Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsInterface ICsInterface IC - transceivers RS422, RS485 1/1 SOIC 8 N

General Description

The MAX3460–MAX3464 are high-speed differential

bus transceivers for RS-485 and RS-422 communica-

tions. They are designed to meet TIA/EIA-422-B,

TIA/EIA-485-A, V.11, and X.27 standards. The trans-

ceiver complies with the Profibus specification provid-

ing +2.1V output level with a 54Ω load, 20Mbps data

rate, and output skew less than 2ns. Each part contains

one three-state differential line driver and one differen-

tial input line receiver. The devices operate from a +5V

supply and feature true fail-safe circuitry, which guaran-

tees a logic-high receiver output when the receiver

inputs are open or shorted. This enables all receiver

outputs on a terminated bus to output logic highs when

all transmitters are disabled.

All devices feature a 1/4 standard unit load receiver

input impedance that allows 128 transceivers on the

bus. Driver and receiver propagation delays are guar-

anteed under 20ns for multidrop, clock distribution

applications. Drivers are short-circuit current limited

and are protected against excessive power dissipation

by thermal shutdown circuitry. The driver and receiver

feature active-high and active-low enables, respective-

ly, that can be connected together externally to serve

as a direction control.

Applications

High-Speed RS-485 Communications

High-Speed RS-422 Communications

Level Translators

Industrial-Control Local Area Networks

Profibus Applications

Features

♦ Recommended for Profibus Applications

♦ Guaranteed 20Mbps Data Rate

♦ 20ns Transmitter and Receiver Propagation Delay

♦ 2ns Transmitter and Receiver Skew

♦ High Differential Driver Output Level (2.1V on 54Ω)

♦ Hot-Swap Versions

♦ 1µA Shutdown Supply Current

♦ Low Supply Current Requirements (2.5mA typ)

♦ Allow Up to 128 Transceivers on the Bus

♦ True Fail-Safe Receiver while Maintaining EIA/TIA-

485 Compatibility

♦ Designed for Multipoint Transmissions on Long

or Noisy Bus Lines

♦ Full Duplex and Half Duplex Versions Available

♦ Phase Controls to Correct for Twisted-Pair

Reversal for 14-Pin Versions

♦ Current-Limiting and Thermal Shutdown for

Driver Overload Protection

MAX3460–MAX3464

+5V, Fail-Safe, 20Mbps, Profibus RS-485/

RS-422 Transceivers

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

PART

NUMBER

HALF/FULL

DUPLEX

RECEIVER/

DRIVER

ENABLE

LOW-

POWER

SHUTDOWN

HOT SWAP

RECEIVER/

DRIVER PHASE

SELECT

INDEPENDENT

SHDN PIN

PIN COUNT

MAX3460 Full Yes Yes Yes Yes Yes 14

MAX3461 Full Yes Yes No Yes Yes 14

MAX3462 Full No No No No No 8

MAX3463 Half Yes Yes Yes No No 8

MAX3464 Half Yes Yes No No No 8

Selector Guide

19-2217; Rev 1; 2/03

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.

Ordering Information continued at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

MAX3460CSD 0°C to +70°C 14 SO

MAX3460CPD 0°C to +70°C 14 Plastic DIP

MAX3460ESD -40°C to +85°C 14 SO

MAX3460EPD -40°C to +85°C 14 Plastic DIP

Pin Configurations appear at end of data sheet.

Summary of content (14 pages)

