1326555919 22364 FT52908 Sumant Khalateimplementing Rs458 on Avr

ImplementingRS-485 on AVR

Khalate Sumant

14th July, 2011

mailto: [email protected]

Contents

I Content 2

1 Introduction 31.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3 Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.4 Handshaking . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.5 Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.6 Pin labeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.7 RS485 in Real World . . . . . . . . . . . . . . . . . . . . . . . 61.8 Waveform example . . . . . . . . . . . . . . . . . . . . . . . . 61.9 Differences between RS232 and RS485 . . . . . . . . . . . . . 7

2 Characteristics of RS485 8

3 MAX485 IC 9

4 Hardware 114.1 Single Master and Slave . . . . . . . . . . . . . . . . . . . . . 114.2 Multi Master and Slave . . . . . . . . . . . . . . . . . . . . . . 13

II Datasheet 15MAX485 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

I

List of Figures

1.1 Waveform of 0xD3 transmitted on RS485 . . . . . . . . . . . 7

3.1 Pinout diagram of MAX485 and its connection . . . . . . . . 10

4.1 Simple RS485 Communication . . . . . . . . . . . . . . . . . . 124.2 Multi Master-Slave RS485 Communication . . . . . . . . . . . 13

1

Part I

Content

2

Chapter 1

Introduction

RS485 is the physical layer for many higher-level protocols, includingModbus1, Profibus2 and other Fieldbus3 systems, SCSI-2, SCSI-3, and BitBus. Unlike RS232, which has a transmit wire and a receive wire, RS485has a transmit wire pair. Typically one wire is labelled A and the other islabelled B, and the wires are twisted together (twisted pair). This allowsRS485 to transmit over much longer distances, using equivalent wires andequivalent transmitters and receivers, than RS232. Many RS485 implemen-tations use 2 wires (1 pair). At all times, at most one device is transmitting onthe pair, and all the other devices on the network are listening (half-duplex).It is the responsibility of user software to ensure that several different devicesdon’t try to transmit at the same time, this can be a tricky coordination task.

1.1 Overview

RS485 only specifies electrical characteristics of the driver and the receiver.It does not specify or recommend any communications protocol. RS485 en-ables the configuration of inexpensive local networks and multi-drop com-munications links. It offers data transmission speeds of 35 Mbit/s up to 10m and 100 kbit/s at 1200 m. Since it uses a differential balanced line overtwisted pair (like RS422), it can span relatively large distances (up to 4,000feet (1,200 m)). A rule of thumb is that the speed in bit/s multiplied by thelength in meters should not exceed 108. Thus a 50 meter cable should notsignal faster than 2 Mbit/s.

1It is a protocol developed by Modicom.2It is another protocol developed by BMBF (German department of education and research)3Protocol developed by

3

1.2. REQUIREMENTS

The recommended arrangement of the wires is as a connected seriesof point-to-point (multi-dropped) nodes, a line or bus, not a star, ring, ormultiply connected network. Ideally, the two ends of the cable will have atermination resistor connected across the two wires. Without terminationresistors, reflections of fast driver edges can cause multiple data edges thatcan cause data corruption. Termination resistors also reduce electrical noisesensitivity due to the lower impedance, and bias resistors are required. Thevalue of each termination resistor should be equal to the cable impedance(typically, 100 ohms for twisted pairs).

1.2 Requirements

A full-duplex RS485 system requires 3 twisted pairs, 2 twisted pairs for sig-nalling, and another conductor for ground. This so-called four-wire RS485system requires 5 wires. A half-duplex system only requires 2 twisted pairsone twisted pair for signalling, and another conductor for ground. This so-called two-wire RS485 system requires 3 wires.

The ground conductor can be eliminated in some cases, but it is safe tostick to Three wire system.

1.3 Limitations

Standard RS485 is limited to a maximum speed of 35 Mbps with a networklength of 12 meters, and 100 Kbps with a network length of 1200 meters.With interface devices that exceed standards and careful network design,higher throughput over longer cables is possible.

With the use of Shielded twisted pair(STP) or Foiled twisted pair(FTP)cable the throughput can be increased even more.

1.4 Handshaking

There is no hardware handshaking in RS485. If handshaking is requiredfor RS485 it can be done using X-On / X-Off handshaking protocol. TheRS485 standard originally used half-duplex communication and handshakingsignals such as RTS / CTS to control the direction of data flow. Many USBto serial converters come with ADDC (Automatic Data Direction Control)to automatically sense and control data direction, making the handshakingsignal method obsolete.

4

1.5. TERMINATION

1.5 Termination

Perhaps the most controversial part of RS485 is what to do at the end ofthe line. There are a wide variety of popular techniques, each of which worksgreat under one narrow range of conditions.

• Unterminated: This is the simplest system, but only works if boththe data rate and length are low enough. A good guideline for when itcan be used is to keep the product of the data rate (in baud) and thelongest end-to-end cable length below four hundred thousand. Numberof transmitters / receivers aren’t important (just keep them withinRS485 specification). This is the only case where a star bus topologyworks reliably.

• One-way resistor termination: Only works if there is only onetransmitter, which must be at the opposite end (from the resistor)of a linear bus.

• Two-way resistor termination: Only works with a linear bus, butallows transmitters only at the endpoints of the bus.

• AC termination: While AC termination may work well on back-planes, others discourage its use on RS485 lines: ”In practice, I havenever seen it”

1.6 Pin labeling

The EIA-485 differential line consists of two pins:

• A aka – aka TxD–/RxD– aka inverting pin

• B aka + aka TxD+/RxD+ aka non-inverting pin

• SC aka G aka reference pin

The SC line is the optional voltage reference connection. This is thereference potential used by the transceiver to measure the A and B voltages.The B line is positive (compared to A) when the line is idle (i.e, data is 1).In addition to the A and B connections, the EIA standard also specifies athird interconnection point called C, which is the common signal referenceground. These names are all in use on various equipment, but the actualstandard released by EIA only uses the names A and B.

