ADM3485EARZ Electronic IC Chips EIA RS-485/RS-422 Transceiver

±15 kV ESD-Protected, 3.3 V,12 Mbps, EIA RS-485/RS-422 Transceiver

ADM3485E

FEATURES                                                                            FUNCTIONAL BLOCK DIAGRAM

• TIA/EIA RS-485/RS-422 compliant

• ±15 kV ESD protection on RS-485 input/output pins

• 12 Mbps data rate

• Half-duplex transceiver

• Up to 32 nodes on the bus

• Receiver open-circuit, fail-safe design

• Low power shutdown current

• Outputs high-Z when disabled or powered off

• Common-mode input range: −7 V to +12 V

• Thermal shutdown and short-circuit protection

• Industry-standard 75176 pinout

• 8-lead narrow SOIC package

APPLICATIONS

• Power/energy metering

• Telecommunications

• EMI-sensitive systems

• Industrial control

• Local area networks

GENERAL DESCRIPTION

The ADM3485E is a 3.3 V, low power data transceiver with ±15 kV ESD protection, suitable for half-duplex communication on multipoint bus transmission lines. The ADM3485E is designed for balanced data transmission and complies with TIA/EIA standards RS­485 and RS-422. The ADM3485E is a half-duplex transceiver that shares differential lines and has separate enable inputs for the driver and the receiver.

The devices have a 12 kΩ receiver input impedance, which allows up to 32 transceivers on a bus. Because only one driver should be enabled at any time, the output of a disabled or powered-down driver is tristated to avoid overloading the bus.

The receiver has a fail-safe feature that 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 part is fully specified over the industrial temperature range and is available in an 8-lead narrow SOIC package.

ABSOLUTE MAXIMUM RATINGS

T_A = 25°C, unless otherwise noted.

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Stock Offer (Hot Sell)