MAXIM MAX481, MAX483, MAX485, MAX487 User Manual

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General Description

The MAX481, MAX483, MAX485, MAX487–MAX491, and
MAX1487 are low-power transceivers for RS-485 and RS­422 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-imped­ance 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 communi­cations are obtained using the MAX488–MAX491, while
the MAX481, MAX483, MAX485, MAX487, and MAX1487
are 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, 1/4
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
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-422
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

MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487

Low-Power, Slew-Rate-Limited

RS-485/RS-422 Transceivers

________________________________________________________________ Maxim Integrated Products 1

______________________________________________________________Selection Table

19-0122; Rev 8; 10/03

MAX481
MAX483
MAX485
MAX487
MAX488
MAX489
MAX490
MAX491

MAX1487

PART

NUMBER

HALF/FULL

DUPLEX

DATA RATE

(Mbps)

SLEW-RATE

LIMITED

LOW-POWER

SHUTDOWN

RECEIVER/

DRIVER

ENABLE

QUIESCENT

CURRENT

(µA)

NUMBER OF

TRANSMITTERS

ON BUS

PIN

COUNT

Half
Half
Half
Half

Full
Full
Full
Full

Half

2.5

0.25

2.5

0.25

0.25

0.25

2.5

2.5

2.5

No

Yes

No
Yes
Yes
Yes

No

No

No

Yes
Yes

No

Yes

No
No
No
No
No

Yes
Yes
Yes
Yes

No

Yes

No
Yes
Yes

300
120
300
120
120
120
300
300
230

32
32
32

128

32
32
32
32

128

8
8
8
8
8

14

8

14

8

Ordering Information appears at end of data sheet.

MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487

Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

Supply Voltage (VCC).............................................................12V

Control Input Voltage (

RE, DE)...................-0.5V to (VCC+ 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_/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= 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

VIN= -7V

VIN= 12V

VIN= -7V

VIN= 12V

Input Current
(A, B)

I

IN2

V

TH

kΩ48-7V ≤ V

CM

≤ 12V, MAX487/MAX1487

R

IN

Receiver 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

IO= -4mA, VID= 200mV

VCM= 0V

-7V ≤ VCM≤ 12V

DE, DI, RE

DE, DI, RE

MAX487/MAX1487,
DE = 0V, V

CC

= 0V or 5.25V

DE, DI, RE

R = 27Ω or 50Ω, Figure 4

R = 27Ω or 50Ω, Figure 4

R = 27Ω or 50Ω, Figure 4

DE = 0V;
V

CC

= 0V or 5.25V,
all devices except
MAX487/MAX1487

CONDITIONS

kΩ12

µA±1I

OZR

Three-State (high impedance)
Output Current at Receiver

V

0.4V

OL

Receiver Output Low Voltage

3.5V

OH

Receiver Output High Voltage

mV70∆V

TH

Receiver Input Hysteresis

V-0.2 0.2

Receiver Differential Threshold
Voltage

-0.2

mA

0.25

mA

-0.8

1.0

1.5 5

V

OD2

Differential Driver Output
(with load)

V

2

V5V

OD1

Differential Driver Output (no load)

µA±2I

IN1

Input Current

V0.8V

IL

Input Low Voltage

V2.0V

IH

Input High Voltage

V0.2∆V

OD

Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States

V0.2∆V

OD

Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States

V3V

OC

Driver Common-Mode Output
Voltage

UNITSMIN TYP MAXSYMBOLPARAMETER

MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487

Low-Power, Slew-Rate-Limited

RS-485/RS-422 Transceivers

_______________________________________________________________________________________ 3

SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487

(VCC= 5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted.) (Notes 1, 2)

DC ELECTRICAL CHARACTERISTICS (continued)

(VCC= 5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted.) (Notes 1, 2)

mA

7950V ≤ VO≤ V

CC

I

OSR

Receiver Short-Circuit Current

mA35 250-7V ≤ VO≤12V (Note 4)I

OSD2

Driver Short-Circuit Current,
VO= Low

mA35 250-7V ≤ VO≤12V (Note 4)I

OSD1

Driver Short-Circuit Current,
VO= High

MAX1487,
RE = 0V or V

CC

250 400

350 650

ns

10 30 60t

PHL

Driver Rise or Fall Time

Figures 6 and 8, R

DIFF

= 54Ω, CL1= CL2= 100pF

ns

MAX490M, MAX491M

MAX490C/E, MAX491C/E 20 90 150

MAX481, MAX485, MAX1487

MAX490M, MAX491M

MAX490C/E, MAX491C/E

MAX481, MAX485, MAX1487

Figures 6 and 8, R

DIFF

= 54Ω,

C

L1

= 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, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 6 and 8,
R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 6 and 10,
R

