Datasheet MAX3089EPD, MAX3089CSD, MAX3089CPD, MAX3088ESA, MAX3088EPA Datasheet (Maxim)

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Selection Table

*Pin-compatible with 75180, with additional features implemented using pins 1, 6, 8, and 13.

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

________________________________________________________________

Maxim Integrated Products

19-1138; Rev 1; 12/97

14 SO-40°C to +85°CMAX3080ESD

14 Plastic DIP

14 SO

14 Plastic DIP

PIN-PACKAGETEMP. RANGE

0°C to +70°C 0°C to +70°C

-40°C to +85°CMAX3080EPD

MAX3080CSD

MAX3080CPD

PART

256

Transceivers

Bus

75180*14375YesYesSelectableSelectableSelectable

MAX3089

751768375YesYesNo10Half

MAX3088

751798375NoNoNo10Full

MAX3087

7518014375YesYesNo10Full

MAX3086

751768375YesYesYes0.5Half

MAX3085

751798375NoNoYes0.5Full

MAX3084

7518014375YesYesYes0.5Full

MAX3083

751768375YesYesYes0.115Half

MAX3082

751798375NoNoYes0.115Full

MAX3081

7518014375YesYesYes0.115Full

MAX3080

IndustryStandard

Pinout

Count

Quiescent

Current

(µA)

Receiver/

Driver

Enable

Low-

Power

Shutdown

Slew Rate

Limited

Data

Rate

(Mbps)

Half/Full

Duplex

Part

Ordering Information continued on last page.

Ordering Information

General Description

The MAX3080–MAX3089 high-speed transceivers for RS-485/RS-422 communication contain one driver and one receiver. These devices feature fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open or shorted. This means that the receiver output will be a logic high if all transmitters on a terminated bus are disabled (high impedance). The MAX3080/MAX3081/MAX3082 feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission up to 115kbps. The MAX3083/MAX3084/MAX3085 offer higher driver output slew-rate limits, allowing transmit speeds up to 500kbps. The MAX3086/MAX3087/MAX3088’s driver slew rates are not limited, making transmit speeds up to 10Mbps possible. The MAX3089’s slew rate is selectable between 115kbps, 500kbps, and 10Mbps by driving a selector pin with a single three-state driver.

These transceivers typically draw 375µA of supply current when unloaded, or when fully loaded with the drivers disabled.

All devices have a 1/8-unit-load receiver input impedance that allows up to 256 transceivers on the bus. The MAX3082/MAX3085/MAX3088 are intended for halfduplex communications, while the MAX3080/MAX3081/ MAX3083/MAX3084/MAX3086/MAX3087 are intended for full-duplex communications. The MAX3089 is selectable between half-duplex and full-duplex operation. It also features independently programmable receiver and transmitter output phase via separate pins.

Features

♦ True Fail-Safe Receiver While Maintaining

EIA/TIA-485 Compatibility

♦ Enhanced Slew-Rate Limiting Facilitates

Error-Free Data Transmission (MAX3080–MAX3085/MAX3089)

♦ 1nA Low-Current Shutdown Mode (except

MAX3081/MAX3084/MAX3087)

♦ Pin-Selectable Full/Half-Duplex Operation

(MAX3089)

♦ Phase Controls to Correct for Twisted-Pair

Reversal (MAX3089)

♦ Allow Up to 256 Transceivers on the Bus

Applications

RS-422/RS-485 Communications Level Translators Transceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769.

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA= +25°C.) (Note 1)

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.

Supply Voltage (VCC) ............................................................+7V

Control Input Voltage (

RE, DE)...................-0.3V to (VCC+ 0.3V)

Special Input Voltage

(H/F, SRL, TXP, RXP)..................................-0.3V to (V

+ 0.3V)

Driver Input Voltage (DI).............................-0.3V to (V

+ 0.3V)

Driver Output Voltage (A, B, Y, Z)........................................±13V

Receiver Input Voltage (A, B)..............................................±13V

Receiver Input Voltage, Full Duplex (A, B)..........................±25V

Receiver Output Voltage (RO)....................-0.3V to (V

+ 0.3V)

Continuous Power Dissipation

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

8-Pin SO (derate 5.88mW/°C above +70°C)................471mW

14-Pin Plastic DIP (derate 10.0mW/°C above +70°C) ....800mW

14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW

Operating Temperature Ranges

MAX308_C_ _ .....................................................0°C to +70°C

MAX308_E_ _...................................................-40°C to +85°C

Storage Temperature Range.............................-65°C to +150°C

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

Figure 5, R = 50Ω (RS-422)

DE = GND, VCC= GND or 5.25V

H/F, TXP, RXP, internal pull-down

DE, DI, RE

SRL = V

SRL

MAX3080–MAX3085, and MAX3089 with SRL = VCCor unconnected

DE, DI, RE, H/F, TXP, RXP

Figure 5, R = 50Ω or R = 27Ω

SRL (Note 3)

DE, DI, RE, H/F, TXP, RXP

SRL

CONDITIONS

µA

125

Output Leakage (Y and Z) Full Duplex

µA

125

IN4

Input Current (A and B) Full Duplex

µA

IN3

SRL Input Current

V0.8V

IL2

Input Low Voltage

V0.4V

0.6V

IM2

Input Middle Voltage

VVCC- 0.8V

IH2

Input High Voltage

2.0

OD2

Differential Driver Output

10 40I

IN2

µA

±2I

IN1

SRL Input Current

mV100V

HYS

DI Input Hysteresis

V0.8V

IL1

Input Low Voltage

V0.2∆V

Change in Magnitude of Differential Output Voltage (Note 2)

