±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces

The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB are complete, electrically isolated, RS-485/RS-422 data communications interface solutions in a hybrid microcircuit. 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 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 high-impedance state. The receiver input has a fail-safe feature that guarantees a known output (RO low for the MAX1480EA/MAX1480EC, active-low RO high for the MAX1490EA/ MAX1490EB) if the input is open circuit.

The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB withstand 1260VRMS (1min) or 1520VRMS (1s). Their isolated 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.

Applications

* Automated Test Equipment (ATE) * HVAC/Building Control Networks * Industrial Control Local Area Networks * Isolated RS-485/RS-422 Data Interface * Telecom * Transceivers for EMI-Sensitive Applications

* Isolated Data Interface, Guaranteed to 1260VRMS (1min)

* +15kV ESD Protection on I/O Pins

* Slew-Rate Limited for Errorless Data Transmission (MAX1480EC/MAX1490EB)

* High-Speed, Isolated, 2.5Mbps RS-485/RS-422 Interface (MAX1480EA/MAX1490EA)

* Full-Duplex Data Communication

* (MAX1490EA/MAX1490EB)

* Single +5V Supply

* Current Limiting and Thermal Shutdown for Driver Overload Protection

* Standard 0.6in DIP Packages

* 28-Pin DIP (MAX1480EA/MAX1480EC)

* 24-Pin DIP (MAX1490EA/MAX1490EB)