DIFF

= 54Ω,

C

L1

= CL2= 100pF

CONDITIONS

ns

510t

SKEW

ns50 200 600t

SHDN

Time to Shutdown

Mbps2.5f

MAX

Maximum Data Rate

ns20 50t

HZ

Receiver Disable Time from High

ns

10 30 60t

PLH

20 50t

LZ

Receiver Disable Time from Low

ns20 50t

ZH

Driver Input to Output

Receiver Enable to Output High

ns20 50t

ZL

Receiver Enable to Output Low

20 90 200

ns

ns

13

40 70t

HZ

t

SKD

Driver Disable Time from High

| t

PLH

- t

PHL

| Differential

Receiver Skew

ns40 70t

LZ

Driver Disable Time from Low

ns

40 70t

ZL

Driver Enable to Output Low

31540

ns

51525

ns

31540

tR, t

F

20 90 200

Driver Output Skew to Output

t

PLH

, t

PHL

Receiver Input to Output

40 70t

ZH

Driver Enable to Output High

UNITSMIN TYP MAXSYMBOLPARAMETER

CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

230 400

300 500

MAX481/MAX485,
RE = 0V or V

CC

500 900

MAX490/MAX491,
DE, DI, RE = 0V or V

CC

300 500

MAX488/MAX489,
DE, DI, RE = 0V or V

CC

120 250

DE = V

CC

300 500DE = 0V

DE = V

CC

DE = 0V

µA

MAX481/483/487, DE = 0V, RE = V

CC

0.1 10I

SHDN

Supply Current in Shutdown

120 250

I

CC

No-Load Supply Current
(Note 3)

DE = 5V

DE = 0V

MAX483
MAX487

MAX483/MAX487,
RE = 0V or V

CC

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

µA

MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487

Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers

4 _______________________________________________________________________________________

SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489

(VCC= 5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted.) (Notes 1, 2)

SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)

(VCC= 5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted.) (Notes 1, 2)

300 1000

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

CONDITIONS

ns40 100t

ZH(SHDN)

Driver Enable from Shutdown to
Output High (MAX481)

ns

Figures 5 and 11, CL= 15pF, S1 closed,
B - A = 2V

t

ZL(SHDN)

Receiver Enable from Shutdown
to Output Low (MAX481)

ns40 100t

ZL(SHDN)

Driver Enable from Shutdown to
Output Low (MAX481)

ns300 1000t

ZH(SHDN)

Receiver Enable from Shutdown
to Output High (MAX481)

UNITSMIN TYP MAXSYMBOLPARAMETER

t

PLH

t

SKEW

Figures 6 and 8, R

DIFF

= 54Ω,

C

L1

= CL2= 100pF

t

PHL

Figures 6 and 8, R

DIFF

= 54Ω,

C

L1

= CL2= 100pF

Driver Input to Output

Driver Output Skew to Output ns100 800

ns

ns2000

MAX483/MAX487, Figures 7 and 9,
C

L

= 100pF, S2 closed

t

ZH(SHDN)

Driver Enable from Shutdown to
Output High

250 2000

ns2500

MAX483/MAX487, Figures 5 and 11,
C

L

= 15pF, S1 closed

t

ZL(SHDN)

Receiver Enable from Shutdown
to Output Low

ns2500

MAX483/MAX487, Figures 5 and 11,
C

L

= 15pF, S2 closed

t

ZH(SHDN)

Receiver Enable from Shutdown
to Output High

ns2000

MAX483/MAX487, Figures 7 and 9,
C

L

= 100pF, S1 closed

t

ZL(SHDN)

Driver Enable from Shutdown to
Output Low

ns50 200 600MAX483/MAX487 (Note 5) t

SHDN

Time to Shutdown

t

PHL

t

PLH

, t

PHL

< 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, R

DIFF

= 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

CONDITIONS

kbps250f

MAX

250 800 2000

Maximum Data Rate

ns20 50t

HZ

Receiver Disable Time from High

ns

250 800 2000

20 50t

LZ

Receiver Disable Time from Low

ns20 50t

ZH

Receiver Enable to Output High

ns20 50t

ZL

Receiver Enable to Output Low

ns

ns

100

300 3000t

HZ

t

SKD

Driver Disable Time from High

I t

PLH

- t

PHL

I Differential

Receiver Skew

Figures 6 and 10, R

DIFF

= 54Ω,

CL1= CL2= 100pF

ns300 3000t

LZ

Driver Disable Time from Low

ns250 2000t

ZL

Driver Enable to Output Low

ns

Figures 6 and 8, R

DIFF

= 54Ω,

CL1= CL2= 100pF

ns250 2000tR, t

F

250 2000

Driver Rise or Fall Time

ns

t

PLH

Receiver Input to Output

250 2000t

ZH

Driver Enable to Output High

UNITSMIN TYP MAXSYMBOLPARAMETER

MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487

Low-Power, Slew-Rate-Limited

RS-485/RS-422 Transceivers

_______________________________________________________________________________________ 5

30

0

02.5

OUTPUT CURRENT vs.

