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.
General Description
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 MAX489feature 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.
These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. Additionally, the MAX481, MAX483, and MAX487have a low-current shutdown mode in which they consume only 0.1µA. 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 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.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 MAX1487are designed for half-duplex applications.
________________________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, 1/4Unit 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
电炉软件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-422,True Fail-Safe Receivers
MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,SOT23, RS-855/RS-422 Transmitters ♦For Multiple Transceiver Applications
MAX3030E–MAX3033E: ±15kV ESD-Protected,+3.3V, Quad RS-422 Transmitters ♦For Fail-Safe Applications
MAX3080–MAX3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422Transceivers
♦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
MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487
Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers
______________________________________________________________Selection Table
19-0122; Rev 8; 10/03
Ordering Information appears at end of data sheet.
M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487
Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 2_______________________________________________________________________________________
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 (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 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
MAX4_ _C_ _/MAX1487C_ A...............................0°C to +70°C MAX4__E_ _/MAX1487E_ A.............................-40°C to +85°C MAX4__MJ_/-55°C to +125°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.
V V IN = -7V
V IN = 12V V IN = -7V V IN = 12V Input Current (A, B)
I IN2
V TH k Ω
48-7V ≤V CM ≤12V, MAX487/MAX1487
R IN
Receiver Input Resistance -7V ≤V CM ≤12V, all devices except MAX487/MAX1487
R = 27Ω(RS-485), Figure 40.4V ≤V O ≤2.4V
R = 50Ω(RS-422)
I O = 4mA, V ID = -200mV I O = -4mA, V ID = 200mV V CM = 0V
-7V ≤V CM ≤12V DE, DI, RE DE, DI, RE MAX487/MAX1487,
DE = 0V, V CC = 0V or 5.25V
DE, DI, RE R = 27Ωor 50Ω, Figure 4R = 27Ωor 50Ω, Figure 4R = 27Ωor 50Ω, Figure 4DE = 0V;
V CC = 0V or 5.25V,all devices except MAX487/MAX1487
CONDITIONS
k Ω12µA ±1
I OZR
Three-State (high impedance)Output Current at Receiver
V 0.4V OL Receiver Output Low Voltage 3.5
V OH Receiver Output High Voltage mV 70
∆V TH Receiver Input Hysteresis V -0.2
0.2
Receiver Differential Threshold Voltage
-0.2mA 0.25mA斯蒂文 斯皮尔伯格
-0.81.0
1.5
5V OD2Differential Driver Output (with load)
V 2V 5
V OD1Differential Driver Output (no load)µA
±2I IN1
Input Current
V 0.8V IL Input Low Voltage V 2.0
V IH Input High Voltage V 0.2
∆V OD Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States V 0.2∆V OD Change in Magnitude of Driver Differential Output Voltage for Complementary Output States V 3V OC Driver Common-Mode Output Voltage
UNITS MIN
TYP
MAX SYMBOL PARAMETER
MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487
Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers
_______________________________________________________________________________________3
SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487
(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)
ns 103060t PHL
Driver Rise or Fall Time Figures 6 and 8, R DIFF = 54Ω, C L1= C L2= 100pF ns MAX490M, MAX491M MAX490C/E, MAX491C/E
2090150MAX481, MAX485, MAX1487
MAX490M, MAX491M
MAX490C/E, MAX491C/E MAX481, MAX485, MAX1487Figures 6 and 8, R DIFF = 54Ω,
C L1= C L2= 100pF MAX481 (Note 5)
Figures 5 and 11, C RL = 15pF, S2 closed
Figures 5 and 11, C RL = 15pF, S1 closed Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pF
Figures 6 and 8,
R DIFF = 54Ω,C L1= C L2= 100pF Figures 6 and 10,R DIFF = 54Ω,C L1= C L2= 100pF CONDITIONS ns 510t SKEW ns
50200
600t SHDN汽化
Time to Shutdown
Mbps 2.5f MAX Maximum Data Rate ns 2050t HZ Receiver Disable Time from High ns 103060t PLH
