Datasheet

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General Description

The MAX3440E–MAX3444E fault-protected RS-485 and

J1708 transceivers feature ±60V protection from signal

faults on communication bus lines. Each device contains

one differential line driver with three-state output and one

differential line receiver with three-state input. The 1/4-unit-

load receiver input impedance allows up to 128 transceiv-

ers on a single bus. The devices operate from a 5V supply

at data rates of up to 10Mbps. True fail-safe inputs guar-

antee a logic-high receiver output when the receiver inputs

are open, shorted, or connected to an idle data line.

Hot-swap circuitry eliminates false transitions on the data

bus during circuit initialization or connection to a live

backplane. Short-circuit current-limiting and thermal shut-

down circuitry protect the driver against excessive power

dissipation, and on-chip ±15kV ESD protection eliminates

costly external protection devices.

The MAX3440E–MAX3444E are available in 8-pin SO

and PDIP packages and are specified over industrial and

automotive temperature ranges.

Applications

● RS-422/RS-485 Communications

● Industrial Networks

● Telecommunications Systems

● HVAC Controls

Features

● ±15kV ESD Protection

● ±60V Fault Protection

● Guaranteed 10Mbps Data Rate

(MAX3441E/MAX3443E)

● Hot Swappable for Telecom Applications

● True Fail-Safe Receiver Inputs

● Enhanced Slew-Rate-Limiting Facilitates

Error-Free Data Transmission

(MAX3440E/MAX3442E/MAX3444E)

● Allow Up to 128 Transceivers on the Bus

● -7V to +12V Common-Mode Input Range

● Automotive Temperature Range (-40°C to +125°C)

● Industry-Standard Pinout

19-2666; Rev 3; 4/14

+Denotes a lead(Pb)-free/RoHS-compliant package.

Ordering Information continued at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

MAX3440EESA+ -40°C to +85°C 8 SO

MAX3440EEPA+ -40°C to +85°C 8 PDIP

MAX3440EASA+ -40°C to +125°C 8 SO

MAX3440EAPA+ -40°C to +125°C 8 PDIP

Ordering Information

Pin Configurations and Typical Operating Circuits continued at end of data sheet.

PART TYPE

DATA RATE

(Mbps)

LOW-POWER

SHUTDOWN

RECEIVER/DRIVER

ENABLE

TRANSCEIVERS

ON BUS

HOT SWAP

MAX3440E RS-485 0.25 No Yes 128 Yes

MAX3441E RS-485 2.5 to 10 No Yes 128 Yes

MAX3442E RS-485 0.25 Yes Yes 128 Yes

MAX3443E RS-485 2.5 to 10 Yes Yes 128 Yes

MAX3444E J1708 0.25 Yes Yes 128 Yes (only RE)

TOP VIEW

GND

DE/RE

FAULT

DE/RE

FAULT

GND

DE/RE

FAULT

DIP/SO DIP/SO

MAX3440E

MAX3441E

MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected,

10Mbps, Fail-Safe RS-485/J1708 Transceivers

Selector Guide

Pin Congurations and Typical Operating Circuits

Summary of content (19 pages)

