Maxim MAX491EESD, MAX491EEPD, MAX491ECSD, MAX491ECPD, MAX488EESA Datasheet

19-0410; Rev 3; 7/96

±15kV ESD-Protected, Slew-Rate-Limited,

Low-Power, RS-485/RS-422 Transceivers

_______________General Description

The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E,
and MAX1487E are low-power transceivers for RS-485 and
RS-422 communications in harsh environments. Each driver
output and receiver input is protected against ±15kV electro­static discharge (ESD) shocks, without latchup. These parts
contain one driver and one receiver. The MAX483E,
MAX487E, MAX488E, and MAX489E feature reduced slew­rate 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
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 current
when unloaded or when fully loaded with disabled drivers
(see

Selection Table

MAX483E, and MAX487E have a low-current shutdown
mode in which they consume only 0.5µA. 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 their 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 MAX487E and MAX1487E feature quarter-unit-load
receiver input impedance, allowing up to 128 transceivers
on the bus. The MAX488E–MAX491E are designed for full­duplex communications, while the MAX481E, MAX483E,
MAX485E, MAX487E, and MAX1487E are designed for half­duplex applications. For applications that are not ESD sen­sitive see the pin- and function-compatible MAX481,
MAX483, MAX485, MAX487–MAX491, and MAX1487.

). Additionally, the MAX481E,

________________________Applications

Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers

____________________________Features

♦ ESD Protection: ±15kV—Human Body Model
♦ Slew-Rate Limited for Error-Free Data

Transmission (MAX483E/487E/488E/489E)

♦ Low Quiescent Current:

120µA (MAX483E/487E/488E/489E)
230µA (MAX1487E)
300µA (MAX481E/485E/490E/491E)

♦ -7V to +12V Common-Mode Input Voltage Range
♦ Three-State Outputs
♦ 30ns Propagation Delays, 5ns Skew

(MAX481E/485E/490E/491E/1487E)

♦ Full-Duplex and Half-Duplex Versions Available
♦ Allows up to 128 Transceivers on the Bus

(MAX487E/MAX1487E)

♦ Current Limiting and Thermal Shutdown for

Driver Overload Protection

______________Ordering Information

PIN-PACKAGETEMP. RANGEPART

MAX481ECPA

Ordering Information continued on last page.

8 Plastic DIP0°C to +70°C
8 SO0°C to +70°CMAX481ECSA
8 Plastic DIP-40°C to +85°CMAX481EEPA
8 SO-40°C to +85°CMAX481EESA

Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks

______________________________________________________________Selection Table

PART

NUMBER

MAX481E
MAX483E
MAX485E
MAX487E
MAX488E
MAX489E
MAX490E
MAX491E

MAX1487E

HALF/FULL

DUPLEX

Half
Half
Half
Half
Full
Full
Full
Full
Half

DATA RATE

(Mbps)

2.5

0.25

2.5

0.25

0.25

0.25

2.5

2.5

2.5

SLEW-RATE

LIMITED

No

Yes

No
Yes
Yes
Yes

No

No

No

LOW-POWER

SHUTDOWN

Yes
Yes

No

Yes

No
No
No
No
No

RECEIVER/

DRIVER

ENABLE

Yes
Yes
Yes
Yes

No

Yes

No
Yes
Yes

QUIESCENT

CURRENT

(µA)

300
120
300
120
120
120
300
300
230

NUMBER OF

TRANSMITTERS

ON BUS

32
32
32

128

32
32
32
32

128

PIN

COUNT

8
8
8
8
8

14

8

14

8

MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E

________________________________________________________________

Maxim Integrated Products

1

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone]

±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers

ABSOLUTE MAXIMUM RATINGS

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

Control Input Voltage (–R—E–, DE)...................-0.5V to (V

Driver Input Voltage (DI).............................-0.5V to (V

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

Continuous Power Dissipation (T

8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ....727mW

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.