V3V

Driver Common-Mode Output Voltage

V0.2∆V

Change In Magnitude of Common-Mode Voltage (Note 2)

V2.0V

IH1

Input High Voltage

UNITSMIN TYP MAXSYMBOLPARAMETER

Figure 5, R = 27Ω (RS-485) 1.5

SRL = GND (Note 3) -75

VIN= 12V

VIN= -7V -100

-75VIN= -7V

Figure 5 V5V

OD1

Differential Driver Output (no load)

mAV

OD1

Driver Short-Circuit Output Current (Note 4)

DRIVER

-7V ≤ V

OUT

≤ V

-250

0V ≤ V

OUT

≤ 12V

0V ≤ V

OUT

≤ V

±25

250

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

_______________________________________________________________________________________ 3

DC ELECTRICAL CHARACTERISTICS (continued)

(VCC= +5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA= +25°C.) (Note 1)

0V ≤ VRO≤ V

-7V ≤ VCM≤ 12V

0.4V ≤ VO≤ 2.4V

-7V ≤ VCM≤ 12V

IO= -4mA, VID= -50mV

DE = GND, VRE= V

IO= 4mA, VID= -200mV

No load, RE = DI = GND or V

, SRL = V

CONDITIONS

µA0.001 10I

SHDN

Supply Current in Shutdown Mode

µA

Supply Current

mA±7 ±95I

OSR

Receiver Output Short-Circuit Current

kΩ96R

Receiver Input Resistance

µA±1I

OZR

Three-State Output Current at Receiver

mV-200 -125 -50V

Receiver Differential Threshold Voltage

mV25∆V

Receiver Input Hysteresis

VVCC-1.5V

Receiver Output High Voltage

V0.4V

Receiver Output Low Voltage

UNITSMIN TYP MAXSYMBOLPARAMETER

No load, RE = DI = GND or V

, SRL = GND

DE = V

420 800

µA

475 1000

DE = GND

430 900 375 600

Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referred to device

ground unless otherwise noted.

Note 2: ∆V

and ∆VOCare the changes in VODand VOC, respectively, when the DI input changes state.

Note 3: The SRL pin is internally biased to V

/ 2 by a 100kΩ/100kΩ resistor divider. It is guaranteed to be V

/ 2 if left

unconnected.

Note 4: Maximum current level applies to peak current just prior to foldback-current limiting; minimum current level applies during

current limiting.

RECEIVER

SUPPLY CURRENT

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

4 _______________________________________________________________________________________

SWITCHING CHARACTERISTICS—MAX3080–MAX3082, and MAX3089 with SRL = Unconnected

(VCC= +5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA= +25°C.)

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 6 and 12, CL= 100pF, S1 closed

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 6 and 12, CL= 100pF, S2 closed

Figures 8 and 10, CL= 15pF, S1 closed

Figures 8 and 10, CL= 15pF, S2 closed

Figures 6 and 12, CL= 100pF, S1 closed

Figures 11 and 13; |V

ID |

≥ 2.0V;

rise and fall time of V

≤ 15ns

(Note 5)

Figures 6 and 12, CL= 100pF, S2 closed

Figures 11 and 13; |V

ID |

≥ 2.0V;

rise and fall time of V

≤ 15ns

Figures 8 and 10, CL= 15pF, S2 closed

Figures 8 and 10, CL= 100pF, S2 closed Figures 8 and 10, CL= 100pF, S1 closed

Figures 6 and 12, CL= 100pF, S1 closed

Figures 8 and 10, CL= 15pF, S1 closed

Figures 6 and 12, CL= 100pF, S2 closed

CONDITIONS

ns3500t

RZL(SHDN)

Receiver Enable from Shutdown to Output Low

ns3500t

RZH(SHDN)

Receiver Enable from Shutdown to Output High

ns6000t

DZL(SHDN)

Driver Enable from Shutdown to Output Low

ns6000t

DZH(SHDN)

Driver Enable from Shutdown to Output High

ns50 200 600t

SHDN

Time to Shutdown

ns20 50t

RHZ

Receiver Disable Time from High

ns20 50t

RLZ

Receiver Disable Time from Low

ns20 50t

RZH

Receiver Enable to Output High

ns667 1320 2500tDR, t

Driver Rise or Fall Time

ns-3 ±200t

DSKEW

500 2030 2600t

DPLH

Driver Input to Output

Driver Output Skew

DPLH

- t

DPHL |

ns20 50t

RZL

Receiver Enable to Output Low

ns3±30t

RSKD

RPLH

- t

RPHL |

Differential

Receiver Skew

ns127 200

RPLH

RPHL

Receiver Input to Output

ns100t

DHZ

Driver Disable Time from High

kbps115f

MAX

Maximum Data Rate

ns3500t

DZH

Driver Enable to Output High

ns3500t

DZL

Driver Enable to Output Low

ns100t

DLZ

Driver Disable Time from Low

UNITSMIN TYP MAXSYMBOLPARAMETER

DPHL

500 2030 2600

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

_______________________________________________________________________________________ 5

SWITCHING CHARACTERISTICS—MAX3083–MAX3085, and MAX3089 with SRL = V

(VCC= +5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA= +25°C.)

