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Selector Guide

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 trans-

ceivers on a single bus. The devices operate from a 5V

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

guarantee 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 ther-

mal shutdown circuitry protect the driver against exces-

sive 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

Truck and Trailer Applications

Industrial Networks

Telecommunications Systems

Automotive Applications

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

MAX3440E–MAX3444E

±15kV ESD-Protected, ±60V Fault-Protected,

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

________________________________________________________________

Maxim Integrated Products

TOP VIEW

GND

DE/RE

FAULT

DE/RE

FAULT

GND

DE/RE

FAULT

DIP/SO DIP/SO

MAX3440E

MAX3441E

Pin Configurations and Typical Operating Circuits

Ordering Information

19-2666; Rev 2; 11/10

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

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

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)

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

Ordering Information continued at end of data sheet.

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

Summary of content (19 pages)

PAGE 1
9-2666; Rev 2; 11/10 ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Features ♦ ±15kV ESD Protection 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
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers MAX3440E–MAX3444E 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 Output High Voltage VOH Figure 2, I OH = -1.6mA Output Low Voltage VOL Figure 2, I OL = 1mA VCC - 0.6 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
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers (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
Typical Operating Characteristics (VCC = +5V, TA = +25°C, unless otherwise noted.) 4 DRIVER DISABLED, RECEIVER ENABLED 3 20 2 1 DRIVER AND RECEIVER ENABLED 16 12 DRIVER DISABLED, RECEIVER ENABLED 8 0.1 MAX3440E/MAX3442E/MAX3444E 0 MAX3442E/MAX3443E/MAX3444E 0.01 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) RECEIVER OUTPUT CURRENT vs.
PAGE 7
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers 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 DI A RL 2 S1 DI 0 tPLHA OUT D GENERATOR (NOTE 4) 1.5V 1.5V tPHLA VOH B 50Ω CL = 50pF (NOTE 5) VCC VOM = VOM A VOM VOL tPHLB VOH + VOL ≈ 1.5V 2 tPLHB VOH B VOM VOM VOL Figure 3. Driver Propagation Times 3V A DI D GENERATOR (NOTE 4) 0 RL B 1.
PAGE 8
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Test Circuits and Waveforms (continued) A DI 0 OR 3V 3V S1 A, B D DE DE GENERATOR (NOTE 4) RL = 500Ω CL = 50pF (NOTE 5) 1.5V 1.5V tPDZH B 0 tPDHS tPDHZ 50Ω 0.25V A, B VOM = VOH VOM VOH + VOL ≈ 1.5V 2 0 Figure 5. Driver Enable and Disable Times VCC 3V A DI 0 OR 3V RL = 500Ω S1 A, B D 1.5V 1.
PAGE 9
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers S1 S3 1.5V A -1.5V VID R RO VCC 1kΩ S2 B CL = 20pF (NOTE 5) GENERATOR (NOTE 4) 50Ω 3V RE 1.5V 0 tRPZH tRPSH tRPWAKE RO 3V S1 OPEN S2 CLOSED VS3 = 1.5V RE 1.5V 0 tRPZL tRPSL VOH VCC RO 1.5V 1.5V 0 VOL 3V RE S1 CLOSED S2 OPEN VS3 = -1.5V 1.5V 0 3V S1 OPEN S2 CLOSED VS3 = 1.5V RE 1.5V 0 S1 CLOSED S2 OPEN VS3 = -1.5V tRPHZ RO tRPLZ VOH 0.5V RO 0 VCC 0.5V VOL Figure 8.
PAGE 10
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers MAX3440E–MAX3444E Pin Description PIN MAX3440E MAX3441E 10 MAX3442E MAX3443E MAX3444E NAME FUNCTION Fault output.
PAGE 11
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers 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) Table 7. MAX3444E (RS-485/RS-422) RECEIVING RECEIVING INPUTS INPUTS OUTPUTS OUTPUTS RE DE (A - B) RO RE DE (A - B) RO 0 X ≥-0.05V 1 0 X ≥-0.05V 1 0 X ≤-0.2V 0 0 X ≤-0.2V 0 0 X Open/shorted 1 0 X Open/shorted 1 1 1 X High-Z 1 0 X High-Z 1 0 X Shutdown 1 1 X Shutdown X = Don’t care.
PAGE 13
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers ESD Test Conditions ESD performance depends on a number of conditions. Contact Maxim for a reliability report that documents test setup, methodology, and results. RC 1MΩ CHARGE-CURRENTLIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 100pF RD 1.5kΩ Driver Output Protection Two mechanisms prevent excessive output current and power dissipation caused by faults or bus contention.
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
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers where tRISE is the transmitter’s rise time. For example, the MAX3442E’s rise time is typically 800ns, which results in excellent waveforms with a stub length up to 53ft. A system can work well with longer unterminated stubs, even with severe reflections, if the waveform settles out before the UART samples them.
PAGE 16
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers 120Ω 120Ω DE/RE B B DI D D DI DE/RE A RO FAULT B A B A A RO R R FAULT R R D D MAX3440E MAX3441E DE/RE RO FAULT DI DI DE/RE RO FAULT Figure 13. MAX3440E/MAX3441E Typical RS-485 Network 120Ω 120Ω DE B B DI D D DI DE RO A B A B A A R R R R D D MAX3442E MAX3443E DI DE RO RE DI DE RO RE Figure 14.
PAGE 17
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers DE Tx D TXD B PART TEMP RANGE PIN-PACKAGE MAX3441EESA+ -40°C to +85°C 8 SO R1 4.7kΩ R3 47Ω MAX3441EEPA+ -40°C to +85°C 8 PDIP MAX3441EASA+ -40°C to +125°C 8 SO MAX3441EAPA+ -40°C to +125°C 8 PDIP C1 2.2nF MAX3442EESA+ -40°C to +85°C C2 2.2nF MAX3444E A Rx R4 47Ω R2 4.7kΩ R RO J1708 BUS RE VCC Figure 15.
PAGE 18
MAX3440E–MAX3444E ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers Chip Information PROCESS: BiCMOS 18 Package Information For the latest package outline information and land patterns, go to www.maxim-ic.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. PACKAGE TYPE PACKAGE CODE OUTLINE NO.
PAGE 19
±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers 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.