Texas Instruments SN74AS34N

Overview

SN74AS34N from Texas Instruments is a hex noninverting buffer IC in a 14-pin plastic DIP package, operating from 0°C to 70°C with 5 V supply, 20 mA low-level output drive, and 5.5 ns typical propagation delay (tPHL). It performs Y = A logic for signal buffering in TTL-compatible digital systems.

For engineers reviewing the SN74AS34N datasheet, SN74AS34N pinout, SN74AS34N application, or SN74AS34N equivalent, key selection criteria include its AS-family speed-power tradeoff, 20 mA sink capability, DIP-14 through-hole compatibility, and commercial-temperature operation without military-grade derating.

Technical Context

The SN74AS34N implements six independent positive-logic noninverting buffers with open-collector–compatible outputs and TTL input thresholds (VIL = 0.8 V, VIH = 2 V). Its bipolar Schottky (AS) process delivers faster switching than ALS variants while maintaining standard 5 V TTL voltage levels.

It features symmetrical AC performance: tPLH ≤ 6.5 ns and tPHL ≤ 6 ns over full temperature range, with guaranteed 20 mA IOL and −2 mA IOH at VCC = 4.5–5.5 V. Power consumption rises with speed-ICCL reaches 34.6 mA at VCC = 5.5 V and VI = 0 V.

Key Specifications

Pinout & Package

SN74AS34N uses a 14-pin plastic dual in-line package (PDIP-14, N package), with 0.3-inch body width and through-hole mounting. Pin 7 is GND and pin 14 is VCC; all six buffers are fully independent with no shared control lines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALS34N and SN74F34N, the SN74AS34N occupies a balanced position: faster than ALS with manageable power (vs F), and more noise-tolerant than F while offering superior drive vs ALS-ideal for mid-speed industrial interfaces needing reliability and margin.

Availability

SN74AS34N is available at Aetrix Electronics and suitable for industrial control panels, digital test equipment, legacy system upgrades, and education & prototyping labs requiring stable component supply and long-term obsolescence management.

Supply support for SN74AS34N 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 solutions with broad industrial and automotive reach.

The SN74AS34N belongs to TI's 74AS logic family-designed for high-speed, TTL-compatible digital systems where propagation delay and output drive are prioritized over ultra-low power consumption.

FAQ

What logic function does the SN74AS34N implement?

The SN74AS34N implements six independent noninverting buffer functions, each performing Y = A. Each of the six input-output pairs operates identically and independently, with no internal logic inversion or enable controls. This makes SN74AS34N ideal for signal conditioning, fanout expansion, and level restoration in TTL-based digital systems where polarity preservation is essential.

Is the SN74AS34N pin-compatible with other 74-series hex buffers?

Yes, the SN74AS34N uses the industry-standard 14-pin DIP layout shared by SN74LS34N, SN74ALS34N, and SN74F34N. Pin 1 is 1A, pin 2 is 1Y, continuing alternately to pin 13 (6Y), with pin 7 as GND and pin 14 as VCC. This allows direct substitution in existing footprints, though designers must verify timing and drive compliance for the target application.

What is the maximum output sink current specification for SN74AS34N?

The SN74AS34N is rated for a minimum low-level output current (IOL) of 20 mA per buffer at VCC = 4.5 V and VOL ≤ 0.5 V. This specification is guaranteed across the full commercial temperature range (0°C to 70°C) and enables direct driving of multiple TTL inputs, LEDs, or small-signal relays without external amplification-making SN74AS34N especially useful in interface and control layer designs.

Does SN74AS34N support mixed-voltage interfacing, such as 3.3 V inputs?

No, the SN74AS34N is a 5 V-only TTL device with input thresholds defined for 5 V operation (VIH ≥ 2 V, VIL ≤ 0.8 V). While it may function with 3.3 V logic highs in some cases, TI does not guarantee correct switching or noise margin under those conditions. For reliable 3.3 V–5 V translation, dedicated level-shifting ICs or buffer families with explicit mixed-voltage support should be used instead of SN74AS34N.

How does the power consumption of SN74AS34N compare to SN74ALS34N?

The SN74AS34N consumes significantly more supply current than SN74ALS34N: ICCL reaches 34.6 mA (max) versus 8 mA (max) for ALS under identical conditions. This reflects the AS family's speed-optimized bipolar Schottky design. Designers selecting SN74AS34N must account for higher thermal load and ensure adequate decoupling and board-level heat dissipation-especially in dense logic clusters where multiple SN74AS34N devices operate simultaneously.