Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsInterface ICsInterface IC - transceivers RS422, RS485 1/1 PDIP 28

_________________General Description

The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB

are complete, electrically isolated, RS-485/RS-422 data

communications interface solutions in a hybrid microcir-

cuit. The RS-485/RS-422 I/O pins are protected against

±15kV electrostatic discharge (ESD) shocks, without

latchup. Transceivers, optocouplers, and a transformer

provide a complete interface in a standard DIP package.

A single +5V supply on the logic side powers both sides

of the interface.

The MAX1480EC/MAX1490EB feature reduced-slew-rate

drivers that minimize EMI and reduce reflections caused

by improperly terminated cables, allowing error-free data

transmission at data rates up to 160kbps. The

MAX1480EA/MAX1490EA driver slew rate is not limited,

allowing transmission rates up to 2.5Mbps. The

MAX1480EA/MAX1480EC are designed for half-duplex

communication, while the MAX1490EA/MAX1490EB fea-

ture full-duplex communication.

Drivers are short-circuit current limited and protected

against excessive power dissipation by thermal shut-

down circuitry that places the driver outputs into a high-

impedance state. The receiver input has a fail-safe

feature that guarantees a known output (RO low for the

MAX1480EA/MAX1480EC, RO high for the MAX1490EA/

MAX1490EB) if the input is open circuit.

The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB

withstand 1260V

RMS

(1min) or 1520V

RMS

(1s). Their iso-

lated outputs meet all RS-485/RS-422 specifications. The

MAX1480EA/MAX1480EC are available in a 28-pin DIP

package, and the MAX1490EA/MAX1490EB are available

in a 24-pin DIP package.

________________________Applications

Isolated RS-485/RS-422 Data Interface

Transceivers for EMI-Sensitive Applications

Industrial-Control Local Area Networks

Automatic Test Equipment

HVAC/Building Control Networks

Telecom

____________________________Features

♦ Isolated Data Interface, Guaranteed to 1260V

RMS

(1min)

♦ ±15kV ESD Protection on I/O Pins

♦ Slew-Rate Limited for Errorless Data

Transmission (MAX1480EC/MAX1490EB)

♦ High-Speed, Isolated, 2.5Mbps RS-485/RS-422

Interface (MAX1480EA/MAX1490EA)

♦ Full-Duplex Data Communication

(MAX1490EA/MAX1490EB)

♦ Single +5V Supply

♦ Current Limiting and Thermal Shutdown for

Driver Overload Protection

♦ Standard 0.6in DIP Packages

28-Pin DIP (MAX1480EA/MAX1480EC)

24-Pin DIP (MAX1490EA/MAX1490EB)

MAX1480E/MAX1490E

±15kV ESD-Protected, Isolated RS-485/RS-422

Data Interfaces

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

AC1

AC2

ISO V

CC1

ISO RO DRVD2

GND1

ISO COM1

ISO DI DRV

ISO V

CC2

ISO RO LED

GND2

DIP

CC2

CC3

CC4

CC1

MAX1490EA/

MAX1490EB

MAX845E

MAX488E

MAX490E

TOP VIEW

ISOLATION BARRIER

19-1940; Rev 0; 4/01

PART

†

MAX1480EACPI

MAX1480EAEPI -40°C to +85°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

28 Wide Plastic DIP*

_______________Ordering Information

Ordering Information continued at end of data sheet.

†

Data rate for A parts is up to 2.5Mbps. Data rate for C parts is

up to 250kbps.

*See Reliability section at end of data sheet.

Pin Configurations continued at end of data sheet.

Selector Guide appears at end of data sheet.

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.