5

1.7. RS485 IN REAL WORLD

However, despite the unambiguous standard, there is much confusionabout which is which, The EIA-485 signaling specification states that signalA is the inverting or ′−′ pin and signal B is the non− inverting or ′+′ pin.This is in conflict with the A/B naming used by a number of differentialtransceiver manufacturers, including, among others.

• Texas Instruments, as seen in their application handbook on EIA-422/485 communications (A=non-inverting, B=inverting).

• Intersil, as seen in their data sheet for the ISL4489 transceiver.

• Maxim, as seen in their data sheet for the MAX485 transceiver

These manufacturers are incorrect, but their practice is in widespreaduse. Therefore, care must be taken when using A/B naming.

1.7 RS485 in Real World

Now being used commonly in the pro audio industry to control digital audioand signal processors such as the DBX driverack and other manufacturersequivalent products. Preferred to RS232 due to cheaper cabling run costsand the common availability of cables (similar to RJ-45 ). When wiring aRS485 network, always connect A to A, B to B, and G to G

Many people recommend writing prototype software as if it will be con-nected to a half-duplex RS485 network. Then the software will work un-changed when connected to a full-duplex RS485 network, a RS232 network,and a variety of other communication media.

Many people recommend wiring things up on a prototype with Category-5cable connected as point-to-point full-duplex RS485. The CAT-5 cable allowsyou to relatively quickly switch to half-duplex RS485, or the 3 wires of RS232,or a variety of other communication protocols without pulling any new cables.The point-to-point full-duplex RS485 network allows you to get the completeprototype system fully operational quickly, since it is easier to debug andmore immune to certain common problems on other systems (noise problemson RS232, turn-around problems on half-duplex RS485, etc.).

1.8 Waveform example

The image below shows potentials of the ′+′ and ′−′ pins of an EIA-485line during transmission of one byte (0xD3, least significant bit first) of datausing an asynchronous start-stop method.

6

1.9. DIFFERENCES BETWEEN RS232 AND RS485

Figure 1.1: Waveform of 0xD3 transmitted on RS485

1.9 Differences between RS232 and RS485

• RS232 signal levels are typically -12 V to +12 V relative to the signalground.

• RS485 signal levels are typically 0 to +5 V relative to the signal ground.

• RS232 uses point-to-point unidirectional signal wires: There are onlytwo devices connected to a RS232 cable. The TxD output of a firstdevice connected to the RxD input of a second device, and the TxDoutput of the second device connected to the RxD input of the firstdevice. In a RS232 cable, data always flows in only one direction onany particular wire, from TxD to RxD.

• RS485 typically uses a linear network with bidirectional signal wires:There are typically many devices along a RS485 shared cable. TheA output of each device is connected to the A output of every otherdevice. In a RS485 cable, data typically flows in both directions alongany particular wire, sometimes from the A of the first device to theA of the second device, and at a later time from the A of the seconddevice to the A of the first device.

7

Chapter 2

Characteristics of RS485

Description RS485

Mode DifferentialMax number of drivers 32

Max number of receivers 32Mode of operation Full Duplex or Half DuplexNetwork topology Multi-Drop

Max distance (acc. standard) 1200m (4000ft)Max speed at 12 m 35 Mbs

Max speed at 1200 m 100 kbsReceiver input resistance ≥ 12ΩDriver load impedance 54Ω

Receiver input sensitivity ± 200mVReceiver input range -7...12V

Max driver output voltage -7...12VMin driver output voltage (with load) 1.5V

8

Chapter 3

MAX485 IC

The MAX485 IC are low-power transceivers for RS-485 and RS- 422communication. Each part contains one driver and one receiver. The driverslew rates of the IC are not limited, allowing them to transmit up to 2.5Mbps.

These transceiver draw between 120µA and 500µA of supply current whenunloaded or fully loaded with disabled drivers. Drivers are short circuitedprotected against excessive power dissipation by thermal shut-down circuitrythat places the driver output into High-impedance state. The receiver inputhas a fail-safe feature that guarantees a logic-high output if the input is opencircuit.

The serial data on DI pin is transmitted on the bus and the data on busis received on RO pin. The direction of data on bus is controlled by RE andDE pins, these pins are connected together and eventually connected to thecontrol device.

• When RE and DE is low, data on the bus is received on RO.

• When they are high the data on DI, is transmitted on bus.

9

MAX 485

MAX 485

Figure 3.1: Pinout diagram of MAX485 and its connection

10

Chapter 4

Hardware

To build the hardware you will require the following things.

1. ATmega32 (AVR Family Micro-controller)

2. MAX-485

3. Twisted Pair Cable

4.1 Single Master and Slave

First we will build a simple hardware with one master and one slave,following are the instructions to building the hardware.

• First connect the RO pin of MAX485 to RxD pin of ATmega32, thenfollowed by DI pin to TxD pin.

• Connect the RE & DE pins of MAX485 to anyone i/o pin of ATmega32.

• Build the same hardware, as stated above and connect it to other side(i.e slave) side.

11

4.1. SINGLE MASTER AND SLAVE

The following schematic shows you how to build thehardware1

100E 100E

Figure 4.1: Simple RS485 Communication

1The RO and DI pins MAX-485 pins are TTL compatible and not RS232

12

4.2. MULTI MASTER AND SLAVE

4.2 Multi Master and Slave

After you have done with simple point-to-point system, you can try com-plex systems with multi master and slave. In this section I have providedan example for two master and two slaves.

.

.

.

.

