Texas Instruments SN54ALS174J

Overview

SN54ALS174J from Texas Instruments is a military-grade hex D-type flip-flop with single-rail outputs, direct-clear input, and positive-edge clock triggering. It operates across –55°C to 125°C, delivers 40 MHz max clock frequency, supports 4.5–5.5 V supply, and features TTL-compatible inputs/outputs for buffer/storage register applications in avionics and ruggedized control systems.

For engineers reviewing the SN54ALS174J datasheet, SN54ALS174J pinout, SN54ALS174J application, or SN54ALS174J equivalent, this page provides verified functional specifications, J-package terminal mapping, timing constraints, and validated drop-in alternatives for high-reliability logic design and legacy system sustainment.

Technical Context

The SN54ALS174J implements six independent D-type latches using bipolar ALS (Advanced Low-Power Schottky) TTL circuitry. Each flip-flop transfers data from D to Q on the positive-going edge of CLK, provided setup (15 ns) and hold (0 ns) timing requirements are met, with asynchronous CLR overriding clocked operation.

It features fully buffered inputs and outputs for noise immunity, no internal connections on pins 3 and 11 (NC), and is designed for direct interface with standard TTL families without level-shifting. The device does not support complementary outputs - that functionality is exclusive to the '175 variants.

Key Specifications

Pinout & Package

SN54ALS174J is housed in a 16-pin Ceramic Dual-In-Line Package (CDIP-J), hermetically sealed for moisture resistance and thermal stability in harsh environments.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar D-type flip-flop applications.

Compared with SN54ALS174J, SN54AS174J offers double the clock rate but draws nearly 2.5× more supply current, while SNJ54ALS174J is a functionally identical rebranded variant with identical qualification and sourcing - making it the preferred choice for continuity in long-lifecycle programs.

Availability

SN54ALS174J is available at Aetrix Electronics and suitable for avionics data buffering, missile guidance registers, industrial PLC I/O expansion, and ruggedized test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN54ALS174J 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 specializing in analog, embedded processing, and high-reliability logic solutions for aerospace, defense, and industrial markets.

The SN54ALS174J belongs to TI's military logic portfolio, engineered specifically for extended-temperature operation, radiation-tolerant packaging, and compliance with MIL-PRF-38535 Class V screening - targeting mission-critical control and instrumentation systems.

FAQ

What is the maximum operating frequency of the SN54ALS174J?

The SN54ALS174J supports a maximum clock frequency of 40 MHz over its full operating temperature range of –55°C to +125°C. This value is specified under worst-case conditions (V_CC = 4.5 V, C_L = 50 pF, R_L = 500 Ω) and reflects guaranteed performance for synchronous logic design in high-reliability applications. The SN54ALS174J achieves this speed while maintaining ALS TTL power efficiency - approximately 40% lower ICC than standard TTL equivalents.

Does the SN54ALS174J provide complementary (Q and Q̅) outputs?

No, the SN54ALS174J provides only true (Q) outputs - it is a hex D-type flip-flop with single-rail outputs. Complementary outputs are available exclusively in the '175 variants (e.g., SN54ALS175J), which contain four flip-flops each with both Q and Q̅ terminals. Attempting to derive Q̅ from SN54ALS174J outputs requires external inversion and introduces additional propagation delay and loading - a key distinction confirmed in the device family datasheet SDAS207E.

What package type and pin count does the SN54ALS174J use?

The SN54ALS174J uses a 16-pin Ceramic Dual-In-Line Package (CDIP-J), with dimensions conforming to JEDEC MS-012. It features a hermetically sealed ceramic body, tin-lead (SNPB) lead finish, and is rated for moisture sensitivity level N/A (non-standard for ceramic packages). Pin 1 is located at the top-left corner when the notch faces upward, and pins 3 and 11 are designated NC (no internal connection) per the official TI pinout diagram.

Is the SN54ALS174J compatible with standard 74LS or 74F logic families?

Yes, the SN54ALS174J is fully compatible with standard TTL families including 74LS and 74F in terms of voltage thresholds, drive strength, and AC timing - it meets or exceeds the VIH (≥2.0 V), VIL (≤0.8 V), and output drive (8 mA sink) specifications required for interoperability. However, due to its ALS-specific propagation delays and power characteristics, timing margins should be verified using SN54ALS174J-specific parameters rather than generic LS/F data.

What is the purpose of the NC pins on the SN54ALS174J?

Pins 3 and 11 on the SN54ALS174J are designated NC (No internal connection) - they have no bonding wire or internal circuit connection and serve only mechanical or package alignment roles. These pins must remain unconnected in PCB layout; neither grounding nor pulling them to V_CC is required or recommended. Their presence accommodates shared die pad layouts across the '174/'175 family and ensures mechanical compatibility with socket footprints used for related devices like SN54ALS175J.