Texas Instruments SN74AC245DWR

Overview

SN74AC245DWR from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between A and B buses in industrial and consumer systems. It operates from 2 V to 6 V, accepts input voltages up to 6 V, achieves 7 ns max propagation delay at 5 V, and features direction control (DIR) and output enable (OE) pins for flexible bus isolation-used in factory automation I/O expansion and pro audio digital signal routing.

For engineers reviewing the SN74AC245DWR datasheet, SN74AC245DWR pinout, SN74AC245DWR application, or SN74AC245DWR equivalent, key selection criteria include its 20-pin SOIC (DW) package, ±24 mA output drive at 5 V, 3.3 V/5 V logic compatibility, and bus-isolation capability via OE assertion-critical for mixed-voltage system interfacing and noise-sensitive data paths.

Technical Context

The SN74AC245DWR implements a CMOS-based octal transceiver architecture with dual-directional data flow controlled by a single DIR input and full bus isolation enabled by an active-low OE input. Its function table defines three operational states: A→B transmission (DIR = H, OE = L), B→A transmission (DIR = L, OE = L), and high-impedance isolation (OE = H).

It supports wide VCC operation (2–6 V) with input tolerance up to 6 V independent of supply, enabling level-shifting between 3.3 V and 5 V domains without external translators. Switching characteristics are specified at both 3.3 V ±0.3 V and 5 V ±0.5 V, with tPLH/tPHL ≤7 ns (max) at 5 V and tPZH/tPLZ ≤12.5 ns (max) for OE-controlled transitions.

Key Specifications

Pinout & Package

SN74AC245DWR uses a 20-pin SOIC (DW) package measuring 12.8 mm × 10.3 mm (body: 12.8 mm × 7.5 mm), RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating for unlimited reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245A and 74ACT245, the SN74AC245DWR uniquely supports 2–6 V operation with 6 V input tolerance-making it the only option among the three for seamless 3.3 V ↔ 5 V bidirectional translation without external components or voltage constraints.

Availability

SN74AC245DWR is available at Aetrix Electronics and suitable for factory automation I/O expansion, pro audio digital interfaces, and home appliance control panels requiring stable component supply across extended temperature ranges and mixed-voltage board designs.

Supply support for SN74AC245DWR 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 connectivity technologies with over 90 years of innovation in industrial, automotive, and consumer electronics.

The SN74AC245DWR belongs to TI's AC-series logic family, engineered for robust voltage-flexible bus interfacing in noise-sensitive, mixed-supply environments-targeting industrial control, audio/video infrastructure, and appliance subsystems.

FAQ

What is the maximum supply voltage for SN74AC245DWR?

The SN74AC245DWR supports a maximum supply voltage of 6 V, with absolute maximum ratings specifying VCC up to 7 V. Operation within the recommended 2 V to 6 V range ensures reliable performance, including full 6 V input tolerance on all A/B/DIR/OE pins-critical for interfacing with 5 V peripherals on 3.3 V systems without level shifters.

Does SN74AC245DWR support 3.3 V and 5 V logic simultaneously?

Yes, SN74AC245DWR supports simultaneous 3.3 V and 5 V logic operation: it can be powered from either voltage (2–6 V range), and its inputs tolerate up to 6 V regardless of VCC. This enables direct bidirectional translation between 3.3 V controllers and 5 V peripherals-no external translators required-as confirmed in TI's recommended operating conditions and input voltage specifications.

What is the function of the DIR and OE pins on SN74AC245DWR?

The DIR (pin 1) controls data direction: HIGH enables A→B transfer; LOW enables B→A transfer. The OE (pin 19) is active-low and disables outputs: when HIGH, all A and B pins enter high-impedance state, isolating both buses. These two pins define three functional modes-A-to-B, B-to-A, or full isolation-as documented in the device function table and verified in switching-characteristics test conditions.

What package type is used for SN74AC245DWR?

SN74AC245DWR uses a 20-pin SOIC (DW) package with dimensions 12.8 mm × 10.3 mm (including leads) and body size 12.8 mm × 7.5 mm. It is RoHS-compliant, features NiPdAu lead finish, and carries MSL Level-1 rating-confirmed in TI's Package Option Addendum and Mechanical, Packaging, and Orderable Information section.

Is SN74AC245DWR suitable for industrial temperature applications?

Yes, SN74AC245DWR is rated for −40 °C to +85 °C operating temperature, meeting industrial environmental requirements. This specification is explicitly stated in Section 5.3 Recommended Operating Conditions and validated across electrical and switching characteristics tables-ensuring reliable performance in factory automation, signage, and appliance control systems.