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 6 and 12, CL= 100pF, S2 closed

Figures 8 and 10, CL= 15pF, S1 closed

Figures 8 and 10, CL= 15pF, S2 closed

Figures 6 and 12, CL= 100pF, S1 closed

Figures 11 and 13; |V

≥ 2.0V;

rise and fall time of V

≤ 15ns

(Note 5)

Figures 6 and 12, CL= 100pF, S2 closed

Figures 11 and 13; |V

≥ 2.0V;

rise and fall time of V

≤ 15ns

Figures 8 and 10, CL= 15pF, S2 closed

Figures 8 and 10, CL= 100pF, S2 closed Figures 8 and 10, CL= 100pF, S1 closed

Figures 6 and 12, CL= 100pF, S1 closed

Figures 8 and 10, CL= 15pF, S1 closed

Figures 6 and 12, CL= 100pF, S2 closed

CONDITIONS

ns3500t

RZH(SHDN)

Receiver Enable from Shutdown to Output High

ns4500t

DZL(SHDN)

Driver Enable from Shutdown to Output Low

ns4500t

DZH(SHDN)

Driver Enable from Shutdown to Output High

ns50 200 600t

SHDN

Time to Shutdown

ns20 50t

RHZ

Receiver Disable Time from High

ns20 50t

RLZ

Receiver Disable Time from Low

ns20 50t

RZH

Receiver Enable to Output High

ns200 530 750t

DR, tDF

Driver Rise or Fall Time

ns-3 ±100t

DSKEW

250 720 1000t

DPLH

Driver Input to Output Driver Output Skew

DPLH

- t

DPHL |

ns20 50t

RZL

Receiver Enable to Output Low

ns3±30t

RSKD

RPLH

- t

RPHL

Differential

Receiver Skew

ns127 200

RPLH

RPHL

Receiver Input to Output

ns100t

DHZ

Driver Disable Time from High

kbps500f

MAX

Maximum Data Rate

ns2500t

DZH

Driver Enable to Output High

ns2500t

DZL

Driver Enable to Output Low

ns100t

DLZ

Driver Disable Time from Low

UNITSMIN TYP MAXSYMBOLPARAMETER

DPHL

Figures 6 and 12, CL= 100pF, S1 closed ns3500t

RZL(SHDN)

Receiver Enable from Shutdown to Output Low

250 720 1000

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

6 _______________________________________________________________________________________

SWITCHING CHARACTERISTICS—MAX3086–MAX3088, and MAX3089 with SRL = GND

(VCC= +5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA= +25°C.)

DPHL

Figures 6 and 12, CL= 100pF, S1 closed ns

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

3500t

RZL(SHDN)

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Receiver Enable from Shutdown to Output Low

Figures 7 and 9, R

DIFF

= 54Ω,

CL1= CL2= 100pF

Figures 6 and 12, CL= 100pF, S2 closed

Figures 8 and 10, CL= 15pF, S1 closed

Figures 8 and 10, CL= 15pF, S2 closed

Figures 6 and 12, CL= 100pF, S1 closed

Figures 11 and 13; |V

ID |

≥ 2.0V;

rise and fall time of V

≤ 15ns

(Note 5)

Figures 6 and 12, CL= 100pF, S2 closed

Figures 11 and 13; |V

ID |

≥ 2.0V;

rise and fall time of V

≤ 15ns

Figures 8 and 10, CL= 15pF, S2 closed

Figures 8 and 10, CL= 100pF, S2 closed Figures 8 and 10, CL= 100pF, S1 closed

Figures 6 and 12, CL= 100pF, S1 closed

Figures 8 and 10, CL= 15pF, S1 closed

Figures 6 and 12, CL= 100pF, S2 closed

CONDITIONS

34 60

ns3500t

RZH(SHDN)

Receiver Enable from Shutdown to Output High

ns250t

DZL(SHDN)

Driver Enable from Shutdown to Output Low

ns250t

DZH(SHDN)

Driver Enable from Shutdown to Output High

ns50 200 600t

SHDN

Time to Shutdown

ns20 50t

RHZ

Receiver Disable Time from High

ns20 50t

RLZ

Receiver Disable Time from Low

ns20 50t

RZH

Receiver Enable to Output High

ns14 25t

DR, tDF

Driver Rise or Fall Time

ns-2.5 ±10t

DSKEW

34 60t

DPLH

Driver Input to Output Driver Output Skew

DPLH

- t

DPHL |

ns20 50t

RZL

Receiver Enable to Output Low

ns0±10t

RSKD

RPLH

- t

RPHL |

Differential

Receiver Skew

ns106 150

RPLH

RPHL

Receiver Input to Output

ns100t

DHZ

Driver Disable Time from High

Mbps10f

MAX

Maximum Data Rate

ns150t

DZH

Driver Enable to Output High

ns150t

DZL

Driver Enable to Output Low

ns100t

DLZ

Driver Disable Time from Low

UNITSMIN TYP MAXSYMBOLPARAMETER

Note 5: The device is put into shutdown by bringing RE high and DE low. If the enable inputs are in this state for less than 50ns, the

device is guaranteed not to enter shutdown. If the enable inputs are in this state for at least 600ns, the device is guaranteed to have entered shutdown.

