ADM3485E

Features:

`Operates with +3.3 V Supply
`ESD Protection: 8 kV Meets IEC1000-4-2
`EFT Protection: 2 kV Meets IEC1000-4-4
`EIA RS-422 and RS-485 Compliant Over Full CM Range
`19 k Input Impedance
`Up to 50 Transceivers on Bus
`20 Mbps Data Rate
`Short Circuit Protection
`Specified Over Full Temperature Range
`Thermal Shutdown
`Interoperable with 5 V Logic
`1 mA Supply Current
`2 nA Shutdown Current
`8 ns Skew




Application

·Telecommunications
·DTE-DCE Interface
·Packet Switching
·Local Area Networks
·Data Concentration
·Data Multiplexers
·Integrated Services Digital Network (ISDN)
·AppleTalk
·Industrial Controls




Pinout








Specifications



V_CC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7 V
Inputs
Driver Input (DI) . . . . . . . . . . . . . .. . . 0.3 V to VCC + 0.3 V
Control Inputs (DE, RE) . . . . . . . . . ..0.3 V to VCC + 0.3 V
Receiver Inputs (A, B) . . . . . . . . . . . .. . . . 7.5 V to +12.5 V
Outputs
Driver Outputs . . . . . . . . . . . . . . . . . .. . . 7.5 V to +12.5 V
Receiver Output . . . . . . . . . . . . . . . . .0.5 V to VCC + 0.5 V
Power Dissipation 8-Lead DIP . . . . . . . . . . . .. . . . . . 800 mW
JA, Thermal Impedance . . . . . . . . . . . . . . ... . . . . 140/W
Power Dissipation 8-Lead SOIC . . . . . . . . . . . . . . . . 650 mW
JA, Thermal Impedance . . . . . . . . . . . . . . . .. . . . . 115/W
Operating Temperature Range
Industrial (A Version) . . . . . . . . . . . . . . . ... 40 to +85
Storage Temperature Range . . . . . . . . . . . . 65 to +150
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . +300
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . .. . . . . +215
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . .. . . +220
ESD Rating: Air (Human Body Model, All Pins) . . . ... . >4 kV
ESD Rating: IEC1000-4-2 Contact (A, B Pins) . . . . .. . >8 kV
EFT Rating: IEC1000-4-4 (A, B Pins) . . . . . . . . . . . . .. >2 kV




Description

The ADM3485E is a low power differential line transceiver designed to operate using a single +3.3 V power supply. Low power consumption makes it ideal for power sensitive applications. It is suitable for communication on multipoint bus transmission lines. Internal protection against electrostatic discharge (ESD) and electrical fast transient (EFT) allows operation in electrically harsh environments.
ADM3485E is intended for balanced data transmission and complies with both EIA Standards RS-485 and RS-422. It contains a differential line driver and a differential line receiver, and is suitable for half duplex data transfer. The input impedance is 19 k allowing up to 50 transceivers to be connected on the bus.

Excessive power dissipation caused by bus contention or by output shorting is prevented by a thermal shutdown circuit. This feature forces the driver output into a high impedance state if, during fault conditions, a significant temperature increase is detected in the internal driver circuitry. The ADM3485E receiver contains a fail-safe feature that results in a logic high output state if the inputs are unconnected (floating).

The ADM3485E is fabricated on BiCMOS, an advanced mixed technology process combining low power CMOS with fast switching bipolar technology.

The ADM3485E is fully specified over the industrial temperature range and is available in 8-lead DIP and SOIC packages.