Datasheet

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

General Description

The MAX13485E/MAX13486E +5V, half-duplex, ±15kV

ESD-protected RS-485 transceivers feature one driver

and one receiver. These devices include fail-safe circuitry,

guaranteeing a logic-high receiver output when receiver

inputs are open or shorted. The receiver outputs a logic-

high if all transmitters on a terminated bus are disabled

(high impedance). The MAX13485E/MAX13486E include

a hot-swap capability to eliminate false transitions on the

bus during power-up or live-insertion.

The MAX13485E features reduced slew-rate drivers

that minimize EMI and reduce reflections caused by

improperly terminated cables, allowing error-free trans-

mission up to 500kbps. The MAX13486E driver slew

rate is not limited, allowing transmit speeds up to

16Mbps.

The MAX13485E/MAX13486E feature a 1/4-unit load

receiver input impedance, allowing up to 128 transceivers

on the bus. These devices are intended for half-duplex

communications. All driver outputs are protected to ±15kV

ESD using the Human Body Model. The MAX13485E/

MAX13486E are available in 8-pin SO and space-saving

8-pin µDFN packages. The devices operate over the

extended -40°C to +85°C temperature range.

Applications

Utility Meters

Industrial Controls

Industrial Motor Drives

Automated HVAC Systems

Features

♦ +5V Operation

♦ True Fail-Safe Receiver While Maintaining

EIA/TIA-485 Compatibility

♦ Hot-Swappable for Telecom Applications

♦ Enhanced Slew-Rate Limiting Facilitates Error-

Free Data Transmission (MAX13485E)

♦ High-Speed Version (MAX13486E) Allows for

Transmission Speeds Up to 16Mbps

♦ Extended ESD Protection for RS-485/RS-422 I/O

Pins ±15kV Using Human Body Model

♦ 1/4 Unit Load, Allowing Up to 128 Transceivers on

the Bus

♦ Available in Space-Saving 8-Pin μDFN or Industry

Standard 8-Pin SO Packages

MAX13485E/MAX13486E

Half-Duplex RS-485/RS-422 Transceivers in µDFN

________________________________________________________________

Maxim Integrated Products

19-0742; Rev 0; 1/07

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/

Selector Guide

PART

PIN-

PACKAGE

SLEW-RATE

LIMITED

PKG

CODE

MAX13485EELA+T 8 µDFN Yes L822-1

MAX13485EESA+ 8 SO Yes S8-2

MAX13486EELA+T 8 µDFN No L822-1

MAX13486EESA+ 8 SO No S8-2

Denotes a lead-free package.

Note: All devices are specified over the -40°C to +85°C operating

temperature range.

123

A GNDB

RO DIDERE

MAX13485E

MAX13486E

DFN

GNDDI

BRE

TOP VIEW

GND

0.1μF

MAX13485E

MAX13486E

Pin Configurations

Summary of content (16 pages)

