MAX3085ESA+

Overview

The MAX3085ESA+ is a half-duplex RS-485/RS-422 transceiver manufactured by Analog Devices Inc./Maxim Integrated. It operates from a single +5V supply and supports data rates up to 500kbps with slew-rate-limited drivers. The device incorporates fail-safe circuitry that guarantees a logic-high receiver output when inputs are open or shorted. It features ±15kV ESD protection on the bus pins, low quiescent current of 375µA, and thermal shutdown protection. Packaged in an 8-pin SOIC format, it allows up to 256 transceivers on the bus due to its 1/8-unit-load receiver input impedance.

Feature Summary

• Fail-safe circuitry ensures a logic-high receiver output during idle or fault conditions
• Slew-rate-limited driver minimizes electromagnetic interference (EMI) and signal reflections
• ±15kV electrostatic discharge (ESD) protection on differential bus lines
• High noise immunity through integrated receiver input filtering

Applications

• RS-422 and RS-485 communication networks
• Industrial control local area networks
• Level translation applications
• Transceivers for EMI-sensitive environments

Procurement Notes

Verify the component authenticity by checking the manufacturer marking against official datasheet specifications. Confirm the package type matches the required PCB footprint. Ensure the temperature grade suffix corresponds to the intended operating environment. Cross-reference the ordering information section to validate the specific part number variant before finalizing procurement.

Selection Notes

Select this component for applications requiring half-duplex communication at speeds up to 500kbps. It is suitable for systems needing robust ESD protection and fail-safe behavior on the bus. Consider the 1/8-unit-load capability if connecting multiple devices to a single line. Verify that the +5V supply voltage aligns with the system power architecture.

Part Context

This device belongs to the MAX3080–MAX3089 family of high-speed transceivers designed for RS-485/RS-422 standards. The family offers various configurations including full-duplex options and selectable data rates. The MAX3085 specifically targets half-duplex applications with moderate speed requirements and enhanced noise immunity features.

Replacement Considerations

The MAX3085 is pin-compatible with industry-standard parts like the 75180. When substituting, verify that the replacement supports the same half-duplex mode and 500kbps data rate. Ensure the substitute also provides equivalent ESD protection levels and fail-safe characteristics.