Texas Instruments SN74S244DWG4

Overview

SN74S244DWG4 from Texas Instruments is an octal non-inverting 3-state buffer/line driver in SOIC-20 package, designed for memory address and bus line driving with dual independent 4-bit channels, 64 mA sink output capability at 5 V, 7 ns typical propagation delay (tPLH/tPHL), and hysteresis-enhanced noise immunity. It serves in high-density bus interface applications such as server memory subsystems and telecom backplanes.

For engineers reviewing the SN74S244DWG4 datasheet, SN74S244DWG4 pinout, SN74S244DWG4 application, or SN74S244DWG4 equivalent, key selection criteria include 3-state output control timing (tPZH/tPLZ), DC input tolerance down to 2 V, PNP-input reduced bus loading, and compatibility with mixed 3.3-V/5-V logic environments.

Technical Context

The SN74S244DWG4 implements Schottky transistor logic (S-TTL) architecture with two independent 4-bit non-inverting buffer sections, each controlled by a dedicated active-low output-enable (G) input. Its PNP input structure lowers DC loading on driven buses, while built-in hysteresis (0.2–0.4 V) improves noise margins on address/data lines.

Each channel operates with symmetrical enable logic: when G is low, A→Y data passes transparently; when G is high, all four Y outputs enter high-impedance state. The device supports terminated line driving down to 133 Ω and delivers 64 mA sink current per output under recommended operating conditions (VCC = 4.75–5.25 V, TA = 0–70 °C).

Key Specifications

Pinout & Package

SN74S244DWG4 is housed in a 20-pin SOIC (DW) package measuring 12.80 mm × 7.50 mm, with standard 0.050″ (1.27 mm) lead pitch and surface-mount gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS244DW and 74ACT244SOIC, SN74S244DWG4 uniquely combines S-TTL speed, PNP-input bus loading reduction, and 2-V input tolerance - making it optimal for upgrading legacy 5-V bus systems with minimal redesign while maintaining noise resilience on long traces.

Availability

SN74S244DWG4 is available at Aetrix Electronics and suitable for server backplane design, telecom infrastructure deployment, and industrial I/O expansion requiring stable component supply across extended production lifecycles.

Supply support for SN74S244DWG4 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 company specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

SN74S244DWG4 belongs to TI's legacy S-TTL logic family, engineered for high-drive, noise-immune bus interfacing in mission-critical computing and infrastructure equipment where reliability under electrical stress is paramount.

FAQ

What is the maximum operating temperature range for the SN74S244DWG4?

The SN74S244DWG4 is rated for commercial operation from 0 °C to +70 °C ambient temperature. This range is specified in the Recommended Operating Conditions table of the official datasheet (SDLS144D, Section 6.3). Operation outside this range may result in parametric degradation or functional failure. Thermal derating is not defined for this part, so designs must ensure junction temperature remains within absolute maximum limits (150 °C) using appropriate PCB copper area and airflow.

Does the SN74S244DWG4 require external pull-up resistors on its G pins?

Yes, the SN74S244DWG4 requires external pull-up resistors on both 1G and 2G pins to ensure predictable high-impedance behavior during power-up and power-down sequences. As stated in Section 8.1, tying G to VCC through a pullup prevents unintended output activation. The minimum resistor value depends on the current-sinking capability of the driving source; TI recommends verifying against the IIL specification (–2 mA per G input) to avoid excessive current draw while maintaining solid logic-high assertion.

Can the SN74S244DWG4 drive a 133-Ω terminated transmission line?

Yes, the SN74S244DWG4 is explicitly characterized to drive terminated lines down to 133 Ω, as confirmed in the Description section (page 1) and Application section (page 14) of the SDLS144D datasheet. This capability stems from its high-output drive strength (64 mA sink) and S-TTL output stage design. For reliable operation, ensure termination is placed at the far end of the line and that VCC remains within 4.75–5.25 V during signal transitions.

How does the hysteresis feature of the SN74S244DWG4 improve system reliability?

The SN74S244DWG4 incorporates 0.2–0.4 V of input hysteresis (VT+ − VT−), which raises the effective noise margin on all A inputs. This prevents false toggling caused by slow-rising edges, ground bounce, or coupled noise on shared bus lines - especially critical in dense PCB layouts with long traces or multiple simultaneously switching outputs. The hysteresis is inherent to the S-TTL input structure and requires no external components.

Is the SN74S244DWG4 pin-compatible with the SN74LS244DW?

Yes, the SN74S244DWG4 and SN74LS244DW share identical SOIC-20 (DW) packaging, pinout, and functional assignment - including dual 4-bit non-inverting buffers with independent active-low G controls. However, they differ electrically: SN74S244DWG4 offers higher drive (64 mA vs. 24 mA), faster speed (7 ns vs. 18 ns), and 2-V input tolerance not present in the LS version. No PCB changes are needed for drop-in replacement, but timing and drive margin analysis must be re-verified.