MAX33072EASA+

Overview

The MAX33072EASA+ is a half-duplex RS-485/RS-422 transceiver in an 8-pin SOIC package. It supports data rates up to 500kbps with a supply voltage range of 3V to 5.5V and operates from -40°C to +125°C. The device features ±65V fault protection, ±40V common-mode range, and ±40kV ESD protection on A/B lines. It includes a polarity inversion input (POL), true fail-safe logic-high output for open/shorted inputs, hot-swap protection, and thermal shutdown at +160°C.

Feature Summary

• Integrated ±65V overvoltage fault protection on driver outputs and receiver inputs ensures robust communication in harsh industrial environments without external components.
• Polarity selection input allows software-controlled swapping of A and B data lines to correct cross-wired field cables.
• True fail-safe circuitry guarantees a known logic-high receiver output state when inputs are open or shorted.
• Hot-swap protection safeguards against unwanted driver activation during board insertion into powered backplanes.

Applications

• Industrial automation equipment
• Home and building automation systems
• Agriculture and heavy machinery control
• Power supply and UPS monitoring
• Elevator control networks

Procurement Notes

Verify the specific suffix to confirm packaging format. The 'A' indicates an 8-pin SOIC package, while '+' denotes lead-free/RoHS compliance. Confirm whether the 'T' suffix is required for tape-and-reel delivery versus tube packaging. Ensure the selected variant matches the required maximum data rate specifications for the target application design.

Selection Notes

Select this component for applications requiring high fault tolerance on RS-485 buses exposed to significant ground potential differences or electrical noise. The integrated polarity inversion feature simplifies installation by allowing software correction of miswired cables. Verify that the 500kbps data rate meets system bandwidth requirements, as higher speeds require the MAX33073E variant.

Part Context

This part belongs to the MAX3307x family of fault-protected transceivers designed for electrically noisy environments. It shares the same pinout and core functionality as the MAX33073E, differing primarily in the maximum supported data rate. Both variants offer identical protection levels and operate within the same supply voltage and temperature ranges.

Replacement Considerations

The MAX33073EASA+ serves as a direct functional substitute if a higher data rate of 2Mbps is required. Other members of the MAX3307x family share the same pin configuration and protection features but may differ in speed capabilities.

FAQ

How does the POL pin function?

The POL pin allows software-controlled inversion of the A and B data lines. Driving POL high swaps the noninverting and inverting outputs, enabling correction of cross-wired field cables.

What happens during a thermal shutdown event?

When the internal junction temperature exceeds +160°C, the driver outputs are disabled and the receiver output goes high impedance. The device re-enables automatically when the temperature falls below +148°C.

Does the device support hot-swapping?

Yes, the MAX33072EASA+ features hot-swap input circuitry on the DE pin. An internal pulldown holds DE low for at least 10μs upon power-up to prevent unwanted driver activation during board insertion.