RECEIVER OUTPUT LOW VOLTAGE

5

25

MAX481-01

OUTPUT LOW VOLTAGE (V)

OUTPUT CURRENT (mA)

1.5

15

10

0.5 1.0 2.0

20

35

40

45

0.9

0.1

-50 -25 25 75

RECEIVER OUTPUT LOW VOLTAGE vs.

TEMPERATURE

0.3

0.7

TEMPERATURE (°C)

OUTPUT LOW VOLTAGE (V)

050

0.5

0.8

0.2

0.6

0.4

0

100

125

MAX481-04

IRO = 8mA

-20

-4

1.5 2.0 3.0 5.0

OUTPUT CURRENT vs.

RECEIVER OUTPUT HIGH VOLTAGE

-8

-16

MAX481-02

OUTPUT HIGH VOLTAGE (V)

OUTPUT CURRENT (mA)

2.5 4.0

-12

-18

-6

-14

-10

-2
0

3.5 4.5

4.8

3.2

-50 -25 25 75

RECEIVER OUTPUT HIGH VOLTAGE vs.

TEMPERATURE

3.6

4.4

TEMPERATURE (°C)

OUTPUT HIGH VOLTAGE (V)

050

4.0

4.6

3.4

4.2

3.8

3.0
100

125

MAX481-03

IRO = 8mA

90

0

01.0 3.04.5

DRIVER OUTPUT CURRENT vs.

DIFFERENTIAL OUTPUT VOLTAGE

10

70

MAX481-05

DIFFERENTIAL OUTPUT VOLTAGE (V)

OUTPUT CURRENT (mA)

2.0 4.0

50

30

80

60

40

20

0.5 1.5 2.5 3.5

2.3

1.5

-50 -25 25 125

DRIVER DIFFERENTIAL OUTPUT VOLTAGE

vs. TEMPERATURE

1.7

2.1

MAX481-06

TEMPERATURE (°C)

DIFFERENTIAL OUTPUT VOLTAGE (V)

075

1.9

2.2

1.6

2.0

1.8

10050

2.4

R = 54

Ω

__________________________________________Typical Operating Characteristics

(VCC= 5V, TA = +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 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 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.

MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487

Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers

6 _______________________________________________________________________________________

____________________________Typical Operating Characteristics (continued)

(VCC= 5V, TA = +25°C, unless otherwise noted.)

120

0

08

OUTPUT CURRENT vs.

DRIVER OUTPUT LOW VOLTAGE

20

100

MAX481-07

OUTPUT LOW VOLTAGE (V)

OUTPUT CURRENT (mA)

6

60

40

24

80

10

12

140

-120

0

-7 -5 -1 5

OUTPUT CURRENT vs.

DRIVER OUTPUT HIGH VOLTAGE

-20

-80

MAX481-08

OUTPUT HIGH VOLTAGE (V)

OUTPUT CURRENT (mA)

-3 1

-60

3

-6 -4 -2 0 2 4

-100

-40

100

-40-60 -20 40 100 120

MAX1487

SUPPLY CURRENT vs. TEMPERATURE

300

MAX481-13

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

20 60 80

500

200

600

400

0

0

140

MAX1487; DE = VCC, RE = X

MAX1487; DE = 0V, RE = X

100

-50 -25 50 100

MAX481/MAX485/MAX490/MAX491

SUPPLY CURRENT vs. TEMPERATURE

300

MAX481-11

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

25 75

500

200

600

400

0

0

125

MAX481/MAX485; DE = VCC, RE = X

MAX485; DE = 0, RE = X,
MAX481; DE = RE = 0
MAX490/MAX491; DE = RE = X

MAX481; DE = 0, RE = V

CC

100

-50 -25 50 100

MAX483/MAX487–MAX489

SUPPLY CURRENT vs. TEMPERATURE

300

MAX481-12

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

25 75

500

200

600

400

0

0

125

MAX483; DE = VCC, RE = X

MAX487; DE = VCC, RE = X

MAX483/MAX487; DE = 0, RE = V

CC

MAX483/MAX487; DE = RE = 0,
MAX488/MAX489; DE = RE = X