The MAX13085EESA+T is a +5.0V, ±15kV ESD-protected RS-485/RS-422 transceiver featuring one driver and one receiver for half-duplex communication. It includes fail-safe circuitry that guarantees a logic-high receiver output when the inputs are open or shorted, so the bus stays in a defined state - maintaining full EIA/TIA-485 compatibility.

The receiver outputs a logic-high if all transmitters on a terminated bus are disabled (high impedance), eliminating false transitions. Hot-swap input structures on DE and RE prevent erroneous bus states when a board is hot-plugged. The slew-rate-limited driver reduces EMI and minimizes reflections from improperly terminated cables, supporting error-free data transmission on RS-485 lines.

Extended ±15kV Human Body Model ESD protection on the RS-485 I/O pins (A and B) makes the device rugged for exposed industrial cabling. A low-current shutdown mode saves power when the bus is idle, and up to 256 transceivers can share the bus - suiting utility meters, industrial control, telecom and Profibus networks.

Note: Refer to the official Maxim MAX13085E datasheet for full electrical parameters and data rate. Subject to change without notice; verify all parameters before final design.

The MAX13085EESA+T is supplied in the industry-standard 8-pin SO (narrow small-outline) package, indicated by the ESA suffix. The 8-pin SO is the de-facto footprint for half-duplex RS-485 transceivers, dropping into existing MAX485-style designs.

The "+" suffix indicates lead-free, RoHS-compliant finish and the "T" suffix tape-and-reel packing. Standard 8-lead SO land patterns and reflow profiles apply; terminate the A/B bus with the characteristic impedance (e.g. 120Ω) at both ends and bypass VCC with 0.1µF. The diagram below shows the typical operating circuit.

The MAX13085E uses the standard half-duplex RS-485 8-pin SO pinout (top view):

• Pin 1 - RO: Receiver output (when RE is low: A-B ≥ -50mV gives RO high; A-B ≤ -200mV gives RO low).
• Pin 2 - RE: Receiver output enable, active-low; RE low enables RO, RE high tri-states it. Hot-swap input.
• Pin 3 - DE: Driver output enable, active-high; DE high enables the driver, DE low tri-states it. Hot-swap input. (RE high + DE low = shutdown.)
• Pin 4 - DI: Driver input.
• Pin 5 - GND: Ground.
• Pin 6 - A / Pin 7 - B: Non-inverting (A) and inverting (B) receiver inputs / driver outputs - the RS-485 bus pins (±15kV ESD).
• Pin 8 - VCC: +5.0V supply (bypass 0.1µF to GND).

Tie RE and DE together to a single direction-control line for simple half-duplex control, and connect A/B to the twisted-pair bus with end termination. Confirm the exact pin assignment against the datasheet image below before layout.

The following parts are listed for reference. Verify duplex, data rate, ESD and package before substituting.

Maxim Integrated, now part of Analog Devices (NASDAQ: ADI), is a leading supplier of analog and mixed-signal semiconductors, long established in rugged RS-485/RS-422 and CAN interface transceivers. The MAX13080E-MAX13089E family of ±15kV ESD-protected, fail-safe RS-485 transceivers is widely used in industrial and metering networks.

Maxim/ADI provides complete datasheets, application notes and long-term supply, with authorized distribution and technical support across China for both prototype and volume programs.