DS36C280MX

Overview

The DS36C280 is a low-power CMOS RS-485 transceiver designed for multipoint data transmission. It operates on a single +5V supply with a maximum quiescent current of 500 μA. The device features adjustable slew rate control via an external resistor to minimize EMI, and includes built-in power-up/down glitch-free circuitry for live insertion. It supports a wide common mode range from −7V to +12V and incorporates thermal shutdown protection. The standard DS36C280 offers a ¼ unit load input impedance, supporting up to 128 nodes on the bus.

Feature Summary

• Adjustable Slew Rate Control: Allows user-defined driver edge rates using an external resistor to reduce electromagnetic interference.
• Glitch-Free Operation: Built-in circuitry prevents output glitches during power-up or power-down sequences.
• High Node Capacity: ¼ unit load receiver design enables connection of up to 128 nodes on a single bus.
• Thermal Protection: On-board thermal shutdown circuitry forces outputs to high impedance to prevent damage from excessive power dissipation.

Applications

• Multipoint data transmission systems requiring RS-485 compliance
• Battery-powered or power-conscious industrial applications
• Systems requiring live transceiver insertion or displacement

Procurement Notes

Verify component authenticity by checking manufacturer markings against official datasheet specifications. Confirm package type and temperature grade match project requirements. Review the latest Texas Instruments documentation for any obsolescence notices or lifecycle changes before finalizing procurement plans.

Selection Notes

Select the DS36C280 when designing for high node density (up to 128 devices) on a single RS-485 bus. Choose this part over standard unit load devices if minimizing power consumption is critical due to its low 500 μA quiescent current. Ensure the application benefits from adjustable EMI reduction through the external slew rate control pin.

Part Context

The DS36C280 belongs to the DS36C2xx series of RS-485 transceivers manufactured by Texas Instruments. This family focuses on low-power CMOS technology compatible with TIA/EIA-422-B standards. Unlike the DS36C279 which features sleep modes, the DS36C280 specifically emphasizes adjustable slew rate control for EMI management in industrial environments.

Replacement Considerations

Publicly confirmed substitutes include the DS36C278 and DS36C279. Note that these alternatives may differ in specific features such as sleep mode functionality or exact unit load configurations. Verify electrical compatibility and pinout alignment before substitution.

FAQ

How does the slew rate control affect the maximum data rate?

Slowing the edge rates of the device by increasing the slew rate resistance will decrease the maximum supported data rate.

What is the guaranteed number of nodes for the DS36C280?

The DS36C280 has a ¼ unit load input impedance, guaranteeing support for up to 128 nodes on the bus.

How does the device handle bus contention or fault situations?

A thermal shutdown circuit detects excessive power dissipation and forces the driver outputs into a high-impedance state to protect the device.