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

_______________________________________________________________________________________

300

-60 100

NO-LOAD SUPPLY CURRENT

vs. TEMPERATURE

350 325

525

MAX3080/3089 TOC-16

TEMPERATURE (°C)

NO-LOAD SUPPLY CURRENT (µA)

450 425

375

400

060

500 475

-40 -20 20 80

A: MAX3086–MAX3088, MAX3089 WITH SRL = GND

B: MAX3080–MAX3085, MAX3089 WITH SRL = OPEN OR V

DE = V

DE = GND

OUTPUT CURRENT

vs. RECEIVER OUTPUT LOW VOLTAGE

MAX3080/3089 TOC-2

OUTPUT LOW VOLTAGE (V)

OUTPUT CURRENT (mA)

OUTPUT CURRENT

vs. RECEIVER OUTPUT HIGH VOLTAGE

MAX3080/3089 TOC-3

OUTPUT HIGH VOLTAGE (V)

OUTPUT CURRENT (mA)

-60 100

SHUTDOWN CURRENT

vs. TEMPERATURE

MAX3080/3089 TOC-1

TEMPERATURE (°C)

SHUTDOWN CURRENT (nA)

060

-40 -20 20 80

0.10

0.15

-60 80 100

RECEIVER OUTPUT LOW VOLTAGE

vs. TEMPERATURE

0.20

0.50

MAX3080/3089 TOC-5

TEMPERATURE (°C)

OUTPUT LOW VOLTAGE (V)

0.40

0.35

0.30

0.25

040

0.45

-40 -20 60

IRO = 8mA

3.8

3.9

-60 80 100

RECEIVER OUTPUT HIGH VOLTAGE

vs. TEMPERATURE

4.0

4.5

MAX3080/3089 TOC-4

TEMPERATURE (°C)

OUTPUT VOLTAGE (V)

4.3

4.2

4.1

040

4.4

-40 -20 60

IRO = 8mA

115

-60 100

RECEIVER PROPAGATION DELAY

(500kbps MODE) vs. TEMPERATURE

120

140

MAX3080/3089 TOC-7

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

130

125

060

135

-40 -20 20 80

LOAD

= 100pF

-60 100

RECEIVER PROPAGATION DELAY

(10Mbps MODE) vs. TEMPERATURE

98 96

112

MAX3080/3089 TOC-8

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

106 104

100

102

060

110 108

-40 -20 20 80

LOAD

= 100pF

1.90

-60 100

DRIVER PROPAGATION DELAY

(115kbps MODE) vs. TEMPERATURE

1.95

2.20

MAX3080/3089 TOC-9

TEMPERATURE (°C)

PROPAGATION DELAY (µs)

2.10

2.00

2.05

060

2.15

-40 -20 20 80

Rt = 54Ω

Typical Operating Characteristics

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

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

8 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

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

520

560

-60 100

DRIVER PROPAGATION DELAY

(500kbps MODE) vs. TEMPERATURE

600

640

920

MAX3080/3089 TOC-10

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

760

800

720 680

060

840

880

-40 -20 20 80

Rt = 54Ω

-60 100

DRIVER PROPAGATION DELAY

(10Mbps MODE) vs. TEMPERATURE

MAX3080/3089 TOC-11

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

40 35

060

-40 -20 20 80

Rt = 54Ω

1.83

1.84

-60 100

DRIVER DIFFERENTIAL OUTPUT VOLTAGE

vs. TEMPERATURE

1.85

1.90

MAX3080/3089 TOC-13

TEMPERATURE (°C)

OUTPUT VOLTAGE (V)

1.88

1.87

1.86

060

1.89

-40 -20 20 80

Rt = 54Ω

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

-8 -2

OUTPUT CURRENT vs.

DRIVER OUTPUT HIGH VOLTAGE

MAX3080/3089 TOC-27

OUTPUT HIGH VOLTAGE (V)

OUTPUT CURRENT (mA)

642-6 -4 0

100

0.01 01

DRIVER OUTPUT CURRENT

vs. DIFFERENTIAL OUTPUT VOLTAGE

0.1

MAX3080 TOC-12

DIFFERENTIAL OUTPUT VOLTAGE (V)

OUTPUT CURRENT (mA)

2345

100

120

140

OUTPUT CURRENT vs.

DRIVER OUTPUT LOW VOLTAGE

MAX3080-25

OUTPUT LOW VOLTAGE (V)

OUTPUT CURRENT (mA)

024681012

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

_______________________________________________________________________________________

2µs/div

DRIVER PROPAGATION DELAY

MAX3080/MAX3081/MAX3082, AND MAX3089

WITH SRL = OPEN

- V

5V/div

2.5V/div

MAX3080/3089 TYP-20

500ns/div

DRIVER PROPAGATION DELAY

MAX3083/MAX3084/MAX3085, AND MAX3089

WITH SRL = V

- V

5V/div

2.5V/div

MAX3080/3089 TYP-21

50ns/div

DRIVER PROPAGATION DELAY

MAX3086/MAX3087/MAX3088, AND MAX3089

WITH SRL = GND

- V

5V/div

2.5V/div

MAX3080/3089 TYP-22

Typical Operating Characteristics (continued)

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

50ns/div

VA - V

2V/div

5V/div

MAX3080/3089 TYP-18

RECEIVER PROPAGATION DELAY

MAX3086–MAX3088, AND MAX3089

WITH SRL = GND

50ns/div

VA - V

2V/div

5V/div

MAX3080/3089 TYP-17

RECEIVER PROPAGATION DELAY

MAX3080–MAX3085, AND MAX3089

WITH SRL = OPEN OR V

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

10 ______________________________________________________________________________________

Pin Description

—95 — Noninverting Driver OutputY9

—

Driver Input. With DE high, a low on DI forces noninverting output low and inverting output high. Similarly, a high on DI forces noninverting output high and inverting output low.

