MAX3430ESA+T

Overview

The MAX3430ESA+T is a +3.3V, half-duplex RS-485 transceiver in an 8-pin SO package. It features ±80V fault protection on driver outputs and receiver inputs against ground faults. The device supports data rates up to 250kbps with internal slew-rate limiting to minimize EMI. Its 1/4-unit-load receiver input impedance allows up to 128 transceivers on a single bus. True fail-safe circuitry guarantees a logic-high output when inputs are open. Hot-swap capability on the DE pin prevents false transitions during board insertion. Supply current is typically 3.5mA, dropping to 200µA in shutdown mode.

Feature Summary

• ±80V Fault Protection: Withstands overvoltage signal faults on communication bus lines without damage, regardless of power state.
• 1/4-Unit Load Receiver: High input impedance (48kΩ) enables connection of up to 128 transceivers on a single bus.
• Hot-Swap Input Structure: Internal pulldown on the DE pin safeguards against unwanted driver activation during hot-swap situations.
• True Fail-Safe Inputs: Differential threshold ensures a logic-high receiver output when inputs are shorted, open, or idle.

Applications

• RS-422/RS-485 Communications
• Industrial-Control Local Area Networks
• Profibus Applications
• Multimaster RS-485 Networks

Procurement Notes

Verify the specific suffix '+T' indicates tape-and-reel packaging rather than tube packaging when sourcing components. Confirm the 'E' designation corresponds to the industrial temperature range (-40°C to +85°C). Ensure compatibility with standard 8-pin SO footprints during PCB layout verification.

Selection Notes

Select this component for applications requiring high node density on RS-485 buses due to its 1/4-unit-load receiver. It is suitable for environments prone to voltage faults or hot-swap operations. Consider alternative models if higher data rates exceeding 250kbps are required, as this device utilizes slew-rate limiting.

Part Context

The MAX3430 belongs to Maxim Integrated's family of low-power RS-485 transceivers designed for 3.3V operation. It distinguishes itself from standard devices through enhanced fault protection and reduced unit load. The ESA variant specifically denotes the industrial temperature grade within the small-outline package lineup.

Replacement Considerations

MAX3430ESA

FAQ

How does the MAX3430 handle hot-swap scenarios?

The device includes a hot-swap input structure on the DE pin. An internal pulldown holds DE low for at least 10µs during power-up, preventing false driver activation when inserting boards into live backplanes.

What is the maximum number of transceivers supported on one bus?

Due to its 1/4-unit-load receiver input impedance (48kΩ), the MAX3430 allows up to 128 transceivers to be connected in parallel on a single communication line.

Does the device offer protection against electrostatic discharge?

Yes, the receiver inputs and driver outputs (A, B) provide ±12kV ESD protection according to the Human Body Model specification.