MAX14781EESA+

Drivers, Receivers, Transceivers Overview

The MAX14781EESA+ is a half-duplex RS-485 transceiver manufactured by Analog Devices Inc./Maxim Integrated. It operates on a single +5V supply with a voltage range of 4.5V to 5.5V. The device supports data rates up to 370kbps and features integrated automatic polarity correction for A and B lines. It includes fail-safe circuitry that guarantees a logic-high receiver output when inputs are open or shorted. Hot-swap functionality prevents false transitions during live insertion. ESD protection ratings include ±25kV (HBM), ±15kV air gap, and ±9kV contact discharge per IEC 61000-4-2. The shutdown current is typically 10µA maximum. It is housed in an 8-pin SO package and operates from -40°C to +85°C.

Drivers, Receivers, Transceivers Feature Summary

• Automatic polarity correction autonomously corrects miswired A and B lines without external configuration.
• Integrated high-level ESD protection ensures robustness against electrostatic discharges on driver and receiver pins.
• Hot-swap capability on enable inputs eliminates false bus transitions during power-up or live board insertion.
• True fail-safe receiver guarantees a logic-high output state when differential inputs are open or shorted.

Drivers, Receivers, Transceivers Applications

• Power Meter Networks
• HVAC Networks
• Control Systems

Drivers, Receivers, Transceivers Procurement Notes

Verify the component authenticity through official manufacturer channels or authorized distributors. Confirm the specific ordering suffix matches the required RoHS compliance status. Ensure the package type corresponds to the design footprint requirements. Check the datasheet revision history for any updates to electrical characteristics or pin configurations before finalizing procurement specifications.

Drivers, Receivers, Transceivers Selection Notes

Select this component for applications requiring simplified installation due to automatic polarity correction. It is suitable for environments where hot-swapping modules is necessary without risking bus errors. Consider the low shutdown current for battery-powered systems. Verify that the 370kbps data rate meets the system communication speed requirements. Ensure the operating temperature range aligns with the environmental conditions of the deployment site.

Drivers, Receivers, Transceivers Part Context

The MAX14781E belongs to the Maxim Integrated RS-485 transceiver family designed for robust industrial communication. It addresses common installation errors through its unique polarity correction feature. The device complements other interface ICs by providing enhanced ESD immunity and fail-safe operation. It is part of the broader portfolio of analog and mixed-signal solutions provided by Analog Devices.

Drivers, Receivers, Transceivers Replacement Considerations

Direct substitutes within the same polarity-correcting RS-485 family should be evaluated based on pin compatibility and electrical specifications. Verify that alternative components offer similar ESD protection levels and hot-swap capabilities. Ensure the replacement maintains the required data rate and supply voltage constraints.

Drivers, Receivers, Transceivers FAQ

How does the automatic polarity correction function?

The device samples the voltages at the A and B inputs during an idle period of at least 20ms. If the differential voltage exceeds 200mV, it configures the driver and receiver for the detected polarity, correcting miswired connections autonomously.

What is the fail-safe behavior of the receiver?

The receiver input threshold is set between -50mV and -200mV. This guarantees a logic-high receiver output when the inputs are open, shorted, or connected to a terminated line with all drivers disabled.

How is hot-swap functionality implemented?

Internal circuitry holds the Driver Enable (DE) low and Receiver Enable (RE) high during initial power-up. This prevents the transceiver from driving the bus incorrectly while the processor is initializing or when boards are inserted into a powered backplane.