Texas Instruments SN74F244DBR

Overview

SN74F244DBR from Texas Instruments is an octal noninverting 3-state buffer/line driver IC designed for memory address and bus interface applications. It features two independent 4-bit channels, active-low output-enable (OE) control per channel, 5 V supply operation, propagation delay of 6.2 ns max at 5 V, and output drive capability of ±64 mA. It is used in legacy industrial control backplanes and TTL-compatible data bus isolation.

For engineers reviewing the SN74F244DBR datasheet, SN74F244DBR pinout, SN74F244DBR application, or SN74F244DBR equivalent, this page delivers verified electrical specs, SSOP-20 package layout, functional role in bus buffering, and validated drop-in alternatives for obsolescence mitigation and design continuity.

Technical Context

The SN74F244DBR implements dual 4-bit noninverting buffers with symmetrical active-low OE inputs - 1OE controls Y1–Y4 outputs from A1–A4 inputs, and 2OE controls Y5–Y8 from A5–A8. Each output enters high-impedance state when its respective OE is high, enabling bidirectional bus sharing without contention.

It belongs to the TI 74F logic family, fabricated using bipolar Schottky technology for improved speed over standard TTL. Its switching characteristics are specified across 0°C to 70°C, with guaranteed tPLH/tPHL ≤ 6.2 ns and tPZL/tPLZ ≤ 8.0 ns under 50 pF load, supporting reliable timing in synchronous digital systems.

Key Specifications

Pinout & Package

SN74F244DBR is housed in a 20-pin Shrink Small-Outline Package (SSOP-DB), measuring 7.5 mm × 5.6 mm × 2.0 mm max height, with 0.65 mm lead pitch and gull-wing leads. The package enables >50% board area reduction versus standard SOIC while maintaining full pin compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74F244DWR, SN74F244DBR saves 55% board area and suits high-density layouts; compared with SN74ACT244DBR, it retains legacy 74F timing and drive strength but consumes more static current and offers narrower noise margins.

Availability

SN74F244DBR is available at Aetrix Electronics and suitable for memory address buffering, legacy bus isolation, and industrial backplane signal conditioning requiring stable component supply and long-term production support.

Supply support for SN74F244DBR 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 SN74F244DBR belongs to TI's legacy 74F logic product line, engineered for high-speed TTL-compatible interfacing in industrial control, test equipment, and military-grade computing systems where reliability and timing predictability are critical.

FAQ

What is the maximum clock frequency supported by SN74F244DBR in bus-driving applications?

The SN74F244DBR does not operate on a clock; it is a combinatorial buffer. Its 6.2 ns maximum propagation delay enables reliable use in systems with bus toggle rates up to approximately 160 MHz under ideal 50 pF loading conditions. Real-world frequency limits depend on trace length, fanout, and termination - for 8-bit data buses in 8-MHz microcontroller systems, SN74F244DBR provides ample timing margin.

Can SN74F244DBR be used with 3.3 V logic inputs?

No - SN74F244DBR is a 5 V-only device with TTL input thresholds (VIH = 2.0 V min, VIL = 0.8 V max). While 3.3 V CMOS outputs may exceed VIH, they lack guaranteed noise margin and risk marginal operation. For mixed-voltage systems, level-shifting or ACT-family alternatives like SN74ACT244DBR are recommended instead of direct interfacing.

Is SN74F244DBR pin-compatible with SN74LS244N?

Yes - SN74F244DBR shares identical pinout and logic function with SN74LS244N and other 20-pin variants (e.g., SN74F244DWR, SN74F244N). All follow the standard 74xx244 layout: inputs A1–A8 on pins 1–2,4–6,8,11–13,15,17; outputs Y1–Y8 on pins 3,5,7,9,12,14,16,18; OE on pins 1 and 19; GND on pin 10; VCC on pin 20.

What is the thermal resistance (θJA) of the SSOP-20 (DB) package for SN74F244DBR?

Texas Instruments does not publish θJA for SN74F244DBR in the SDFS063A datasheet. However, based on JEDEC-standard SSOP-20 thermal models and TI's DB package characterization, typical θJA is ~120°C/W on 1-layer 1-oz copper. For sustained 64 mA output loading, junction temperature rise remains within safe limits below 70°C ambient - no heatsink required in standard applications.

Does SN74F244DBR support hot-swap or live-insertion?

No - SN74F244DBR lacks hot-swap protection circuitry such as power-up/down sequencing control, bus-fault current limiting, or Ioff partial-power-down mode. Applying VCC before GND or driving inputs while unpowered risks latch-up or excessive current flow. Always power GND first, then VCC, and assert OE high before applying input signals during system initialization.