Hangzhou, May 27, 2025 — With the rapid advancement of industrial automation, stable and reliable RS-485 communication networks have become the "central nervous system" for device interconnectivity. As a domestic semiconductor company with over a decade of expertise in signal chain chips, RuiMon Technology upholds the principle of independent innovation and has introduced the high-reliability auto-direction-switching half-duplex RS-485 transceiver MS2549. Its automatic transmit/receive control technology significantly reduces the complexity of industrial communication systems, delivering a cost-effective domestic chip solution for applications such as isolated RS-485 interfaces, industrial control, and HVAC systems.

Key Features
1. Intelligent Auto-Control Design, Cost-Efficient
➤ Integrated auto-direction control eliminates the need for separate receiver/transmitter switching, simplifying isolated communication design and reducing isolation component costs.
➤ 1/4 unit load supports 128-node networking, ideal for high-density wiring scenarios like PLCs and DCS systems.
2. Industrial-Grade Reliability
➤ High robustness bus pins with ESD protection ≥15kV (HBM).
➤ Hot-swap protection circuit ensures zero interference during power-on/off, enhancing system stability.
3. Wide Voltage Compatibility & Flexibility
➤ 3.3V–5.5V wide operating voltage, compatible with mainstream industrial power architectures.
➤ Wide common-mode input range (-7V to +12V), ensuring reliable long-line transmission in noisy environments.
Product Specifications
| Key Parameters | Performance |
|---|---|
| TX/RX Channels | 1/1 |
| Operating Voltage | 3.3V–5.5V |
| Common-Mode Input Range | -7V to +12V (5V); -7V to +7V (3.3V) |
| Receiver Threshold | -50mV to +50mV |
| Transmission Mode | Half-Duplex |
| ESD (Bus Pins) | 15kV (HBM) |
| Quiescent Current | 4mA |
| Max Data Rate | 20Mbps |
| Bus Polarity | Polarized |
| Package | SOP8 |

(Typical Application Diagram)
Application Scenarios
The MS2549 is designed for RS-485 bus transmission, supporting multi-node, half-duplex, bidirectional data communication.
Cost Advantage in Isolated 485 Solutions
Traditional isolated RS-485 designs require three signal lines (DE, R, D) for full data isolation. However, thanks to its integrated auto-direction control, the MS2549 automatically manages transmitter/receiver switching d on bus and D-line levels, eliminating the need for DE signal isolation. This reduces the number of isolation components and PCB space, making it a highly cost-effective solution for isolated RS-485 communications.