1 2

_1 _2

100E 100E

Figure 4.2: Multi Master-Slave RS485 Communication

13

Reference

• Wikipedia

Powred by: LATEX 2εAuthor: Khalate Sumant

14

http://en.wikipedia.org/wiki/RS-485

http://www.wikipedia.com/wiki/LaTeX

mailto:[email protected]

Part II

Datasheet

15

MAX 485

16

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.com.

General DescriptionThe MAX481, MAX483, MAX485, MAX487–MAX491, andMAX1487 are low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and onereceiver. The MAX483, MAX487, MAX488, and MAX489feature reduced slew-rate drivers that minimize EMI andreduce 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 totransmit up to 2.5Mbps.These transceivers draw between 120µA and 500µA ofsupply current when unloaded or fully loaded with disableddrivers. Additionally, the MAX481, MAX483, and MAX487have a low-current shutdown mode in which they consumeonly 0.1µA. All parts operate from a single 5V supply.Drivers are short-circuit current limited and are protectedagainst excessive power dissipation by thermal shutdowncircuitry that places the driver outputs into a high-imped-ance state. The receiver input has a fail-safe feature thatguarantees a logic-high output if the input is open circuit.The MAX487 and MAX1487 feature quarter-unit-loadreceiver input impedance, allowing up to 128 MAX487/MAX1487 transceivers on the bus. Full-duplex communi-cations are obtained using the MAX488–MAX491, whilethe MAX481, MAX483, MAX485, MAX487, and MAX1487are 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

____________________________Features In µMAX Package: Smallest 8-Pin SO

Slew-Rate Limited for Error-Free DataTransmission (MAX483/487/488/489)

0.1µALow-Current Shutdown Mode(MAX481/483/487)

Low Quiescent Current:120µA (MAX483/487/488/489)230µA (MAX1487)300µA (MAX481/485/490/491)

-7V to +12V Common-Mode Input Voltage Range

Three-State Outputs

30ns Propagation Delays, 5ns Skew (MAX481/485/490/491/1487)

Full-Duplex and Half-Duplex Versions Available

Operate from a Single 5V Supply

Allows up to 128 Transceivers on the Bus(MAX487/MAX1487)

Current-Limiting and Thermal Shutdown forDriver Overload Protection

Ordering Information

Ordering Information continued at end of data sheet.*Contact factory for dice specifications.

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

________________________________________________________________ Maxim Integrated Products 1

______________________________________________________________Selection Table

19-0122; Rev 7; 6/03

PART TEMP RANGE PIN-PACKAGE

MAX481CPA 0°C to +70°C 8 Plastic DIP

MAX481CSA 0°C to +70°C 8 SO

MAX481CUA 0°C to +70°C 8 µMAXMAX481C/D 0°C to +70°C Dice*

MAX481

MAX483

MAX485

MAX487

MAX488

MAX489

MAX490

MAX491

MAX1487

PARTNUMBER

HALF/FULLDUPLEX

DATA RATE(Mbps)

SLEW-RATELIMITED

LOW-POWERSHUTDOWN

RECEIVER/DRIVERENABLE

QUIESCENTCURRENT

(µA)

NUMBER OFTRANSMITTERS

ON BUS

PINCOUNT

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

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2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGSSupply Voltage (VCC).............................................................12VControl 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 +12.5VReceiver Input Voltage (A, B).................................-8V to +12.5VReceiver 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) ....727mW14-Pin Plastic DIP (derate 10.00mW/°C above +70°C) ..800mW8-Pin SO (derate 5.88mW/°C above +70°C).................471mW

14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW8-Pin µMAX (derate 4.1mW/°C above +70°C) ..............830mW8-Pin CERDIP (derate 8.00mW/°C above +70°C).........640mW14-Pin CERDIP (derate 9.09mW/°C above +70°C).......727mW

Operating Temperature RangesMAX4_ _C_ _/MAX1487C_ A ...............................0°C to +70°CMAX4_ _E_ _/MAX1487E_ A.............................-40°C to +85°CMAX4_ _MJ_/MAX1487MJA ...........................-55°C to +125°C

Storage Temperature Range .............................-65°C to +160°CLead Temperature (soldering, 10sec) .............................+300°C

DC ELECTRICAL CHARACTERISTICS(VCC = 5V ±5%, TA = TMIN to 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 functionaloperation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure toabsolute maximum rating conditions for extended periods may affect device reliability.

V

VIN = -7V

VIN = 12V

VIN = -7V

VIN = 12V

Input Current(A, B)

IIN2

VTH

kΩ48-7V ≤ VCM ≤ 12V, MAX487/MAX1487

RINReceiver Input Resistance

-7V ≤ VCM ≤ 12V, all devices exceptMAX487/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, VCC = 0V or 5.25V

DE, DI, RE

R = 27Ω or 50Ω, Figure 4



DE = 0V;VCC = 0V or 5.25V,all devices exceptMAX487/MAX1487

CONDITIONS

kΩ12

µA±1IOZRThree-State (high impedance)Output Current at Receiver

V

0.4VOLReceiver Output Low Voltage

3.5VOHReceiver Output High Voltage

mV70∆VTHReceiver Input Hysteresis

V-0.2 0.2Receiver Differential ThresholdVoltage

-0.2mA

0.25

mA-0.8

1.0

1.5 5VOD2

Differential Driver Output(with load)

V2

V5VOD1Differential Driver Output (no load)

µA±2IIN1Input Current

V0.8VILInput Low Voltage

V2.0VIHInput High Voltage

V0.2∆VOD

Change in Magnitude of DriverCommon-Mode Output Voltagefor Complementary Output States

V0.2∆VOD

Change in Magnitude of DriverDifferential Output Voltage forComplementary Output States

V3VOCDriver Common-Mode OutputVoltage

UNITSMIN TYP MAXSYMBOLPARAMETER

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SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487(VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2)

