MAX4831ELT+ ,50mA/100mA Current-Limit Switches with NO-LOAD Flag in µDFNELECTRICAL CHARACTERISTICS(V = +2.3V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..
MAX4831ELT+T ,50mA/100mA Current-Limit Switches with NO-LOAD Flag in µDFNapplications. In addition to the current-limit♦ Fault Flag (FFLG)fault flag (FFLG), an open-drain n ..
MAX4834ETT30C ,250mA LDO Linear Regulators with Current-Limiting SwitchApplicationsMAX4835ETTxy_dd+T -40°C to +85°C 6 TDFN-EP*● SDIO Ports and Devices ● Notebook Computer ..
MAX4835ETT18BD2V+T ,250mA LDO Linear Regulators with Current-Limiting SwitchElectrical Characteristics(V = V + 1V, SHDN = IN, C = 3.3µF, T = -40°C to +85°C, unless otherwise n ..
MAX4837ETT25BD3+ ,500mA LDO Linear Regulators with Current-Limiting SwitchApplicationsMAX4836ETTxy_-T -40°C to +85°C 6 TDFN-6SDIO Ports and Devices Notebook ComputersMAX4837 ..
MAX4838EXT+T ,Overvoltage Protection Controllers with Status FLAGELECTRICAL CHARACTERISTICS(V = +5V (MAX4838–MAX4841), V = +4V (MAX4842), T = -40°C to +85°C, unless ..
MAX8878EZK32-T ,Low-Noise, Low-Dropout, 150mA Linear Regulators with '2982 Pinout
MAX8878EZK33+T ,Low-Noise, Low-Dropout, 150mA Linear Regulators with '2982 Pinout
MAX8878EZK36+T ,Low-Noise, Low-Dropout, 150mA Linear Regulators with '2982 Pinout
MAX8878EZK36-T ,Low-Noise, Low-Dropout, 150mA Linear Regulators with '2982 Pinout
MAX8878EZK50+T ,Low-Noise, Low-Dropout, 150mA Linear Regulators with '2982 Pinout
MAX887EVKIT ,Evaluation Kit for the MAX887features a low-current (2.5µA typ) shutdownV = 3.3V @ I = 0.2AOUT OUTmode, as well as current-mode ..
MAX1487-MAX483-MAX485-MAX489-MAX490-MAX491
Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers
General DescriptionThe 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.
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.
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 MAX1487
are designed for half-duplex applications.
________________________ApplicationsLow-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
__Next Generation Device FeaturesFor Fault-Tolerant Applications
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 TransceiversFor 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
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-485/RS-422 TransmittersFor Multiple Transceiver Applications
MAX3030E–MAX3033E: ±15kV ESD-Protected,
+3.3V, Quad RS-422 TransmittersFor Fail-Safe Applications
MAX3080–MAX3089: Fail-Safe, High-Speed
(10Mbps), Slew-Rate-Limited RS-485/RS-422
TransceiversFor 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
PART
NUMBER
HALF/FULL
DUPLEX
DATA
RATE
(Mbps)
SLEW-RATE
LIMITED
LOW-
POWER
SHUTDOWN
RECEIVER/
DRIVER
ENABLE
QUIESCENT
CURRENT
(μA)
NUMBER OF
RECEIVERS ON
BUS
PIN
COUNT
MAX481 Half2.5NoYesYes300328
MAX483 Half0.25YesYesYes120328
MAX485 Half2.5NoNoYes300328
MAX487 Half0.25YesYesYes1201288
MAX488 Full0.25YesNoNo120328
MAX489 Full0.25YesNoYes1203214
MAX490 Full2.5NoNoNo300328
MAX491 Full2.5NoNoYes3003214
Ordering Information appears at end of data sheet.
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
ABSOLUTE MAXIMUM RATINGSSupply Voltage (VCC).............................................................12V
Control Input Voltage (RE, DE)...................-0.5V to (VCC+ 0.5V)
Driver Input Voltage (DI).............................-0.5V to (VCC+ 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 (VCC+ 0.5V)
Continuous Power Dissipation (TA= +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__M_/MAX1487MJA.............................-55°C to +125°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
DC ELECTRICAL CHARACTERISTICS(VCC= 5V ±5%, TA= TMINto TMAX, 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.
