General Description
The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E are low-power transceivers for RS-485 and RS-422 communications in harsh environ-ments. 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 termi-nated 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 cur-rent when unloaded or when fully loaded with disabled drivers (see Selector Guide ). Additionally, the MAX481E,MAX483E, and MAX487E have a low-current shutdown mode in which they consume only 0.5µA. All parts oper-ate 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 guar-antees 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 trans-ceivers 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 sensitive see the pin-and function-compatible MAX481, MAX483, MAX485,MAX487–MAX491, 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
Next-Generation Device Features
♦For Fault-Tolerant Applications:
MAX3430: ±80V Fault-Protected, Fail-Safe, 1/4-Unit Load, +3.3V, RS-485 Transceiver
MAX3080–MAX3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited, RS-485/RS-422Transceivers ♦For Space-Constrained Applications:
MAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,Profibus, RS-485/RS-422 Transceivers
MAX3362: +3.3V, High-Speed, RS-485/RS-422Transceiver in a SOT23 Package
MAX3280E–MAX3284E: ±15kV ESD-Protected,52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422True Fail-Safe Receivers
MAX3030E–MAX3033E: ±15kV ESD-Protected,+3.3V, Quad RS-422 Transmitters ♦For Multiple Transceiver Applications:
MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,SOT23, RS-485/RS-422 Transmitters ♦For Fail-Safe Applications:
MAX3440E–MAX3444E: ±15kV ESD-Protected,±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers ♦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
MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E
±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers
________________________________________________________________Maxim Integrated Products 1
Ordering Information
19-0410; Rev 4; 10/03
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.
Ordering Information continued at end of data sheet.Selector Guide appears at end of data sheet .
M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E
±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 = +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 -65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°C
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 3V Change in Magnitude of Driver Differential Output Voltage for Complementary Output States ∆V OD 0.2V 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 0.8V Input Current
I IN1
±2µA
Differential Driver Output (no load)V OD15
V 2V Differential Driver Output (with load)
V OD2 1.5
51.0
-0.8mA
0.25mA -0.2Receiver Differential Threshold Voltage
-0.2
0.2
V Receiver Input Hysteresis ∆V TH 70
mV Receiver Output High Voltage V OH 3.5
十六大报告Receiver Output Low Voltage V OL 0.4V Three-State (high impedance)Output Current at Receiver
I OZR
±1
µA 12k ΩCONDITIONS
DE = 0V;
V CC = 0V or 5.25V,all devices except MAX487E/MAX1487E R = 27Ωor 50Ω, Figure 8R = 27Ωor 50Ω, Figure 8R = 27Ωor 50Ω, Figure 8DE, 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 = 50Ω(RS-422)
0.4V ≤V O ≤2.4V
R = 27Ω(RS-485), Figure 8-7V ≤V CM ≤12V, all devices except MAX487E/MAX1487E
Receiver Input Resistance R IN
-7V ≤V CM ≤12V, MAX487E/MAX1487E
48k Ω
V TH I IN2
Input Current (A, B)
V IN = 12V V IN = -7V V IN = 12V V IN = -7V
V
MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E
±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers
SWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E
DC ELECTRICAL CHARACTERISTICS (continued)
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E
±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 45100t 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
配合比
to Output Low (MAX481E)
ns 45100t ZL(SHDN)
Driver Enable from Shutdown to
Output Low (MAX481E)
ns 2251000t 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 = 54Ω,C L1= C L2= 100pF
p2pcachet PHL Figures 10 and 12, R DIFF = 54Ω,C L1= C L2= 100pF
Driver Input to Output Driver Output Skew to Output ns 20
800ns ns 2000MAX483E/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 2500MAX483E/MAX487E, Figures 9 and 15,C L = 15pF, S2 closed
t ZH(SHDN)Receiver Enable from Shutdown to Output High
ns 2000MAX483E/MAX487E, Figures 11 and 13,C L = 100pF, S1 closed
t ZL(SHDN)Driver Enable from Shutdown to Output Low
ns 50
200
600MAX483E/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 = 54Ω,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 250f MAX 250
8002000Maximum Data Rate ns 25
50
t HZ Receiver Disable Time from High ns 25080020002550t LZ Receiver Disable Time from Low ns 2550t ZH Receiver Enable to Output High ns 2550t ZL Receiver Enable to Output Low ns ns 1003003000t HZ t SKD Driver Disable Time from High I t PLH - t PHL I Differential
Receiver Skew
Figures 10 and 14, R DIFF = 54Ω,C L1= C L2= 100pF
ns 3003000t LZ Driver Disable Time from Low ns 2502000t ZL Driver Enable to Output Low ns Figures 10 and 12, R DIFF = 54Ω,C L1= C L2= 100pF
ns 2502000t R , t F 2502000Driver Rise or Fall Time ns t PLH Receiver Input to Output
2502000t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETER
MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E
±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers
_______________________________________________________________________________________5
05101520253035404550OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
M A X 481E -01
OUTPUT LOW VOLTAGE (V)
O U T P U T C U R R E N T (m A )
1.5
2.0
2.5
1.0
0.5
0.10.20.30.40.50.60.70.80.9-60-20
60RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
TEMPERATURE (°C)
O U T P U T L O W V O L T A G E (V )
20
100-4040
800
-5-10
-15
-20
-251.5
3.0
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
M A X 481E -02
OUTPUT HIGH VOLTAGE (V)
O U T P U T C U R R E N T (m A )
5.0
4.5
4.0
2.0
2.5
3.5
3.0
3.2
3.43.63.8
4.04.24.44.64.8
-60-20
60
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
TEMPERATURE (°C)
O U T P U T H I G H V O L T A G E (V )
20
广西大学雨无声网站
100
-4040
800
102030405060708090
DRIVER OUTPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGE
M A X 481E -05
DIFFERENTIAL OUTPUT VOLTAGE (V)
O U T P U T C U R R E N T (m A )
1.5
2.0 2.5
3.0 3.5
4.0 4.51.00.50__________________________________________Typical Operating Characteristics
(V CC = 5V, T A = +25°C, 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 = +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 –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.
M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E
±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers
6_______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)
(V CC = 5V, T A = +25°C, unless otherwise noted.)
1.5
2.32.22.12.01.91.81.71.6-60-20
60
DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURE运筹学单纯形法 TEMPERATURE (°C)
D I F F
E R E N T I A L O U T P U T V O L T A G E (V )
20
100
-4040
80020406080100120140OUTPUT CURRENT vs. DRIVER OUTPUT LOW VOLTAGE
M A X 481E -07
OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )
2
4
6
8
10
120
-10-20-30-40-50-60-70-80-90-100
-8-2OUTPUT CURRENT vs. DRIVER OUTPUT HIGH VOLTAGE
M A X 481E -08
OUTPUT HIGH VOLTAGE (V)
O U T P U T C U R R E N T (m A )
6
42-6-400
100200300400500600
-60-20
60
MAX481E/MAX485E/MAX490E/MAX491E SUPPLY CURRENT vs. TEMPERATURE
TEMPERATURE (°C)
S U P P L Y C U R R E N T (µA )
20
100
-4040
800
100
200300
60
MAX483E/MAX487E–MAX489E SUPPLY CURRENT vs. TEMPERATURE
TEMPERATURE (°C)
S U P P L Y C U R R E N T (µA )
20
100
-4040
80
100
200300
400500600-60-20
60
MAX1487E
SUPPLY CURRENT vs. TEMPERATURE
TEMPERATURE (°C)
S U P P L Y C U R R E N T (µA )
20
100
-4040
80
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