MAX1480A_05 Datasheet, PDF (1/21 Pages) Maxim Integrated Products – Complete, Isolated RS-485/RS-422 Data Interface

19-0259; Rev 5; 5/05
Complete, Isolated RS-485/RS-422
Data Interface
_________________General Description
The MAX1480A/MAX1480B/MAX1480C/MAX1490A/
MAX1490B are complete, electrically isolated, RS-485/
RS-422 data-communications interface solutions in a
hybrid microcircuit. Transceivers, optocouplers, and a
transformer provide a complete interface in a standard
DIP package. A single +5V supply on the logic side pow-
ers both sides of the interface.
The MAX1480B/MAX1480C/MAX1490B feature reduced-
slew-rate drivers that minimize EMI and reduce reflec-
tions caused by improperly terminated cables, allowing
error-free data transmission at data rates up to 250kbps.
The MAX1480A/MAX1490A driver slew rate is not limited,
allowing transmission rates up to 2.5Mbps. The
MAX1480A/B/C are designed for half-duplex communi-
cation, while the MAX1490A/B feature full-duplex com-
munication.
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
MAX1480A/B/C, RO high for the MAX1490A/B/C) if the
input is open circuit.
The MAX1480A/MAX1480B/MAX1480C/MAX1490A/
MAX1490B typically withstand 1600V_RMS (1 minute) or
2000V_RMS (1 second). Their isolated outputs meet all
RS-485/RS-422 specifications. The MAX1480A/B/C are
available in a 28-pin DIP package, and the MAX1490A/B
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
Next-Generation Device Features
o For Integrated ESD Protection
MAX1480E/MAX1490E: ±15kV ESD-Protected,
Isolated RS-485/RS-422 Data Interfaces
o For Space-Constrained Applications
MAX3157: High CMRR, RS-485 Transceiver with
±50V Isolation
_______________Ordering Information
PART^†
TEMP RANGE
PIN-PACKAGE
MAX1480ACPI
0°C to +70°C
28 Wide Plastic DIP
MAX1480AEPI -40°C to +85°C
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 “B” and}
“C” parts is up to 250kbps.
_____________________Selection Table
PART
HALF/
FULL
DUPLEX
DATA
RATE
(MBPS)
SLEW-
RATE
LIMITED
DRIVER
ENABLE
TIME
(µS)
MAX1480A
Half
2.5
No
0.2
MAX1480B
Half
0.25
Yes
35
MAX1480C
Half
0.25
Yes
0.5
MAX1490A
Full
2.5
No
—
MAX1490B
Full
0.25
Yes
—
Pin Configurations
TOP VIEW
V_{CC1 1}
V_{CC2 2}
D1 3
D2 4
GND1 5
FS 6
SD 7
V_CC3 8
DI 9
V_CC4 10
RO 11
GND2 12
24 AC1 MAX1490A/B
23 AC2
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 VCC2
13 ISO RO LED
ISOLATION BARRIER
DIP
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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