ISL81485
5V, Half Duplex, 30Mbps, RS-485/RS-422 Transceiver

Key Features

• Specified for 10% Tolerance Supplies
• High Data Rates up to 30Mbps
• Large Differential Output Voltage 2.0V(min.) into 54Ω
• Drop-In Replacement for the ADM1485
• One Unit Load Allows up to 32 Devices on the Bus
• Low Quiescent Current 800µA
• -7V to +12V Common Mode Input Voltage Range
• Three State Rx and Tx Outputs
• 15ns (Max) Propagation Delays, 5ns (Max) Skew
• Operates from a Single +5V Supply (10% Tolerance)
• Current Limiting and Thermal Shutdown for driver Overload Protection
• Pb-free available

Description

The Intersil ISL81485 is a BiCMOS, 5V powered, single transceiver that meets both the RS-485 and RS-422 standards for balanced communication, and features a larger output voltage and higher data rate to benefit high speed applications.

Unlike competitive devices, this Intersil transceiver is specified for 10% tolerance supplies (4.5V to 5.5V), and it delivers a much larger worst case differential output voltage (2.0V compared to the typical 1.5V) over the full supply range. The increased output voltage translates into longer reach, or better data integrity, at the 30Mbps data rate. This device presents a "1 unit load" to the RS-485 bus, which allows up to 32 transceivers on the network.

Receiver (Rx) inputs feature a "fail-safe if open" design, which ensures a logic high Rx output if Rx inputs are floating.

Driver (Tx) outputs are short circuit protected, even for voltages exceeding the power supply voltage. Additionally, on-chip thermal shutdown circuitry disables the Tx outputs to prevent damage if power dissipation becomes excessive.

Applications

• SCSI "Fast 20" Drivers and Receivers
• Factory Automation
• Field Bus Networks
• Security Networks
• Building Environmental Control Systems
• Industrial/Process Control Networks