Summary of content (19 pages)

PAGE 1
9-1940; Rev 0; 4/01 ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces ____________________________Features The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB are complete, electrically isolated, RS-485/RS-422 data communications interface solutions in a hybrid microcircuit. The RS-485/RS-422 I/O pins are protected against ±15kV electrostatic discharge (ESD) shocks, without latchup. Transceivers, optocouplers, and a transformer provide a complete interface in a standard DIP package.
PAGE 2
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces ABSOLUTE MAXIMUM RATINGS With Respect to GND_ Supply Voltage (VCC_)..........................................-0.3V to +6V Control Input Voltage (SD, FS)..............-0.3V to (VCC_ + 0.3V) Receiver Output Voltage (RO, RO).......-0.3V to (VCC_ + 0.3V) Output Switch Voltage (D1, D2).......................................+12V With Respect to ISO COM_ Control Input Voltage (ISO DE_) ....-0.3V to (ISO VCC_ + 0.
PAGE 3
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces (VCC_ = +5V ±10%, VFS = VCC_, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC_ = +5V and TA = +25°C.) (Notes 1, 2) PARAMETER SYMBOL Change in Magnitude of Driver Output Voltage for Complementary Output States ∆VOD Driver Common-Mode Output VOC CONDITIONS ISO IIN Receiver Differential Threshold 0.3 Common mode 0.3 DE´ = 0, VCC_ = 0 or +5.
PAGE 4
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces SWITCHING CHARACTERISTICS—MAX1480EA/MAX1490EA (continued) (VCC_ = +5V ±10%, VFS = VCC_, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC_ = +5V and TA = +25°C.
PAGE 5
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces 50 40 30 -20 -15 -10 20 10 0 -40 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 20 40 60 80 OUTPUT CURRENT vs. DRIVER OUTPUT LOW VOLTAGE OUTPUT CURRENT vs. DRIVER OUTPUT HIGH VOLTAGE 0.2 120 100 80 60 -80 -70 -60 -50 -40 -30 40 -20 0.1 20 -10 0 0 -20 0 20 40 60 0 0 80 1 2 3 4 5 6 7 8 9 10 11 12 TEMPERATURE (°C) OUTPUT LOW VOLTAGE (V) DRIVER OUTPUT CURRENT vs.
PAGE 6
____________________________Typical Operating Characteristics (continued) (VCC_ = +5V, VFS = VCC_, Figures 1 and 2, TA = +25°C, unless otherwise noted.) 100 DE´ = VCC RL = ∞ 80 60 40 VCC = +5.5V VCC = +4.5V 20 100 VCC = +5V 90 VCC = +4.5V 80 DE´ = VCC 70 60 VCC = +5.5V 50 VCC = +5V VCC = +5V 40 0 VCC = +4.5V 20 -20 0 20 40 60 80 RL = 54Ω VCC = +5.5V 180 VCC = +5V 160 VCC = +4.5V 140 VCC = +5.5V 120 VCC = +5V RL = ∞ 100 30 -40 RL = ∞ 200 SUPPLY CURRENT (mA) VCC = +4.
PAGE 7
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces (VCC_ = +5V, VFS = VCC_, VDI´ = 0, DE´ toggled 0 to 5V at 5kHz, Figures 1 and 2, TA = +25°C, unless otherwise noted.
PAGE 8
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces ________________________________________________________________Pin Description PIN 8 MAX1480EA/ MAX1480EC MAX1490EA/ MAX1490EB NAME FUNCTION 1, 2, 8, 10 3, 4 5 1, 2, 8, 10 3, 4 5 VCC1–VCC4 D1, D2 GND1 6 6 FS Frequency Select Input. If FS = VCC_ or is open, switch frequency is high; if FS = GND, switch frequency is low. For optimal performance and minimal supply current, connect FS to VCC_ or leave unconnected.
PAGE 9
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces PIN MAX1480EA/ MAX1480EC MAX1490EA/ MAX1490EB NAME — — — — 21 22 23 17 18 19 20 — — — Y Z B A ISO DE IN ISO DI IN A 24 21 ISO RO DRV 25 26 27, 28 — 22 23, 24 B ISO VCC1 AC2, AC1 FUNCTION Noninverting Driver Output Inverting Driver Output Inverting Receiver Input Noninverting Receiver Input Isolated Driver-Enable Input. Connect to ISO DE DRV for normal operation. Isolated Driver Input. Connect to ISO DI DRV for normal operation.
