Texas Instruments THVD1406DR

Overview

THVD1406DR from Texas Instruments is a half-duplex RS-485 transceiver with auto-direction control, 500-kbps data rate, ±12-kV IEC 61000-4-2 contact ESD protection, and 3.3-V to 5.5-V single-supply operation. It serves as the physical-layer interface in industrial serial networks, enabling robust point-to-multipoint communication over long cables in factory automation and building control systems.

For engineers reviewing the THVD1406DR datasheet, THVD1406DR pinout, THVD1406DR application, or THVD1406DR equivalent, key selection considerations include its auto-direction timing (4–14 µs driver activation), 1/8 unit load support for up to 256 nodes, fail-safe receiver behavior under open/short/idle bus conditions, and compatibility with SOIC-8 and SOT-8 packages for layout flexibility.

Technical Context

The THVD1406DR implements auto-direction control via the D input pin-eliminating separate DE/RE control lines-by driving the bus for a fixed duration (t_{device_auto-dir} = 4–14 µs) upon D transition, then automatically disabling the driver and enabling the receiver. Its receiver features large hysteresis (30–50 mV) and failsafe logic that outputs high during open, shorted, or idle bus states.

It operates across –40°C to +125°C with ±16-V bus fault tolerance, 1.7 mA typical quiescent current during operation, and 3 µA standby supply current. The device meets TIA/EIA-485A and includes integrated IEC 61000-4-2 (±12 kV contact), IEC 61000-4-4 (±4 kV), and HBM (±16 kV) ESD protection on bus pins A and B.

Key Specifications

Pinout & Package

THVD1406DR is available in an 8-pin SOT package (2.1 mm × 1.2 mm) and also offered in SOIC-8 (4.9 mm × 3.91 mm). The SOT variant enables space-constrained PCB designs while maintaining co-layout compatibility with standard SOIC footprints.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RS-485 transceiver applications.

Compared with MAX13487EESA+ and SN65HVD72DR, THVD1406DR uniquely combines 3.3-V/5-V dual-supply operation, integrated auto-direction, and industry-standard ±12-kV IEC ESD in a space-saving SOT-8 package-making it optimal for cost-sensitive, pin-constrained, and voltage-flexible industrial endpoints.

Availability

THVD1406DR is available at Aetrix Electronics and suitable for factory automation, building management, and smart utility metering requiring stable component supply across extended temperature and ESD stress conditions.

Supply support for THVD1406DR 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

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The THVD14x6 product line was designed specifically for robust, low-pin-count RS-485 communication in harsh industrial environments-emphasizing auto-direction simplification, integrated ESD resilience, and extended temperature operation.

FAQ

What is the maximum data rate supported by THVD1406DR?

The THVD1406DR supports a maximum data rate of 500 kbps, as specified in its switching characteristics table under recommended operating conditions. This rate is validated across the full –40°C to +125°C temperature range with RL = 54 Ω and CL = 50 pF. It is optimized for medium-speed industrial protocols such as Modbus RTU and BACnet MS/TP, where signal integrity over long cables takes priority over raw speed.

Does THVD1406DR require external direction-control signals?

No, THVD1406DR does not require external direction-control signals. It implements auto-direction control using only the D (data input) pin: a rising edge on D activates the driver for 4–14 µs, after which the driver disables and the receiver automatically enables. This eliminates the need for separate DE (driver enable) and RE (receiver enable) control lines, reducing GPIO usage and isolation component count in the THVD1406DR design.

What package options are available for THVD1406DR?

THVD1406DR is offered in two package variants: an 8-pin SOIC (D) package measuring 4.90 mm × 3.91 mm, and an 8-pin SOT (DRL) package measuring 2.10 mm × 1.20 mm. Both share identical pinout and electrical specifications. The SOT-8 option provides significant board-area savings and is co-layout compatible with SOIC-8 footprints per TI's layout guidelines.

How does THVD1406DR handle bus fault conditions?

THVD1406DR provides ±16-V bus fault protection on A and B pins, meaning it can withstand sustained DC overvoltages up to ±16 V without damage or functional disruption. During fault events, internal clamping and thermal shutdown (triggering at 150–170°C junction temperature) protect the device. Bus pins also feature ±12-kV IEC 61000-4-2 contact ESD protection, making external transient suppressors unnecessary in most industrial deployments of THVD1406DR.

Is THVD1406DR compatible with 3.3-V microcontrollers?

Yes, THVD1406DR is fully compatible with 3.3-V microcontrollers. It operates from a single 3.0-V to 5.5-V supply and accepts logic-level inputs (D, RE, SHDN) with VIH ≥ 2.0 V and VIL ≤ 0.8 V-well within standard 3.3-V CMOS thresholds. Its R output is TTL/CMOS-compatible and drives high to VCC – 0.2 V, ensuring reliable interfacing with 3.3-V MCUs without level shifters in the THVD1406DR signal path.