Datasheet

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General Description

The MAX13487E/MAX13488E +5V, half-duplex, ±15kV

ESD-protected RS-485/RS-422-compatible transceivers

feature one driver and one receiver. The MAX13487E/

MAX13488E include a hot-swap capability to eliminate

false transitions on the bus during power-up or live

insertion.

The MAX13487E/MAX13488E feature Maxim’s propri-

etary AutoDirection control. This architecture makes the

devices ideal for applications, such as isolated RS-485

ports, where the driver input is used in conjunction with

the driver-enable signal to drive the differential bus.

The MAX13487E 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 MAX13488E driver slew

rate is not limited, allowing transmit speeds up to

16Mbps.

The MAX13487E/MAX13488E feature a 1/4-unit load

receiver input impedance, allowing up to 128 trans-

ceivers 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 MAX13487E/MAX13488E are available in an 8-pin

SO package. The devices operate over the extended

-40°C to +85°C temperature range.

Applications

Isolated RS-485 Interfaces

Utility Meters

Industrial Controls

Industrial Motor Drives

Automated HVAC Systems

Features

♦ +5V Operation

♦ AutoDirection Enables Driver Automatically on

Transmission

♦ Hot-Swappable for Telecom Applications

♦ Enhanced Slew-Rate Limiting Facilitates Error-

Free Data Transmission (MAX13487E)

♦ High-Speed Version (MAX13488E) Allows for

Transmission Speeds Up to 16Mbps

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

±15kV Human Body Model

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

the Bus

♦ 8-Pin SO Package

MAX13487E/MAX13488E

Half-Duplex RS-485-/RS-422-Compatible

Transceiver with AutoDirection Control

________________________________________________________________

Maxim Integrated Products

19-0740; 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.

EVALUATION KIT

AVAILABLE

Ordering Information/

Selector Guide

PART

PIN-

PACKAGE

SLEW-RATE

LIMITED

PKG

CODE

MAX13487EESA+ 8 SO Yes S8-2

MAX13488EESA+ 8 SO No S8-2

Denotes a lead-free package

Note: All devices operate over the -40°C to +85°C temperature

range.

Pin Configuration/Typical Application Circuit appear at end

of data sheet.

STATE

MACHINE

COM

GND

SHDN

MAX13487E

MAX13488E

Functional Diagram

Summary of content (17 pages)

