Texas Instruments SN74ABTH25245DW

Overview

SN74ABTH25245DW from Texas Instruments is a 25-Ω octal bus transceiver with 3-state outputs in SOIC-24 package, designed for asynchronous bidirectional data transfer between buses. It supports incident-wave switching on 25-Ω transmission lines, sinks up to 188 mA (A port) and 64 mA (B port), operates from –40°C to 85°C, and features bus-hold circuitry eliminating external pull resistors.

For engineers reviewing the SN74ABTH25245DW datasheet, SN74ABTH25245DW pinout, SN74ABTH25245DW application, or SN74ABTH25245DW equivalent, key selection considerations include its 25-Ω line-driving capability, distributed V_CC/GND pin layout for noise reduction, high-impedance state during power-up/down, and compatibility with TTL-level control signals.

Technical Context

This device implements a noninverting bidirectional bus transceiver architecture with separate direction (DIR) and output-enable (OE) controls. It uses EPIC-II^B BiCMOS process to achieve low power dissipation while maintaining high-speed switching performance on controlled-impedance lines.

The transceiver provides active bus-hold on all A/B data inputs, enabling stable logic levels without external components. Its distributed V_CC and GND pins across the SOIC-24 package reduce simultaneous switching noise, and it enters high-impedance state when V_CC is below 2.1 V during power sequencing.

Key Specifications

Pinout & Package

SN74ABTH25245DW is housed in a 24-pin SOIC (DW) package with 300-mil body width and gull-wing leads. Pin spacing is 0.050 inch (1.27 mm), and thermal resistance θ_JA is 81°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ABTH25245DW, SN74ABT245DW offers greater voltage margin but sacrifices bus-hold and 25-Ω optimization, while SN74LVC245APW reduces footprint and power but eliminates 5-V compatibility and incident-wave line driving capability.

Availability

SN74ABTH25245DW is available at Aetrix Electronics and suitable for industrial PLCs, memory subsystems, backplane interconnects, and legacy bus bridge designs requiring stable component supply and long-term obsolescence management.

Supply support for SN74ABTH25245DW 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 specializing in analog, embedded processing, and logic solutions, with decades of heritage in high-reliability industrial and military-grade components.

The ABTH25245 product line was developed specifically for high-speed, low-noise bidirectional bus interfacing in 5-V systems requiring controlled-impedance line driving and robust power sequencing behavior.

FAQ

What is the function of the DIR pin on the SN74ABTH25245DW?

The DIR (direction) pin on the SN74ABTH25245DW controls data flow direction: when DIR is low, data passes from the B bus to the A bus; when DIR is high, data flows from the A bus to the B bus. This bidirectional control enables flexible bus arbitration in systems like memory expansion or backplane interconnects, and the SN74ABTH25245DW maintains noninverting signal polarity regardless of direction.

Does the SN74ABTH25245DW support hot insertion or live bus swapping?

The SN74ABTH25245DW supports safe hot insertion due to its high-impedance state during power-up/down (V_CC < 2.1 V) and robust ESD protection (>2000 V HBM). However, full hot-swap compliance requires external circuitry (e.g., slew-rate limiting, current limiting) since the SN74ABTH25245DW itself does not implement soft-start or fault reporting.

Can the SN74ABTH25245DW drive 50-Ω transmission lines effectively?

The SN74ABTH25245DW is specifically optimized for 25-Ω lines and does not deliver optimal performance on 50-Ω traces. Its 188 mA A-port sink current is calibrated for 25-Ω incident-wave switching; using it on 50-Ω lines results in undershoot/overshoot and degraded signal integrity. For 50-Ω applications, TI recommends SN74ABT245DW instead.

How does bus-hold functionality work on the SN74ABTH25245DW?

The SN74ABTH25245DW integrates active bus-hold circuitry on all A and B data pins, providing ±100 µA hold current to maintain the last-valid logic state when inputs float. This eliminates external pull resistors, reduces BOM count, and prevents metastability in unconnected or unterminated bus segments - a key advantage in modular or expandable systems using the SN74ABTH25245DW.

Is the SN74ABTH25245DW pin-compatible with other ABT-series transceivers?

The SN74ABTH25245DW shares the same SOIC-24 pinout as SN74ABT245DW and SN74ABT25245DW, but functional differences exist: SN74ABTH25245DW includes bus-hold and 25-Ω drive tuning, whereas SN74ABT245DW lacks bus-hold and targets 50-Ω lines. Direct substitution may cause signal integrity or logic-level issues unless system design accounts for these distinctions in the SN74ABTH25245DW.