PAGE 1
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers General Description The MAX3440E–MAX3444E fault-protected RS-485 and J1708 transceivers feature ±60V protection from signal faults on communication bus lines. Each device contains one differential line driver with three-state output and one differential line receiver with three-state input. The 1/4-unitload receiver input impedance allows up to 128 transceivers on a single bus.
PAGE 2
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Absolute Maximum Ratings Voltages Referenced to GND VCC.........................................................................................+7V FAULT, DE/RE, RE, DE, DE, DI, TXD....... -0.3V to (VCC + 0.3V) A, B (Note 1)........................................................................±60V RO............................................................. -0.3V to (VCC + 0.
PAGE 3
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers DC Electrical Characteristics (continued) (VCC = +4.75V to +5.25V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS RECEIVER LOGIC VCC – 0.6 Output High Voltage VOH Figure 2, IOH = -1.6mA V Output Low Voltage VOL Figure 2, IOL = 1mA 0.
PAGE 4
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Switching Characteristics (MAX3440E/MAX3442E/MAX3444E) (VCC = +4.75V to +5.25V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.
PAGE 5
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Switching Characteristics (MAX3441E/MAX3443E) (VCC = +4.75V to +5.25V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.
PAGE 6
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Typical Operating Characteristics (VCC = +5V, TA = +25°C, unless otherwise noted.) DRIVER DISABLED, RECEIVER ENABLED 3 2 1 16 12 8 DRIVER DISABLED, RECEIVER ENABLED RECEIVER OUTPUT VOLTAGE vs. TEMPERATURE 15 10 5 35 30 25 20 15 10 5 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.0 RECEIVER OUTPUT VOLTAGE (V) 20 RECEIVER OUTPUT CURRENT (mA) 25 40 MAX3443E toc05 RECEIVER OUTPUT CURRENT vs.
PAGE 7
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Test Circuits and Waveforms RL 2 A DI VOD D B RL VCC VOC 2 Figure 1. Driver VOD and VOC A VID RO R B 0 VOL IOL (+) VOH IOH (-) Figure 2. Receiver VOH and VOL 3V VOM A DI GENERATOR (NOTE 4) S1 B 0 CL = 50pF (NOTE 5) VCC VOM = 1.5V 1.5V tPLHA OUT D 50Ω DI RL 2 tPHLA VOH VOM A VOM VOL tPHLB VOH + VOL ª 1.5V 2 tPLHB VOH B VOM VOM VOL Figure 3.
PAGE 8
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Test Circuits and Waveforms (continued) 0 OR 3V DI A DE GENERATOR (NOTE 4) 3V S1 A, B D DE RL = 500W CL = 50pF (NOTE 5) 1.5V 1.5V tPDZH B tPDHS 0 tPDHZ 50W 0.25V A, B VOM = VOH VOM VOH + VOL ª 1.5V 2 0 Figure 5. Driver Enable and Disable Times VCC 0 OR 3V DI A GENERATOR (NOTE 4) S1 tPDLS B CL = 50pF (NOTE 5) 1.5V 1.
PAGE 9
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Test Circuits and Waveforms (continued) S3 1.5V S1 A -1.5V VID R RO VCC 1kΩ S2 B GENERATOR (NOTE 4) CL = 20pF (NOTE 5) 50Ω 3V RE 1.5V 0 tRPZH tRPSH tRPWAKE RO S1 OPEN S2 CLOSED VS3 = 1.5V 3V RE 1.5V VOH VCC RO 1.5V 1.5V 0 3V RE 1.5V 0 VOL S1 OPEN S2 CLOSED VS3 = 1.5V 3V RE 1.5V 0 tRPHZ RO 0.5V tRPLZ VOH RO 0 0 tRPZL tRPSL S1 CLOSED S2 OPEN VS3 = -1.
PAGE 10
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Pin Description PIN MAX3440E MAX3441E MAX3442E MAX3443E MAX3444E NAME FUNCTION Fault output.
PAGE 11
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Function Tables Table 1. MAX3440E/MAX3441E Fault Table INPUTS A-B VID DIFFERENTIAL INPUT VOLTAGE OUTPUTS COMMON-MODE VOLTAGE RO FAULT CONDITIONED BY DELAY FAULT CONDITION ≥0.45V 1 0 Normal operation <0.45V and ≥0.27V 1 Indeterminate Indeterminate <0.27V and ≥-0.05V 1 1 Low-input differential voltage ≤-0.05V and ≥-0.
PAGE 12
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Function Tables (continued) Table 6. MAX3442E/MAX3443E (RS-485/RS-422) RE 0 0 0 1 1 X = Don’t care. RECEIVING INPUTS DE (A - B) X ≥-0.05V X ≤-0.2V X Open/shorted 1 X 0 X Table 7. MAX3444E (RS-485/RS-422) OUTPUTS RO 1 0 1 High-Z Shutdown RECEIVING INPUTS OUTPUTS RE DE (A - B) RO 0 X ≥-0.05V 1 0 X £-0.2V 0 0 X Open/shorted 1 1 0 X High-Z 1 1 X Shutdown X = Don’t care.
PAGE 13
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers ±15kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against ESD encountered during handling and assembly. The MAX3440E– MAX3444E receiver inputs/driver outputs (A, B) have extra protection against static electricity found in normal operation.
PAGE 14
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Hot-Swap Capability Hot-Swap Inputs Inserting circuit boards into a hot, or powered, backplane may cause voltage transients on DE, DE/RE, RE, and receiver inputs A and B that can lead to data errors. For example, upon initial circuit board insertion, the processor undergoes a power-up sequence.
PAGE 15
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers 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 = tRISE/(10 x 1.5ns/ft) where tRISE is the transmitter’s rise time.
PAGE 16
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers 120Ω 120Ω B DI DE/RE B D D DI DE/RE A RO FAULT B A B A A RO R R FAULT R MAX3440E MAX3441E R D D DE/RE RO FAULT DI DI DE/RE RO FAULT Figure 13. MAX3440E/MAX3441E Typical RS-485 Network 120Ω 120Ω B DI DE B D D DI DE A RO B A B A A R R RO RE RE R MAX3442E MAX3443E R D D DI DE RO RE DI DE RO RE Figure 14.
PAGE 17
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Ordering Information (continued) PART DE Tx TXD D R1 4.7kΩ R3 47Ω B C1 2.2nF C2 2.2nF MAX3444E A Rx R4 47Ω R2 4.7kΩ R RO J1708 BUS RE VCC Figure 15.
PAGE 18
MAX3440E–MAX3444E Chip Information PROCESS: BiCMOS www.maximintegrated.com ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.
PAGE 19
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Revision History PAGES CHANGED — REVISION NUMBER REVISION DATE 0 10/02 Initial release 1 12/05 Corrected the supply current units from µA to mA for the Shutdown Supply Current vs.