Texas Instruments SN74ALS29827NT

Overview

SN74ALS29827NT from Texas Instruments is a 10-bit non-inverting buffer and bus driver with dual 3-state enable inputs (OE1, OE2), designed for high-performance memory address register buffering and wide-data-path bus interfacing in TTL-compatible systems. It operates at 4.75–5.25 V, delivers ±24 mA output drive, supports 0°C to 70°C operation, and features pnp-input structure to reduce DC loading.

For engineers reviewing the SN74ALS29827NT datasheet, SN74ALS29827NT pinout, SN74ALS29827NT application, or SN74ALS29827NT equivalent, key selection criteria include true-output logic polarity, dual-NOR 3-state control architecture, 14 ns max propagation delay at 50 pF load, and compatibility with legacy ALS-level timing and voltage thresholds.

Technical Context

This device implements a dual-gated 3-state output control using a 2-input NOR logic structure: either OE1 or OE2 asserted high forces all ten Y outputs into high-impedance state. Inputs use pnp-based TTL-compatible circuitry to minimize DC current draw on driving sources.

The SN74ALS29827NT provides true (non-inverted) data translation across all ten channels (A1–A10 → Y1–Y10), with data flow-through pinout-inputs on one side (pins 1–11), outputs and enables on the opposite side (pins 13–24)-enabling clean PCB layout and minimizing signal crosstalk in dense bus applications.

Key Specifications

Pinout & Package

SN74ALS29827NT uses a 300-mil plastic DIP (Dual In-line Package) with 24 leads. Pin numbering follows standard top-view orientation with notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit non-inverting bus driver applications.

Compared with AM29827 and SN74ALS244N, the SN74ALS29827NT uniquely combines 10-bit width, true-output logic, and dual-NOR 3-state control in a single 24-pin DIP - reducing component count and eliminating inter-device skew in critical address-bus applications.

Availability

SN74ALS29827NT is available at Aetrix Electronics and suitable for memory address buffering, parallel bus isolation, and legacy system repair requiring stable component supply and long-term obsolescence support.

Supply support for SN74ALS29827NT 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic ICs with broad industrial, automotive, and communications reach.

The SN74ALS29827NT belongs to TI's Advanced Low-Power Schottky (ALS) logic family, engineered for high-speed, low-power TTL-compatible digital interfacing in 1980s–1990s computing and control systems.

FAQ

What logic polarity does SN74ALS29827NT implement?

SN74ALS29827NT implements true (non-inverting) logic: each output Yn replicates its corresponding input An without inversion. This distinguishes it from the SN74ALS29828, which provides inverted outputs. The device is explicitly designated as the "true" variant in TI's SDAS095B datasheet, and its logic symbol confirms direct A→Y mapping with no bubble indicators.

How does the dual 3-state enable (OE1/OE2) work on SN74ALS29827NT?

The SN74ALS29827NT uses a 2-input NOR gate for 3-state control: if either OE1 or OE2 is driven high, all ten outputs enter high-impedance state. Both enables must be low for normal buffered operation. This architecture allows flexible bus arbitration - for example, OE1 can be tied to a master controller and OE2 to a backup, ensuring only one driver is active at any time.

Is SN74ALS29827NT compatible with modern 5 V systems?

Yes, SN74ALS29827NT operates within 4.75–5.25 V and interfaces directly with standard 5 V TTL and ALS logic families. Its input thresholds (VIH = 2.0 V, VIL = 0.8 V) and output levels (VOH ≥ 2.4 V, VOL ≤ 0.5 V) meet legacy 5 V noise-margin requirements. However, it is not 3.3 V tolerant and requires level-shifting when interfacing with newer low-voltage logic.

What package type is used by SN74ALS29827NT?

SN74ALS29827NT uses a 24-pin plastic DIP (dual in-line package) with 300-mil width, designated "NT" in TI's packaging nomenclature. This through-hole package is distinct from the SOIC (DW) variant and is intended for prototyping, repair, and legacy board assembly where socketing or manual soldering is required.

Does SN74ALS29827NT have power-up immunity?

Yes, SN74ALS29827NT features a power-up high-impedance state: outputs remain in Hi-Z until both OE1 and OE2 are actively driven low after VCC stabilizes. This prevents bus contention during power sequencing and eliminates the need for external reset coordination in systems where address/data buses initialize before control logic asserts enables.