ADM3491E Datasheet

• TIA/EIA RS-485/RS-422 compliant 
• ±15 kV ESD-protection on RS-485 input/output pins 
• Data rates - ADM3491E: 12 Mbps 
• Full duplex 
• 32 nodes on the bus 
• Receiver open-circuit, fail-safe design
• Low power shutdown current (ADM3491E only) 
• Outputs high-Z when disabled or powered off 
• −7 V to +12 V common-mode input range 
• Thermal shutdown and short-circuit protection 
• Industry-standard 75176 pinout 
• 14-lead SOIC package

• Power/energy metering
• Telecommunications
• EMI-sensitive systems
• Industrial control
• Local area networks

The ADM3491E are 3.3 V low power data transceivers with ±15 kV ESD protection suitable for full and half-duplex communication on multipoint bus transmission lines. They are designed for balanced data transmission and comply with TIA/EIA standards RS-485 and RS-422. The ADM3491E also features enable inputs for the driver and receiver.

The devices have a 12 kΩ receiver input impedance which allows up to 32 transceivers on a bus. Since only one driver should be enabled at any time, the output of a disabled or powered down driver is three-stated to avoid overloading the bus. The receiver has a failsafe feature which ensures a logic high output when the inputs are floating. Excessive power dissipation caused by bus contention or by output shorting is prevented with a thermal shutdown circuit. The parts are fully specified over the industrial temperature ranges and are available in narrow 14-lead (ADM3491E) SOIC packages.