Intersil’s ISL3259E is a ±15kV IEC61000 ESD Protected, 5V powered, single transceiver that meets both the RS-485 and RS-422 standards for balanced communication. It also features the larger output voltage and higher data rate (up to 100Mbps) required by high speed PROFIBUS applications. The low bus currents (+220μA/-150μA) present a “1/5 unit load” to the RS-485 bus, thus allowing up to 160 transceivers on the network without violating the RS-485 specification’s load limit, and without using repeaters.

This transceiver requires a 5V supply, and delivers at least a 2.1V differential output voltage. This translates into better noise immunity (data integrity), longer reach, or the ability to drive up to six 120Ω terminations in “star” or other non-standard bus topologies.

SCSI applications benefit from the ISL3259’s low receiver and transmitter part-to-part skews, which make it perfect for high speed parallel applications where large numbers of bits must be simultaneously captured. The low bit-to-bit skew eases the timing constraints on the data latching signal.

Receiver (Rx) inputs feature a “Full Fail-Safe” design, which ensures a logic high Rx output if Rx inputs are floating, shorted, or terminated but undriven. Rx outputs feature high drive levels (typically >30mA @ V_OL = 1V) to ease the design of optically isolated interfaces.

Hot Plug circuitry ensures that the Tx and Rx outputs remain in a high impedance state while the power supply stabilizes.

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.

• IEC61000 ESD Protection on RS-485 I/O Pins ±15kV
  • Class 3 HBM ESD Level on all Other Pins >9kV
• Large Differential VOUT 2.8V into 54Ω Better Noise Immunity, or Drive up to 6 Terminations
• Very High Data Rate up to 100Mbps
• 11/13ns (Max) Tx/Rx Propagation Delays; 1.5ns (Max) Skew
• 1/5 Unit Load Allows up to 160 Devices on the Bus
• Full Fail-Safe (Open, Shorted, Terminated/Undriven) Receiver
• High Rx IOL to Drive Opto-Couplers for Isolated Applications
• Hot Plug - Tx and Rx Outputs Remain Three-State During Power-Up
• Low Quiescent Supply Current 4mA
• Low Current Shutdown Mode 1μA
• -7V to +12V Common Mode Input Voltage Range
• Three-State Rx and Tx Outputs
• Operates from a Single +5V Supply
• Current Limiting and Thermal Shutdown for Driver Overload Protection
• Pb-Free (RoHS Compliant)

• PROFIBUS® DP and FMS Networks
• SCSI “Fast 40” Drivers and Receivers
• Motor Controller/Position Encoder Systems
• Factory Automation
• Field Bus Networks
• Security Networks
• Building Environmental Control Systems
• Industrial/Process Control Networks