DI5

Slew-Rate-Limit Selector Pin. Connect SRL to GND for 10Mbps communication rate; connect to VCCfor 500kbps communication rate. Leave unconnected for 115kbps communication rate.

SRL—

GroundGND6, 7

88— — TXP—

44— 3

Driver Output Enable. Drive DE high to enable driver outputs. These outputs are high impedance when DE is low. Drive RE high and DE low to enter low-power shutdown mode.

DE4

HALF-

DUPLEX

MODE

MAX3089

FULL-

DUPLEX

MODE

—

FULL-DUPLEX

DEVICES

—

MAX3081 MAX3084 MAX3087

HALF-

DUPLEX

DEVICES

—

MAX3082 MAX3085 MAX3088

Receiver Output. When RE is low and if A - B ≥ -50mV, RO will be high; if A - B ≤ -200mV, RO will be low.

RO2

Receiver Output Enable. Drive RE low to enable RO; RO is high impedance when RE is high. Drive RE high and DE low to enter low-power shutdown mode.

FUNCTIONNAME

Half/Full-Duplex Selector Pin. Connect H/F to VCCfor half-duplex mode; connect to GND or leave unconnected for full-duplex mode.

H/F

—

MAX3080 MAX3083 MAX3086

Transmitter Phase. Connect TXP to GND, or leave floating for normal transmitter phase/polarity. Connect to VCCto invert the transmitter phase/polarity.

— — — — 9 Y Noninverting Receiver Input and Noninverting Driver Output* 10 6 — 10 — Z Inverting Driver Output — — — — 10 Z Inverting Receiver Input and Inverting Driver Output* 11 7 — 11 — B Inverting Receiver Input — — — — 11 B Receiver Input Resistors* — — 7 — — B Inverting Receiver Input and Inverting Driver Output

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

______________________________________________________________________________________ 11

Pin Description (continued)

12 8 — 12 — A Noninverting Receiver Input — — — — 12 A

HALF-

DUPLEX

MODE

MAX3089

FULL-

DUPLEX

MODE

FULL-DUPLEX

DEVICES

MAX3081 MAX3084 MAX3087

HALF-

DUPLEX

DEVICES

MAX3082 MAX3085 MAX3088

FUNCTIONNAME

MAX3080 MAX3083 MAX3086

Receiver Input Resistors*

— — 6 — — A Noninverting Receiver Input and Noninverting Driver Output

— — — 13 13 RXP

Receiver Phase. Connect RXP to GND, or leave unconnected for normal transmitter phase/polarity. Connect to VCCto invert the receiver phase/polarity.

14 1 8 14 14 V

Positive Supply; 4.75V ≤ VCC≤ 5.25V

1, 8, 13 — — — — N.C. Not Connected. Not internally connected.

Function Tables

TRANSMITTING

INPUTS OUTPUTS

DE DI Z Y X 1 1 0 1 X 1 0 1 0 0 0 X High-Z High-Z 1 0 X Shutdown

RECEIVING

INPUTS OUTPUT

DE A-B RO 0 X ≥ -0.05V 1 0 X ≤ -0.2V 0 0 X Open/shorted 1 1 1 X High-Z 1 0 X Shutdown

TRANSMITTING

INPUT OUTPUTS

DI Z Y

1 0 1 0 1 0

RECEIVING

INPUTS OUTPUT

A-B RO

≥ -0.05V 1

≤ -0.2V 0

Open/shorted 1

X = Don’t care Shutdown mode, driver and receiver outputs high impedance

(MAX3089 only.) In half-duplex mode, the driver outputs serve as receiver inputs. The full-duplex receiver inputs (A and B) will still

have a 1/8-unit load, but are not connected to the receiver.

MAX3081/MAX3084/MAX3087MAX3080/MAX3083/MAX3086

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

12 ______________________________________________________________________________________

Function Tables (continued)

TRANSMITTING

INPUTS OUTPUTS

DE DI B/Z A/Y X 1 1 0 1 X 1 0 1 0 0 0 X High-Z High-Z 1 0 X Shutdown

RECEIVING

INPUTS OUTPUT

DE A-B RO 0 X ≥ -0.05V 1 0 X ≤ -0.2V 0 0 X Open/shorted 1 1 1 X High-Z 1 0 X Shutdown

MAX3089

TRANSMITTING

INPUTS OUTPUTS

TXP

DE DI Z Y 0 X 1 1 0 1 0 X 1 0 1 0 1 X 1 1 1 0 1 X 1 0 0 1 X 0 0 X High-Z High-Z X 1 0 X Shutdown

INPUTS OUTPUT

H/F

RXP

DE A-B Y-Z RO 0 0 0 X ≥-0.05V X 1 0 0 0 X ≤ -0.2V X 0 0 1 0 X ≥-0.05V X 0 0 1 0 X ≤ -0.2V X 1 1 0 0 0 X ≥ -0.05V 1 1 0 0 0 X ≤ -0.2V 0 1 1 0 0 X ≥ -0.05V 0 1 1 0 0 X ≤ -0.2V 1

