Texas Instruments DS36276MX

Overview

DS36276MX from National Semiconductor is a FAILSAFE multipoint transceiver for bidirectional differential RS-485/RS-422 busses, featuring guaranteed HIGH receiver output under open, shorted, or terminated line conditions, ±7V to +12V common-mode range, and 5.0V supply operation. It serves as a robust interface between UART controllers and industrial field busses in noisy environments.

For engineers reviewing the DS36276MX datasheet, DS36276MX pinout, DS36276MX application, or DS36276MX equivalent, this device is selected for fail-safe bus integrity in multi-drop serial networks where line fault resilience and compatibility with legacy RS-485 transceivers are critical design requirements.

Technical Context

The DS36276MX implements a dual-function transceiver architecture with independent driver enable (DE) and receiver enable (RE) controls, enabling precise half-duplex bus arbitration. Its receiver incorporates internal hysteresis (50 mV) and failsafe biasing that forces RO = HIGH when differential input voltage |VID| < 200 mV - covering floating, idle, and faulted bus states.

Driver output meets TIA/EIA-485 (RL = 54Ω) and TIA/EIA-422-A (RL = 100Ω) load requirements, delivering VT1 ≥ 1.5 V (min) and balanced differential swing (ΔVT1 ≤ ±0.2 V). Bus common-mode tolerance of −7V to +12V supports long-cable deployments across electrically noisy industrial zones.

Key Specifications

Pinout & Package

DS36276MX is housed in an 8-pin SOIC package (NS Package Number M08A), with gull-wing leads, 1.27 mm pitch, and JEDEC MS-012AC outline. The package supports surface-mount reflow and is rated for industrial temperature operation (0°C to +70°C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multipoint transceiver applications.

Compared with SN65HVD12DR and MAX13487EESA+, the DS36276MX offers deterministic hardware-enforced failsafe behavior without external components, full DE/RE independence for custom timing, and proven legacy interoperability - making it optimal for retrofitting failsafe capability into existing RS-485 designs.

Availability

DS36276MX is available at Aetrix Electronics and suitable for industrial automation, building management, and utility metering applications requiring stable component supply, long-term lifecycle support, and guaranteed failsafe bus behavior.

Supply support for DS36276MX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

National Semiconductor was a U.S.-based analog and interface IC manufacturer, acquired by Texas Instruments in 2011; its legacy products maintain industrial qualification and long-term support.

The DS36276MX belongs to National's RS-485 transceiver product line, engineered specifically for industrial multipoint networks where bus fault resilience, legacy compatibility, and deterministic receiver behavior are mandatory.

FAQ

What does "FAILSAFE" mean for the DS36276MX?

The DS36276MX FAILSAFE feature guarantees that its receiver output (RO) remains HIGH under three critical bus conditions: open-circuit inputs, shorted inputs, and terminated-but-idle lines. This prevents undefined logic states at the UART input, eliminating false start bits and framing errors during cable disconnects or transceiver failures - a key reliability requirement in unattended industrial systems where the DS36276MX is deployed.

Is the DS36276MX pin-compatible with older National Semiconductor transceivers?

Yes, the DS36276MX is explicitly pin-compatible with DS75176B, SN75176A/B, DS96176, and DS3695 per its datasheet. All share identical 8-pin SOIC (M08A) layout, pin functions (DI, DE, RE, RO, DO/RI, GND, VCC, NC), and logic-level thresholds. This allows direct PCB replacement to add failsafe functionality without layout changes - a documented advantage confirmed in the DS36276MX connection diagram and compatibility notes.

What is the maximum recommended data rate for the DS36276MX?

The DS36276MX supports data rates up to approximately 10 Mbps under ideal conditions (short traces, matched termination, low capacitance), based on its propagation delay specifications (tPLH/tPHL = 15–70 ns) and rise/fall times (12–50 ns). However, for robust operation over 1200-meter RS-485 links with multiple stubs and noise, design guidelines recommend limiting to 115.2 kbps - the DS36276MX's electrical characteristics ensure reliable signal integrity within these real-world constraints.

Does the DS36276MX require external termination resistors?

Yes, the DS36276MX requires external termination - typically a 120Ω resistor across the A/B bus lines at the farthest node - to prevent signal reflections in RS-485 networks. The device itself contains no integrated termination; its input resistance (12–19 kΩ) is designed to present minimal loading. Proper termination is essential to meet the DS36276MX's specified VT1 and timing performance, especially beyond 100 meters or at higher data rates.

How does the DS36276MX handle ground potential differences between nodes?

The DS36276MX handles ground potential differences via its −7V to +12V bus common-mode voltage range, which allows the differential receiver to correctly interpret signals even when node grounds differ by up to 19V. This specification directly supports long-distance RS-485 deployments across disparate equipment cabinets or building floors - a core design requirement validated in the DS36276MX's absolute maximum ratings and electrical characteristics tables.