.0
60
50
0.5
0.4
1.9
1.8
1.7
40
30
20
10
0.3
0.2
0.1
1.6
1.5
0
0
-50 -25
0
25
50
75 100 125
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
DIFFERENTIAL OUTPUT VOLTAGE (V)
-50 -25
0
25
50
75 100 125
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
____________________________Typical Operating Characteristics (continued)
(V
CC
= 5V, T = +25°C, unless otherwise noted.)
A
MAX481/MAX485/MAX490/MAX491
SUPPLY CURRENT vs. TEMPERATURE
OUTPUT CURRENT vs.
DRIVER OUTPUT LOW VOLTAGE
OUTPUT CURRENT vs.
DRIVER OUTPUT HIGH VOLTAGE
600
500
140
-120
-100
-80
MAX481/MAX485; DE = VCC, RE = X
120
100
80
400
300
200
100
0
-60
-40
-20
0
60
MAX485; DE = 0, RE = X,
MAX481; DE = RE = 0
MAX490/MAX491; DE = RE = X
40
20
0
MAX481; DE = 0, RE = VCC
-50 -25
0
25
50
75 100 125
0
2
4
6
8
10
12
-7 -6 -5 -4 -3 -2 -1
0
1
2
3
4 5
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
OUTPUT HIGH VOLTAGE (V)
MAX1487
SUPPLY CURRENT vs. TEMPERATURE
MAX483/MAX487–MAX489
SUPPLY CURRENT vs. TEMPERATURE
600
500
600
500
400
300
200
100
0
400
300
200
100
0
MAX483; DE = VCC, RE = X
MAX487; DE = VCC, RE = X
MAX1487; DE = VCC, RE = X
MAX1487; DE = 0V, RE = X
MAX483/MAX487; DE = RE = 0,
MAX488/MAX489; DE = RE = X
MAX483/MAX487; DE = 0, RE = VCC
-60 -40 -20
0
20 40 60 80 100 120 140
-50 -25
0
25
50
75 100 125
TEMPERATURE (°C)
TEMPERATURE (°C)
6
_______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
______________________________________________________________Pin Description
PIN
MAX481/MAX483/
MAX485/MAX487/
MAX1487
NAME
FUNCTION
MAX488/
MAX490
MAX489/
MAX491
DIP/SO
µMAX
DIP/SO
µMAX
DIP/SO
Receiver Output: If A > B by 200mV, RO will be high;
If A < B by 200mV, RO will be low.
1
3
2
4
2
RO
Receiver Output Enable. RO is enabled when RE is low; RO is
high impedance when RE is high.
2
3
4
4
5
6
—
—
—
5
3
4
5
RE
Driver Output Enable. The driver outputs, Y and Z, are enabled
by bringing DE high. They are high impedance when DE is low. If
the driver outputs are enabled, the parts function as line drivers.
While they are high impedance, they function as line receivers if
RE is low.
—
3
DE
Driver Input. A low on DI forces output Y low and output Z high.
Similarly, a high on DI forces output Y high and output Z low.
DI
5
—
—
6
7
—
—
8
4
5
6
7
6, 7
9
GND
Y
Ground
Noninverting Driver Output
6
8
10
Z
Inverting Driver Output
—
8
—
2
—
A
Noninverting Receiver Input and Noninverting Driver Output
Noninverting Receiver Input
—
7
—
1
12
A
—
7
—
1
—
B
Inverting Receiver Input and Inverting Driver Output
Inverting Receiver Input
—
8
—
2
11
B
1
3
14
V
Positive Supply: 4.75V ≤ V
≤ 5.25V
CC
CC
—
—
—
—
1, 8, 13
N.C.
No Connect—not internally connected
TOP VIEW
R
RO
RE
DE
DI
1
2
3
4
8
7
6
5
V
CC
MAX481
MAX483
MAX485
MAX487
MAX1487
B
DE
A
DI
R
RO
RE
DE
DI
1
8
7
V
D
D
CC
GND
B
B
A
2
3
4
Rt
Rt
DIP/SO
6
5
A
RO
R
D
GND
1
2
3
4
A
B
8
7
6
5
V
CC
GND
DI
MAX481
MAX483
MAX485
MAX487
MAX1487
RE
RO
DE
RE
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.