PAGE 1
KIT ATION EVALU E L B AVAILA 19-0740; Rev 0; 1/07 Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control Features The MAX13487E/MAX13488E +5V, half-duplex, ±15kV ESD-protected RS-485/RS-422-compatible transceivers feature one driver and one receiver. The MAX13487E/ MAX13488E include a hot-swap capability to eliminate false transitions on the bus during power-up or live insertion. The MAX13487E/MAX13488E feature Maxim’s proprietary AutoDirection control.
PAGE 2
MAX13487E/MAX13488E Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) Supply Voltage VCC ...............................................................+6V SHDN, RE, DI..............................................................-0.3V to +6 A, B........................................................................... -8V to +13V Short-Circuit Duration (RO, A, B) to GND ..................
PAGE 3
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control (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 POWER SUPPLY Supply Voltage VCC Supply Current ICC Shutdown Supply Current ISHDN 5.25 V SHDN = 1, RE = 0, no load 4.75 4.
PAGE 4
MAX13487E/MAX13488E Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control SWITCHING CHARACTERISTICS—MAX13487E (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-Compatible Transceiver with AutoDirection Control (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER SYMBOL Receiver Enable from Shutdown to Output Low CONDITIONS MIN TYP MAX UNITS tRZL (SHDN) Figure 8 2200 ns tRED Figure 3 70 ns 700 ns Receiver Enable Delay Time to Shutdown tSHDN 50 340 Note 1: All currents into the device are positive. All currents out of the device are negative.
PAGE 6
Typical Operating Characteristics (continued) (VCC = +5.0V, TA = +25°C, unless otherwise noted.) 2.0 1.5 1.0 0.5 60 40 -15 10 35 60 85 80 60 40 20 0 0 -40 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 0 5 2 4 6 8 10 12 OUTPUT-LOW VOLTAGE (V) SHUTDOWN CURRENT vs. TEMPERATURE DRIVER PROPAGATION vs. TEMPERATURE (MAX13487E) DRIVER PROPAGATION vs.
PAGE 7
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control 30 DRIVER PROPAGATION (16Mbps) (MAX13488E) MAX13487Etoc18 MAX13487Etoc16 DI 2V/div DI 2V/div tRPLH 20 tRPHL A-B 5V/div 10 A-B 5V/div WAVEFORM INTENSITY: 68% 0 10 35 60 85 400ns/div 10ns/div TEMPERATURE (°C) MAX13487Etoc20 DRIVING 16nF (19.2kbps) (MAX13487E) RECEIVER PROPAGATION (16Mbps) (MAX13488E) B 2V/div DI 2V/div A 2V/div A-B 5V/div RO 2V/div 10μs/div 10ns/div DRIVING 16nF (19.
PAGE 8
MAX13487E/MAX13488E Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control Test Circuits and Waveforms A RDIFF RL 2 DI VOD CL A VCC GND VID B RDIFF RL 2 VOC B Figure 2. Driver-Timing Test Circuit Figure 1. Driver DC Test Load RE = VCC VCC f = 1MHz, tLH ≤ 3ns, tHL ≤ 3ns 1.5V DI 1.5V 0 tDPLH 1/2 VO tDPHL B VO A 1/2 VO RO O tDDD, tRED (RO PULLED LOW) VDIFF = V(A) - V(B) VO VDIFF 90% 90% 0 10% 10% -VO tLH tHL Figure 3.
PAGE 9
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control VCC 1.5V SHDN 0 tDZL(SHDN) A, B 500Ω OUTPUT UNDER TEST S1 CL VCC 2.3V OUTPUT NORMALLY LOW VOL S2 OUTPUT NORMALLY HIGH A, B 2.3V 0 tDZH(SHDN) Figure 4. Driver Enable and Disable Times B R VID ATE RECEIVER OUTPUT A Figure 5. Receiver-Propagation-Delay Test Circuit f = 1MHz, tLH ≤ 3ns, tHL ≤ 3ns A 1V -1V B tRPLH tRPHL VOH RO 1.5V VOL 1.5V tRSKEW = | tRPHL - tRPLH | Figure 6.
PAGE 10
MAX13487E/MAX13488E Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control Test Circuits and Waveforms (continued) VCC RE 1.5V 1.5V 0 tRZL(SHDN), tRZL tRHZ VCC RO 2.3V 0 VOH + 0.5V OUTPUT NORMALLY LOW OUTPUT NORMALLY HIGH VCC 2.3V RO VOH + 0.5V 0 tRZH(SHDN), tRZH DI = 0V tRHZ Figure 7. Receiver Enable and Disable Times VCC 1.5V SHDN 0 tRZL(SHDN) VCC 500Ω RO CL S1 VCC 2.3V RO 0 S2 OUTPUT NORMALLY LOW OUTPUT NORMALLY HIGH VCC 2.
PAGE 11
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control PIN NAME 1 RO Receiver Output. When receiver is enabled and V(A) - V(B) > +200mV, RO is high. If V(A) - V(B) < -200mV, RO is low. 2 RE Receiver Output Enable. Drive RE low to enable the RO. Drive RE high to let the AutoDirection circuit control the receiver. RE is a hot-swap input (see the Hot-Swap Capability section for more details). 3 SHDN Shutdown. Drive SHDN high to let the device operate in normal operation.
PAGE 12
MAX13487E/MAX13488E Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control Detailed Description The MAX13487E/MAX13488E half-duplex, high-speed transceivers for RS-485/RS-422 communication contain one driver and one receiver. The MAX13487E/ MAX13488E feature a hot-swap capability allowing line insertion without erroneous data transfer (see the HotSwap Capability section).
PAGE 13
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control VCC 15μs TIMER SR LATCH TIMER ±15kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. The driver outputs and receiver inputs of the MAX13487E/MAX13488E have extra protection against static electricity.
PAGE 14
RC 1MΩ RD 1500Ω CHARGE-CURRENTLIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 100pF RC 50MΩ TO 100MΩ DISCHARGE RESISTANCE CHARGE-CURRENTLIMIT RESISTOR DEVICE UNDER TEST STORAGE CAPACITOR Figure 10a. Human Body ESD Test Model IP 100% 90% Ir HIGHVOLTAGE DC SOURCE Cs 150pF RD 330Ω DISCHARGE RESISTANCE STORAGE CAPACITOR DEVICE UNDER TEST Figure 10c.
PAGE 15
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control DI D VCC Rt SHDN RO RE D Rt VCC SHDN VCC R R MAX13487E MAX13488E R RO RE R D D DI DI SHDN RO RE DI SHDN RO RE Figure 11. Typical Half-Duplex RS-485 Network Typical Applications The MAX13487E/MAX13488E transceivers are designed for half-duplex, bidirectional data communications on multipoint bus transmission lines. Figure 11 shows a typical network application.
PAGE 16
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control MAX13487E/MAX13488E Pin Configuration/Typical Application Circuit VSYS RXD VISO VCC 0.
PAGE 17
Half-Duplex RS-485-/RS-422-Compatible Transceiver with AutoDirection Control N E H INCHES MILLIMETERS MAX MIN 0.053 0.069 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.050 0.016 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.