MAX1481/MAX1484/MAX1485/MAX1486
19-1312; Rev 1; 3/06
Software-Selectable, Half-/Full-Duplex, Slew-Rate-Limited,
12Mbps, RS-485/RS-422 Transceivers in MAX Package
_______________General Description ____________________________Features
The MAX1481/MAX1484/MAX1485/MAX1486 provide
' 10-Pin MAX Package: Smallest 10-Pin Package
software-selectable, half-/full-duplex, low-power, slew-
' Software-Selectable Half-/Full-Duplex Operation
rate-limited, and high-speed (12Mbps) RS-485/RS-422
(MAX1485/MAX1486)
operation in a 10-pin MAX packagethe smal-
lest 10-pin package available.
' 0.1A Low-Current Shutdown Mode (MAX1481)
The software-selectable, half-/full-duplex MAX1485/
' Slew-Rate Limiting Allows Error-Free Data
MAX1486 make obsolete the normally larger and more
Transmission (MAX1481/MAX1485)
expensive solutions required for selectable half-/full-
duplex RS-485/RS-422 operation: 1) a 14-pin, full-
' 12Mbps High-Speed Operation
duplex transceiver configured via jumpers between
(MAX1484/MAX1486)
receiver and transmitter lines, or 2) two 8-pin, half-
' Allow up to 256 Transceivers on the Bus
duplex transceivers, which require an additional invert-
er logic gate for software selectability.
The MAX1481/MAX1484 are functionally equivalent to
the industry-standard MAX491 and 75180, and are ______________Ordering Information
designed for space-constrained, full-duplex RS-422
PART TEMP RANGE PIN-PACKAGE
applications.
MAX1481CUB 0C to +70C 10 MAX
All parts contain one driver and one receiver and fea-
MAX1481EUB -40C to +85C 10 MAX
ture a 1/8-unit-load receiver input impedance, allowing
up to 256 transceivers on the bus. The MAX1481/ MAX1484CUB 0C to +70C 10 MAX
MAX1485 feature reduced-slew-rate drivers that mini-
MAX1484EUB -40C to +85C 10 MAX
mize EMI and reduce reflections caused by improperly
MAX1485CUB 0C to +70C 10 MAX
terminated cables, allowing error-free data transmission
MAX1485EUB -40C to +85C 10 MAX
up to 250kbps. The MAX1484/MAX1486 driver slew
MAX1486CUB 0C to +70C 10 MAX
rates are not limited, allowing them to transmit up to
MAX1486EUB -40C to +85C 10 MAX
12Mbps.
The MAX1481/MAX1484/MAX1485/MAX1486 draw only
300A of supply current. The MAX1481 has a low-power
shutdown mode that reduces supply current to only
________________________Applications
0.1A. All devices operate from a single 5V supply.
Low-Power RS-422/RS-485 Communications
Drivers are output short-circuit current limited and are
Level Translators
protected against excessive power dissipation by
Hand-Held Equipment
thermal-shutdown circuitry that places the driver outputs
into a high-impedance state. The receiver input has a fail-
Battery-Powered Equipment
safe feature that guarantees a logic-high output if the
Transceiver for EMI-Sensitive Applications
input is open circuit.
Industrial-Control Local Area Networks
MAX is a registered trademark of Maxim Integrated Products, Inc.
______________________________________________________________Selection Table
Data Slew- Low- Quiescent
Half/Full Driver Receiver Transceivers Pin-
Part Rate Rate Power Current
Duplex Enable Enable on Bus Package
(Mbps) Limited Shutdown (A)
MAX1481 Full 0.250 Yes Yes Yes Yes 300 256 10 MAX
MAX1484 Full 12 No No Yes Yes 300 256 10 MAX
MAX1485 Selectable 0.250 Yes No Yes No 300 256 10 MAX
MAX1486 Selectable 12 No No Yes No 300 256 10 MAX
________________________________________________________________ Maxim Integrated Products 1
________________________________________________________________ Maxim Integrated Products 1
For free samples & the latest literature: Software-Selectable, Half-/Full-Duplex, Slew-Rate-Limited,
12Mbps, RS-485/RS-422 Transceivers in MAX Package
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V ) ............................................................+7V Continuous Power Dissipation
CC
Control Input Voltage (RE, DE, H/F) ...........-0.3V to (V + 0.3V) 10-Pin MAX (derate 5.6mW/C above +70C) ............444mW
CC
Driver Input Voltage (DI).............................-0.3V to (V + 0.3V) Operating Temperature Ranges
CC
Driver Output Voltage (A, B, Y, Z) ..........................-8V to +12.5V MAX148_C_ _ ......................................................0C to +70C
Receiver Input Voltage, Half Duplex (Y, Z) ............-8V to +12.5V MAX148_E_ _....................................................-40C to +85C
Receiver Input Voltage, Full Duplex (A, B).............-8V to +12.5V Storage Temperature Range .............................-65C to +160C
Receiver Output Voltage (RO)....................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10sec) .............................+300C
CC
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V = +5V 5%, T = T to T , unless otherwise noted. Typical values are at V = +5V and T = +25C.) (Note 1)
CC A MIN MAX CC A
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DRIVER
V No load, Figure 5 5
OD1
Differential Driver Output R = 50 (RS-422), Figure 5 2.0 V
V
OD2
R = 27 (RS-485), Figure 5 1.5 5
Change in Magnitude of
Differential Output Voltage V R = 50 or 27, Figure 5 0.2 V
OD
(Note 2)
Driver Common-Mode Output
V R = 50 or 27, Figure 5 3 V
OC
Voltage
Change in Magnitude of
V R = 50 or 27, Figure 5 0.2 V
OC
Common-Mode Voltage (Note 2)
Input High Voltage V DE, DI, RE, H/F 2.0 V
IH1
Input Low Voltage V 0.8 V
IL1 DE, DI, RE, H/F
Input Current I DE, DI, RE, H/F 2 A
IN1
V = 12V 0.125
Input Current (Y and Z for Half IN
DE = GND,
I mA
IN2
Duplex, A and B for Full Duplex) V = GND or 5.25V
CC V = -7V -0.1
IN
V = 12V 10
IN
Output Leakage (Y and Z)
I DE = GND A
O
(MAX1481/MAX1484 Only)
V = -7V -10
IN
V = 12V 125
Output Leakage (Y and Z) IN
I DE = GND A
O
(MAX1485/MAX1486 Only)
V = -7V -100
IN
Driver Output Short-Circuit
I -7V V 12V 35 250 mA
OSD OUT
Current (Note 3)
2 _______________________________________________________________________________________
MAX1481/MAX1484/MAX1485/MAX1486