Texas Instruments SN74LV244ATNS

Overview

SN74LV244ATNS from Texas Instruments is an octal buffer/driver with 3-state outputs, designed for memory-address, clock, and bus-oriented applications. It features dual 4-bit channels, independent output-enable (OE) controls, 4.5–5.5 V supply operation, typical propagation delay of 5.4 ns at 5 V, and Ioff support for partial-power-down mode. It is used in industrial control backplanes and embedded system data buses.

For engineers reviewing the SN74LV244ATNS datasheet, SN74LV244ATNS pinout, SN74LV244ATNS application, or SN74LV244ATNS equivalent, key selection criteria include 3-state bus driving capability, TTL-compatible inputs, Ioff protection, thermal performance in NS package (θJA = 60°C/W), and compatibility with mixed-mode voltage interfaces on all ports.

Technical Context

This device implements two independent 4-bit noninverting buffers, each with dedicated active-low output-enable (1OE, 2OE) pins controlling high-impedance state entry/exit. Its logic diagram confirms direct A→Y signal path with no inversion, and functional table specifies that OE = L enables pass-through while OE = H forces outputs to high-Z.

It supports partial-power-down via Ioff circuitry that disables outputs when VCC = 0, preventing current backflow. Input voltage range extends to 5.5 V regardless of VCC, enabling interfacing with higher-voltage logic domains while operating at 4.5–5.5 V.

Key Specifications

Pinout & Package

The SN74LV244ATNS is supplied in a 20-pin SO (Small Outline) package with 0.65 mm lead pitch and JEDEC MS-012AC dimensions (body size 7.5 mm × 5.3 mm). Thermal resistance θJA is 60°C/W, supporting continuous operation at up to 85°C ambient under typical PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV244ATNS, SN74LVC244APWR offers superior speed and lower voltage operation but sacrifices TTL compatibility and mixed-mode interface capability, while 74ACT244SCX delivers higher drive at the cost of Ioff protection and broader input voltage tolerance-making SN74LV244ATNS the balanced choice for industrial 5 V systems requiring robustness and interoperability.

Availability

SN74LV244ATNS is available at Aetrix Electronics and suitable for industrial backplane bus driving, memory address buffering, legacy logic interfacing, and programmable logic I/O expansion requiring stable component supply and long-term lifecycle assurance.

Supply support for SN74LV244ATNS 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, precision, and industrial-grade qualification.

The SN74LV244ATNS belongs to TI's LV-A family of low-voltage, TTL-compatible logic devices engineered for robust 5 V system interfacing with enhanced power-down safety and noise resilience.

FAQ

What is the recommended power-up sequence for SN74LV244ATNS to ensure outputs remain in high-impedance state?

TI specifies that OE pins must be held high (tied to VCC via pullup resistor) during power-up to guarantee high-impedance outputs before internal circuitry stabilizes. For SN74LV244ATNS, a 10 kΩ pullup on both 1OE and 2OE is sufficient; this prevents bus contention if inputs float or settle late relative to VCC ramp. The Ioff feature further protects against back-current if VCC rises after other rails.

Does SN74LV244ATNS support hot-swap applications where VCC may be disconnected while signals remain active?

Yes-SN74LV244ATNS includes Ioff circuitry that actively disables outputs when VCC = 0 V, limiting reverse current to <5 µA even with inputs or outputs biased to 5.5 V. This makes SN74LV244ATNS suitable for hot-swap backplane slots where card insertion/removal occurs under live bus conditions, provided OE is externally held high during disconnection.

Can SN74LV244ATNS drive a 50 pF capacitive load while maintaining timing specifications?

Yes-SN74LV244ATNS switching characteristics are explicitly characterized at CL = 50 pF. At VCC = 5 V and TA = 25°C, tPLH/tPHL are 5.9 ns (max), tPZH/tPHZ are 8.8 ns (max), and tPZL/tPLZ are 8.8 ns (max), all meeting industrial timing margins. Layout best practices (short traces, ground plane) are still required to avoid exceeding total load.

What is the maximum allowable input voltage on SN74LV244ATNS pins when VCC = 4.5 V?

The absolute maximum input voltage rating for SN74LV244ATNS is 7 V, but the recommended operating condition specifies VI ≤ 5.5 V across all VCC values (4.5–5.5 V). Therefore, even at VCC = 4.5 V, inputs may safely reach 5.5 V-enabling direct interfacing with 5 V TTL outputs without clamping diodes or level shifters, a key advantage over non-mixed-mode buffers.

How does the thermal performance of SN74LV244ATNS compare to other 20-pin SO packages in the LV-A family?

SN74LV244ATNS in NS package has θJA = 60°C/W, which is 2–10°C/W better than DW (58°C/W) and PW (83°C/W) variants due to optimized leadframe geometry and mold compound. This allows higher sustained output current or operation in hotter ambient environments-e.g., at 85°C ambient, SN74LV244ATNS can deliver full ±16 mA per output with 20°C junction rise, whereas PW-packaged equivalents require derating.