0 0 0 X

Open/

shorted

X 1

1 0 0 0 X

Open/

shorted

0 1 0 X

Open/

shorted

X 0

1 1 0 0 X

Open/

shorted

X X 1 1 X X High-Z X X 1 0 X X Shutdown

RECEIVING

X = Don’t care Shutdown mode, driver and receiver outputs high impedance

MAX3082/MAX3085/MAX3088

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

______________________________________________________________________________________ 13

MAX3081 MAX3084 MAX3087

TOP VIEW

1 2 3 4

GND

8 7 6 5

A B Z Y

DIP/SO

5 6

GND

Y Z

0.1µF

Figure 2. MAX3081/MAX3084/MAX3087 Pin Configuration and Typical Full-Duplex Operating Circuit

MAX3080 MAX3083 MAX3086

DIP/SO

TOP VIEW

GND

VCCRE

GND DE

9 10

12 11

0.1µF

1, 8, 13

3 6, 7

144

1 2 3 4 5 6 7

14 13 12 11 10

9 8

N.C.

A B Z Y

N.C.

DI GND GND

Figure 1. MAX3080/MAX3083/MAX3086 Pin Configuration and Typical Full-Duplex Operating Circuit

MAX3082 MAX3085 MAX3088

TOP VIEW

NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH.

1 2 3 4

0.1µF

GND

7 6

1 2 3 4

8 7 6 5

B A GND

DIP/SO

Figure 3. MAX3082/MAX3085/MAX3088 Pin Configuration and Typical Half-Duplex Operating Circuit

TOP VIEW

MAX3080–MAX3089

Detailed Description

Fail-Safe

section). The MAX3080/ MAX3081/MAX3082 feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission up to 115kbps (see

Reduced EMI and

Reflections

section). The MAX3083/MAX3084/MAX3085 offer higher driver output slew-rate limits, allowing transmit speeds up to 500kbps. The MAX3086/ MAX3087/MAX3088’s driver slew rates are not limited, making transmit speeds up to 10Mbps possible. The MAX3089’s slew rate is selectable between 115kbps, 500kbps, and 10Mbps by driving a selector pin with a three-state driver.

The MAX3082/MAX3085/MAX3088 are half-duplex transceivers, while the MAX3080/MAX3081/MAX3083/ MAX3084/MAX3086/MAX3087 are full-duplex transceivers. The MAX3089 is selectable between half- and full-duplex communication by driving a selector pin high or low, respectively.

All of these parts operate from a single +5V supply. Drivers are output short-circuit current limited. Thermal shutdown circuitry protects drivers against excessive power dissipation. When activated, the thermal shutdown circuitry places the driver outputs into a highimpedance state.

Receiver Input Filtering

The receivers of the MAX3080–MAX3085, and the MAX3089 when operating in 115kbps or 500kbps mode, incorporate input filtering in addition to input hysteresis. This filtering enhances noise immunity with differential signals that have very slow rise and fall times. Receiver propagation delay increases by 20% due to this filtering.

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

14 ______________________________________________________________________________________

DIP/SO

TOP VIEW

1 2 3 4 5 6 7

14 13 12 11 10

9 8

RXP

TXP

A B Z Y

SRL

GND

H/F

MAX3089

TXP

GND DE SRL

MAX3089

H/F

NOTE: SWITCH POSITIONS INDICATED FOR H/F = GND

Figure 4. MAX3089 Pin Configuration and Functional Diagram

Fail-Safe

The MAX3080 family guarantees a logic-high receiver output when the receiver inputs are shorted or open, or when they are connected to a terminated transmission line with all drivers disabled. This is done by setting the receiver threshold between -50mV and -200mV. If the differential receiver input voltage (A-B) is greater than or equal to -50mV, RO is logic high. If A-B is less than or equal to -200mV, RO is logic low. In the case of a terminated bus with all transmitters disabled, the receiver’s differential input voltage is pulled to 0V by the termination. With the receiver thresholds of the MAX3080 family, this results in a logic high with a 50mV minimum noise margin. Unlike previous fail-safe devices, the -50mV to -200mV threshold complies with the ±200mV EIA/TIA-485 standard.

MAX3089 Programming

The MAX3089 has several programmable operating modes. Transmitter rise and fall times are programmable between 2500ns, 750ns, and 25ns, resulting in maximum data rates of 115kbps, 500kbps, and 10Mbps, respectively. To select the desired data rate, drive SRL to one of three possible states by using a three-state driver, by connecting it to VCCor GND, or by leaving it unconnected. For 115kbps operation, set the three-state device in high-impedance mode or leave SRL unconnected. For 500kbps operation, drive SRL high or connect it to VCC. For 10Mbps operation, drive SRL low or connect it to GND. SRL can be changed during operation without interrupting data communications.

Occasionally, twisted-pair lines are connected backward from normal orientation. The MAX3089 has two pins that invert the phase of the driver and the receiver to correct for this problem. For normal operation, drive

TXP and RXP low, connect them to ground, or leave them unconnected (internal pull-down). To invert the driver phase, drive TXP high or connect it to V

. To invert the receiver phase, drive RXP high or connect it to VCC. Note that the receiver threshold is positive when RXP is high.

