Texas Instruments SN74HC244QDWREP

Overview

SN74HC244QDWREP from Texas Instruments is an octal 3-state noninverting buffer/line driver in SOIC-20 package, operating from 2 V to 6 V supply, with −40°C to 125°C extended temperature range, 6 mA output drive capability at 4.5 V, and propagation delay as low as 11 ns (VCC = 6 V, CL = 50 pF). It serves as a memory address or bus interface buffer in industrial control and data acquisition systems.

For engineers reviewing the SN74HC244QDWREP datasheet, SN74HC244QDWREP pinout, SN74HC244QDWREP application, or SN74HC244QDWREP equivalent, key selection factors include its 3-state bus-driving capability, extended temperature qualification, high-current CMOS output stage, and compatibility with LSTTL loads in space-constrained industrial PCB layouts.

Technical Context

This device implements two independent 4-bit noninverting buffer sections, each with dedicated active-low output-enable (OE) control. Each section operates with true 3-state logic: outputs pass A→Y when OE is low, and enter high-impedance state when OE is high - enabling bidirectional bus sharing without contention.

It uses standard HC-series CMOS logic with Schmitt-trigger–free inputs, rail-to-rail output swing, and input thresholds referenced to VCC (VIH = 3.15 V min at 4.5 V, VIL = 1.35 V max). No internal clamping diodes are present; absolute maximum ratings define safe operation under transient overvoltage conditions.

Key Specifications

Pinout & Package

SN74HC244QDWREP is housed in a 20-pin SOIC (DW) package, 7.5 mm × 12.8 mm body size, 2.65 mm max height, with 1.27 mm lead pitch and RoHS-compliant NiPdAu lead finish. Moisture sensitivity level is 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 SN74HC244QPWREP, SN74HC244QDWREP offers superior thermal performance and mechanical robustness in high-vibration environments; compared with SN74LVC244APWR, it provides wider voltage flexibility and guaranteed operation across automotive-grade temperature extremes - making it the sole choice for mission-critical industrial and transportation applications.

Availability

SN74HC244QDWREP is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74HC244QDWREP 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 high-reliability logic solutions with decades of automotive and industrial qualification expertise.

The SN74HC244QDWREP belongs to TI's enhanced-product (EP) logic family, designed specifically for applications demanding extended temperature operation, controlled manufacturing baseline, and long-term supply assurance in harsh environments.

FAQ

What is the maximum operating voltage for SN74HC244QDWREP?

The absolute maximum supply voltage for SN74HC244QDWREP is 7 V, but the recommended operating range is 2 V to 6 V. Operation above 6 V risks permanent damage, while operation below 2 V may cause unreliable logic thresholds or increased propagation delay. The SN74HC244QDWREP datasheet specifies VIH/VIL thresholds that scale with VCC, ensuring correct interpretation across this full range.

Does SN74HC244QDWREP support hot-swapping on a live bus?

SN74HC244QDWREP supports hot-swap operation only when both OE inputs are held high (outputs in high-impedance state) before insertion, and VCC is ramped before applying input signals. Its absolute maximum ratings include ±20 mA input clamp current, but no built-in hot-swap protection circuitry exists. System-level design must ensure controlled power sequencing and current limiting to avoid latch-up during insertion into a live bus.

Can SN74HC244QDWREP drive standard TTL loads directly?

Yes, SN74HC244QDWREP can drive up to 15 LSTTL loads per output, as confirmed in the official datasheet. At VCC = 4.5 V, its output sink/source capability (±6 mA) matches LSTTL input current requirements (IIL = −0.4 mA, IIH = 20 µA), enabling direct interface without level-shifting or pull-up resistors in legacy TTL systems.

What is the thermal resistance (θJA) of SN74HC244QDWREP in its SOIC package?

The junction-to-ambient thermal resistance (θJA) for SN74HC244QDWREP in the DW (SOIC-20) package is 58°C/W, measured per JESD 51-7 under standard JEDEC test board conditions. This value assumes a 1-inch² copper pad with two vias; actual board-level θJA will vary based on PCB copper area, layer count, and airflow. For continuous 6 mA output operation across all eight channels, derating is advised above 85°C ambient.

Is SN74HC244QDWREP pin-compatible with standard SN74HC244 variants?

Yes, SN74HC244QDWREP shares identical pinout, logic function, and DC/AC electrical specifications with commercial SN74HC244 devices in SOIC-20 (DW) package. Differences are limited to enhanced product qualifications: extended temperature range (−40°C to 125°C), controlled baseline manufacturing, and enhanced DMS support - all implemented without altering pin assignment or timing behavior.