Texas Instruments SN74AC244NG4

Overview

SN74AC244NG4 from Texas Instruments is an octal 3-state buffer/driver IC designed for bus-oriented signal routing in digital systems. It operates across 2V–6V V_CC, supports 5V and 3.3V logic domains, delivers ≤7.5ns propagation delay at 5V, and features dual independent output-enable controls. It is used in server memory address buffering, LED display column drivers, and telecom backplane interface isolation.

For engineers reviewing the SN74AC244NG4 datasheet, SN74AC244NG4 pinout, SN74AC244NG4 application, or SN74AC244NG4 equivalent, this page provides verified functional specifications, validated package mapping (PDIP-20), confirmed pin functions, real-world use-case implementation details, and two technically documented alternative parts with explicit differences in voltage range and thermal performance.

Technical Context

The SN74AC244NG4 implements two independent 4-bit non-inverting buffer sections, each with dedicated 3-state output-enable (1OE, 2OE) inputs. Its TTL-compatible input thresholds and rail-to-rail output swing enable interoperability with both CMOS and legacy logic families across 2V–6V supply operation.

Each buffer section drives up to ±24mA at 5V with guaranteed VOH ≥4.4V and VOL ≤0.44V under load, while maintaining high noise immunity via VIH/VIL thresholds that scale with V_CC. The device supports hot-swap capable 3-state control and includes internal clamp diodes rated for ±20mA input/output current.

Key Specifications

Pinout & Package

SN74AC244NG4 is supplied in a 20-pin Plastic Dual In-line Package (PDIP-20) with 0.300″ body width and 0.100″ lead pitch. Pin 1 is located at the left end of the top row, identified by a notch or dot marking. The package is through-hole mountable and RoHS-compliant with NIPDAU lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and 74AC244PC, SN74AC244NG4 uniquely supports mixed 3.3V/5V system integration without level shifters, offers superior 5V timing performance, and maintains active TI product lifecycle support with full documentation and application engineering resources.

Availability

SN74AC244NG4 is available at Aetrix Electronics and suitable for server motherboard design, LED display manufacturing, and telecom infrastructure projects requiring stable component supply and long-term production continuity.

Supply support for SN74AC244NG4 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 SN74AC244NG4 belongs to TI's 74AC logic family, engineered for high-speed, low-noise digital interfacing in mission-critical infrastructure equipment where reliability, wide voltage operation, and precise timing are essential.

FAQ

What is the maximum operating voltage for SN74AC244NG4?

The SN74AC244NG4 supports a supply voltage range of 2V to 6V. Its absolute maximum rating is 7V on V_CC, but continuous operation above 6V is not recommended. At 5.5V, it delivers guaranteed VOH ≥4.76V and VOL ≤0.44V with 24mA load, making SN74AC244NG4 ideal for robust 5V system interfacing without derating.

Does SN74AC244NG4 support hot-swap operation?

Yes, SN74AC244NG4 supports hot-swap operation due to its 3-state outputs and input clamp diodes rated for ±20mA. When OE is held high during insertion, all outputs remain in high-impedance state, preventing bus contention. Its V_CC-tolerant inputs (up to V_CC+0.5V) further protect against supply sequencing issues during live plug-in-key for SN74AC244NG4 use in modular telecom line cards.

What is the pin 1 marking method for SN74AC244NG4?

SN74AC244NG4 in PDIP-20 packaging uses a molded notch at the top-left corner of the package to indicate pin 1 location. Alternatively, a small circular indentation or white dot may appear adjacent to pin 1. This physical marking aligns with JEDEC MS-001 standard and is visible on both top and bottom views-critical for correct orientation during manual soldering or automated placement of SN74AC244NG4.

Can SN74AC244NG4 drive 50Ω transmission lines directly?

Yes, SN74AC244NG4 can drive 50Ω transmission lines directly. With ±24mA output capability at 5V and typical output impedance of ~15Ω, it achieves near-50Ω source termination when combined with series resistors (e.g., 33Ω). Measured t_pd remains ≤7.5ns, and waveform integrity is maintained per TI's application layout guidelines-making SN74AC244NG4 suitable for short-haul backplane signaling without external line drivers.

How does the dual OE architecture of SN74AC244NG4 improve system design?

The dual OE inputs (1OE and 2OE) in SN74AC244NG4 enable independent control of two 4-bit buffer groups, allowing time-multiplexed or spatially partitioned bus access. For example, one group can drive memory address bits while the other handles control signals-reducing external logic and PCB routing complexity. This architecture directly supports SN74AC244NG4 deployment in multi-bank memory controllers and segmented LED displays without additional gating logic.