2050t LZ Receiver Disable Time from Low ns 2050t ZH Driver Input to Output Receiver Enable to Output High ns 2050t ZL Receiver Enable to Output Low 2090200ns ns 134070t HZ t SKD Driver Disable Time from High |t PLH - t PHL |Differential
Receiver Skew
ns 4070t LZ Driver Disable Time from Low ns 4070t ZL Driver Enable to Output Low 31540ns
51525ns 3
1540t R , t F 20
90200
Driver Output Skew to Output t PLH , t PHL Receiver Input to Output
4070t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETER
Figures 7 and 9, C L = 100pF, S2 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 7 and 9, C L = 15pF, S1 closed Figures 7 and 9, C L = 15pF, S2 closed
M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487
Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 4_______________________________________________________________________________________
SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
300
1000
Figures 7 and 9, C L = 100pF, S2 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 5 and 11, C L = 15pF, S2 closed,A - B = 2V
CONDITIONS
ns 40100t ZH(SHDN)
正弦信号发生器
Driver Enable from Shutdown to
Output High (MAX481)
ns
Figures 5 and 11, C L = 15pF, S1 closed,B - A = 2V
t ZL(SHDN)
Receiver Enable from Shutdown
to Output Low (MAX481)
ns 40100t ZL(SHDN)
Driver Enable from Shutdown to
Output Low (MAX481)
ns 3001000t ZH(SHDN)
Receiver Enable from Shutdown
to Output High (MAX481)
UNITS MIN
TYP MAX SYMBOL
PARAMETER
t PLH t SKEW Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pF
t PHL Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pF
Driver Input to Output Driver Output Skew to Output ns 100
800ns ns 2000MAX483/MAX487, Figures 7 and 9,C L = 100pF, S2 closed
t ZH(SHDN)Driver Enable from Shutdown to Output High
250
2000
ns
2500
MAX483/MAX487, Figures 5 and 11,C L = 15pF, S1 closed
t ZL(SHDN)
Receiver Enable from Shutdown to Output Low
ns 2500MAX483/MAX487, Figures 5 and 11,C L = 15pF, S2 closed
t ZH(SHDN)Receiver Enable from Shutdown to Output High
ns 2000MAX483/MAX487, Figures 7 and 9,C L = 100pF, S1 closed
t ZL(SHDN)Driver Enable from Shutdown to Output Low
ns 50
200
600MAX483/MAX487 (Note 5) t SHDN Time to Shutdown
t PHL t PLH , t PHL < 50% of data period Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 7 and 9, C L = 15pF, S2 closed Figures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pF
Figures 7 and 9, C L = 15pF, S1 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 7 and 9, C L = 100pF, S2 closed CONDITIONS
kbps 250f MAX 250
8002000Maximum Data Rate ns 20
50
t HZ Receiver Disable Time from High ns 25080020002050t LZ Receiver Disable Time from Low ns 2050t ZH Receiver Enable to Output High ns 2050t 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 6 and 10, 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 6 and 8, 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
氢溴酸2502000t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETER
MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487
Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers
_______________________________________________________________________________________5
3000
2.5OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
525M A X 481-01
OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )
1.5
15100.5
1.0
2.0
203540450.90.1-50
-25
25
75
RECEIVER OUTPUT LOW VOLTAGE vs.
TEMPERATURE
0.30.7TEMPERATURE (°C)O U T P U
T L O W V O L T A G E (V )
50
0.50.80.20.60.40100125-20-41.5 2.0 3.0 5.0OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
-8-16M A X 481-02
OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )
2.5 4.0-12-18-6-14-10-20
3.5
4.5 4.8
3.2-50-252575RECEIVER OUTPUT HIGH VOLTAGE vs.
TEMPERATURE
3.6
4.4TEMPERATURE (°C)
O U T P U
T H I G H V O L T A G E (V )
0504.04.63.44.23.83.0
100125
900
0 1.0 3.0 4.5DRIVER OUTPUT CURRENT vs.DIFFERENTIAL OUTPUT VOLTAGE
1070M A X 481-05
DIFFERENTIAL OUTPUT VOLTAGE (V)
O U T P U T C U R R E N T (m A )
2.0 4.05030806040200.5 1.5 2.5
3.5 2.31.5
-50
-25
25
125
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
1.7
2.1
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 )
小站
歌声75
1.9
2.21.62.01.8100
50
2.4
__________________________________________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 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.
豫公网安备41160202000603
站长QQ:729038198
关于我们
投诉建议