= +70°C)

A

CC
CC

CC

+ 0.5V)
+ 0.5V)

+ 0.5V)

DC ELECTRICAL CHARACTERISTICS

(VCC= 5V ±5%, TA= T

PARAMETER SYMBOL MIN TYP MAX UNITS

Differential Driver Output (no load) V
Differential Driver Output

(with load)

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

Driver Common-Mode Output
Voltage

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

Input High Voltage V
Input Low Voltage V
Input Current I

Input Current
(A, B)

Receiver Differential Threshold
Voltage

Receiver Input Hysteresis ∆V
Receiver Output High Voltage V
Receiver Output Low Voltage V

Three-State (high impedance)
Output Current at Receiver

Receiver Input Resistance R

MIN

to T

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

MAX

OD1

V

∆V

∆V

R = 50Ω (RS-422)

OD2

R = 27Ω (RS-485), Figure 8

R = 27Ω or 50Ω, Figure 8

OD

V

R = 27Ω or 50Ω, Figure 8

OC

R = 27Ω or 50Ω, Figure 8

OD

DE, DI, –R—E

IH

DE, DI, –R—E

IL

DE, DI, –R—E

IN1

DE = 0V;
VCC= 0V or 5.25V,
all devices except

I

IN2

MAX487E/MAX1487E
MAX487E/MAX1487E,

DE = 0V, VCC= 0V or 5.25V

-7V ≤ VCM≤ 12V

V

TH

VCM= 0V

TH

IO= -4mA, VID= 200mV

OH

IO = 4mA, VID= -200mV

OL

I

0.4V ≤ VO≤ 2.4V

OZR

-7V ≤ VCM≤ 12V, all devices except
MAX487E/MAX1487E

IN

-7V ≤ V

CM

–
–
–

≤ 12V, MAX487E/MAX1487E 48 kΩ

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 Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

CONDITIONS

2

1.5 5

0.2 V

0.2 V

2.0 V

0.8 V
±2 µA

VIN= 12V

VIN= -7V
VIN= 12V

VIN= -7V

-0.2 0.2 V

3.5

12 kΩ

1.0

-0.8

0.25

-0.2

70 mV

0.4
±1 µA

5 V

V

3 V

mA

mA

V
V

MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E

2 _______________________________________________________________________________________

±15kV ESD-Protected, Slew-Rate-Limited,

Low-Power, RS-485/RS-422 Transceivers

DC ELECTRICAL CHARACTERISTICS (continued)

(VCC= 5V ±5%, TA= T

No-Load Supply Current
(Note 3)

Supply Current in Shutdown
Driver Short-Circuit Current,

VO= High
Driver Short-Circuit Current,

VO= Low
Receiver Short-Circuit Current

MIN

to T

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

MAX

MAX488E/MAX489E,
DE, DI, –R—E–= 0V or V

MAX490E/MAX491E,
DE, DI, –R—E–= 0V or V

MAX481E/MAX485E,
–R—E–

I

CC

SHDN

OSD1

OSD2

I

OSR

= 0V or V

MAX1487E,
–R—E–

= 0V or V

MAX483E/MAX487E,
–R—E–

= 0V or V

CC

CC

CC

CC

CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

CC

CC

DE = V

CC

120 250

300 500
500 900

300 500DE = 0V
DE = V
DE = 0V

DE = V
DE = 0V

CC

CC

MAX483E
MAX487E

CC

300 500

230 400

350 650

250 400

120 250

0.5 10I

7950V ≤ VO≤ V

SWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E

(VCC= 5V ±5%, TA= T

PARAMETER SYMBOL MIN TYP MAX UNITS

Driver Input to Output
Driver Output Skew to Output

Driver Rise or Fall Time tR, t

Driver Enable to Output High t
Driver Enable to Output Low t
Driver Disable Time from Low t
Driver Disable Time from High

