DS485N

Overview

The DS485N is a low-power RS-485/RS-422 multipoint transceiver manufactured by Texas Instruments. It integrates one driver and one receiver, operating from a single +5V supply with a typical quiescent current of 200 μA. The device supports data rates up to 2.5 Mbps and features a half-duplex flow-through pinout. Electrical characteristics include a common-mode input voltage range of -7V to +12V, short-circuit current limiting, and thermal shutdown protection. It accommodates up to 32 transceivers on the bus and operates within an industrial temperature range of 0°C to +70°C.

Feature Summary

• Half-duplex operation with flow-through pinout for simplified system design
• Integrated thermal shutdown and short-circuit protection for fault tolerance
• Failsafe receiver ensures logic-high output during open-circuit conditions
• Compatible with MAX485 and LTC485 pinouts and functionality

Applications

• Multipoint RS-485 communication networks
• Industrial process control systems
• Building automation and security systems

Procurement Notes

Verify component authenticity through authorized channels. Confirm package integrity and marking accuracy against datasheet specifications. Ensure storage conditions prevent electrostatic discharge damage prior to installation. Review lifecycle status as the device may be subject to discontinuation notices.

Selection Notes

Select this component for applications requiring standard unit load compatibility on RS-485 buses. Verify that the operating temperature range meets environmental requirements. Consider power consumption constraints relative to the 200 μA typical quiescent current. Ensure interface logic levels align with the single +5V supply requirement.

Part Context

The DS485 belongs to Texas Instruments' low-power RS-485 transceiver family. It serves as a functional replacement for legacy components like the MAX485 and LTC485. The device is designed for robust communication in noisy environments, providing reliable differential signaling across multipoint bus architectures.

Replacement Considerations

DS485M/NOPB (SOIC Package)

FAQ

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

The DS485 provides a standard unit load, allowing up to 32 transceivers to be connected to the bus.

How does the device handle fault conditions?

The driver includes short-circuit current limiting and thermal shutdown circuitry that places outputs into TRI-STATE if excessive power dissipation occurs.

What happens if the receiver inputs are left open?

The receiver features a failsafe mechanism that ensures a logic-high output if the input is open circuit.