Texas Instruments SN74LVC244ADW

Overview

SN74LVC244ADW from Texas Instruments is an octal noninverting 3-state buffer/driver IC designed for asynchronous bus interfacing in 1.65V–3.6V systems. It features dual 4-bit banks, 5.9ns max propagation delay at 3.3V, 5.5V-tolerant inputs, and Ioff support for live insertion-used in server backplanes, LED display controllers, and telecom switch data paths.

For engineers reviewing the SN74LVC244ADW datasheet, SN74LVC244ADW pinout, SN74LVC244ADW application, or SN74LVC244ADW equivalent, this page delivers verified package mapping (SOIC-20 DW), real-world timing specs, confirmed 3-state control behavior, and validated alternatives for mixed-voltage signal translation and bus isolation tasks.

Technical Context

The SN74LVC244ADW implements two independent 4-bit noninverting buffer banks, each controlled by a dedicated output-enable input (1OE, 2OE). Its CMOS architecture supports bidirectional voltage translation: 5.5V-tolerant inputs operate with VCC as low as 1.65V, enabling down-translation from legacy 5V logic to 3.3V or 2.5V domains.

Each bank's outputs enter high-impedance state when its OE is high; both OEs must be low for full 8-bit drive. Ioff circuitry ensures zero current flow during partial power-down, while balanced CMOS outputs deliver ±24mA drive at 3.0V-critical for driving long PCB traces or capacitive loads in network switches and motor driver I/O expanders.

Key Specifications

Pinout & Package

SN74LVC244ADW uses the DW package: 20-pin SOIC with 12.80mm × 10.3mm body size and 0.65mm lead pitch. Pin 1 is top-left corner (notch/indentation side), with GND at pin 10 and VCC at pin 20.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with SN74LVC244ADW, the 74LVC244APW offers smaller footprint but reduced thermal margin, while SN74LVCH244A adds bus-hold for robustness at the cost of higher static current-neither is pin-compatible without layout revision.

Availability

SN74LVC244ADW is available at Aetrix Electronics and suitable for server backplanes, LED display controllers, and industrial network switches requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVC244ADW 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 with emphasis on reliability, scalability, and broad ecosystem support.

The SN74LVC244ADW belongs to TI's LVC logic family-designed specifically for low-voltage, high-speed, mixed-signal interfacing in industrial, computing, and communications infrastructure.

FAQ

What is the maximum operating voltage on the inputs of the SN74LVC244ADW?

The SN74LVC244ADW inputs tolerate up to 5.5V regardless of VCC level, enabling direct interfacing with 5V logic families without external level-shifting components. This specification is guaranteed across the full –40°C to +125°C temperature range and applies to all input pins (1A1–1A4, 2A1–2A4, 1OE, 2OE). The SN74LVC244ADW maintains valid logic thresholds and avoids damage even when inputs exceed VCC by up to 2.0V.

Does the SN74LVC244ADW support hot-swap or live-insertion applications?

Yes-the SN74LVC244ADW incorporates Ioff circuitry that disables all outputs and limits leakage to ±10µA when VCC = 0V, preventing back-drive into powered circuitry during hot-plug events. This feature is explicitly validated per JEDEC JESD78 and supports safe insertion into live backplanes or modular I/O carriers. The SN74LVC244ADW also exhibits latch-up immunity exceeding 250mA, further enhancing system robustness.

What is the recommended bypass capacitor for the SN74LVC244ADW?

A 0.1µF ceramic capacitor placed as close as possible to the VCC pin (pin 20) and GND (pin 10) is the minimum recommended bypass for the SN74LVC244ADW. For improved high-frequency noise suppression, TI recommends paralleling it with a 1µF capacitor. Layout best practices require short, wide traces to both capacitor terminals and placement on the same PCB layer as the SN74LVC244ADW to minimize inductance and ensure stable supply rail integrity.

Can the SN74LVC244ADW drive a 50Ω transmission line directly?

Yes-the SN74LVC244ADW can source/sink ±24mA at 3.0V, which is sufficient to drive a 50Ω line terminated at the receiver (e.g., 50Ω to GND or VCC/2). Signal integrity analysis shows clean edges with <1ns skew across all 8 outputs when loaded with 50pF and damped using a 22Ω series resistor near the SN74LVC244ADW output. For traces >12cm, source termination is required to suppress reflections.

How does the SN74LVC244ADW handle unused input pins?

All unused inputs on the SN74LVC244ADW-including 1A1–1A4, 2A1–2A4, 1OE, and 2OE-must be tied to a valid logic level (VCC or GND) to prevent floating nodes, excessive current draw, or oscillation. TI specifies that leaving inputs unconnected violates Recommended Operating Conditions. A 10kΩ pull-up or pull-down resistor is acceptable; direct connection is preferred for lowest noise and power. This requirement applies regardless of whether the associated output bank is enabled.