µMAX
Figure 1. MAX481/MAX483/MAX485/MAX487/MAX1487 Pin Configuration and Typical Operating Circuit
_______________________________________________________________________________________
7
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
TOP VIEW
V
CC
V
CC
V
1
2
3
4
R
8
7
6
5
A
B
Z
Y
CC
MAX488
MAX490
1
RO
DI
Y
Z
5
6
3
2
Rt
GND
DI
RO
DI
D
D
R
DIP/SO
8
7
A
B
Rt
RO
R
D
B
A
1
2
3
4
8
7
6
5
Z
Y
MAX488
MAX490
V
CC
GND
DI
4
RO
GND
NOTE: TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE.
GND
µMAX
Figure 2. MAX488/MAX490 Pin Configuration and Typical Operating Circuit
TOP VIEW
DE
V
V
CC
RE
CC
MAX489
MAX491
4
14
N.C.
RO
1
2
3
4
5
6
7
14
V
CC
9
Y
R
13 N.C.
5
Rt
DI
RO
DI
D
R
10
RE
12
11
10
9
A
Z
DE
B
12
11
A
2
DI
Z
Rt
RO
NC
R
D
D
GND
GND
Y
B
1, 8, 13
8
N.C.
3
6, 7
RE GND
DIP/SO
GND DE
Figure 3. MAX489/MAX491 Pin Configuration and Typical Operating Circuit
MAX487/MAX1487:
__________Applications Information
128 Transceivers on the Bus
The MAX481/MAX483/MAX485/MAX487–MAX491 and
1
The 48kΩ, / -unit-load receiver input impedance of the
4
MAX1487 are low-power transceivers for RS-485 and RS-
422 communications. The MAX481, MAX485, MAX490,
MAX491, and MAX1487 can transmit and receive at data
rates up to 2.5Mbps, while the MAX483, MAX487,
MAX488, and MAX489 are specified for data rates up to
250kbps. The MAX488–MAX491 are full-duplex trans-
ceivers while the MAX481, MAX483, MAX485, MAX487,
and MAX1487 are half-duplex. In addition, Driver Enable
(DE) and Receiver Enable (RE) pins are included on the
MAX481, MAX483, MAX485, MAX487, MAX489,
MAX491, and MAX1487. When disabled, the driver and
receiver outputs are high impedance.
MAX487 and MAX1487 allows up to 128 transceivers
on a bus, compared to the 1-unit load (12kΩ input
impedance) of standard RS-485 drivers (32 trans-
ceivers maximum). Any combination of MAX487/
MAX1487 and other RS-485 transceivers with a total of
32 unit loads or less can be put on the bus. The
MAX481/MAX483/MAX485 and MAX488–MAX491 have
standard 12kΩ Receiver Input impedance.
8
_______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
_________________________________________________________________Test Circuits
Y
1kΩ
R
R
TEST POINT
RECEIVER
OUTPUT
V
CC
S1
S2
V
OD
C
RL
1kΩ
15pF
V
OC
Z
Figure 4. Driver DC Test Load
Figure 5. Receiver Timing Test Load
3V
DE
V
CC
S1
S2
C
500Ω
L1
A
OUTPUT
UNDER TEST
Y
R
DIFF
RO
DI
C
L
V
ID
B
Z
RE
C
L2
Figure 6. Driver/Receiver Timing Test Circuit
Figure 7. Driver Timing Test Load
monics with large amplitudes are evident. Figure 13
shows the same information displayed for a MAX483,
MAX487, MAX488, or MAX489 transmitting under the
same conditions. Figure 13’s high-frequency harmonics
have much lower amplitudes, and the potential for EMI
is significantly reduced.