DC ELECTRICAL CHARACTERISTICS (continued)(VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2)

mA7 950V ≤ VO ≤ VCCIOSRReceiver Short-Circuit Current

mA35 250-7V ≤ VO ≤12V (Note 4)IOSD2Driver Short-Circuit Current,VO = Low

mA35 250-7V ≤ VO ≤12V (Note 4)IOSD1Driver Short-Circuit Current,VO = High

MAX1487,RE = 0V or VCC

250 400

350 650

ns

10 30 60tPHL

Driver Rise or Fall Time

Figures 6 and 8, RDIFF = 54Ω, CL1 = CL2 = 100pF

ns

MAX490M, MAX491MMAX490C/E, MAX491C/E 20 90 150MAX481, MAX485, MAX1487

MAX490M, MAX491MMAX490C/E, MAX491C/EMAX481, MAX485, MAX1487

Figures 6 and 8, RDIFF = 54Ω,CL1 = CL2 = 100pF

MAX481 (Note 5)

Figures 5 and 11, CRL = 15pF, S2 closedFigures 5 and 11, CRL = 15pF, S1 closedFigures 5 and 11, CRL = 15pF, S2 closedFigures 5 and 11, CRL = 15pF, S1 closed


Figures 6 and 8,RDIFF = 54Ω,CL1 = CL2 = 100pF

Figures 6 and 10,RDIFF = 54Ω,CL1 = CL2 = 100pF

CONDITIONS

ns

5 10tSKEW

ns50 200 600tSHDNTime to ShutdownMbps2.5fMAXMaximum Data Rate

ns20 50tHZReceiver Disable Time from Highns

10 30 60tPLH

20 50tLZReceiver Disable Time from Lowns20 50tZH

Driver Input to Output

Receiver Enable to Output Highns20 50tZLReceiver Enable to Output Low

20 90 200

ns

ns

13

40 70tHZ

tSKD

Driver Disable Time from High

| tPLH - tPHL | DifferentialReceiver Skew

ns40 70tLZDriver Disable Time from Low

ns40 70tZLDriver Enable to Output Low

3 15 40

ns

5 15 25 ns3 15 40

tR, tF

20 90 200

Driver Output Skew to Output

tPLH, tPHLReceiver Input to Output

40 70tZHDriver Enable to Output High


CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

230 400

300 500

MAX481/MAX485,RE = 0V or VCC

500 900

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

300 500

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

120 250

DE = VCC

300 500DE = 0V

DE = VCC

DE = 0V

µAMAX481/483/487, DE = 0V, RE = VCC 0.1 10ISHDNSupply Current in Shutdown 120 250

ICCNo-Load Supply Current(Note 3)

DE = 5V

DE = 0V

MAX483

MAX487MAX483/MAX487,RE = 0V or VCC

Figures 7 and 9, CL = 100pF, S2 closedFigures 7 and 9, CL = 100pF, S1 closedFigures 7 and 9, CL = 15pF, S1 closedFigures 7 and 9, CL = 15pF, S2 closed

µA

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SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489(VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2)

SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)(VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2)

300 1000

Figures 7 and 9, CL = 100pF, S2 closed


Figures 5 and 11, CL = 15pF, S2 closed,A - B = 2V

CONDITIONS

ns40 100tZH(SHDN)Driver Enable from Shutdown toOutput High (MAX481)

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

tZL(SHDN)Receiver Enable from Shutdownto Output Low (MAX481)

ns40 100tZL(SHDN)Driver Enable from Shutdown toOutput Low (MAX481)

ns300 1000tZH(SHDN)Receiver Enable from Shutdownto Output High (MAX481)


tPLH

tSKEWFigures 6 and 8, RDIFF = 54Ω,CL1 = CL2 = 100pF

tPHL


Driver Input to Output

Driver Output Skew to Output ns100 800

ns

ns2000MAX483/MAX487, Figures 7 and 9,CL = 100pF, S2 closed

tZH(SHDN)Driver Enable from Shutdown toOutput High

250 2000


tZL(SHDN)Receiver Enable from Shutdownto Output Low


tZH(SHDN)Receiver Enable from Shutdownto Output High


tZL(SHDN)Driver Enable from Shutdown toOutput Low

ns50 200 600MAX483/MAX487 (Note 5) tSHDNTime to Shutdown

tPHL

tPLH, tPHL < 50% of data period

Figures 5 and 11, CRL = 15pF, S2 closed









CONDITIONS

kbps250fMAX

250 800 2000

Maximum Data Rate

ns20 50tHZReceiver Disable Time from High

ns

250 800 2000

20 50tLZReceiver Disable Time from Low

ns20 50tZHReceiver Enable to Output High

ns20 50tZLReceiver Enable to Output Low

ns

ns

100

300 3000tHZ

tSKD

Driver Disable Time from High

I tPLH - tPHL I DifferentialReceiver Skew


ns300 3000tLZDriver Disable Time from Low

ns250 2000tZLDriver Enable to Output Low

ns


ns250 2000tR, tF

250 2000

Driver Rise or Fall Time

ns

tPLHReceiver Input to Output

250 2000tZHDriver Enable to Output High


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_______________________________________________________________________________________ 5

30

00 2.5

OUTPUT CURRENT vs.RECEIVER OUTPUT LOW VOLTAGE

5

25

MAX

481-

01

OUTPUT LOW VOLTAGE (V)

OUTP

UT C

URRE

NT (m

A)

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)

OUTP

UT L

OW V

OLTA

GE (V

)

0 50

0.5

0.8

0.2

0.6

0.4

0100 125

MAX

481-

04

IRO = 8mA

-20

-4

1.5 2.0 3.0 5.0

OUTPUT CURRENT vs.RECEIVER OUTPUT HIGH VOLTAGE

-8

-16

MAX

481-

02

OUTPUT HIGH VOLTAGE (V)

