19-1940; Rev 0; 4/01
±15kV ESD-Protected, Isolated RS-485/RS-422
Data Interfaces
_________________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.
.
____________________________Features
o
Isolated Data Interface, Guaranteed to 1260V
RMS
(1min)
o
±15kV ESD Protection on I/O Pins
o
Slew-Rate Limited for Errorless Data
Transmission (MAX1480EC/MAX1490EB)
o
High-Speed, Isolated, 2.5Mbps RS-485/RS-422
Interface (MAX1480EA/MAX1490EA)
o
Full-Duplex Data Communication
(MAX1490EA/MAX1490EB)
o
Single +5V Supply
o
Current Limiting and Thermal Shutdown for
Driver Overload Protection
o
Standard 0.6in DIP Packages
28-Pin DIP (MAX1480EA/MAX1480EC)
24-Pin DIP (MAX1490EA/MAX1490EB)
MAX1480E/MAX1490E
_______________Ordering Information
PART
†
MAX1480EACPI
MAX1480EAEPI
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
28 Wide Plastic DIP*
28 Wide Plastic DIP*
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
TOP VIEW
V
CC1
V
CC2
D1
D2
GND1
1
2
3
4
5
MAX845E
MAX488E
MAX490E
24 AC1
23 AC2
________________________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
MAX1490EA/
MAX1490EB
22 ISO V
CC1
21 ISO RO DRV
20 A
19 B
18 Z
17 Y
16 ISO COM1
15 ISO DI DRV
14 ISO V
CC2
13 ISO RO LED
ISOLATION BARRIER
FS 6
SD
7
V
CC3
8
DI
9
V
CC4
10
RO 11
GND2 12
DIP
Selector Guide appears at end of data sheet.
Pin Configurations continued at end of data sheet.
1
________________________________________________________________
Maxim Integrated Products
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
