ADM1485JN

Overview

The ADM1485JN is a differential line transceiver designed for high-speed bidirectional data communication on multipoint bus transmission lines. It complies with EIA RS-485 and RS-422 standards, featuring one driver and one receiver. The device operates from a single 5 V power supply with a typical data rate of 30 Mbps. Driver propagation delay is typically 10 ns, while receiver propagation delay is typically 15 ns. It supports a bus common-mode range from –7 V to +12 V and includes thermal shutdown protection. The component is available in an 8-Lead PDIP package and functions within the commercial temperature range of 0°C to 70°C.

Feature Summary

• Complies with EIA RS-485 and RS-422 standards for balanced data transmission
• Features thermal shutdown circuitry to prevent excessive power dissipation during fault conditions
• Includes fail-safe receiver that guarantees a logic high output when inputs are unconnected
• Maintains high output impedance when disabled or powered down to minimize bus loading

Applications

• Low Power RS-485 Systems
• DTE-DCE Interface
• Packet Switching
• Local Area Networks
• Data Concentration

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact package type and temperature rating. The base model designation corresponds to the commercial grade variant. Ensure compatibility with system voltage requirements and interface standards before procurement.

Selection Notes

Select this component for applications requiring half-duplex communication over multipoint buses. Verify that the system environment remains within the specified commercial temperature limits. Confirm that the 5 V supply voltage aligns with the design constraints and that the 30 Mbps data rate meets the application's throughput requirements.

Part Context

The ADM1485 series consists of low-power EIA RS-485 transceivers fabricated using BiCMOS technology. This process combines low-power CMOS with fast-switching bipolar technology to achieve high speed and low power consumption. The J suffix specifically denotes the commercial temperature range variant, distinguishing it from industrial grade options within the same product family.

Replacement Considerations

The datasheet identifies the LTC1485 as a superior upgrade target. Verify pinout compatibility and electrical specifications when substituting components. Ensure that any replacement part maintains the required RS-485 compliance and thermal protection features.