OUTP

UT C

URRE

NT (m

A)

2.5 4.0

-12

-18

-6

-14

-10

-2

03.5 4.5

4.8

3.2

-50 -25 25 75

RECEIVER OUTPUT HIGH VOLTAGE vs.TEMPERATURE

3.6

4.4

TEMPERATURE (°C)

OUTP

UT H

IGH

VOLT

AGE

(V)

0 50

4.0

4.6

3.4

4.2

3.8

3.0100 125

MAX

481-

03

IRO = 8mA

90

00 1.0 3.0 4.5

DRIVER OUTPUT CURRENT vs.DIFFERENTIAL OUTPUT VOLTAGE

10

70

MAX

481-

05

DIFFERENTIAL OUTPUT VOLTAGE (V)

OUTP

UT C

URRE

NT (m

A)

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 VOLTAGEvs. TEMPERATURE

1.7

2.1

MAX

481-

06

TEMPERATURE (°C)

DIFF

EREN

TIAL

OUT

PUT

VOLT

AGE

(V)

0 75

1.9

2.2

1.6

2.0

1.8

10050

2.4

R = 54Ω

__________________________________________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 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 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 areguaranteed to have entered shutdown. See Low-Power Shutdown Mode section.

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


6 _______________________________________________________________________________________

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

120

00 8

OUTPUT CURRENT vs.DRIVER OUTPUT LOW VOLTAGE

20

100

MAX

481-

07

OUTPUT LOW VOLTAGE (V)

OUTP

UT C

URRE

NT (m

A)

6

60

40

2 4

80

10 12

140 -120

0-7 -5 -1 5

OUTPUT CURRENT vs.DRIVER OUTPUT HIGH VOLTAGE

-20

-80

MAX

481-

08

OUTPUT HIGH VOLTAGE (V)

OUTP

UT C

URRE

NT (m

A)

-3 1

-60

3-6 -4 -2 0 2 4

-100

-40

100

-40-60 -20 40 100 120

MAX1487SUPPLY CURRENT vs. TEMPERATURE

300M

AX48

1-13

TEMPERATURE (°C)

SUPP

LY C

URRE

NT (µ

A)

20 60 80

500

200

600

400

00 140

MAX1487; DE = VCC, RE = X

MAX1487; DE = 0V, RE = X

100

-50 -25 50 100

MAX481/MAX485/MAX490/MAX491SUPPLY CURRENT vs. TEMPERATURE

300

MAX

481-

11

TEMPERATURE (°C)

SUPP

LY C

URRE

NT (µ

A)

25 75

500

200

600

400

00 125

MAX481/MAX485; DE = VCC, RE = X

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

MAX481; DE = 0, RE = VCC

100

-50 -25 50 100

MAX483/MAX487–MAX489SUPPLY CURRENT vs. TEMPERATURE

300

MAX

481-

12

TEMPERATURE (°C)

SUPP

LY C

URRE

NT (µ

A)

25 75

500

200

600

400

00 125



MAX483/MAX487; DE = 0, RE = VCC

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

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


_______________________________________________________________________________________ 7

______________________________________________________________Pin Description

MAX481MAX483MAX485MAX487MAX1487

TOP 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.

1

2

3

4

8

5

VCC

GND DI

DE

RE

RO R

D

RtRt7

6

D

R

DE

RE

DI

ROA

B

1

2

3

4

8

7

6

5

VCC

B

A

GND DI

DE

RE

RO

DIP/SO

R

D

1

2

3

4

8

7

6

5

VCC

A

GND

DERE

B

RO

µMAX

B

A

DI


Figure 1. MAX481/MAX483/MAX485/MAX487/MAX1487 Pin Configuration and Typical Operating Circuit

µMAX

—

—

5

6

7

8

—

2

—

1

3

—

µMAX

4

5

6

7

—

—

8

—

1

—

2

—

DIP/SO DIP/SO

2 3Receiver Output Enable. RO is enabled when RE is low; RO ishigh impedance when RE is high.

3 4

Driver Output Enable. The driver outputs, Y and Z, are enabledby bringing DE high. They are high impedance when DE is low. Ifthe driver outputs are enabled, the parts function as line drivers.While they are high impedance, they function as line receivers ifRE is low.

DIP/SO

—

4 5Driver 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.

5 6, 7 Ground

— 9 Noninverting Driver Output

— 10 Inverting Driver Output

—

3

4

6 — Noninverting Receiver Input and Noninverting Driver Output

— 12 Noninverting Receiver Input

5

6

—

8

RE

DE

DI

GND

Y

Z

A

A

7 — — B Inverting Receiver Input and Inverting Driver Output

— 7 11 B Inverting Receiver Input

8 1 14 VCC Positive Supply: 4.75V ≤ VCC ≤ 5.25V

— — 1, 8, 13 N.C. No Connect—not internally connected

FUNCTIONNAME

431 2Receiver Output: If A > B by 200mV, RO will be high;If A < B by 200mV, RO will be low.

2 RO

PIN

FUNCTIONNAMEMAX481/MAX483/MAX485/MAX487/

MAX1487

MAX488/MAX490

MAX489/MAX491

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7

__________Applications InformationThe MAX481/MAX483/MAX485/MAX487–MAX491 andMAX1487 are low-power transceivers for RS-485 and RS-422 communications. The MAX481, MAX485, MAX490,MAX491, and MAX1487 can transmit and receive at datarates up to 2.5Mbps, while the MAX483, MAX487,MAX488, and MAX489 are specified for data rates up to250kbps. 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 theMAX481, MAX483, MAX485, MAX487, MAX489,MAX491, and MAX1487. When disabled, the driver andreceiver outputs are high impedance.

