MAX1480BCPI Electronics Components 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 powers both sides of the interface.

The MAX1480B/MAX1480C/MAX1490B feature reducedslew-rate drivers that minimize EMI and reduce reflections 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 communication, while the MAX1490A/B feature full-duplex communication.

Drivers are short-circuit current limited and protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a highimpedance 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 1600VRMS (1 minute) or 2000VRMS (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

♦ For Integrated ESD Protection MAX1480E/MAX1490E: ±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces

♦ For Space-Constrained Applications MAX3157: High CMRR, RS-485 Transceiver with ±50V Isolation

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_ + 0.3V)

Driver Input Voltage (ISO DI_ ) .......-0.3V to (ISO VCC_ + 0.3V)

Receiver Output Voltage (ISO RO_) ...-0.3V to (ISO VCC_ + 0.3V)

Driver Output Voltage (A, B, Y, Z ) ......................-8V to +12.5V

Receiver Input Voltage (A, B)..............................-8V to +12.5V

LED Forward Current (DI, DE, ISO RO LED) ......................50mA

Continuous Power Dissipation (TA = +70°C)

24-Pin Plastic DIP (derate 8.7mW°C above +70°C) .....696mW

28-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ..727mW

Operating Temperature Ranges

MAX1480_CPI/MAX1490_CPG............................0°C to +70°C

MAX1480_EPI/MAX1490_EPG .........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10s) .................................+300°C

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.

Pin Configurations