Texas Instruments SN74LV244ATDWR

Overview

SN74LV244ATDWR from Texas Instruments is an octal buffer/driver IC with 3-state outputs, designed for memory-address, clock, and bus-oriented applications. It operates from 4.5 V to 5.5 V, delivers typical propagation delay of 5.4 ns at 5 V, supports TTL-voltage-compatible inputs, and features Ioff partial-power-down protection. Used in industrial control backplanes and data acquisition system buses.

For engineers reviewing the SN74LV244ATDWR datasheet, SN74LV244ATDWR pinout, SN74LV244ATDWR application, or SN74LV244ATDWR equivalent, key selection criteria include 3-state output timing (tPLZ/tPHZ ≤ 8 ns), SOIC-20 package compatibility, mixed-mode voltage operation support, and Ioff-enabled power sequencing robustness.

Technical Context

This device implements two independent 4-bit noninverting buffers, each with dedicated output-enable (OE) control. Each OE input controls four Y outputs simultaneously, enabling/disabling signal pass-through from A inputs to Y outputs without inversion.

It uses CMOS logic with TTL-level input thresholds (VIH = 2 V, VIL = 0.8 V at VCC = 4.5–5.5 V), supports bidirectional mixed-voltage interfacing, and includes Ioff circuitry that disables outputs during power-down to prevent current backflow when VCC = 0 V.

Key Specifications

Pinout & Package

SN74LV244ATDWR is housed in a 20-pin SOIC (DW) package measuring 7.5 mm × 12.8 mm × 2.65 mm, with 1.27-mm lead pitch and gull-wing leads. Thermal resistance θJA = 58 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV244ATDWR, SN74LVC244APWR offers faster timing but sacrifices 5-V compatibility and Ioff protection, while 74ACT244SCX provides stronger drive at the cost of higher static current and no power-down isolation-making SN74LV244ATDWR the balanced choice for industrial 5-V bus systems requiring reliability and flexibility.

Availability

SN74LV244ATDWR is available at Aetrix Electronics and suitable for industrial PLC backplanes, medical data acquisition interfaces, and automotive body control modules requiring stable component supply across extended temperature ranges (–40°C to +85°C).

Supply support for SN74LV244ATDWR 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 decades of experience in industrial, automotive, and communications markets.

The SN74LV244AT series belongs to TI's LV logic family, engineered for robust 5-V operation with enhanced noise immunity and power sequencing resilience in harsh industrial environments.

FAQ

What is the recommended power-up sequence for SN74LV244ATDWR to avoid bus contention?

TI recommends tying both OE pins to VCC through ≥10-kΩ pullup resistors during power-up. This ensures outputs remain in high-impedance state until VCC stabilizes and the controlling logic asserts valid OE signals. The Ioff feature further protects against back-current if VCC ramps after other system rails, making SN74LV244ATDWR suitable for uncontrolled power sequencing scenarios where other buffers may fail.

Does SN74LV244ATDWR support mixed-voltage operation between 3.3-V and 5-V logic domains?

Yes, SN74LV244ATDWR supports mixed-mode voltage operation: its inputs accept 3.3-V or 5-V signals while powered from a 5-V VCC rail. The VIH/VIL thresholds (2.0 V / 0.8 V) allow reliable recognition of both logic families. However, outputs swing rail-to-rail (0 V to VCC), so downstream 3.3-V receivers require level translation unless tolerant of 5-V inputs.

What is the maximum capacitive load SN74LV244ATDWR can drive while maintaining specified timing?

SN74LV244ATDWR is characterized up to CL = 50 pF, with tPLH/tPHL ≤ 9.5 ns and tPZH/tPZL ≤ 13 ns at VCC = 5 V. Driving loads beyond 50 pF increases propagation and enable/disable delays nonlinearly and may cause excessive VOH/VOL degradation. For heavier loads, add series termination or use a driver with higher IOL/IOH, such as SN74LV244ATDWR's higher-drive variants.

Can SN74LV244ATDWR replace older 74LS244 devices in existing designs?

Yes, SN74LV244ATDWR is a drop-in replacement for 74LS244 in most cases: same SOIC-20 pinout, identical function, TTL-compatible inputs, and improved parameters (lower ICC, faster tpd, better noise margins). However, verify that the 5.5-V absolute max VCC rating and absence of LS-family open-collector outputs meet your design's electrical constraints before substitution.

Is thermal performance sufficient for continuous operation in sealed industrial enclosures?

With θJA = 58 °C/W in SOIC-20, SN74LV244ATDWR dissipates ≤15 mW under typical conditions (ICC ≈ 20 µA, IOL/IOH ≤ 16 mA). At 85°C ambient and 5-V supply, junction temperature remains below 100°C even without airflow-well within its rated range. For high-density layouts, ensure ≥25 mm² copper pour under the exposed pad area (if using thermally enhanced variants) or maintain ≥2 mm clearance from heat sources.