Receiver Input to Output t

| t

- t

PLH

| Differential

PHL

Receiver Skew
Receiver Enable to Output Low t

Time to Shutdown t

MIN

to T

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

MAX

t

Figures 10 and 12, R

PLH

CL1= CL2= 100pF

t

PHL

t

SKEW

Figures 10 and 12, R
Figures 10 and 12,

R

F

ZH
ZL
LZ

t

HZ

= 54Ω,

DIFF

CL1= CL2= 100pF
Figures 11 and 13, CL= 100pF, S2 closed

Figures 11 and 13, CL= 100pF, S1 closed
Figures 11 and 13, CL= 15pF, S1 closed
Figures 11 and 13, CL= 15pF, S2 closed

Figures 10 and 14,

, t

R

PLH

t

SKD

ZL

t

ZH
LZ
HZ

MAX

SHDN

PHL

= 54Ω,

DIFF

CL1= CL2= 100pF
Figures 10 and 14, R

CL1= CL2= 100pF
Figures 9 and 15, CRL= 15pF, S1 closed
Figures 9 and 15, CRL= 15pF, S2 closed
Figures 9 and 15, CRL= 15pF, S1 closed
Figures 9 and 15, CRL= 15pF, S2 closed

MAX481E (Note 5)

CONDITIONS

= 54Ω,

DIFF

= 54Ω, CL1= CL2= 100pF

DIFF

MAX481E, MAX485E, MAX1487E

MAX481E, MAX485E, MAX1487E
MAX490EC/E, MAX491EC/E

= 54Ω,

DIFF

10 40 60
10 40 60

510

32040
52025MAX490EC/E, MAX491EC/E

45 70
45 70 ns
45 70
45 70

20 60 200
20 60 150

5 ns

20 50
20 50
20 50
20 50

2.5
50 200 600

MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E

µA

µAMAX481E/483E/487E, DE = 0V, –R—E–= V

mA35 250-7V ≤ VO≤12V (Note 4)I

mA35 250-7V ≤ VO≤12V (Note 4)I
mA

kV±15A, B, Y and Z pins, tested using Human Body ModelESD Protection

ns
ns

ns

ns

ns
ns

ns

ns
nsReceiver Enable to Output High
nsReceiver Disable Time from Low t
nsReceiver Disable Time from High t

MbpsMaximum Data Rate f

ns

_______________________________________________________________________________________ 3

±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers

SWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E

(VCC= 5V ±5%, TA= T

Driver Enable from Shutdown to
Output High (MAX481E)

Driver Enable from Shutdown to
Output Low (MAX481E)

Receiver Enable from Shutdown
to Output High (MAX481E)

Receiver Enable from Shutdown
to Output Low (MAX481E)

MIN

to T

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

MAX

ZH(SHDN)

ZL(SHDN)

ZH(SHDN)

t

ZL(SHDN)

SWITCHING CHARACTERISTICS—MAX483E, MAX487E/MAX488E/MAX489E

(VCC= 5V ±5%, TA= T

Driver Input to Output

Driver Output Skew to Output ns20 800

Driver Rise or Fall Time
Driver Enable to Output High

Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High

Receiver Input to Output

I t

- t

PLH

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
Time to Shutdown
Driver Enable from Shutdown to

Output High
Driver Enable from Shutdown to

Output Low
Receiver Enable from Shutdown

to Output High
Receiver Enable from Shutdown

to Output Low

MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E

I Differential

PHL

MIN

to T

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

MAX

t

PLH

t

PHL

t

SKEW

ZH
ZL
LZ
HZ

t

PLH

t

PHL

t

SKD

ZL
ZH
LZ
HZ

MAX

SHDN

t

ZH(SHDN)

t

ZL(SHDN)

t

ZH(SHDN)

t

ZL(SHDN)

(continued)

CONDITIONS

Figures 11 and 13, CL= 100pF, S2 closed

Figures 11 and 13, CL= 100pF, S1 closed

Figures 9 and 15, CL= 15pF, S2 closed,
A - B = 2V

Figures 9 and 15, CL= 15pF, S1 closed,
B - A = 2V

CONDITIONS

Figures 10 and 12, R
CL1= CL2= 100pF

Figures 10 and 12, R
CL1= CL2= 100pF

Figures 10 and 12, R

F

CL1= CL2= 100pF
Figures 11 and 13, CL= 100pF, S2 closed

Figures 11 and 13, CL= 100pF, S1 closed
Figures 11 and 13, CL= 15pF, S1 closed
Figures 11 and 13, CL= 15pF, S2 closed

