Texas Instruments SN74ABTR2245DWR

Overview

SN74ABTR2245DWR from Texas Instruments is an octal transceiver with 3-state outputs, designed for asynchronous bidirectional data bus communication between A and B ports. It features integrated 25-Ω series output resistors, operates from 4.5 V to 5.5 V, supports –40°C to 85°C temperature range, and delivers 12 mA sink/source capability per I/O. It is used in industrial control backplanes and memory interface isolation.

For engineers reviewing the SN74ABTR2245DWR datasheet, SN74ABTR2245DWR pinout, SN74ABTR2245DWR application, or SN74ABTR2245DWR equivalent, key selection considerations include direction-control logic behavior, 3-state isolation timing (tPZH/tPLZ ≤ 6.3 ns), high-impedance state during power-up/down, and SOIC-20 package compatibility with legacy board layouts.

Technical Context

This device implements dual-octet bidirectional bus transceivers using EPIC-II^B BiCMOS technology, enabling low-power operation while maintaining TTL-compatible voltage thresholds (VIH = 2 V, VIL = 0.8 V). Its DIR input selects data flow direction (A→B or B→A), and OE enables/disables both ports simultaneously into high-impedance states.

The internal 25-Ω series resistor on each output reduces signal overshoot/undershoot without external components. During VCC ramping between 0–2.1 V, the device auto-enters high-Z; above 2.1 V, OE must be actively pulled high to guarantee isolation - a design requirement critical for hot-swap and power sequencing robustness.

Key Specifications

Pinout & Package

SN74ABTR2245DWR is housed in a 20-pin SOIC (DW) package, 7.5 mm × 12.8 mm footprint, 2.65 mm max height, RoHS-compliant, with NIPDAU lead finish and MSL Level-1 rating (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ABTR2245DWR, SN74LVC2245APW offers modern low-voltage efficiency but mandates full system voltage redesign, while SN74ABT2245N preserves electrical compatibility at the cost of thermal performance and SMT scalability.

Availability

SN74ABTR2245DWR is available at Aetrix Electronics and suitable for industrial backplane interfaces, memory bus isolation, and legacy system bus extension requiring stable component supply and long-term obsolescence management.

Supply support for SN74ABTR2245DWR 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 over 90 years of innovation in industrial, automotive, and communications markets.

SN74ABTR2245DWR belongs to TI's ABT logic family - engineered for high-speed, low-noise bidirectional bus interfacing in 5-V industrial systems where signal integrity and power-up safety are critical.

FAQ

What is the function of the DIR pin on the SN74ABTR2245DWR?

The DIR (direction) pin on the SN74ABTR2245DWR controls data flow direction between the A and B ports. When DIR is LOW, data transfers 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 allows flexible bus arbitration without external logic, and is essential for implementing shared-memory or multi-master communication schemes using the SN74ABTR2245DWR.

Does the SN74ABTR2245DWR require external termination resistors?

No, the SN74ABTR2245DWR does not require external termination resistors because each output includes an integrated 25-Ω series resistor. This feature reduces signal overshoot and undershoot on transmission lines, simplifying PCB layout and lowering BOM cost. The internal resistance is tightly controlled and optimized for standard 50-Ω or 75-Ω trace impedances commonly found in industrial backplane designs using the SN74ABTR2245DWR.

How does the SN74ABTR2245DWR behave during power-up and power-down?

When VCC is between 0 V and 2.1 V, the SN74ABTR2245DWR automatically enters a high-impedance state on all I/O pins - preventing bus contention or back-driving during power sequencing. Above 2.1 V, OE must be actively driven HIGH (e.g., via pull-up resistor) to maintain isolation. This dual-mode behavior ensures safe operation in hot-swap and mixed-rail systems where the SN74ABTR2245DWR serves as a bus guard.

What is the maximum output current rating for the SN74ABTR2245DWR?

The SN74ABTR2245DWR supports ±12 mA per I/O pin under recommended operating conditions (VCC = 4.5–5.5 V, TA = –40°C to +85°C). This rating applies to both sourcing (IOH) and sinking (IOL) current, enabling direct drive of standard TTL loads and stubbed bus structures. Exceeding this limit risks exceeding absolute maximum ratings (30 mA) and may degrade timing or cause thermal stress in sustained operation of the SN74ABTR2245DWR.

Is the SN74ABTR2245DWR pin-compatible with other members of the ABT family?

Yes, the SN74ABTR2245DWR shares identical pinout and functional behavior with SN74ABT2245N (PDIP-20) and SN74ABTR2245PW (TSSOP-20), differing only in package type and thermal characteristics. All three variants use the same DIR/OE control logic, 25-Ω output termination, and electrical specifications - allowing drop-in substitution across SOIC, PDIP, and TSSOP footprints when mechanical constraints permit. This consistency simplifies design reuse for the SN74ABTR2245DWR across prototyping and production stages.