MAX487/MAX1487:128 Transceivers on the Bus

The 48kΩ, 1/4-unit-load receiver input impedance of theMAX487 and MAX1487 allows up to 128 transceiverson a bus, compared to the 1-unit load (12kΩ inputimpedance) of standard RS-485 drivers (32 trans-ceivers maximum). Any combination of MAX487/MAX1487 and other RS-485 transceivers with a total of32 unit loads or less can be put on the bus. TheMAX481/MAX483/MAX485 and MAX488–MAX491 havestandard 12kΩ Receiver Input impedance.


8 _______________________________________________________________________________________

MAX488MAX490

TOP VIEW

1

2

3

4

RO

DI

GND

8

7

6

5

A

B

Z

Y

VCC

DIP/SO

R

DRt

Rt

VCC

5

6

7

8

RO

DI

GND

4

GND

DI

RO

3

2A

B

Y

Z

VCC

D R

R D

1

3VCC

4RO

2A

1

6

5

7

8

GND

DI

Y

ZB

µMAX

MAX488MAX490

NOTE: TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE.

MAX489MAX491

DIP/SO

TOP VIEW

Rt

Rt

DE VCC

RE GND

VCC RE

GND DE

RO

DI

9

10

12

11B

A

Z

Y5

RO

NC

DI

2

1, 8, 13

3 6, 7

144

1

2

3

4

5

6

7

14

13

12

11

10

9

8

VCC

N.C.

N.C.

A

B

Z

Y

N.C.

RO

RE

DE

DI

GND

GND

R

D

D

R D

R

Figure 2. MAX488/MAX490 Pin Configuration and Typical Operating Circuit

Figure 3. MAX489/MAX491 Pin Configuration and Typical Operating Circuit

MAX483/MAX487/MAX488/MAX489:Reduced EMI and Reflections

The MAX483 and MAX487–MAX489 are slew-rate limit-ed, minimizing EMI and reducing reflections caused byimproperly terminated cables. Figure 12 shows the dri-ver output waveform and its Fourier analysis of a150kHz signal transmitted by a MAX481, MAX485,MAX490, MAX491, or MAX1487. High-frequency har-

monics with large amplitudes are evident. Figure 13shows the same information displayed for a MAX483,MAX487, MAX488, or MAX489 transmitting under thesame conditions. Figure 13’s high-frequency harmonicshave much lower amplitudes, and the potential for EMIis significantly reduced.

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


_______________________________________________________________________________________ 9

R

R

Y

Z

VOD

VOC

RECEIVEROUTPUT

TEST POINT

1kΩ

1kΩ

S1

S2

VCC

CRL15pF

DI

DE3V

Y

Z

CL1

CL2

A

B

RO

RE

RDIFFVID

OUTPUTUNDER TEST

500Ω S1

S2

VCC

CL

_________________________________________________________________Test Circuits

Figure 4. Driver DC Test Load Figure 5. Receiver Timing Test Load

Figure 6. Driver/Receiver Timing Test Circuit Figure 7. Driver Timing Test Load

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


10 ______________________________________________________________________________________

_______________________________________________________Switching Waveforms

DI3V

0V

Z

Y

VO0V

-VO

VO

1.5V

tPLH

1/2 VO

10%

tR

90% 90%

tPHL

1.5V

1/2 VO

10%

tF

VDIFF = V (Y) - V (Z)

VDIFF

tSKEW = | tPLH - tPHL |

OUTPUT NORMALLY LOW

OUTPUT NORMALLY HIGH

3V

0V

Y, Z

VOL

Y, Z

0V

1.5V 1.5V

VOL +0.5V

VOH -0.5V2.3V

2.3V

tZL(SHDN), tZL tLZ

tZH(SHDN), tZH tHZ

DE

VOH

VOL

VID

-VID

1.5V

0V

1.5VOUTPUT

INPUT 0V

RO

A-BtPLHtPHL

OUTPUT NORMALLY LOW

OUTPUT NORMALLY HIGH

3V

0V

VCCRO

RO0V

1.5V 1.5V

VOL + 0.5V

VOH - 0.5V1.5V

1.5V

tZL(SHDN), tZL tLZ

tZH(SHDN), tZH tHZ

RE

_________________Function Tables (MAX481/MAX483/MAX485/MAX487/MAX1487)

Figure 8. Driver Propagation Delays Figure 9. Driver Enable and Disable Times (except MAX488 andMAX490)

Figure 10. Receiver Propagation Delays Figure 11. Receiver Enable and Disable Times (except MAX488and MAX490)

Table 1. Transmitting Table 2. Receiving

INPUTS OUTPUT

RE DE A-B RO

0

0

0

1

0

0

0

0

> +0.2V

< -0.2V

Inputs open

X

1

0

1

High-Z*X = Don't careHigh-Z = High impedance

* Shutdown mode for MAX481/MAX483/MAX487

INPUTS OUTPUTS

RE DE DI Z Y

X

X

0

1

1

1

0

0

1

0

X

X

0

1

High-Z

High-Z*

1

0

High-Z

High-Z*X = Don't careHigh-Z = High impedance

* Shutdown mode for MAX481/MAX483/MAX487

Low-Power Shutdown Mode(MAX481/MAX483/MAX487)

A low-power shutdown mode is initiated by bringingboth RE high and DE low. The devices will not shutdown unless both the driver and receiver are disabled.In shutdown, the devices typically draw only 0.1µA ofsupply current.

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

For the MAX481, MAX483, and MAX487, the tZH andtZL enable times assume the part was not in the low-power shutdown state (the MAX485/MAX488–MAX491and MAX1487 can not be shut down). The tZH(SHDN)and tZL(SHDN) enable times assume the parts were shutdown (see Electrical Characteristics).