The MAX3089 can operate in full- or half-duplex mode. Drive the H/F pin low, leave it unconnected (internal pull-down), or connect it to GND for full-duplex operation, and drive it high for half-duplex operation. In fullduplex mode, the pin configuration of the driver and receiver is the same as that of a MAX3080 (Figure 4). In half-duplex mode, the receiver inputs are switched to the driver outputs, connecting outputs Y and Z to inputs A and B, respectively. In half-duplex mode, the internal full-duplex receiver input resistors are still connected to pins 11 and 12.

Applications Information

256 Transceivers on the Bus

The standard RS-485 receiver input impedance is 12kΩ (one-unit load), and the standard driver can drive up to 32 unit loads. The MAX3080 family of transceivers have a 1/8-unit-load receiver input impedance (96kΩ), allowing up to 256 transceivers to be connected in parallel on one communication line. Any combination of these devices and/or other RS-485 transceivers with a total of 32 unit loads or less can be connected to the line.

Reduced EMI and Reflections

The MAX3080–MAX3085, and MAX3089 with SRL = V

or unconnected, are slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. Figure 14 shows the driver output waveform and its Fourier analysis of a 20kHz signal transmitted by a MAX3086/MAX3087/MAX3088, and MAX3089 with SRL = GND. High-frequency harmonic

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

______________________________________________________________________________________ 15

Figure 5. Driver DC Test Load

RECEIVER

OUTPUT

TEST POINT

15pF

Figure 6. Receiver Enable/Disable Timing Test Load

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

16 ______________________________________________________________________________________

DIFF

Figure 7. Driver Timing Test Circuit Figure 8. Driver Enable/Disable Timing Test Load

3V 0V

Z Y

-V

1.5V t

PLH

1/2 V

10%

90%

PHL

1.5V 1/2 V

10%

DIFF

= V (Y) - V (Z)

DIFF

SKEW = | tPLH

- t

PHL

Figure 9. Driver Propagation Delays Figure 10. Driver Enable and Disable Times (except

MAX3081/MAX3084/MAX3087)

A B

-1V

1.5V 1.5V

OUTPUT

INPUT

PLH

PHL

Figure 11. Receiver Propagation Delays Figure 12. Receiver Enable and Disable Times (except

MAX3081/MAX3084/MAX3087)

OUTPUT

500Ω

UNDER TEST

1.5V 1.5V

, t

ZL(SHDN)

Y, Z V

Y, Z

2.3V

OUTPUT NORMALLY LOW

OUTPUT NORMALLY HIGH

, t

ZH(SHDN)

1.5V 1.5V

, t

ZL(SHDN)

1.5V

OUTPUT NORMALLY LOW

OUTPUT NORMALLY HIGH

1.5V

, t

ZH(SHDN)

+0.5V

-0.5V

+ 0.5V

- 0.5V

components with large amplitudes are evident. Figure 15 shows the same signal displayed for a MAX3083/ MAX3084/MAX3085, and MAX3089 with SRL = VCC), transmitting under the same conditions. Figure 15’s high-frequency harmonic components are much lower in amplitude, compared with Figure 14’s, and the potential for EMI is significantly reduced. Figure 16 shows the same signal displayed for a MAX3080/ MAX3081/MAX3082, and MAX3089 with SRL = unconnected, transmitting under the same conditions. Figure 16’s high-frequency harmonic components are even lower.

In general, a transmitter’s rise time relates directly to the length of an unterminated stub, which can be driven with only minor waveform reflections. The following equation expresses this relationship conservatively:

Length = t

RISE

/ (10 x 1.5ns/ft)

where t

RISE

is the transmitter’s rise time.

For example, the MAX3080’s rise time is typically 1320ns, which results in excellent waveforms with a stub length up to 90 feet. A system can work well with longer unterminated stubs, even with severe reflections, if the waveform settles out before the UART samples them.

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

______________________________________________________________________________________ 17

RECEIVER OUTPUT

ATE

Figure 13. Receiver Propagation Delay Test Circuit

100kHz/div0Hz 1MHz

20dB/div

MAX3080/3089 FIG-14

Figure 14. Driver Output Waveform and FFT Plot of MAX3086/MAX3087/MAX3088, and MAX3089 with SRL = GND, Transmitting a 20kHz Signal

100kHz/div0Hz 1MHz

20dB/div

MAX3080/3089 FIG-15

Figure 15. Driver Output Waveform and FFT Plot of MAX3083/MAX3084/MAX3085, and MAX3089 with SRL = V

CC,

Transmitting a 20kHz Signal

100kHz/div0Hz 1MHz

20dB/div

MAX3080/3089 FIG-16

Figure 16. Driver Output Waveform and FFT Plot of MAX3080/MAX3081/MAX3082, and MAX3089 with SRL = Unconnected, Transmitting a 20kHz Signal

MAX3080–MAX3089

Low-Power Shutdown Mode

(except MAX3082/MAX3085/MAX3088)

Low-power shutdown mode is initiated by bringing both RE high and DE low. In shutdown, the devices typically draw only 1nA of supply current.

RE and DE may be driven simultaneously; the parts are guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown.

Enable times tZHand tZLin the

Switching Char-

acteristics

tables assume the part was not in a low-

power shutdown state. Enable times t

ZH(SHDN)

and

ZL(SHDN)

assume the parts were shut down. It takes drivers and receivers longer to become enabled from low-power shutdown mode (t

ZH(SHDN)

, t

ZH(SHDN)

) than

from driver/receiver-disable mode (tZH, tZL).