MAX483/MAX487/MAX488/MAX489:
Reduced EMI and Reflections
The MAX483 and MAX487–MAX489 are slew-rate limit-
ed, minimizing EMI and reducing reflections caused by
improperly terminated cables. Figure 12 shows the dri-
ver output waveform and its Fourier analysis of a
150kHz signal transmitted by a MAX481, MAX485,
MAX490, MAX491, or MAX1487. High-frequency har-
_______________________________________________________________________________________
9
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
_______________________________________________________Switching Waveforms
3V
0V
3V
0V
DE
DI
1.5V
1.5V
1.5V
1.5V
V
t
t
PHL
PLH
1/2 V
O
t
t
, t
LZ
ZL(SHDN) ZL
Z
Y, Z
V
2.3V
+0.5V
-0.5V
O
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
OL
V
OL
Y
1/2 V
O
V
= V (Y) - V (Z)
DIFF
Y, Z
0V
V
O
V
OH
2.3V
V
DIFF
90%
90%
0V
-V
10%
10%
O
t
, t
t
HZ
ZH(SHDN) ZH
t
R
t
F
t | t - t
SKEW = PLH PHL
|
Figure 8. Driver Propagation Delays
Figure 9. Driver Enable and Disable Times (except MAX488 and
MAX490)
3V
RE
1.5V
1.5V
0V
V
OH
t
LZ
t
, t
ZL(SHDN) ZL
RO
1.5V
1.5V
V
V
CC
OUTPUT
OL
RO
1.5V
V
V
+ 0.5V
- 0.5V
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
OL
t
t
PLH
PHL
V
ID
A-B
0V
0V
-V
ID
INPUT
RO
1.5V
OH
0V
t
, t
t
HZ
ZH(SHDN) ZH
Figure 11. Receiver Enable and Disable Times (except MAX488
and MAX490)
Figure 10. Receiver Propagation Delays
_________________Function Tables (MAX481/MAX483/MAX485/MAX487/MAX1487)
Table 1. Transmitting
Table 2. Receiving
INPUTS
OUTPUTS
INPUTS
OUTPUT
RE
DE
A-B
RO
RE
DE
DI
Z
Y
0
0
> +0.2V
1
0
1
X
1
1
0
1
0
0
0
0
0
< -0.2V
Inputs open
X
X
0
1
0
0
0
X
X
1
0
High-Z
High-Z
High-Z
1
High-Z
1
High-Z
*
*
*
X = Don't care
X = Don't care
High-Z = High impedance
Shutdown mode for MAX481/MAX483/MAX487
High-Z = High impedance
Shutdown mode for MAX481/MAX483/MAX487
*
*
10 ______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
10dB/div
10dB/div
0Hz
5MHz
0Hz
5MHz
500kHz/div
500kHz/div
Figure 12. Driver Output Waveform and FFT Plot of MAX481/
MAX485/MAX490/MAX491/MAX1487 Transmitting a 150kHz
Signal
Figure 13. Driver Output Waveform and FFT Plot of MAX483/
MAX487–MAX489 Transmitting a 150kHz Signal
Low-Power Shutdown Mode
(MAX481/MAX483/MAX487)
A low-power shutdown mode is initiated by bringing
both RE high and DE low. The devices will not shut
down unless both the driver and receiver are disabled.
In shutdown, the devices typically draw only 0.1µA of
supply current.
Driver Output Protection
Excessive output current and power dissipation caused
by faults or by bus contention are prevented by two
mechanisms. A foldback current limit on the output
stage provides immediate protection against short cir-
cuits over the whole common-mode voltage range (see
Typical Operating Characteristics). In addition, a ther-
mal shutdown circuit forces the driver outputs into a
high-impedance state if the die temperature rises
excessively.
RE and DE may be driven simultaneously; the parts are
guaranteed not to enter shutdown if RE is high and DE
is low for less than 50ns. If the inputs are in this state
for at least 600ns, the parts are guaranteed to enter
shutdown.
Propagation Delay
Many digital encoding schemes depend on the differ-
ence between the driver and receiver propagation
delay times. Typical propagation delays are shown in
Figures 15–18 using Figure 14’s test circuit.
For the MAX481, MAX483, and MAX487, the t
and
ZH
t
enable times assume the part was not in the low-
ZL
power shutdown state (the MAX485/MAX488–MAX491
and MAX1487 can not be shut down). The t
ZH(SHDN)
The difference in receiver delay times, | t
- t
|, is
PLH PHL
and t
enable times assume the parts were shut
down (see Electrical Characteristics).
ZL(SHDN)
typically under 13ns for the MAX481, MAX485,
MAX490, MAX491, and MAX1487 and is typically less
than 100ns for the MAX483 and MAX487–MAX489.
It takes the drivers and receivers longer to become
enabled from the low-power shutdown state
The driver skew times are typically 5ns (10ns max) for
the MAX481, MAX485, MAX490, MAX491, and
MAX1487, and are typically 100ns (800ns max) for the
MAX483 and MAX487–MAX489.
(t
), t
) than from the operating mode
ZL(SHDN)
ZH(SHDN
–—–
(t , t ). (The parts are in operating mode if the RE,
ZH ZL
DE inputs equal a logical 0,1 or 1,1 or 0, 0.)
