52 Mbps RS-485/-422 Transceivers Feature High-Differential (2.4V) Output Voltage Swing

Date: 2/2/2010

52 Mbps RS-485/-422 Transceivers Feature High-Differential (2.4V) Output Voltage Swing

Advanced features include superior electrostatic discharge (ESD) protection, hotswap and failsafe making the new XR548xE Series of transceivers ideal for harsh industrial environments

Exar Corporation has introduced three new RS-485/RS-422 transceivers that offer 52 Mbps performance with a high-differential output swing ( min.2.4V). Representing the company’s second generation of PROFIBUS transceivers the XR5486E, XR5487E and XR5488E are ideal for industrial applications such as field bus networks, high-speed motor control, factory & building automation, security systems and remote meter reading.

Exar has designed its XR548xE series transceivers for reliable, bidirectional communication on multipoint bus transmission lines. The higher differential driver output swing enables more reliable communication over longer cable lengths. Each of the three devices in the series contains one differential driver and one differential receiver. The XR5488E is a half-duplex device, while the XR5486E and XR5487E are full-duplex. All three devices comply with TIA/EIA-485 and TIA/EIA-422 standards.

Rated across the Industrial (-40 to +85ºC) operating temperature range , the three new transceivers offer a number of features that render them ideal for use in harsh operating conditions over the entire common-mode voltage range from -7 to +12V:
• Receivers are specially designed to fail-safe to a logic high output state if the inputs are left un-driven or shorted.
• All RS-485 bus-pins are protected against severe ESD events up to ±15kV (Air-Gap and Human Body Model) and up to ±8kV Contact Discharge (IEC-61000-4-2).
• Drivers are protected from excess current flow caused by bus contention or output short-circuits by both an internal current limit and a thermal-overload shutdown.
• Receivers have exceptionally high input impedance, which places only 1/8th the standard load on a shared bus. Up to 256 transceivers may coexist while preserving full signal margin.

According to Hensen Wong, Exar’s technical marketing manager, Interface Products, the XR548xE series is unique in the industry: “The 52 Mbps performance and higher driver output swing provides designers with maximum design flexibility for PROFIBUS and ultra high-speed RS-485/RS-422 communications applications," Wong said. "The standard pin out and low power consumption enables customers to easily migrate to high-speed applications with significantly reduced time-to-market."

The XR5486E, XR5487E and XR5488E operate from a single 5.0V power supply and draw negligible quiescent power. The XR5486E and XR5488E devices are able to independently enable and disable their driver and receiver and enter a low power shutdown mode if both driver and receiver are disabled. All outputs maintain high impedance in shutdown or when powered-off.

All three devices in the XR548xE series are fully available in volume quantities in a RoHS compliant, halogen free packages. The XR5486E is shipped in a14-pin nSOIC package while the XR5487E and XR5488E are shipped in an 8-pin nSOIC packages.