It takes the drivers and receivers longer to becomeenabled from the low-power shutdown state(tZH(SHDN), tZL(SHDN)) than from the operating mode(tZH, tZL). (The parts are in operating mode if the

–R—E–

,DE inputs equal a logical 0,1 or 1,1 or 0, 0.)

Driver Output Protection Excessive output current and power dissipation causedby faults or by bus contention are prevented by twomechanisms. A foldback current limit on the outputstage provides immediate protection against short cir-cuits over the whole common-mode voltage range (seeTypical Operating Characteristics). In addition, a ther-mal shutdown circuit forces the driver outputs into ahigh-impedance state if the die temperature risesexcessively.

Propagation DelayMany digital encoding schemes depend on the differ-ence between the driver and receiver propagationdelay times. Typical propagation delays are shown inFigures 15–18 using Figure 14’s test circuit.

The difference in receiver delay times, | tPLH - tPHL |, istypically under 13ns for the MAX481, MAX485,MAX490, MAX491, and MAX1487 and is typically lessthan 100ns for the MAX483 and MAX487–MAX489.

The driver skew times are typically 5ns (10ns max) forthe MAX481, MAX485, MAX490, MAX491, andMAX1487, and are typically 100ns (800ns max) for theMAX483 and MAX487–MAX489.

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


______________________________________________________________________________________ 11

10dB/div

0Hz 5MHz500kHz/div

10dB/div

0Hz 5MHz500kHz/div

Figure 12. Driver Output Waveform and FFT Plot of MAX481/MAX485/MAX490/MAX491/MAX1487 Transmitting a 150kHzSignal

Figure 13. Driver Output Waveform and FFT Plot of MAX483/MAX487–MAX489 Transmitting a 150kHz Signal

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


12 ______________________________________________________________________________________

TTL INtR, tF < 6ns D R

100pF

B

100pF

A

RECEIVEROUT

R = 54Ω

Z

Y

500mV/div

20ns/div

A

B

RO

2V/div

VCC = 5VTA = +25°C 500mV/div

20ns/div

A

B

RO

2V/div

VCC = 5VTA = +25°C

500mV/div

400ns/div

A

B

RO

2V/div

VCC = 5VTA = +25°C

500mV/div

400ns/div

A

B

RO

2V/div

VCC = 5VTA = +25°C

Figure 14. Receiver Propagation Delay Test Circuit

Figure 15. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver tPHL

Figure 16. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver tPLH

Figure 17. MAX483, MAX487–MAX489 Receiver tPHL Figure 18. MAX483, MAX487–MAX489 Receiver tPLH

Line Length vs. Data RateThe RS-485/RS-422 standard covers line lengths up to4000 feet. For line lengths greater than 4000 feet, seeFigure 23.

Figures 19 and 20 show the system differential voltagefor the parts driving 4000 feet of 26AWG twisted-pairwire at 110kHz into 120Ω loads.

Typical ApplicationsThe MAX481, MAX483, MAX485, MAX487–MAX491, andMAX1487 transceivers are designed for bidirectional datacommunications on multipoint bus transmission lines.

Figures 21 and 22 show typical network applicationscircuits. These parts can also be used as l inerepeaters, with cable lengths longer than 4000 feet, asshown in Figure 23.

To minimize reflections, the line should be terminated atboth ends in its characteristic impedance, and stublengths off the main line should be kept as short as possi-ble. The slew-rate-limited MAX483 and MAX487–MAX489are more tolerant of imperfect termination.

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


______________________________________________________________________________________ 13

DI

VY-VZ

RO

5V

0V

1V

0V-1V

5V

0V

2µs/div

DI

VY-VZ

RO

5V

0V

1V

0V-1V

5V

0V

2µs/div

DI RO DE

RE

A

B

RE

RERE

RO

RO

RO

DI

DI

DI

DE

DE

DE

D D

D

RR

R

B B

B

AAA

120Ω 120Ω

D

R


Figure 19. MAX481/MAX485/MAX490/MAX491/MAX1487 SystemDifferential Voltage at 110kHz Driving 4000ft of Cable

Figure 20. MAX483, MAX487–MAX489 System DifferentialVoltage at 110kHz Driving 4000ft of Cable

Figure 21. MAX481/MAX483/MAX485/MAX487/MAX1487 Typical Half-Duplex RS-485 Network

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


14 ______________________________________________________________________________________

Figure 22. MAX488–MAX491 Full-Duplex RS-485 Network

120Ω 120ΩR

D

RO

RE

DE

DI

A

B

Y

120Ω 120ΩDI

DI DIRO RO

RO

DE DE

DE

RE

RE

RE

Z

Z

Z

Z

Y Y

Y

A A AB B

B

D D

D

R R

R

MAX489MAX491

NOTE: RE AND DE ON MAX489/MAX491 ONLY.

Figure 23. Line Repeater for MAX488–MAX491

120Ω

120Ω DATA IN

DATA OUT

R

D

ROREDE

DI

A

B

Z

Y

MAX488–MAX491

NOTE: RE AND DE ON MAX489/MAX491 ONLY.

Isolated RS-485For isolated RS-485 applications, see the MAX253 andMAX1480 data sheets.

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


______________________________________________________________________________________ 15

__Ordering Information (continued)

_________________Chip TopographiesMAX481/MAX483/MAX485/MAX487/MAX1487

N.C.

RO

0.054"(1.372mm)

0.080"(2.032mm)

DE

DI

GND

B

N.C.

VCC

A

RE

* Contact factory for dice specifications.