______________________________________________________________________________________ 11
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
100pF
Z
B
A
TTL IN
t , t < 6ns
RECEIVER
OUT
R
D
R
F
R = 54Ω
Y
100pF
Figure 14. Receiver Propagation Delay Test Circuit
A
B
V
= 5V
CC
500mV/div
V
= 5V
CC
500mV/div
T = +25°C
A
T = +25°C
A
B
A
RO
2V/div
RO
2V/div
20ns/div
20ns/div
Figure 15. MAX481/MAX485/MAX490/MAX491/MAX1487
Receiver t
Figure 16. MAX481/MAX485/MAX490/MAX491/MAX1487
Receiver t
PHL
PLH
A
B
500mV/div
500mV/div
V
CC
= 5V
V
CC
= 5V
T = +25°C
A
T = +25°C
A
B
A
RO
2V/div
2V/div
RO
400ns/div
400ns/div
Figure 17. MAX483, MAX487–MAX489 Receiver t
Figure 18. MAX483, MAX487–MAX489 Receiver t
PLH
PHL
12 ______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
Figures 21 and 22 show typical network applications
circuits. These parts can also be used as line
repeaters, with cable lengths longer than 4000 feet, as
shown in Figure 23.
Line Length vs. Data Rate
The RS-485/RS-422 standard covers line lengths up to
4000 feet. For line lengths greater than 4000 feet, see
Figure 23.
To minimize reflections, the line should be terminated at
both ends in its characteristic impedance, and stub
lengths off the main line should be kept as short as possi-
ble. The slew-rate-limited MAX483 and MAX487–MAX489
are more tolerant of imperfect termination.
Figures 19 and 20 show the system differential voltage
for the parts driving 4000 feet of 26AWG twisted-pair
wire at 110kHz into 120Ω loads.
Typical Applications
The MAX481, MAX483, MAX485, MAX487–MAX491, and
MAX1487 transceivers are designed for bidirectional data
communications on multipoint bus transmission lines.
5V
5V
DI
DI
0V
0V
1V
1V
V -V
Y
Z
V -V
0V
Y
Z
0V
-1V
-1V
5V
0V
5V
0V
RO
RO
2µs/div
2µs/div
Figure 20. MAX483, MAX487–MAX489 System Differential
Voltage at 110kHz Driving 4000ft of Cable
Figure 19. MAX481/MAX485/MAX490/MAX491/MAX1487 System
Differential Voltage at 110kHz Driving 4000ft of Cable
120Ω
120Ω
DE
B
B
DI
D
D
DI
DE
A
B
A
B
A
A
RO
RE
RO
RE
R
R
R
R
D
D
MAX481
MAX483
MAX485
MAX487
MAX1487
DE
DI
RO
RE
DI
RO RE
DE
Figure 21. MAX481/MAX483/MAX485/MAX487/MAX1487 Typical Half-Duplex RS-485 Network
______________________________________________________________________________________ 13
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
A
Y
120Ω
120Ω
120Ω
RO
RE
R
DI
D
B
Z
Z
DE
DE
B
RE
RO
120Ω
DI
R
D
Y
A
Y
Z
B
A
Y
Z
B
A
R
R
D
D
MAX489
MAX491
DI
DE RE RO
DI
DE RE RO
NOTE: RE AND DE ON MAX489/MAX491 ONLY.
Figure 22. MAX488–MAX491 Full-Duplex RS-485 Network
Isolated RS-485
For isolated RS-485 applications, see the MAX253 and
MAX1480 data sheets.
MAX488–MAX491
A
RO
RE
DE
120Ω
120Ω
R
DATA IN
B
Z
DI
DATA OUT
D
Y
NOTE: RE AND DE ON MAX489/MAX491 ONLY.