Figures 10 and 14, R
CL1= CL2= 100pF

Figures 10 and 14, R
CL1= CL2= 100pF

Figures 9 and 15, CRL= 15pF, S1 closed
Figures 9 and 15, CRL= 15pF, S2 closed
Figures 9 and 15, CRL= 15pF, S1 closed
Figures 9 and 15, CRL= 15pF, S2 closed
t

, t

PLH

MAX483E/MAX487E, Figures 11 and 13,
CL= 100pF, S2 closed

MAX483E/MAX487E, Figures 11 and 13,
CL= 100pF, S1 closed

MAX483E/MAX487E, Figures 9 and 15,
CL= 15pF, S2 closed

MAX483E/MAX487E, Figures 9 and 15,
CL= 15pF, S1 closed

< 50% of data period

PHL

DIFF

DIFF

DIFF

DIFF

DIFF

= 54Ω,

= 54Ω,

= 54Ω,

= 54Ω,

= 54Ω,

225 1000

250 800 2000
250 800 2000

250 2000t

300 3000t
250 2000
250 2000

100

25 50t

UNITSMIN TYP MAXSYMBOLPARAMETER

ns45 100t

ns45 100t

ns225 1000t

ns

UNITSMIN TYP MAXSYMBOLPARAMETER

ns

ns250 2000tR, t
ns

ns250 2000t
ns300 3000t
ns

ns

ns
ns25 50t

ns25 50t
ns
ns25 50t

kbps250f

ns50 200 600MAX483E/MAX487E (Note 5) t
ns2000

ns2000

ns2500

ns2500

4 _______________________________________________________________________________________

±15kV ESD-Protected, Slew-Rate-Limited,

Low-Power, 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
Note 3: Supply current specification is valid for loaded transmitters when DE = 0V.
Note 4: Applies to peak current. See

Typical Operating Characteristics.

= 5V and TA= +25°C.

CC

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.

__________________________________________Typical Operating Characteristics

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

OUTPUT CURRENT vs.

RECEIVER OUTPUT LOW VOLTAGE

50
45
40
35
30
25
20
15

OUTPUT CURRENT (mA)

10

5
0

OUTPUT LOW VOLTAGE (V)

OUTPUT LOW VOLTAGE (V)

1.5 2.0 2.51.00.50

RECEIVER OUTPUT LOW VOLTAGE

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1
0

-60 -20 60

vs. TEMPERATURE

20 100-40 40080

TEMPERATURE (°C)

-25

MAX481E-01

-20

-15

-10

OUTPUT CURRENT (mA)

-5

0

I

= 8mA

RO

OUTPUT CURRENT vs.

RECEIVER OUTPUT HIGH VOLTAGE

1.5 3.0
OUTPUT HIGH VOLTAGE (V)

MAX481E-04

OUTPUT CURRENT (mA)

4.8

4.6

MAX481E-02

4.4

4.2

4.0

3.8

3.6

OUTPUT HIGH VOLTAGE (V)

3.4

3.2

3.0

5.04.54.02.0 2.5 3.5

DRIVER OUTPUT CURRENT vs.

DIFFERENTIAL OUTPUT VOLTAGE

90
80
70
60
50
40
30
20
10

0

1.5 2.0 2.5 3.0 3.5 4.0 4.51.00.50

DIFFERENTIAL OUTPUT VOLTAGE (V)

RECEIVER OUTPUT HIGH VOLTAGE

vs. TEMPERATURE

I

-60 -20 60

20 100-40 40080

TEMPERATURE (°C)

MAX481E-05

RO

= 8mA

MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E

MAX481E-03

_______________________________________________________________________________________

5