32Mbps 3.3V RS-485 & RS-422 family target Industrial Automation Platforms

Date: 9/6/2009

32Mbps 3.3V RS-485 & RS-422 family target Industrial Automation Platforms

Exar Corp. has released a family of high speed 3.3V RS-485/RS-422 transceivers that support current 20Mbps applications but offer extendibility to 32Mbps levels for next generation industrial automation applications.

Designed for  security networks, process control, plant environmental control, remote sensing and metering applications, the SP3495E, SP3496E, and the SP3497E transceivers and are fully synergistic with Exar’s interface product portfolio, which includes other RS-485/RS-422, RS-232 and multiprotocol transceivers and the innovative family of Universal Asynchronous Receiver Transmitters (UARTs).

The SP3495E/96E/97E transceivers offer robust ESD protection, advanced fail-safe feature, and hot swap glitch protection – critical features for precision control of motor positioning in industrial automation systems that require high speed bidirectional communication on multipoint and multidrop bus transmission lines.

Short circuit protection and thermal shutdown prevent excessive power dissipation caused by bus contention or by shorting outputs to ground or a voltage source. This feature forces the driver output into high impedance state if the absolute value of the output current exceeds 250mA or if junction temperature exceeds 165°C. The advanced fail-safe feature guarantees a logic-high receiver output if the receiver’s differential inputs are shorted, open-circuit, or if they are shunted by a termination resistor. All inputs and outputs have ESD protection. Bus-pins are ESD protected up to ±15kV Human Body Model.

Useful options
The SP349xE family is designed for balanced data transmission. All three devices contain one differential driver and one differential receiver and comply with both RS-485 and RS-422 EIA Standards. They offer several useful options: half-duplex, full-duplex or full-duplex with enable/shutdown. Separate enable pins independently control the driver and receiver but when externally connected can be used to provide direction control. The series operates from a single 3.3V power supply and loads the data bus only half as much as a standard RS-485 unit-load. This allows simultaneous connection of up to 64 devices on a bus without violating required RS-485 signal margin and without using repeaters.

Samples of the SP3495E and SP3496E are available now in an 8-pin SOIC package supporting the -40°C to +85°C temperature range. Samples of the SP3497E are available in SOIC package supporting the -40°C to +85°C temperature range. Lead-free and RoHS compliant packages are available. To request samples or further information on the SP349xE transceiver family please use the “more information” link below.