Texas Instruments SN74LV244ADWR

Overview

SN74LV244ADWR 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 operation, and includes Ioff partial-power-down protection. It is used in server backplanes to isolate and drive address/data lines between CPU and memory controllers.

For engineers reviewing the SN74LV244ADWR datasheet, SN74LV244ADWR pinout, SN74LV244ADWR application, or SN74LV244ADWR equivalent, key selection criteria include its 20-pin SOIC (DW) package, 3-state output architecture, ±16 mA drive capability at 3.3 V/5 V, thermal performance (RθJA = 102.3°C/W), and compatibility with industrial-temperature (–40°C to 125°C) embedded bus interfaces.

Technical Context

The SN74LV244ADWR implements two independent 4-bit noninverting buffer sections, each with dedicated active-low output-enable (1OE, 2OE) inputs controlling high-impedance state entry/exit. Its balanced CMOS 3-state outputs provide symmetrical sourcing and sinking (±16 mA at VCC = 4.5–5.5 V), enabling robust driving of capacitive loads up to 50 pF while maintaining fast edge rates.

It integrates Ioff circuitry that disables all outputs when VCC = 0 V, limiting input/output leakage to ≤5 µA - critical for hot-swap and partial-power-down systems. Input thresholds scale with VCC (VIH = 0.7×VCC, VIL = 0.3×VCC), supporting interoperability across 2.5 V, 3.3 V, and 5 V logic domains without level shifters.

Key Specifications

Pinout & Package

SN74LV244ADWR is packaged in a 20-pin SOIC (DW) body measuring 12.80 mm × 10.3 mm, with gull-wing leads and standard JEDEC MS-013 outline. The package supports automated optical inspection (AOI) and reflow soldering per IPC-J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV244ADWR, the 74LVC244APW offers faster speed and smaller footprint but sacrifices 5-V operation and mixed-voltage flexibility; the SN74AHCT244N retains full 5-V compatibility and TTL input robustness but lacks Ioff and has lower drive strength - making SN74LV244ADWR optimal for new industrial designs requiring wide VCC range and hot-swap safety.

Availability

SN74LV244ADWR is available at Aetrix Electronics and suitable for server backplanes, LED display modules, telecom line cards, and motor-drive control boards requiring stable component supply across extended temperature and voltage ranges.

Supply support for SN74LV244ADWR 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, with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74LV244ADWR belongs to TI's LV (Low-Voltage) logic family, engineered for high-speed, low-power, mixed-voltage interfacing in space- and energy-constrained embedded systems.

FAQ

What is the maximum capacitive load SN74LV244ADWR can drive while meeting datasheet timing specs?

The SN74LV244ADWR is characterized for loads up to 50 pF across all VCC conditions (2 V–5.5 V) and temperature ranges. At CL = 50 pF, it achieves tpd ≤6.5 ns at 5 V and ten ≤10.5 ns. Driving larger capacitances increases propagation delay and may cause signal integrity issues like ringing or overshoot - especially with fast edges - so board layout and termination must be optimized if exceeding 50 pF.

Does SN74LV244ADWR support hot-swap or partial-power-down operation?

Yes, SN74LV244ADWR includes Ioff circuitry that actively disables all outputs when VCC = 0 V, limiting input/output leakage current to ≤5 µA. This prevents back-driving of live buses during card insertion/removal in telecom or server chassis. To ensure safe operation, all unused inputs must be tied to VCC or GND, and OE pins should be pulled high through resistors during power ramp-up.

Can SN74LV244ADWR interface between 3.3-V and 5-V logic domains?

Yes, SN74LV244ADWR supports mixed-mode voltage operation: its inputs tolerate up to 5.5 V regardless of VCC, and outputs swing rail-to-rail (0 V to VCC). When powered at 3.3 V, it accepts 5-V inputs safely; when powered at 5 V, it drives 5-V logic levels. No external level shifters are needed - making SN74LV244ADWR ideal for bridging legacy 5-V peripherals and modern 3.3-V controllers.

What is the recommended decoupling strategy for SN74LV244ADWR?

TI recommends a 0.1-µF ceramic capacitor placed physically adjacent to the VCC pin (Pin 20) and connected directly to the GND pin (Pin 10) with minimal trace length (<3 mm). For systems with multiple SN74LV244ADWR devices or high-frequency noise, add a bulk 4.7-µF tantalum or aluminum electrolytic capacitor near the power entry point. Avoid shared vias between decoupling paths to maintain low-inductance grounding.

How does the output-enable (OE) pin behavior affect bus arbitration in multi-driver systems?

Each OE pin (1OE, 2OE) controls four outputs independently: when low, the corresponding Y outputs follow A inputs; when high, all four outputs enter high-impedance state. This allows time-multiplexed bus sharing - e.g., one SN74LV244ADWR driving address lines while another handles data - without contention. OE must be driven actively or pulled high via ≥10-kΩ resistor to avoid floating states during power transitions, ensuring deterministic bus release.