PAGE 10
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces VCC3 ISO VCC1 D1 MAX845E Q OSC 1.07MHz/ 1.45MHz FS MAX1480EA: MAX1487E MAX1480EC: MAX487E N T F/F B ISO DI IN D D2 Q N A ISO DE IN ISO RO DRV R RE GND1 SD ISO COM1 EXTERNAL RS-485/RS-422 WIRING VIN +5V C1 22µF C2 0.
PAGE 11
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces MAX1480E/MAX1490E VCC3 D1 MAX845 Q OSC 1.07MHz/ 1.45MHz FS N T F/F A R D2 Q ISO RO DRV B ISO DI DRV N MAX1490EA: MAX490E MAX1490EB: MAX488E Z D SD MAX1490EA/ MAX1490EB VIN +5V VCC1 C1 22µF C2 0.
PAGE 12
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces MAX1480EA VIN +5V Si9433DY VCC1 1 28 AC1 VCC2 2 27 AC2 D1 3 26 ISO VCC1 D2 4 25 B 24 ISO RO DRV GND1 5 P FS 6 SHUTDOWN R1 DI´ R2 MAX845 MAX1487E 22 ISO DI IN VCC3 8 21 ISO DE IN DI 9 20 ISO COM1 VCC4 10 19 ISO DI DRV DE 11 DE´ R3 18 ISO VCC2 GND2 12 17 ISO DE DRV RO 13 RO 23 A SD 7 VCC5 16 ISO COM2 15 ISO RO LED 14 ISOLATION BARRIER GND Figure 3.
PAGE 13
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces ISO VCC_ S1 500Ω OUTPUT UNDER TEST CL S2 Figure 6. Driver Timing Test Load Switching Waveforms VCC_ - 0.4V DI´ VCC_ - 0.4V 2 VCC_ - 0.4V 2 0 tPLH DE´ tPHL 0 1/2 VO VCC_ - 0.4V 2 VCC_ - 0.4V 2 tLZ tZL B A, B VO A 2.3V OUTPUT NORMALLY LOW VOL 1/2 VO VO VDIFF 0 -VO VCC_ -0.4V 10% VDIFF = V (A) - V (B) 90% tR OUTPUT NORMALLY HIGH A, B 90% VOL + 0.5V VOH - 0.5V 2.
PAGE 14
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces cuits over the entire common-mode range (see Typical Operating Characteristics). In addition, a thermal shutdown circuit forces the driver outputs into a high-im pedance state if the die temperature rises excessively. _____________________Function Tables Half-Duplex Devices (MAX1480EA/MAX1480EC) Propagation Delay Skew Propagation delay skew is the difference between the low-to-high and high-to-low propagation delay.
PAGE 15
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces These E versions of the MAX1480EA/MAX1480EC/ 1490EA/MAX1490EB provide extra protection against ESD. The rugged MAX1480EA/MAX1480EC/MAX1490EA/ MAX1490EB are intended for harsh environments where high-speed communication is important. These devices eliminate the need for transient suppressor diodes or the use of discrete protection components.
PAGE 16
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces TERMINATING RESISTOR (ONE RESISTOR ON EACH END) B DI D 120Ω DE A A A B B RO R 100Ω RE R RE R RE D D RO DE DI RO DE DI MAX1480EA/ MAX1480EC VIN +5V C1 22µF C2 0.
PAGE 17
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces C1 22µF C2 0.
PAGE 18
MAX1480E/MAX1490E ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces rents may flow. These currents are by their nature unstable and unpredictable. In addition, they may cause noise to be injected into sensitive instrumentation and, in severe cases, might actually cause physical damage to such equipment. Figure 17 shows a half-duplex (2-wire), bidirectional, party-line repeater system that prevents interference and/or damage from ground-potential differences.
PAGE 19
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces Pin Configurations (continued) PART† TEMP. RANGE MAX1480ECCPI 0°C to +70°C 28 Wide Plastic DIP MAX1480ECEPI -40°C to +85°C 28 Wide Plastic DIP 0°C to +70°C 24 Wide Plastic DIP -40°C to +85°C 24 Wide Plastic DIP 0°C to +70°C 24 Wide Plastic DIP VCC1 1 24 Wide Plastic DIP VCC2 2 MAX1490EACPG MAX1490EAEPG MAX1490EBCPG MAX1490EBEPG -40°C to +85°C PIN-PACKAGE † Data rate for A parts is up to 2500kbps.