VIN= -7V
VIN= 12V
VIN= -7V
VIN= 12V
Input Current
(A, B)IIN2
VTH48-7V ≤VCM ≤12V, MAX487/MAX1487
RINReceiver Input Resistance
-7V ≤VCM≤12V, all devices except
MAX487/MAX1487
R = 27Ω(RS-485), Figure 4
0.4V ≤VO≤2.4V
R = 50Ω(RS-422)
IO = 4mA, VID= -200mV= -4mA, VID= 200mV
VCM= 0V
-7V ≤VCM≤12V
DE, DI, RE
DE, DI, RE
MAX487/MAX1487,
DE = 0V, VCC= 0V or 5.25V
DE, DI, RE
R = 27Ωor 50Ω, Figure 4
R = 27Ωor 50Ω, Figure 4
R = 27Ωor 50Ω, Figure 4
DE = 0V;
VCC= 0V or 5.25V,
all devices except
MAX487/MAX1487
CONDITIONS12±1IOZRThree-State (high impedance)
Output Current at Receiver
0.4VOLReceiver Output Low Voltage
3.5VOHReceiver Output High Voltage70ΔVTHReceiver Input Hysteresis-0.20.2Receiver Differential Threshold
Voltage
-0.2mA0.25
1.55VOD2Differential Driver Output
(with load)V25VOD1Differential Driver Output (no load)±2IIN1Input Current0.8VILInput Low Voltage2.0VIHInput High Voltage0.2ΔVOD
Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States0.2ΔVOD
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States3VOCDriver Common-Mode Output
Voltage
UNITSMINTYPMAXSYMBOLPARAMETER
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487(VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)
DC ELECTRICAL CHARACTERISTICS (continued)(VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)7950V ≤VO≤VCCIOSRReceiver Short-Circuit Current35250-7V ≤VO≤12V (Note 4)IOSD2Driver Short-Circuit Current,= Low35250-7V ≤VO≤12V (Note 4)IOSD1Driver Short-Circuit Current,= High
MAX1487,= 0V or VCC
3506503060tPHL
Driver Rise or Fall Time
Figures 6 and 8, RDIFF= 54Ω, CL1= CL2= 100pF
MAX490M, MAX491M
MAX490C/E, MAX491C/E2090150
MAX481, MAX485, MAX1487
MAX490M, MAX491M
MAX490C/E, MAX491C/E
MAX481, MAX485, MAX1487
Figures 6 and 8, RDIFF= 54Ω,
CL1= CL2= 100pF
MAX481 (Note 5)
Figures 5 and 11, CRL= 15pF, S2 closed
Figures 5 and 11, CRL= 15pF, S1 closed
Figures 5 and 11, CRL= 15pF, S2 closed
Figures 5 and 11, CRL= 15pF, S1 closed
Figures 6 and 10, RDIFF= 54Ω,
CL1= CL2= 100pF
Figures 6 and 8,
RDIFF= 54Ω,
CL1= CL2= 100pF
Figures 6 and 10,
RDIFF= 54Ω,
CL1= CL2= 100pF
CONDITIONS510tSKEW50200600tSHDNTime to Shutdown
Mbps2.5fMAXMaximum Data Rate2050tHZReceiver Disable Time from High3060tPLH50tLZReceiver Disable Time from Low2050tZH
Driver Input to Output
Receiver Enable to Output High2050tZLReceiver Enable to Output Low9020070tHZ
tSKD
Driver Disable Time from HightPLH- tPHL|Differential
Receiver Skew4070tLZDriver Disable Time from Low70tZLDriver Enable to Output Low
51525ns
tR, tF90200
Driver Output Skew to Output
tPLH, tPHLReceiver Input to Output70tZHDriver Enable to Output High
UNITSMINTYPMAXSYMBOLPARAMETER
CONDITIONSUNITSMINTYPMAXSYMBOLPARAMETERMAX481/MAX485,= 0V or VCC
MAX490/MAX491,
DE, DI, RE= 0V or VCC300500
MAX488/MAX489,
DE, DI, RE= 0V or VCC120250
DE = VCC
300500DE = 0V
DE = VCC
DE = 0VMAX481/483/487, DE = 0V, RE= VCC0.110ISHDNSupply Current in Shutdown
ICCNo-Load Supply Current
(Note 3)
DE = 5V
DE = 0V
MAX483
MAX487MAX483/MAX487,= 0V or VCC
Figures 7 and 9, CL= 100pF, S2 closed
Figures 7 and 9, CL= 100pF, S1 closed
Figures 7 and 9, CL= 15pF, S1 closed
Figures 7 and 9, CL= 15pF, S2 closed
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489(VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)
SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)(VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)
Figures 7 and 9, CL= 100pF, S2 closed
Figures 7 and 9, CL= 100pF, S1 closed
Figures 5 and 11, CL= 15pF, S2 closed,
A - B = 2V
CONDITIONS40100tZH(SHDN)Driver Enable from Shutdown to
Output High (MAX481)Figures 5 and 11, CL= 15pF, S1 closed,
B - A = 2VtZL(SHDN)Receiver Enable from Shutdown
to Output Low (MAX481)40100tZL(SHDN)Driver Enable from Shutdown to
Output Low (MAX481)3001000tZH(SHDN)Receiver Enable from Shutdown
to Output High (MAX481)
UNITSMINTYPMAXSYMBOLPARAMETERtPLH
tSKEWFigures 6 and 8, RDIFF= 54Ω,
CL1= CL2= 100pF
tPHL
Figures 6 and 8, RDIFF= 54Ω,
CL1= CL2= 100pFDriver Input to Output
Driver Output Skew to Outputns1008002000MAX483/MAX487, Figures 7 and 9,= 100pF, S2 closedtZH(SHDN)Driver Enable from Shutdown to
Output High
25020002500MAX483/MAX487, Figures 5 and 11,= 15pF, S1 closedtZL(SHDN)Receiver Enable from Shutdown
to Output Low 2500MAX483/MAX487, Figures 5 and 11,= 15pF, S2 closedtZH(SHDN)Receiver Enable from Shutdown
to Output High 2000MAX483/MAX487, Figures 7 and 9,= 100pF, S1 closedtZL(SHDN)Driver Enable from Shutdown to
Output Low 50200600MAX483/MAX487 (Note 5) tSHDNTime to Shutdown
tPHL
tPLH, tPHL< 50% of data period
Figures 5 and 11, CRL= 15pF, S2 closed
Figures 5 and 11, CRL= 15pF, S1 closed
Figures 5 and 11, CRL= 15pF, S2 closed
Figures 5 and 11, CRL= 15pF, S1 closed
Figures 7 and 9, CL= 15pF, S2 closed
Figures 6 and 10, RDIFF= 54Ω,
CL1= CL2= 100pF
Figures 7 and 9, CL= 15pF, S1 closed
Figures 7 and 9, CL= 100pF, S1 closed
Figures 7 and 9, CL= 100pF, S2 closed
CONDITIONSkbps250fMAX
Maximum Data Rate2050tHZReceiver Disable Time from High
250800200050tLZReceiver Disable Time from Low2050tZHReceiver Enable to Output High2050tZLReceiver Enable to Output Low
3003000tHZ
tSKD
Driver Disable Time from HightPLH- tPHLIDifferential
Receiver Skew
Figures 6 and 10, RDIFF= 54Ω,
CL1= CL2= 100pF3003000tLZDriver Disable Time from Low2502000tZLDriver Enable to Output Low
Figures 6 and 8, RDIFF= 54Ω,
CL1= CL2= 100pFns2502000tR, tF
Driver Rise or Fall Time
tPLHReceiver Input to Output
2502000tZHDriver Enable to Output High
UNITSMINTYPMAXSYMBOLPARAMETER
MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
MAX481-01
OUTPUT LOW VOLTAGE (V)
OUTPUT CURRENT (mA)
RECEIVER OUTPUT LOW VOLTAGE vs.
TEMPERATURE
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
MAX481-04IRO = 8mA
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
MAX481-02
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
RECEIVER OUTPUT HIGH VOLTAGE vs.
TEMPERATURE
TEMPERATURE (°C)
OUTPUT HIGH VOLTAGE (V)
MAX481-03IRO = 8mA1.03.04.5
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGEMAX481-05
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
MAX481-06
TEMPERATURE (°C)
DIFFERENTIAL OUTPUT VOLTAGE (V)
R = 54Ω
__________________________________________Typical Operating Characteristics(VCC= 5V, TA = +25°C, unless otherwise noted.)
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
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 VCC= 5V and TA= +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 bringingREhigh 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 (MAX481/MAX483/MAX487)section.
MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487
____________________________Typical Operating Characteristics (continued)(VCC= 5V, TA = +25°C, unless otherwise noted.)
OUTPUT CURRENT vs.
DRIVER OUTPUT LOW VOLTAGE
MAX481-07
OUTPUT LOW VOLTAGE (V)
OUTPUT CURRENT (mA)12
OUTPUT CURRENT vs.
DRIVER OUTPUT HIGH VOLTAGE
MAX481-08
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)1
MAX1487
SUPPLY CURRENT vs. TEMPERATURE
MAX481-13
TEMPERATURE (°C)
SUPPLY CURRENT (6080
MAX1487; DE = VCC, RE = X
MAX1487; DE = 0V, RE = X
MAX481/MAX485/MAX490/MAX491
SUPPLY CURRENT vs. TEMPERATURE
MAX481-11
TEMPERATURE (°C)
SUPPLY CURRENT (75
MAX481/MAX485; DE = VCC, RE = X
MAX481; DE = 0, RE = VCC
MAX485; DE = 0, RE = X,
MAX481; DE = RE = 0
MAX490/MAX491; DE = RE = X
MAX483/MAX487–MAX489
SUPPLY CURRENT vs. TEMPERATURE
MAX481-12
TEMPERATURE (°C)
SUPPLY CURRENT (75
MAX483; DE = VCC, RE = X
MAX487; DE = VCC, RE = X
MAX483/MAX487; DE = 0, RE = VCC
MAX483/MAX487; DE = RE = 0,
MAX488/MAX489; DE = RE = X
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
______________________________________________________________Pin Description
MAX481
MAX483
MAX485
MAX487
MAX1487TOP VIEW
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.
VCC
GND DIRRtA
VCC
GND DI
DIP/SOVCC
GND RE
µMAX
MAX481
MAX483
MAX485
MAX487
MAX1487
µMAX
µMAX
DIP/SODIP/SO3Receiver Output Enable. RO is enabled whenREis low; RO is
high impedance whenREis high.4
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, theyfunction as line receivers ifis low.
DIP/SO5Driver 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.6, 7Ground9Noninverting Driver Output10Inverting Driver Output—Noninverting Receiver Input and Noninverting Driver Output12Noninverting Receiver Input
GND——BInverting Receiver Input and Inverting Driver Output711BInverting Receiver Input114VCCPositive Supply: 4.75V ≤VCC≤5.25V—1, 8, 13N.C.No Connect—not internally connected
FUNCTIONNAME312Receiver Output: If A > B by 200mV, RO will be high;
If A < B by 200mV, RO will be low.2RO
PIN
FUNCTIONNAME
MAX481/MAX483/
MAX485/MAX487/
MAX1487
MAX488/
MAX490
MAX489/
MAX491
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
__________Applications InformationThe MAX481/MAX483/MAX485/MAX487–MAX491 and
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/MAX1487:
128 Transceivers on the BusThe 48kΩ, 1/4-unit-load receiver input impedance of the
MAX487 and MAX1487 allows up to 128 transceivers
on a bus, compared to the 1-unit load (12kΩinput
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 12kΩReceiver Input impedance.
MAX488
MAX490TOP VIEW
GND
VCC
DIP/SORt
VCC
GND
GND
VCCDVCCROA
GNDB
µMAX
MAX488
MAX490NOTE: TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE.
MAX489
MAX491
DIP/SOTOP VIEWVCCGND
VCCRE
GNDDE
1, 8, 136, 74
VCC
N.C.
N.C.
N.C.
GND
GND
Figure 2. MAX488/MAX490 Pin Configuration and Typical Operating Circuit
Figure 3. MAX489/MAX491 Pin Configuration and Typical Operating Circuit
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
MAX483/MAX487/MAX488/MAX489:
Reduced EMI and ReflectionsThe 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-
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.
VOD
VOC
RECEIVER
OUTPUT
TEST POINT
1kΩ
1kΩ
VCC
CRL
15pF
CL1
CL2
RDIFF
VID
OUTPUT
UNDER TEST
500ΩS1
VCC
_________________________________________________________________Test CircuitsFigure 4. Driver DC Test LoadFigure 5. Receiver Timing Test Load
Figure 6. Driver/Receiver Timing Test CircuitFigure 7. Driver Timing Test Load
