The SD485N is a half-duplex RS-485/RS-422 transceiver with a single 5V supply, featuring automatic bus-polarity correction and transient protection. Designed for long-distance, multi-node balanced transmission in industrial environments, it features an enhanced built-in slew-rate limiter that suppresses signal reflections and electromagnetic emissions, enabling error-free data transmission up to 500 kbps.
The chip provides transient immunity protection in compliance with the IEC61000 standard, safeguarding against electrostatic discharge (ESD) and electrical fast transient (EFT) bursts. The bus pins are protected against ESD with a ±15 kV Human Body Model, while also meeting the specifications for Air-Gap Discharge and Contact Discharge, ensuring communication reliability in harsh electromagnetic environments.
The receiver features a 1/8-unit load input impedance, allowing up to 256 transceivers to be connected to the bus. Its wide common-mode voltage range supports multi-point communication applications over long cable runs. The device is available in an SOP8 package and operates over a junction temperature range of -40°C to +125°C.
Exceeds Requirements of EIA-485 Standard
Bus-Polarity Correction within 100 ms meet SGCC spec
Wide Supply Voltage 3V to 5.5V
Data Rate: Up to 500 kbps
Up to 256 transceivers may share Bus
Receivers with Advanced Full Fail-Safe Protection for Open, Shorted, or Terminated Lines
Tx and Rx Outputs Remain Three-State During Power-Up/Power-Down
±15kV ESD protection for RS-485 pins
Small Form Factor NSOIC Package with SOIC-8 Backward Compatibility
| Product Name | Package form | Marking | Hazardous Substance Control | Packing Type | Remarks |
|---|---|---|---|---|---|
| SD485NSATR | SOP-8-225-1.27 | SD485N | Halogen free | Tape & Reel | |
| SD485NSA | SOP-8-225-1.27 | SD485N | Halogen free | Tube |

| title | Types of | Size (KB) | date | Download the latest English version |
|---|---|---|---|---|
| SD485N | 0 | 2026-05-15 | SD485N Brief Datasheet |