MAX3072EEPA+

Overview

The MAX3072EEPA+ is a half-duplex RS-485 transceiver operating from a single +3.3V supply. It features one driver and one receiver with fail-safe circuitry that guarantees a logic-high output when inputs are open or shorted. The device includes hot-swap capability to prevent false transitions during power-up or insertion. Slew-rate-limited drivers minimize EMI and reflections, supporting data rates up to 250kbps. It provides ±15kV ESD protection on I/O pins and draws 800µA of supply current in unloaded conditions.

Feature Summary

• Hot-swap input structure prevents erroneous bus transitions during board insertion or power-up sequences.
• Fail-safe receiver design ensures a logic-high output state when differential inputs are left open or shorted.
• Slew-rate-limited drivers reduce electromagnetic interference and signal reflections for reliable communication.

Applications

• Industrial control systems
• Telecommunications equipment
• Security systems

Procurement Notes

Verify the component against official Analog Devices documentation to confirm pinout compatibility and electrical specifications. Ensure the selected package variant matches the required PCB footprint. Cross-reference the manufacturer's latest datasheet to validate operational limits before finalizing procurement decisions.

Selection Notes

Select this component for applications requiring robust half-duplex RS-485 communication at speeds up to 250kbps. The integrated hot-swap feature makes it suitable for systems requiring board insertion while powered. Verify that the 3.3V supply voltage aligns with the system architecture and that the thermal requirements fit within the specified operating temperature range.

Part Context

This part belongs to the MAX3070E–MAX3079E family of high-speed RS-485/RS-422 transceivers manufactured by Analog Devices. The MAX3072E specifically denotes the half-duplex variant with slew-rate limiting. The 'E' suffix indicates an extended industrial temperature range, while 'PA+' identifies the plastic DIP-8 through-hole package configuration.

Replacement Considerations

Direct functional substitutes within the same series include the MAX3075E and MAX3078E, which share identical half-duplex characteristics and slew-rate limitations. When replacing, ensure the new component supports the same 3.3V supply voltage and maintains compatibility with the existing PCB layout and interface signals.

FAQ

How does the MAX3072EEPA+ handle bus contention during hot insertion?

The device incorporates a hot-swap input structure on the DE and RE pins. Internal circuitry holds the driver disabled and receiver enabled until the supply voltage stabilizes, preventing false data transitions caused by parasitic capacitance or leakage currents during board insertion.

What is the behavior of the receiver when the bus lines are unconnected?

The MAX3072EEPA+ features fail-safe circuitry that guarantees a logic-high receiver output if the differential inputs (A and B) are open, shorted, or connected to a terminated line with all transmitters disabled. This occurs because the input threshold is set between -50mV and -200mV.

Why are the drivers slew-rate limited in this specific model?

The slew-rate limitation minimizes electromagnetic interference (EMI) and reduces signal reflections caused by improperly terminated cables. This design allows for error-free data transmission up to 250kbps, making it suitable for noisy industrial environments.