Texas Instruments SN74ABT245BDWR

Overview

SN74ABT245BDWR from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between A and B buses in 5-V TTL systems. It features high-drive outputs (−32 mA IOH, 64 mA IOL), supports hot insertion via Ioff and power-up 3-state, and operates across −40°C to 85°C. Used in industrial backplane interfaces and legacy system bus bridging.

For engineers reviewing the SN74ABT245BDWR datasheet, SN74ABT245BDWR pinout, SN74ABT245BDWR application, or SN74ABT245BDWR equivalent, key selection criteria include its 20-pin SOIC-DW package, 3.2 ns typical propagation delay, ±100 µA Ioff at VCC = 0 V, and compatibility with 5-V TTL logic families in bus isolation and level-shifting roles.

Technical Context

This device implements dual-directional 8-bit data flow controlled by DIR (direction) and OE (output enable) inputs. Its output-enable circuitry ensures true high-impedance state during power-up/down, preventing bus contention. The Ioff specification (±100 µA) actively blocks current backflow when powered down, enabling safe hot-plug operation in modular systems.

It uses standard TTL-compatible input thresholds (VIH = 2 V min, VIL = 0.8 V max) and delivers rail-to-rail switching with VOL ≤ 0.55 V at IOL = 64 mA and VOH ≥ 2 V at IOH = −32 mA. Propagation delays are symmetric (tPLH/tPHL ≤ 3.9 ns) and enable/disable times (tPZL/tPHZ ≤ 6.2 ns) support high-speed bus arbitration in real-time control applications.

Key Specifications

Pinout & Package

SN74ABT245BDWR is housed in a 20-pin SOIC (DW) package, 7.5 mm wide × 12.8 mm long × 2.65 mm max height, with 0.65 mm lead pitch and NiPdAu lead finish. RoHS-compliant, MSL Level-1, tape-and-reel packaging (2000 pcs/reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245A and SN74ABT245BN, the SN74ABT245BDWR uniquely combines 5-V TTL compatibility, hot-insertion robustness, and surface-mount SOIC-DW packaging-making it optimal for production-grade industrial backplanes where reliability, density, and live maintenance are required.

Availability

SN74ABT245BDWR is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy system bus bridging, and modular PLC I/O expansion requiring stable component supply across extended product lifecycles.

Supply support for SN74ABT245BDWR 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 logic solutions for industrial, automotive, and communications markets.

The SN74ABT245B family was engineered for robust 5-V TTL bus interfacing in harsh environments-prioritizing hot-swap resilience, high noise immunity, and consistent timing across temperature extremes.

FAQ

What is the maximum allowable supply voltage for SN74ABT245BDWR?

The absolute maximum supply voltage for SN74ABT245BDWR is 7 V, but the recommended operating range is strictly 4.5 V to 5.5 V per TI SCBS081L. Operation outside this window risks parametric shift or latch-up. For sustained reliability, maintain VCC within ±5% of 5 V using low-ESR bulk and ceramic decoupling near Pin 20.

How does SN74ABT245BDWR support hot insertion?

SN74ABT245BDWR supports hot insertion via two integrated features: Ioff circuitry limits current to ±100 µA when VCC = 0 V, blocking backflow into powered-down modules; and power-up 3-state holds outputs in high-Z until VCC stabilizes. Both functions are intrinsic to the silicon design and require no external components to activate.

Can SN74ABT245BDWR interface between 3.3-V and 5-V logic domains?

No-SN74ABT245BDWR is a 5-V-only device with TTL-compatible input thresholds (VIH = 2 V min) and 5-V output swing. Driving it from 3.3-V logic may cause marginal VIH violation; connecting its 5-V outputs to 3.3-V inputs risks overvoltage damage. Use dedicated level translators like TXB0108 for mixed-voltage interfacing.

What is the thermal resistance (θJA) of the SN74ABT245BDWR SOIC package?

The junction-to-ambient thermal resistance (θJA) for SN74ABT245BDWR in the SOIC-DW package is 58°C/W, measured per JESD 51-7 on a standard 4-layer JEDEC test board. This value assumes 1 in² of 2-oz copper pour under the exposed pad area; actual board layout can raise θJA by 15–25% if thermal vias or copper area are reduced.

Is SN74ABT245BDWR pin-compatible with other members of the SN74ABT245B family?

Yes-SN74ABT245BDWR shares identical 20-pin SOIC-DW pinout and function mapping with all SN74ABT245B variants in DW, DB, NS, PW, DGV, RGY, GQN, and ZQN packages. Electrical behavior, timing, and DC specs are identical; only package dimensions, thermal performance, and assembly methods differ.