DS485MX

Overview

The DS485MX is a low-power RS-485/RS-422 multipoint transceiver manufactured by Texas Instruments. It integrates one driver and one receiver in an 8-pin SOIC package, supporting data rates up to 2.5 Mbps. The device operates from a single +5V supply with typical quiescent current of 200 μA. Electrical specifications include a driver propagation delay of 40 ns typ, receiver propagation delay of 200 ns typ, and a common-mode input voltage range of −7V to +12V. It features short-circuit current limiting and thermal shutdown protection.

Feature Summary

• Supports half-duplex communication with tri-state outputs on both the driver and receiver sections.
• Includes failsafe circuitry that ensures a logic-high output if the differential input is open circuit.
• Provides thermal shutdown protection that places driver outputs into a high-impedance state during excessive power dissipation.

Applications

• Multipoint RS-485 communication networks
• RS-422 point-to-point or multipoint links
• Industrial bus systems requiring standard unit loads

Procurement Notes

Verify component authenticity through authorized distributors or TI directly. Confirm the specific suffix matches the required package and temperature rating. Check for RoHS compliance status and lifecycle stage, as this part may be designated for lifetime buy or obsolete depending on the region and date.

Selection Notes

Select this component for applications requiring pin and functional compatibility with MAX485 and LTC485 devices. Ensure the design supports a single 5V supply and accommodates the specified 0°C to 70°C operating temperature range. Verify that the bus topology allows for up to 32 standard unit loads.

Part Context

This device belongs to the DS485 family of low-power transceivers from Texas Instruments. It is functionally compatible with industry-standard parts like the MAX485. The 'MX' suffix indicates the SOIC package variant characterized for industrial temperature operation.

Replacement Considerations

Public confirmed substitutes include DS485M/NOPB and DS485TMX/NOPB. These variants share identical functionality but differ in packaging quantities or extended temperature ranges.

FAQ

What is the maximum data rate supported by the DS485MX?

The device supports data rates up to 2.5 Mbps based on a driver transition time to unit interval ratio of 10%.

How does the failsafe feature operate?

The receiver ensures a logic-high output if the input is open circuit, preventing indeterminate states on the bus.

What protection mechanisms are included for the driver?

The driver includes short-circuit current limiting and thermal shutdown circuitry that activates if junction temperature exceeds safe limits.