14 CERDIP-55°C to +125°CMAX489MJD14 SO-40°C to +85°CMAX489ESD14 Plastic DIP-40°C to +85°CMAX489EPDDice*0°C to +70°CMAX489C/D14 SO0°C to +70°CMAX489CSD14 Plastic DIP0°C to +70°CMAX489CPD8 CERDIP-55°C to +125°CMAX488MJA8 SO-40°C to +85°CMAX488ESA8 Plastic DIP-40°C to +85°CMAX488EPADice*0°C to +70°CMAX488C/D

8 SO0°C to +70°CMAX488CSA8 Plastic DIP0°C to +70°CMAX488CPA8 CERDIP-55°C to +125°CMAX487MJA8 SO-40°C to +85°CMAX487ESA8 Plastic DIP-40°C to +85°CMAX487EPADice*0°C to +70°CMAX487C/D

8 SO0°C to +70°CMAX487CSA8 Plastic DIP0°C to +70°CMAX487CPA8 CERDIP-55°C to +125°CMAX485MJA8 SO-40°C to +85°CMAX485ESA8 Plastic DIP-40°C to +85°CMAX485EPADice*0°C to +70°CMAX485C/D

8 SO0°C to +70°CMAX485CSA8 Plastic DIP0°C to +70°CMAX485CPA8 CERDIP-55°C to +125°CMAX483MJA8 SO-40°C to +85°CMAX483ESA8 Plastic DIP-40°C to +85°CMAX483EPA

8 CERDIP-55°C to +125°CMAX481MJA

8 Plastic DIP-40°C to +85°CMAX481EPA

PIN-PACKAGETEMP. RANGEPART

14 CERDIP-55°C to +125°CMAX491MJD14 SO-40°C to +85°CMAX491ESD14 Plastic DIP-40°C to +85°CMAX491EPDDice*0°C to +70°CMAX491C/D14 SO0°C to +70°CMAX491CSD14 Plastic DIP0°C to +70°CMAX491CPD8 CERDIP-55°C to +125°CMAX490MJA8 SO-40°C to +85°CMAX490ESA8 Plastic DIP-40°C to +85°CMAX490EPADice*0°C to +70°CMAX490C/D

8 Plastic DIP0°C to +70°CMAX490CPAPIN-PACKAGETEMP. RANGEPART

8 SO-40°C to +85°CMAX481ESA

8 µMAX0°C to +70°CMAX485CUA



8 SO0°C to +70°CMAX490CSA8 µMAX0°C to +70°CMAX490CUA

__Ordering Information (continued)

8 CERDIP-55°C to +125°CMAX1487MJA8 SO-40°C to +85°CMAX1487ESA8 Plastic DIP-40°C to +85°CMAX1487EPADice*0°C to +70°CMAX1487C/D

8 SO0°C to +70°CMAX1487CSA8 Plastic DIP0°C to +70°CMAX1487CPA



Dice*0°C to +70°CMAX483C/D

8 SO0°C to +70°CMAX483CSA

8 Plastic DIP0°C to +70°CMAX483CPA

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


16 ______________________________________________________________________________________

TRANSISTOR COUNT: 248

SUBSTRATE CONNECTED TO GND

MAX488/MAX490

B

RO

0.054"(1.372mm)

0.080"(2.032mm)

N.C.

DI

GND

Z

A

VCC

Y

N.C.

_____________________________________________Chip Topographies (continued)

MAX489/MAX491

B

RO

0.054"(1.372mm)

0.080"(2.032mm)

DE

DI

GND

Z

A

VCC

Y

RE

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


______________________________________________________________________________________ 17

Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline informationgo to www.maxim-ic.com/packages.)

SO

ICN

.EP

SPACKAGE OUTLINE, .150" SOIC

11

21-0041 BREV.DOCUMENT CONTROL NO.APPROVAL

PROPRIETARY INFORMATION

TITLE:

TOP VIEW

FRONT VIEW

MAX

0.010

0.069

0.019

0.157

0.010

INCHES

0.150

0.007

E

C

DIM

0.014

0.004

B

A1

MIN

0.053A

0.19

3.80 4.00

0.25

MILLIMETERS

0.10

0.35

1.35

MIN

0.49

0.25

MAX

1.75

0.0500.016L 0.40 1.27

0.3940.386D

D

MINDIM

D

INCHES

MAX

9.80 10.00

MILLIMETERS

MIN MAX

16 AC

0.337 0.344 AB8.758.55 14

0.189 0.197 AA5.004.80 8

N MS012

N

SIDE VIEW

H 0.2440.228 5.80 6.20

e 0.050 BSC 1.27 BSC

C

HE

e B A1

A

D

0∞-8∞L

1

VARIATIONS:

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7


18 ______________________________________________________________________________________

8LU

MA

XD

.EP

S

PACKAGE OUTLINE, 8L uMAX/uSOP

11

21-0036 JREV.DOCUMENT CONTROL NO.APPROVAL

PROPRIETARY INFORMATION

TITLE:

MAX0.043

0.006

0.014

0.120

0.120

0.198

0.026

0.007

0.037

0.0207 BSC

0.0256 BSC

A2 A1

ce

b

A

L

FRONT VIEW SIDE VIEW

E H

0.6±0.1

0.6±0.1

ÿ 0.50±0.1

1

TOP VIEW

D

8

A2 0.030

BOTTOM VIEW

16∞

S

b

L

HE

De

c

0∞

0.010

0.116

0.116

0.188

0.016

0.005

84X S

INCHES

-

A1

A

MIN

0.002

0.950.75

0.5250 BSC

0.25 0.36

2.95 3.05

2.95 3.05

4.78

0.41

0.65 BSC

5.03

0.66

6∞0∞

0.13 0.18

MAXMIN

MILLIMETERS

- 1.10

0.05 0.15

α

α

DIM

Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline informationgo to www.maxim-ic.com/packages.)

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91


Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. 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 ____________________ 19

© 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

MA

X4

81

/MA

X4

83

/MA

X4

85

/MA

X4

87

–MA

X4

91

/MA

X1

48

7

PD

IPN

.EP

S

Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline informationgo to www.maxim-ic.com/packages.)

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