Texas Instruments SN74ACT244NSR

Overview

SN74ACT244NSR from Texas Instruments is an octal 3-state non-inverting buffer/driver IC designed for bus-oriented data transmission, clock distribution, and memory address driving in 5-V digital systems. It features dual 4-bit sections with independent active-low output-enable (OE) controls, 4.5–5.5-V supply operation, TTL-compatible inputs, and a maximum propagation delay of 9.5 ns at 5 V. It is commonly used in LED display drivers and telecom switching networks.

For engineers reviewing the SN74ACT244NSR datasheet, SN74ACT244NSR pinout, SN74ACT244NSR application, or SN74ACT244NSR equivalent, key selection criteria include 3-state bus-driving capability, 24-mA output drive strength per channel, input voltage tolerance up to 5.5 V, thermal performance in SO package (RθJA = 106.2 °C/W), and compatibility with legacy 5-V TTL logic interfaces.

Technical Context

The SN74ACT244NSR implements two independent 4-bit non-inverting buffer sections, each controlled by its own active-low OE input. When OE is low, data passes transparently from A inputs to Y outputs; when OE is high, all corresponding outputs enter high-impedance state-enabling bidirectional bus sharing without contention.

Its ACT (Advanced CMOS TTL-compatible) logic family delivers rail-to-rail output swing, 24-mA sink/source capability at VCC = 5 V, and guaranteed operation across –40°C to +85°C. Input thresholds meet TTL specifications (VIH ≥ 2.0 V, VIL ≤ 0.8 V), and inputs tolerate up to 5.5 V regardless of VCC level-supporting mixed-voltage interfacing.

Key Specifications

Pinout & Package

SN74ACT244NSR is packaged in a 20-pin SO (Small Outline) package (NS), 7.5 mm × 12.8 mm body, with 1.27 mm lead pitch and gull-wing leads. The package is RoHS-compliant, tape-and-reel formatted (2000 pcs/reel), and rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS244N and SN74LVC244APWR, the SN74ACT244NSR uniquely balances 5-V system compatibility, 24-mA drive, sub-10-ns speed, and ±3000-V HBM ESD robustness-making it optimal for new industrial 5-V bus and display designs where reliability and timing margin are critical.

Availability

SN74ACT244NSR is available at Aetrix Electronics and suitable for LED display driving, telecom switching networks, and industrial bus interface applications requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for SN74ACT244NSR 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 decades of experience in high-reliability industrial and communications ICs.

The SN74ACT244NSR belongs to TI's legacy ACT logic family-designed specifically for high-drive, low-delay 5-V bus interfacing in industrial control, telecom infrastructure, and instrumentation systems.

FAQ

What is the operating temperature range for SN74ACT244NSR?

The SN74ACT244NSR is specified for industrial operation from –40°C to +85°C. This range is validated per TI's production test flow and supports deployment in enclosed control cabinets, outdoor telecom enclosures, and factory-floor automation hardware where ambient temperatures fluctuate significantly. The SO package's thermal resistance (RθJA = 106.2 °C/W) ensures junction temperature remains within safe limits under typical 24-mA load conditions.

Does SN74ACT244NSR support 3.3-V input logic levels?

No-SN74ACT244NSR is a 5-V-only device with TTL-compatible input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V at VCC = 5 V). While it accepts input voltages up to 5.5 V, it does not guarantee recognition of 3.3-V logic highs when VCC = 5 V. For 3.3-V system interfacing, use SN74LVC244APWR instead. SN74ACT244NSR must be driven by 5-V logic sources to ensure correct functional behavior.

Can SN74ACT244NSR drive LEDs directly?

Yes-SN74ACT244NSR can directly sink up to 24 mA per output, making it suitable for driving common-cathode LEDs with appropriate current-limiting resistors. For a 5-V supply and red LED (VF ≈ 1.8 V), a 130-Ω resistor yields ~24 mA. Ensure total package power dissipation stays within limits: at full 8-channel 24-mA sink, PD ≈ 8 × (1.8 V × 0.024 A) ≈ 346 mW, well below the SO package's 750-mW rating at 85°C ambient.

What is the meaning of "NS" in SN74ACT244NSR?

The "NS" suffix in SN74ACT244NSR denotes the Small Outline (SO) package type-a 20-pin surface-mount plastic package with gull-wing leads and 1.27-mm pitch. The "R" indicates tape-and-reel packaging (2000 units per reel), and the absence of "E4" or "G4" means standard NiPdAu lead finish. This package is distinct from DW (SOIC), PW (TSSOP), or DGS (VSSOP) variants and is optimized for cost-sensitive industrial PCBs with moderate density requirements.

How does the output-enable (OE) logic work on SN74ACT244NSR?

SN74ACT244NSR has two active-low output-enable inputs: 1OE (pin 1) controls outputs 1Y1–1Y4 (pins 18, 16, 14, 12), and 2OE (pin 19) controls outputs 2Y1–2Y4 (pins 9, 7, 5, 3). When OE is low, the corresponding Y outputs replicate their A inputs non-inverted; when OE is high, those outputs go high-impedance. This allows independent gating of two 4-bit data paths-critical for bus arbitration and multiplexed display driving in the SN74ACT244NSR.