ADM485AN

Product Summary

The ADM485AN is an EIA RS-485 Transceiver. The ADM485AN is a differential line transceiver suitable for high speed bidirectional data communication on multipoint bus transmission lines. It is designed for balanced data transmission and complies with both EIA Standards RS-485 and RS-422. The part contains a differential line driver and a differential line receiver. Both the driver and the receiver may be enabled independently. When disabled, the outputs are tristated. The ADM485AN operates from a single +5 V power supply. 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. Up to 32 transceivers may be connected simultaneously on a bus, but only one driver should be enabled at any time. It is important, therefore, that the remaining disabled drivers do not load the bus. To ensure this, the ADM485AN driver features high output impedance when disabled and also when powered down. The applications of the ADM485AN include Low Power RS-485 Systems, DTE-DCE Interface, Packet Switching, Local Area Networks, Data Concentration, Data Multiplexers and Integrated Services Digital Network (ISDN).

Parametrics

ADM485AN absolute maximum ratings: (1)VCC: +7 V; (2)Inputs Driver Input (DI): –0.3 V to VCC + 0.3 V; (3)Control Inputs (DE, RE): –0.3 V to VCC + 0.3 V; (4)Receiver Inputs (A, B): –14 V to +14 V; (5)Outputs Driver Outputs: –14 V to +14 V; (6)Receiver Output: –0.5 V to VCC +0.5 V; (7)Power Dissipation 8-Pin DIP: 500 mW; (8)θJA, Thermal Impedance: +130℃/W; (9)Power Dissipation 8-Pin SOIC: 450 mW; (10)θJA, Thermal Impedance: +170℃/W; (11)Power Dissipation 8-Pin Cerdip: 500 mW; (12)θJA, Thermal Impedance: +125℃/W; (13)Operating Temperature Range Commercial (J Version): 0℃ to +70℃; (14)Industrial (A Version): –40℃ to +85℃; (15)Storage Temperature Range: –65℃ to +150℃; (16)Lead Temperature (Soldering, 10 sec): +300℃; (17)Vapour Phase (60 sec): +215℃; (18)Infrared (15 sec): +220℃.

Features

ADM485AN features: (1)Meets EIA RS-485 Standard; (2)5 Mb/s Data Rate; (3)Single +5 V Supply; (4)–7 V to +12 V Bus Common-Mode Range; (5)High Speed, Low Power BiCMOS; (6)Thermal Shutdown Protection; (7)Short Circuit Protection; (8)Zero Skew Driver; (9)Driver Propagation Delay: 10 ns; (10)Receiver Propagation Delay: 25 ns; (11)High Z Outputs with Power Off; (12)Superior Upgrade for LTC485.

Diagrams