Driver Output Protection

Two mechanisms prevent excessive output current and power dissipation caused by faults or by bus contention. The first, a foldback current limit on the output stage, provides immediate protection against short circuits over the whole common-mode voltage range (see

Typical Operating Characteristics

). The second, a thermal shutdown circuit, forces the driver outputs into a high-impedance state if the die temperature becomes excessive.

Line Length vs. Data Rate

The RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, use the repeater application shown in Figure 17.

Figures 18, 19, and 20 show the system differential voltage for the parts driving 4000 feet of 26AWG twistedpair wire at 110kHz into 120Ω loads.

Typical Applications

The MAX3082/MAX3085/MAX3088/MAX3089 transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 21 and 22 show typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in Figure 17.

To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possible. The slew-rate-limited MAX3082/MAX3085, and the two modes of the MAX3089, are more tolerant of imperfect termination.

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

18 ______________________________________________________________________________________

120Ω

DATA IN

DATA OUT

RE DE

A B

Z Y

MAX3080/MAX3081/MAX3083/ MAX3084/MAX3086/MAX3087/

MAX3089 (FULL DUPLEX)

NOTE: RE AND DE ON MAX3080/MAX3083/MAX3086/MAX3089 ONLY.

Figure 17. Line Repeater for MAX3080/MAX3081/ MAX3083/MAX3084/MAX3086/MAX3087, and MAX3089 in Full-Duplex Mode

5µs/div

VA - V

1V/div

5V/div

MAX3080/3089 FIG-18

Figure 18. MAX3080/MAX3081/MAX3082, and MAX3089 with SRL = Unconnected, System Differential Voltage at 50kHz Driving 4000 feet of Cable

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps),

Slew-Rate-Limited RS-485/RS-422 Transceivers

______________________________________________________________________________________ 19

2µs/div

VA - V

1V/div

5V/div

MAX3080/3089 FIG-19

Figure 19. MAX3083/MAX3084/MAX3085, and MAX3089 with SRL = V

CC,

System Differential Voltage at 50kHz Driving 4000

feet of Cable

1µs/div

VA - V

1V/div

5V/div

MAX3080/3089 FIG-20

Figure 20. MAX3086/MAX3087/MAX3088, and MAX3089 with SRL = GND, System Differential Voltage at 200kHz Driving 4000 feet of Cable

DI RO DE

RERE

120Ω

MAX3082 MAX3085 MAX3088

MAX3089 (HALF-DUPLEX)

Figure 21. Typical Half-Duplex RS-485 Network

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

MAX3080–MAX3089

Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers

Figure 22. Typical Full-Duplex RS-485 Network

120Ω

DI DIRO RO

DE DE

MAX3080 MAX3081 MAX3083 MAX3084 MAX3086 MAX3087

MAX3089 (FULL-DUPLEX)

NOTE: RE AND DE ON MAX3080/MAX3083/MAX3086/MAX3089 ONLY.

PART TEMP. RANGE PIN-PACKAGE

MAX3086CSD 0°C to +70°C 14 SO MAX3086EPD -40°C to +85°C 14 Plastic DIP MAX3086ESD -40°C to +85°C 14 SO MAX3087CPA

0°C to +70°C 8 Plastic DIP MAX3087CSA 0°C to +70°C 8 SO MAX3087EPA -40°C to +85°C 8 Plastic DIP MAX3087ESA -40°C to +85°C 8 SO MAX3088CPA

0°C to +70°C 8 Plastic DIP MAX3088CSA 0°C to +70°C 8 SO MAX3088EPA -40°C to +85°C 8 Plastic DIP MAX3088ESA -40°C to +85°C 8 SO MAX3089CPD

0°C to +70°C 14 Plastic DIP MAX3089CSD 0°C to +70°C 14 SO MAX3089EPD -40°C to +85°C 14 Plastic DIP MAX3089ESD -40°C to +85°C 14 SO

8 SO-40°C to +85°CMAX3085ESA

14 Plastic DIP-40°C to +85°CMAX3083EPD

14 SO0°C to +70°CMAX3083CSD

14 Plastic DIP0°C to +70°C

MAX3083CPD

8 SO-40°C to +85°CMAX3082ESA

8 Plastic DIP-40°C to +85°CMAX3082EPA

8 SO0°C to +70°CMAX3082CSA

8 Plastic DIP0°C to +70°C

MAX3082CPA

8 SO-40°C to +85°CMAX3081ESA

8 Plastic DIP-40°C to +85°CMAX3081EPA

8 SO0°C to +70°CMAX3081CSA

8 Plastic DIP0°C to +70°C

MAX3081CPA

PIN-PACKAGETEMP. RANGEPART

14 SO-40°C to +85°CMAX3083ESD 8 Plastic DIP0°C to +70°C

MAX3084CPA

8 SO0°C to +70°CMAX3084CSA 8 Plastic DIP-40°C to +85°CMAX3084EPA 8 SO-40°C to +85°CMAX3084ESA 8 Plastic DIP0°C to +70°C

MAX3085CPA

8 SO0°C to +70°C

MAX3085CSA

8 Plastic DIP-40°C to +85°CMAX3085EPA

Ordering Information (continued)

MAX3086CPD

0°C to +70°C 14 Plastic DIP

Datasheet MAX3089EPD, MAX3089CSD, MAX3089CPD, MAX3088ESA, MAX3088EPA Datasheet (Maxim)

Specifications and Main Features

Frequently Asked Questions

User Manual