Texas Instruments SN74HC244PW

Overview

SN74HC244PW from Texas Instruments is an octal noninverting 3-state buffer/line driver IC, organized as two independent 4-bit banks with separate output-enable (OE) controls. It operates from 2V to 6V, delivers ±6mA output drive at 5V, exhibits typical propagation delay of 11ns (VCC = 6V, CL = 50pF), and draws ≤80µA ICC (max) - enabling high-density bus interfacing in memory address drivers and clock distribution networks.

For engineers reviewing the SN74HC244PW datasheet, SN74HC244PW pinout, SN74HC244PW application, or SN74HC244PW equivalent, key selection criteria include its dual-bank 3-state architecture, TSSOP-20 package footprint (6.5mm × 6.4mm), wide supply range compatibility, and verified performance across –40°C to 125°C industrial temperature operation.

Technical Context

The SN74HC244PW implements two electrically isolated 4-bit buffer groups, each controlled by its own OE input (1OE on Pin 1, 2OE on Pin 19). When OE is low, the corresponding Y outputs replicate A inputs with noninverted logic; when OE is high, all four outputs enter high-impedance state - enabling bidirectional bus sharing without contention.

Its CMOS input structure ensures ≤1µA max input current and supports fast edge rates (Δt/Δv ≤ 400 ns/V at VCC = 6V), while output drive capability (±6mA at 5V) allows direct interfacing with up to 15 LSTTL loads. Thermal resistance RθJA is 131.8°C/W in the PW (TSSOP-20) package, requiring attention to PCB copper area and airflow in high-density layouts.

Key Specifications

Pinout & Package

PW package is a 20-pin Thin Shrink Small Outline Package (TSSOP) with 0.65mm pitch, body size 6.5mm × 4.4mm, and overall footprint 6.5mm × 6.4mm - optimized for high-density PCB layouts with thermal pad grounding capability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC244D,653 and MC74HC244ADTR2G, the SN74HC244PW offers the tightest propagation delay consistency (11ns typ), lowest quiescent current (8µA max), and TI's validated 125°C operation - making it optimal for thermally constrained, timing-sensitive industrial control designs.

Availability

SN74HC244PW is available at Aetrix Electronics and suitable for industrial I/O expansion, LED display column driving, memory address buffering, and network switch control bus applications requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for SN74HC244PW 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 connectivity technologies with over 50 years of innovation in logic and interface ICs.

The SN74HC244PW belongs to TI's HC (High-Speed CMOS) logic family, designed for robust, low-power, pin-compatible upgrades to legacy TTL systems in industrial automation and communications infrastructure.

FAQ

What is the maximum operating temperature for the SN74HC244PW?

The SN74HC244PW is specified for continuous operation from –40°C to +125°C, meeting industrial temperature grade requirements. This rating is confirmed in Section 5.3 of the official datasheet and applies specifically to the PW (TSSOP-20) package variant. Derating curves in Section 5.4 show junction-to-ambient thermal resistance of 131.8°C/W, so PCB layout must provide adequate copper area to maintain TJ < 150°C under full load.

Does the SN74HC244PW support 3.3V logic levels?

Yes, the SN74HC244PW fully supports 3.3V operation: VIH is guaranteed ≥1.35V at VCC = 4.5V (and scales down linearly), and VOL remains ≤0.26V at IOL = 6mA - ensuring noise margins >0.7V with standard 3.3V CMOS receivers. Its 2V–6V supply range makes it interoperable with both 3.3V and 5V systems without level translation.

How should unused inputs be handled on the SN74HC244PW?

All unused inputs on the SN74HC244PW must be tied to either VCC or GND - floating CMOS inputs cause excessive current draw and potential oscillation. The datasheet explicitly states this in Section 5.3 Note (1). For OE pins, connect to VCC via a 10kΩ pull-up to ensure high-impedance state at power-up; for A inputs, direct connection is preferred over resistive termination unless signal routing constraints require it.

What is the recommended bypass capacitor for the SN74HC244PW?

Texas Instruments recommends a 0.1µF ceramic capacitor placed as close as possible to the VCC pin (Pin 20) with a low-inductance path to GND (Pin 10). This is specified in Section 8.3 and Figure 8-4 of the datasheet. For improved high-frequency noise suppression, a parallel 1µF capacitor may be added - but the 0.1µF unit is mandatory and must have minimal trace length to avoid degrading transient response.

Is the SN74HC244PW pin-compatible with other 74HC244 variants?

Yes, the SN74HC244PW shares identical pinout and logic function with all industry-standard 74HC244 variants in 20-pin packages (including SOIC, PDIP, SSOP, and TSSOP), as confirmed by the unified pin configuration diagram (Figure 4-1) covering DB, DW, N, NS, and PW packages. However, thermal and timing parameters differ by package - the PW variant has higher RθJA (131.8°C/W) and tighter tpd distribution than SOIC or PDIP versions.