PAGE 1
9-0742; Rev 0; 1/07 Half-Duplex RS-485/RS-422 Transceivers in µDFN The MAX13485E/MAX13486E +5V, half-duplex, ±15kV ESD-protected RS-485 transceivers feature one driver and one receiver. These devices include fail-safe circuitry, guaranteeing a logic-high receiver output when receiver inputs are open or shorted. The receiver outputs a logichigh if all transmitters on a terminated bus are disabled (high impedance).
PAGE 2
MAX13485E/MAX13486E Half-Duplex RS-485/RS-422 Transceivers in µDFN ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) VCC ........................................................................................+6V DE, RE, DI.................................................................-0.3V to +6V A, B ..............................................................................-8V to 13V Short-Circuit Duration (RO, A, B) to GND ..................
PAGE 3
Half-Duplex RS-485/RS-422 Transceivers in µDFN ELECTRICAL CHARACTERISTICS (continued) MAX UNITS Output-Low Voltage PARAMETER SYMBOL VOL IO = 1mA, VA - VB < -VTH CONDITIONS MIN TYP 0.4 V Tri-State Output Current at Receiver IOZR 0V < VO < VCC ±1 µA Receiver Input Resistance RIN -7V < VCM < +12V 48 Receiver-Output Short-Circuit Current IOSR 0V < VRO < VCC ±7 ±95 mA 4.75 5.25 V DE = 1, RE = 0, no load 4.
PAGE 4
MAX13485E/MAX13486E Half-Duplex RS-485/RS-422 Transceivers in µDFN SWITCHING CHARACTERISTICS—MAX13485E (continued) (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.
PAGE 5
Half-Duplex RS-485/RS-422 Transceivers in µDFN (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.
PAGE 6
Typical Operating Characteristics (continued) (VCC = +5V, TA = +25°C, unless otherwise noted.) RECEIVER OUTPUT HIGH VOLTAGE vs. TEMPERATURE 4.8 4.6 4.4 0.4 0.3 0.2 80 MAX13485-86E toc06 IO = 1mA OUTPUT CURRENT (mA) 5.0 MAX13485-86E toc05 OUTPUT HIGH VOLTAGE (V) 5.2 DIFFERENTIAL OUPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGE 0.5 OUTPUT LOW VOLTAGE (V) IO = 1mA RECEIVER OUTPUT LOW VOLTAGE vs. TEMPERATURE MAX13485-86E toc04 5.4 60 40 20 0.1 4.2 4.
PAGE 7
Half-Duplex RS-485/RS-422 Transceivers in µDFN RECEIVER PROPAGATION vs. TEMPERATURE (MAX13485E) tRPHL 40 20 MAX13485-86E toc14 60 DRIVER PROPAGATION (500kbps) (MAX13485E) MAX13485/86E toc15 40 RECEIVER PROPAGATION (ns) MAX13485-86E toc13 PROPAGATION DELAY (ns) 80 RECEIVER PROPAGATION vs.
PAGE 8
MAX13485E/MAX13486E Half-Duplex RS-485/RS-422 Transceivers in µDFN Test Circuits and Waveforms A 5V RDIFF DE 2 A DI VOD VID CL RDIFF B RDIFF VOC 2 B Figure 2. Driver Timing Test Circuit Figure 1. Driver DC Test Load f = 1MHz, tLH ≤ 3ns, tHL ≤ 3ns VCC DI 1.5V 1.5V 0 1/2 VO tDPHL tDPLH B A 1/2 VO VO VDIFF = V(A) - V(B) VO VDIFF 90% 90% 0 10% 10% -VO tHL tLH tDSKEW = |tDPLH - tDPHL| Figure 3.
PAGE 9
Half-Duplex RS-485/RS-422 Transceivers in µDFN VCC DE 1.5V 1.5V 0 tDLZ tDZL(SHDN),tDZL A, B 2.3V VOL + 0.5V OUTPUT NORMALLY LOW VOL OUTPUT NORMALLY HIGH A, B 2.3V VOH + 0.5V 0 tDZH(SHDN),tDZH tDHZ Figure 4. Driver Enable and Disable Times 500Ω S1 VCC B OUTPUT UNDER TEST R VID ATE CL RECEIVER OUTPUT A S2 Figure 5. Driver-Enable and -Disable-Timing Test Load Figure 6. Receiver Propagation Delay Test Circuit f = 1MHz, tLH ≤ 3ns, tHL ≤ 3ns A 1V B -1V tRPHL tRPLH VOH RO 1.
PAGE 10
MAX13485E/MAX13486E Half-Duplex RS-485/RS-422 Transceivers in µDFN Pin Description PIN NAME 1 RO Receiver Output FUNCTION 2 RE 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. RE is a hot-swap input (see the Hot-Swap Capability section for more details). 3 DE Driver Output Enable. Drive DE high to enable the driver outputs. These outputs are high-impedance when DE is low.
PAGE 11
Half-Duplex RS-485/RS-422 Transceivers in µDFN S1 +1V S3 VCC 1kΩ -1V VID CL 15pF GENERATOR S2 50Ω S1 OPEN S2 CLOSED S3 = +1V S1 CLOSED S2 OPEN S3 = -1V VCC VCC VCC/2 VCC/2 RE RE 0 0 tRZH, tRZH(SHDN) tRZL, tRZL(SHDN) VOH RO VCC VOH/2 (VOL + VCC)/2 RO 0 S1 OPEN S2 CLOSED S3 = +1V VOL S1 CLOSED S2 OPEN S3 = -1V VCC VCC/2 VCC/2 RE 0 RE VCC 0 tRLZ tRHZ VCC VOH RO 0.25V 0 RO 0.25V Figure 8.
PAGE 12
MAX13485E/MAX13486E Half-Duplex RS-485/RS-422 Transceivers in µDFN Detailed Description The MAX13485E/MAX13486E half-duplex, high-speed transceivers for RS-485/RS-422 communication contain one driver and one receiver. These devices feature failsafe circuitry that guarantees a logic-high receiver output when receiver inputs are open or shorted, or when they are connected to a terminated transmission line with all drivers disabled (see the Fail-Safe section).
PAGE 13
Half-Duplex RS-485/RS-422 Transceivers in µDFN CHARGE-CURRENT LIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 100pF RC 50MΩ TO 100MΩ RD 1500Ω CHARGE-CURRENT LIMIT RESISTOR DISCHARGE RESISTANCE DEVICE UNDER TEST STORAGE CAPACITOR Figure 10a. Human Body ESD Test Model IP 100% 90% Cs 150pF RD 330Ω DISCHARGE RESISTANCE STORAGE CAPACITOR DEVICE UNDER TEST Figure 10c.
PAGE 14
MAX13485E/MAX13486E Half-Duplex RS-485/RS-422 Transceivers in µDFN DI D Rt D Rt DE RO RE DI DE R R R MAX13485E MAX13486E R D D DI RO RE DE RO RE DI DE RO RE Figure 11. Typical Half-Duplex RS-485 Network withstand voltage measured to IEC 61000-4-2 is generally lower than that measured using the Human Body Model. Figure 10c shows the IEC 61000-4-2 model, and Figure 10d shows the current waveform for the IEC 61000-4-2 ESD Contact Discharge test.
PAGE 15
Half-Duplex RS-485/RS-422 Transceivers in µDFN 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 16
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.) A D XXXX XXXX XXXX b e 6, 8, 10L UDFN.EPS MAX13485E/MAX13486E Half-Duplex RS-485/RS-422 Transceivers in µDFN N SOLDER MASK COVERAGE E PIN 1 0.