MAX3480EA Datasheet, PDF (1/16 Pages) Maxim Integrated Products – +-15kV ESD-Protected, Isolated, 3.3V RS-485/RS-422 Data Interfaces

19-1941; Rev 0; 4/01
±15kV ESD-Protected, Isolated, 3.3V
RS-485/RS-422 Data Interfaces
General Description
The MAX3480EA/MAX3480EB are electrically isolated
RS-485/RS-422 data-communications interfaces. The
RS-485/RS-422 I/O pins are protected against ±15kV
electrostatic discharge (ESD) shocks, without latchup.
Transceivers, optocouplers, and a transformer are all
included in one low-cost, 28-pin DIP package. A single
+3.3V supply on the logic side powers both sides of the
interface.
The MAX3480EB features 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
MAX3480EA’s driver slew rate is not limited, allowing
transmission rates up to 2.5Mbps.
Drivers are short-circuit current limited and are protect-
ed against excessive power dissipation by thermal
shutdown circuitry that places the driver outputs into a
high-impedance state. The receiver input has a fail-safe
feature that guarantees a logic-high output if the input
is open circuit.
The MAX3480EA/MAX3480EB are guaranteed to with-
stand 1260V_RMS (1min) or 1520V_RMS (1s). Their isolated
inputs and outputs meet RS-485/RS-422 specifications.
________________________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
Ordering Information
PART
TEMP.
RANGE
PIN-
PACKAGE*
MAX3480EACPI 0°C to +70°C 28 Plastic DIP
MAX3480EAEPI -40°C to +85°C 28 Plastic DIP
MAX3480EBCPI 0°C to +70°C 28 Plastic DIP
MAX3480EBEPI -40°C to +85°C 28 Plastic DIP
*See Reliability section at end of data sheet.
DATA
RATE
(kbps)
2500
2500
250
250
____________________________Features
o Isolated Data Interface Guaranteed to 1260V_RMS
(1min)
o ±15kV ESD Protection for I/O Pins
o Slew-Rate-Limited Data Transmission (160kbps for
MAX3480EB)
o High-Speed, Isolated, 2.5Mbps RS-485 Interface
(MAX3480EA)
o Single +3.3V Supply
o Current Limiting and Thermal Shutdown for
Driver Overload Protection
o Standard 28-Pin DIP Package
o Allows Up to 128 Transceivers on the Bus
Pin Configuration
TOP VIEW
V_{CC1 1}
V_CC2 2
D1 3
D2 4
GND1 5
FS 6
MAX845
SD 7
V_CC3 8
DI 9
V_CC4 10
DE 11
GND2 12
RO 13
V_{CC5 14}
MAX3480EA
MAX3480EB
28 ^AC1
27 ^AC2
26 ^{ISO V}CC1
25 B
MAX485E
MAX487E
24 ISO RO DRV
23 A
22 ISO DI IN
21 ISO DE IN
20 ISO COM1
19 ISO DI DRV
18 ISO VCC2
17 ISO DE DRV
16 ISO COM2
15 ISO RO LED
ISOLATION BARRIER
DIP
________________________________________________________________ Maxim Integrated Products 1
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.