Texas Instruments SN74S244DW

Overview

SN74S244DW from Texas Instruments is an octal non-inverting 3-state buffer/line driver designed for memory address and bus interface applications. It features two independent 4-bit channels (1A→1Y, 2A→2Y), 5-V operation, maximum propagation delay of 9 ns (tPLH/tPHL), ±15 mA output drive capability, and PNP input structure reducing DC loading on buses.

For engineers reviewing the SN74S244DW datasheet, SN74S244DW pinout, SN74S244DW application, or SN74S244DW equivalent, this page delivers verified electrical specs, functional pin mapping, real-world use cases in bus buffering and signal restoration, and validated alternative parts for design continuity.

Technical Context

The SN74S244DW implements Schottky transistor logic (S-TTL) with active-low 3-state enable inputs (1G, 2G/2G) controlling independent 4-bit output groups. Each channel passes data unidirectionally from A-side inputs to Y-side outputs when its G input is low; outputs enter high-impedance state when G is high.

It supports terminated line driving down to 133 Ω, exhibits 0.2–0.4 V input hysteresis for noise immunity, and accepts 3.3-V or 2.5-V logic inputs while operating at 5 V - enabling mixed-voltage system interfacing without level shifters.

Key Specifications

Pinout & Package

SN74S244DW is housed in a 20-pin SOIC (DW) package measuring 12.80 mm × 7.50 mm, optimized for surface-mount assembly and moderate thermal performance.

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 74ACT244PW, SN74S244DW delivers superior bus drive (64 mA vs. 24 mA) and faster edge rates for legacy TTL systems, but consumes more quiescent current and lacks CMOS-level noise immunity - making it optimal for high-reliability industrial backplanes where signal fidelity outweighs power efficiency.

Availability

SN74S244DW is available at Aetrix Electronics and suitable for memory address buffering, system bus driving, LED display multiplexing, and legacy peripheral interface applications requiring stable component supply and long-term obsolescence management.

Supply support for SN74S244DW 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 50 years of innovation in industrial, automotive, and communications markets.

SN74S244DW belongs to TI's legacy S-TTL logic portfolio, engineered for high-speed, high-drive bus interfacing in mission-critical industrial control, telecom infrastructure, and retro-computing systems where robustness and timing predictability are paramount.

FAQ

What is the maximum operating temperature range for SN74S244DW?

The SN74S244DW is rated for commercial operation from 0°C to +70°C ambient temperature. This range is defined in the Recommended Operating Conditions table of the official datasheet (SDLS144D, Section 6.3). Operation outside this range may result in parametric degradation or reliability risk. For extended temperature applications, consider the military-grade SN54S244J variant rated from –55°C to +125°C.

Does SN74S244DW support bidirectional data flow?

No, SN74S244DW is a unidirectional octal non-inverting buffer - data flows only from A inputs to Y outputs. It does not contain internal direction control or bus transceiver logic. For bidirectional applications, TI offers the SN74LS245 or SN74S245, which include a direction-control (DIR) pin and true transceiver architecture. SN74S244DW must be paired with complementary devices for full-duplex operation.

Can SN74S244DW be used with 3.3-V microcontrollers?

Yes, SN74S244DW inputs tolerate 3.3-V logic levels while operating at 5 V supply - confirmed by the "Inputs Tolerant Down to 2 V" feature and VIH = 2 V specification. Its PNP input structure ensures compatibility without external level-shifting circuitry. However, outputs swing to 5-V logic levels, so downstream 3.3-V receivers must be 5-V tolerant or protected with series resistors/clamp diodes.

What is the recommended decoupling for SN74S244DW?

TI recommends placing a 0.1-µF ceramic capacitor between VCC (pin 20) and GND (pin 10), located within 5 mm of the SN74S244DW package. This minimizes high-frequency supply noise caused by rapid output transitions. For systems with multiple SN74S244DW units, add a bulk 4.7-µF tantalum capacitor per 5–10 ICs on the same 5-V rail to suppress low-frequency droop during simultaneous switching events.

How does SN74S244DW differ from SN74LS244DW in practical design?

SN74S244DW offers 2.7× higher output sink current (64 mA vs. 24 mA), 2× faster propagation delay (9 ns vs. 18 ns), and stronger drive into terminated lines (133 Ω vs. unspecified for LS), but draws significantly more supply current (160 mA max vs. 54 mA). Use SN74S244DW when driving long traces or heavy capacitive loads; choose SN74LS244DW for lower power and better noise immunity in less timing-critical circuits.