Texas Instruments SN74ALS29828NT

Overview

SN74ALS29828NT from Texas Instruments is a 10-bit inverting bus driver with dual 3-state enable (OE1/OE2), designed for high-performance memory address buffering and wide-data-path bus interfacing in industrial and computing systems. It operates at 4.75–5.25 V, delivers ±48 mA output drive, features 7 ns propagation delay (CL = 50 pF), and maintains high-impedance on power-up.

For engineers reviewing the SN74ALS29828NT datasheet, SN74ALS29828NT pinout, SN74ALS29828NT application, or SN74ALS29828NT equivalent, key selection criteria include its inverted-output logic, dual-NOR 3-state control architecture, pnp-input DC loading reduction, data flow-through pinout, and compatibility with ALS-family timing and voltage thresholds.

Technical Context

This device implements a dual-gated 3-state output structure where either OE1 or OE2 high forces all ten Y outputs into high-impedance - no internal OR logic; each enable operates independently per NOR gate. The inverted output function (Y = NOT A) is hardwired and distinct from the true-output SN74ALS29827.

It uses bipolar ALS (Advanced Low-Power Schottky) technology, delivering faster switching than standard LS while maintaining TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V) and robust output current (IOL = 48 mA, IOH = –24 mA) under 5-V operation.

Key Specifications

Pinout & Package

SN74ALS29828NT is supplied in a 300-mil plastic DIP (Dual In-line Package) with 24 leads, body width 0.300 inch, standard through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALS29827NT and AM29828PC, the SN74ALS29828NT provides guaranteed inverted logic, full production support, and documented ALS process reliability - making it the preferred choice for new industrial designs requiring assured supply and specification traceability.

Availability

SN74ALS29828NT is available at Aetrix Electronics and suitable for memory address buffering, parallel bus isolation, legacy system upgrades, and industrial control backplane applications requiring stable component supply and long-lifecycle assurance.

Supply support for SN74ALS29828NT 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 decades of heritage in TTL and advanced logic families.

The SN74ALS29828NT belongs to TI's ALS (Advanced Low-Power Schottky) logic portfolio, engineered for high-speed, low-power bus interface in commercial and industrial computing systems operating at 5 V.

FAQ

What logic function does the SN74ALS29828NT implement?

The SN74ALS29828NT implements a 10-bit inverting buffer function: each output Yn is the logical inverse of its corresponding input An (Yn = NOT An). This distinguishes it from the true-output SN74ALS29827NT. The device contains no internal logic beyond inversion and dual 3-state control - all functionality is fixed and deterministic per the ALS29828 design.

How does the 3-state enable logic work on the SN74ALS29828NT?

The SN74ALS29828NT uses a dual-input NOR gate for 3-state control: if either OE1 or OE2 is driven high, all ten outputs (Y1–Y10) enter high-impedance mode simultaneously. Both enables must be low for normal inverted output operation. This architecture allows flexible bus arbitration - for example, OE1 can control one subsystem while OE2 controls another, with automatic disable if either is asserted.

Is the SN74ALS29828NT pin-compatible with the AM29828?

Yes - the SN74ALS29828NT is functionally and pin-compatible with AMD's AM29828, including identical 24-pin DIP (NT) package, pin assignments, electrical specifications, and timing parameters. TI explicitly states functional equivalence in the datasheet, enabling direct replacement in legacy AM29828-based designs without PCB or firmware changes.

What is the maximum capacitive load the SN74ALS29828NT can drive reliably?

The SN74ALS29828NT is characterized for loads up to 300 pF, with specified switching times (e.g., tPLH/tPHL = 15 ns) under that condition. At lower 50-pF loads, propagation delay improves to 7 ns. Its 48 mA sink capability supports driving multiple TTL inputs or longer PCB traces, but sustained operation above 300 pF may degrade timing margins and should be verified with board-level simulation or measurement.

Does the SN74ALS29828NT require external pull-up or pull-down resistors on its inputs or outputs?

No - the SN74ALS29828NT has TTL-compatible inputs with defined VIH (2 V) and VIL (0.8 V) thresholds and does not require external biasing. Outputs are actively driven high or low in normal mode and present high impedance when disabled; pull-ups are only needed if a defined logic level is required during 3-state periods - which depends on system architecture, not device requirement.