MAX3085ESA+T

Overview

The MAX3085ESA+T is a half-duplex RS-485/RS-422 transceiver manufactured by Analog Devices Inc./Maxim Integrated. It contains one driver and one receiver, operating from a single +5V supply (4.75V to 5.25V). The device supports data rates up to 500kbps with slew-rate-limited drivers to minimize EMI. It features fail-safe circuitry guaranteeing a logic-high receiver output when inputs are open or shorted. The receiver input impedance is 1/8-unit-load, allowing up to 256 transceivers on the bus. Typical quiescent current is 375µA. It operates within an industrial temperature range of -40°C to +85°C and is housed in an 8-pin SOIC package.

Feature Summary

• Slew-rate-limited driver outputs reduce electromagnetic interference and signal reflections for error-free transmission at speeds up to 500kbps.
• Fail-safe receiver circuitry ensures a logic-high output state when differential inputs are open, shorted, or disconnected.
• High-impedance 1/8-unit-load receiver inputs enable connection of up to 256 devices on a single communication bus.

Applications

• RS-422/RS-485 communications
• Industrial-control local area networks
• Transceivers for EMI-sensitive applications

Procurement Notes

Verify the specific ordering suffix against official documentation to confirm package type and temperature grade. Confirm RoHS compliance status as indicated by the plus sign in the part number. Ensure the component matches the required half-duplex functionality and 500kbps data rate specifications before integration into the design.

Selection Notes

Select this component for applications requiring half-duplex RS-485/RS-422 communication with controlled slew rates. It is suitable for systems needing high noise immunity via fail-safe thresholds and support for multiple nodes on a shared bus. Verify that the 5V supply voltage and 8-pin SOIC package constraints align with the system requirements.

Part Context

The MAX3085 is part of the MAX3080–MAX3089 family of high-speed transceivers designed for RS-485/RS-422 standards. This family includes variants supporting different duplex modes and data rates, ranging from 115kbps to 10Mbps. The MAX3085 specifically targets the 500kbps half-duplex segment of this product line.

Replacement Considerations

The datasheet notes pin compatibility with the industry-standard 75180 transceiver. Designers should verify functional equivalence regarding electrical characteristics and pin assignments when considering alternative sources.