Texas Instruments SN74LV244APWT

Overview

SN74LV244APWT from Texas Instruments is an octal 3-state buffer/driver IC designed for bidirectional signal buffering in bus-oriented systems. It features dual 4-bit groups with independent output-enable (OE) controls, operates from 2 V to 5.5 V, delivers ≤6.5 ns propagation delay at 5 V, supports mixed-mode voltage interfacing, and includes Ioff partial-power-down protection. It is used in server memory address buffering and telecom infrastructure backplane drivers.

For engineers reviewing the SN74LV244APWT datasheet, SN74LV244APWT pinout, SN74LV244APWT application, or SN74LV244APWT equivalent, this page provides verified functional role, validated TSSOP-20 pin mapping, confirmed 3-state drive capability (±16 mA), thermal metrics for PCB layout planning, and two industry-validated alternative parts with documented functional trade-offs.

Technical Context

The SN74LV244APWT implements two independent 4-bit non-inverting buffer groups, each with dedicated active-low OE control. Its CMOS inputs accept TTL- and LVCMOS-compatible logic levels across 2–5.5 V supply, while balanced 3-state outputs support bidirectional bus isolation with ±16 mA drive strength at 3.3 V.

It integrates Ioff circuitry enabling safe operation during partial power-down, and features low ground bounce (<0.8 V) and undershoot (>2.3 V) at 3.3 V - critical for noise-sensitive telecom and server applications where signal integrity on shared buses must be preserved across temperature (–40°C to 125°C).

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.50 mm × 7.8 mm body, 0.65 mm lead pitch, exposed pad optional (not electrically required). Pin 1 marked by dot; pin 10 = GND, pin 20 = VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV244APWT, the 74LVC244APW offers faster speed at 3.3 V but lacks Ioff and mixed-voltage robustness, while SN74AHCT244PW provides TTL compatibility at 5 V but sacrifices flexibility and thermal margin - making SN74LV244APWT the optimal choice for modern multi-rail industrial and telecom systems.

Availability

SN74LV244APWT is available at Aetrix Electronics and suitable for server motherboard design, telecom line card development, and industrial motor-drive control requiring stable component supply across extended temperature and mixed-voltage conditions.

Supply support for SN74LV244APWT 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 for industrial, automotive, and communications markets.

The SN74LV244APWT belongs to TI's LV logic family, engineered for low-voltage operation (2–5.5 V), high noise immunity, and robust 3-state bus interface performance in space-constrained, thermally demanding applications.

FAQ

What is the maximum capacitive load the SN74LV244APWT can drive while maintaining specified timing?

The SN74LV244APWT is characterized for CL ≤ 50 pF in its switching specifications - including tpd, ten, and tdis - across all VCC conditions (2.5 V, 3.3 V, 5 V). Driving loads beyond 50 pF increases propagation delay and may degrade edge rates; for reliable timing closure in high-speed bus applications, keep total net capacitance (trace + receiver input + probe) at or below this value. The SN74LV244APWT datasheet confirms this limit in Section 6.8–6.10.

Does the SN74LV244APWT support hot-swap or partial-power-down operation?

Yes, the SN74LV244APWT includes Ioff circuitry that actively disables outputs when VCC = 0 V, limiting Ioff leakage to ≤5 µA per I/O. This prevents back-driving and bus contention during live insertion/removal of daughter cards - a key requirement in telecom and modular server architectures. The feature is explicitly tested and guaranteed per JESD78, and documented in Section 8.3.3 of the SN74LV244APWT datasheet.

Can the SN74LV244APWT interface between 3.3 V and 5 V logic domains without external level shifters?

Yes. The SN74LV244APWT accepts input voltages up to 5.5 V independent of VCC, and its outputs swing rail-to-rail (0 V to VCC) - enabling direct connection from a 5 V microcontroller to a 3.3 V FPGA input, provided VCC = 3.3 V. This mixed-mode operation is guaranteed across the full operating temperature range and is a defining feature of the LV family, confirmed in Section 6.3 and 8.3.1 of the SN74LV244APWT datasheet.

What is the recommended power supply decoupling for the SN74LV244APWT in a high-density PCB layout?

Texas Instruments specifies a minimum 0.1 µF ceramic capacitor placed as close as possible between VCC (Pin 20) and GND (Pin 10), with short, low-inductance traces. For systems with multiple SN74LV244APWT devices or noisy supplies, add a bulk 4.7–10 µF tantalum or aluminum electrolytic capacitor nearby. This decoupling strategy is validated in Section 9.3 and Figure 9-1 of the SN74LV244APWT datasheet to suppress switching noise and maintain stable VCC under dynamic load.

How does the SN74LV244APWT handle unused inputs and outputs?

All unused inputs of the SN74LV244APWT must be tied to VCC or GND - floating CMOS inputs cause excessive current and potential oscillation. Unused outputs may be left unconnected (floating) in high-impedance state, but must never be hard-connected to VCC or GND. This guidance is mandated in Section 6.3 (Note 1) and Section 8.3.2 of the SN74LV244APWT datasheet to ensure reliable operation and prevent device damage.