PAGE 1
9-2217; Rev 1; 2/03 +5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers Features ♦ Recommended for Profibus Applications ♦ Guaranteed 20Mbps Data Rate ♦ 20ns Transmitter and Receiver Propagation Delay ♦ 2ns Transmitter and Receiver Skew ♦ High Differential Driver Output Level (2.1V on 54Ω) ♦ Hot-Swap Versions ♦ 1µA Shutdown Supply Current ♦ Low Supply Current Requirements (2.
PAGE 2
MAX3460–MAX3464 +5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) to GND ..................................-0.3V to +6V Control Input Voltage (RE, DE, DI, SHDN, TXP, RXP) to GND....................................................-0.3V to (VCC + 0.3V) Driver Output Voltage (Y, Z) to GND .........................-8V to +13V Receiver Input Voltage (A, B) to GND.......................-8V to +13V Differential Driver Output Voltage (Y - Z) ................
PAGE 3
+5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Receiver Input Hysteresis ∆VTH V A + VB = 0 Receiver Output High Voltage VOH IO = -4mA, VA - VB = VTH Receiver Output Low Voltage VOL IO = 4mA, VB - VA = VTH 0.
PAGE 4
ELECTRICAL CHARACTERISTICS (continued) (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.
PAGE 5
+5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers 30 20 10 0 120 100 -15 10 35 60 4.80 4.75 4.70 4.60 -40 -15 10 35 60 -40 85 -15 10 35 60 85 TEMPERATURE (°C) TEMPERATURE (°C) RECEIVER PROPAGATION DELAY vs. TEMPERATURE DRIVER PROPAGATION DELAY vs. TEMPERATURE DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURE 8 7 -15 10 35 60 4.0 MAX3460-64 toc08 RDIFF = 54Ω CL = 50pF 10 OUTPUT VOLTAGE (V) PROPAGATION DELAY (ns) MAX3460-64 toc07 9 12 8 RDIFF = 54Ω 3.
PAGE 6
Typical Operating Characteristics (continued) (VCC = +5V, TA = +25°C, unless otherwise noted.
PAGE 7
+5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers MAX3460/MAX3461 MAX3462 TRANSMITTING TRANSMITTING INPUTS OUTPUTS INPUT OUTPUTS RE DE DI SHDN Z Y DI Z Y X 1 1 0 0 1 1 0 1 X 1 0 0 1 0 0 1 0 0 0 X 0 High-Z High-Z 1 0 X X Shutdown X X X 1 Shutdown RECEIVING RECEIVING INPUTS 1 ≤ -0.2V 0 Open/Shorted 1 A–B SHDN RO 0 X ≥ -0.05V 0 1 0 X ≤ -0.2V 0 0 0 X Open/Shorted 0 1 1 1 X 0 High-Z 1 0 X X Shutdown X 1 RO ≥ -0.
PAGE 8
MAX3460–MAX3464 +5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers Pin Configurations and Typical Operating Circuit VCC DE TOP VIEW 4 SHDN 1 VCC RE 2 RE 3 12 A DE 4 11 B 9 13 RXP R DI 5 DI 5 D GND 7 8 12 RO Y TXP Rt 10 10 Z 9 Y RO R Z D GND 6 0.1µF 14 14 VCC RO MAX3460 MAX3461 TXP RXP 2 R 8 A Rt 11 DI D B 13 3 6, 7 GND DIP/SO RE DE GND Figure 1. MAX3460/MAX3461 Pin Configuration and Typical Full-Duplex Operating Circuit 0.
PAGE 9
+5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers The MAX3460–MAX3464 high-speed transceivers for RS-485/RS-422 communication contain one driver and one receiver. These devices feature true fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open or shorted, or when they are connected to a terminated transmission line with all drivers disabled (see the True Fail-Safe section). The MAX3460–MAX3464’s driver slew rates allow transmit speeds up to 20Mbps.
PAGE 10
MAX3460–MAX3464 +5V, Fail-Safe, 20Mbps, Profibus RS-485/ Y R OUTPUT UNDER TEST VOD VCC S1 RL CL R S2 VOC Z Figure 8. Enable/Disable Timing Test Load Figure 5. Driver DC Test Load 3V DE 1.5V 1.5V 0 tLZ tZL(SHDN), tZL Y, Z 2.3V VOL OUTPUT NORMALLY HIGH Y, Z 2.3V 3V VOH - 0.5V 0 DE DI VOL + 0.5V OUTPUT NORMALLY LOW tHZ tZH(SHDN), tZH Y VID RDIFF CL Figure 9. Driver Enable and Disable Times Z ƒ = 1MHz, tR ≤ 3ns, tF ≤ 3ns VOH RO 1.5V 1V A -1V B 1.5V OUTPUT VOL Figure 6.
PAGE 11
+5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers B ATE R VID RECEIVER OUTPUT A Figure 12. Receiver Propagation Delay Test Circuit Propagation Delay Many digital encoding schemes depend on the difference between the driver and receiver propagation delay times. Typical propagation delays are shown in the Typical Operating Characteristics. The difference in receiver delay times, |tPLH - tPHL|, is a maximum of 2ns. The driver skew time |tPLH - tPHL| is also a maximum of 2ns.
PAGE 12
MAX3460–MAX3464 +5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers 120Ω 120Ω B DI B DE D D DE A B A B A DI A R RO R RO RE RE R R D D MAX3463 MAX3464 (HALF-DUPLEX) DI DE RO DI RE DE RO RE Figure 13.
PAGE 13
+5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers N E H INCHES MILLIMETERS MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 SOICN .EPS DIM A A1 B C e E H L 1.27 VARIATIONS: 1 INCHES TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.
PAGE 14
Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) PDIPN.EPS MAX3460–MAX3464 +5V, Fail-Safe, 20Mbps, Profibus RS-485/ RS-422 Transceivers Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.