Figure 23. Line Repeater for MAX488–MAX491
14 ______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
_______________Ordering Information
__Ordering Information (continued)
PART
TEMP. RANGE
0°C to +70°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
-55°C to +125°C
0°C to +70°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
-55°C to +125°C
0°C to +70°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
-55°C to +125°C
0°C to +70°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
-55°C to +125°C
0°C to +70°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
-55°C to +125°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
-55°C to +125°C
PIN-PACKAGE
8 Plastic DIP
8 SO
PART
TEMP. RANGE
0°C to +70°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
-55°C to +125°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
-55°C to +125°C
0°C to +70°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
-55°C to +125°C
PIN-PACKAGE
8 Plastic DIP
8 SO
MAX490CPA
MAX490CSA
MAX490CUA
MAX490C/D
MAX490EPA
MAX490ESA
MAX490MJA
MAX491CPD
MAX491CSD
MAX491C/D
MAX491EPD
MAX491ESD
MAX491MJD
MAX1487CPA
MAX1487CSA
MAX1487CUA
MAX1487C/D
MAX1487EPA
MAX1487ESA
MAX1487MJA
MAX481CPA
MAX481CSA
MAX481CUA
MAX481C/D
MAX481EPA
MAX481ESA
MAX481MJA
MAX483CPA
MAX483CSA
MAX483CUA
MAX483C/D
MAX483EPA
MAX483ESA
MAX483MJA
MAX485CPA
MAX485CSA
MAX485CUA
MAX485C/D
MAX485EPA
MAX485ESA
MAX485MJA
MAX487CPA
MAX487CSA
MAX487CUA
MAX487C/D
MAX487EPA
MAX487ESA
MAX487MJA
MAX488CPA
MAX488CSA
MAX488CUA
MAX488C/D
MAX488EPA
MAX488ESA
MAX488MJA
MAX489CPD
MAX489CSD
MAX489C/D
MAX489EPD
MAX489ESD
MAX489MJD
8 µMAX
8 µMAX
Dice*
Dice*
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 CERDIP
14 Plastic DIP
14 SO
8 CERDIP
8 Plastic DIP
8 SO
Dice*
8 µMAX
14 Plastic DIP
14 SO
Dice*
8 Plastic DIP
8 SO
14 CERDIP
8 Plastic DIP
8 SO
8 CERDIP
8 Plastic DIP
8 SO
8 µMAX
Dice*
8 µMAX
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 CERDIP
* Contact factory for dice specifications.
8 CERDIP
8 Plastic DIP
8 SO
8 µMAX
Dice*
_________________Chip Topographies
8 Plastic DIP
8 SO
MAX481/MAX483/MAX485/MAX487/MAX1487
8 CERDIP
8 Plastic DIP
8 SO
V
CC
RO
N.C.
8 µMAX
N.C.
B
Dice*
RE
DE
DI
0.054"
(1.372mm)
8 Plastic DIP
8 SO
A
8 CERDIP
14 Plastic DIP
14 SO
GND
Dice*
0.080"
(2.032mm)
14 Plastic DIP
14 SO
14 CERDIP
______________________________________________________________________________________ 15
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
_____________________________________________Chip Topographies (continued)
MAX488/MAX490
MAX489/MAX491
V
CC
V
CC
RO
A
RO
A
B
Z
B
Z
RE
DE
DI
0.054"
(1.372mm)
N.C.
N.C.
DI
0.054"
(1.372mm)
Y
Y
GND
GND
0.080"
0.080"
(2.032mm)
(2.032mm)
TRANSISTOR COUNT: 248
SUBSTRATE CONNECTED TO GND
16 ______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
INCHES
MILLIMETERS
DIM
A
MIN
MAX
0.069
0.010
0.019
0.010
MIN
1.35
0.10
0.35
0.19
MAX
1.75
0.25
0.49
0.25
0.053
0.004
0.014
0.007
N
A1
B
C
e
0.050 BSC
1.27 BSC
E
0.150
0.228
0.016
0.157
0.244
0.050
3.80
5.80
0.40
4.00
6.20
1.27
E
H
H
L
VARIATIONS:
INCHES
1
MILLIMETERS
DIM
D
MIN
MAX
0.197
0.344
0.394
MIN
4.80
8.55
9.80
MAX
5.00
N
8
MS012
AA
TOP VIEW
0.189
0.337
0.386
D
8.75 14
10.00 16
AB
D
AC
D
C
A
B
0∞-8∞
e
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0041
B
1
______________________________________________________________________________________ 17
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
4X S
8
8
MILLIMETERS
INCHES
DIM MIN
MAX
MAX
MIN
-
-
0.043
0.006
0.037
0.014
0.007
0.120
1.10
0.15
0.95
0.36
0.18
3.05
A
0.002
0.030
0.010
0.005
0.116
0.05
0.75
0.25
0.13
2.95
A1
A2
b
E
H
ÿ 0.50±0.1
c
D
e
0.0256 BSC
0.65 BSC
0.6±0.1
E
H
0.116
0.188
0.016
0∞
0.120
2.95
4.78
0.41
0∞
3.05
5.03
0.66
6∞
0.198
0.026
6∞
L
1
1
α
S
0.6±0.1
0.0207 BSC
0.5250 BSC
D
BOTTOM VIEW
TOP VIEW
A1
A2
A
c
α
e
L
b
SIDE VIEW
FRONT VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 8L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0036
J
1
18 ______________________________________________________________________________________
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 19
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
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VISHAY
SI9137DB
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
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VISHAY
SI9137LG
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
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VISHAY
SI9122E
500-kHz Half-Bridge DC/DC Controller with Integrated Secondary Synchronous Rectification DriversWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
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VISHAY
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