Part of the Day · MAX485 — SOIC-8 RS-485 transceiver

Part of the Day · 2026-10-23

A transceiver that converts UART signals into RS-485 differential signals for long cable runs. It communicates in half-duplex over two wires (A and B) and is widely used in industrial equipment and Modbus communication.

Actual size

↓ Actual size, left edge aligned to 0 on the ruler

One ruler tick = 1mm. On PC this is actual size on a 24-inch FHD monitor at 100% zoom; on iPhone it adjusts automatically. For other screens, use “Calibrate ruler” below.

Enlarged (SOIC-8 · top view · approx. 15×)

Pins 1 RO (receiver output) · 2 RE (receiver enable, Low) · 3 DE (driver enable, High) · 4 DI (driver input) · 5 GND · 6A (non-inverting I/O) · 7 B (inverting I/O) · 8 VCC (5V)

Package SOIC-8

Key specifications

Values are from the Analog Devices (Maxim) datasheet.

Marking and pins

Typical uses

• RS-485 industrial communication such as Modbus RTU
• Extending an MCU UART to tens or hundreds of metres
• Multidrop bus connecting multiple devices on two wires

Companion & similar parts

• MAX487 — Low-EMI version from the same datasheet, slowed to 250kbps — 1/4 unit load for up to 128 devices, low-current shutdown mode
• MAX1487 — Same pinout and 2.5Mbps, 1/4 unit load for up to 128 devices
• MAX490 — Full-duplex 8-pin version from the same datasheet — different pinout

RE (pin 2) and DE (pin 3) are often tied together so a single MCU pin switches between transmit and receive. The MAX485 has no low-current shutdown mode. Fit termination resistors at both ends of the line.