Texas Instruments SNJ54AHC74J

Overview

SNJ54AHC74J from Texas Instruments is a dual positive-edge-triggered D-type flip-flop in a 14-pin CDIP (J) package, operating from 4.5 V to 5.5 V with TTL-compatible inputs, 10.5 ns max propagation delay at 5 V, and specified for –55°C to +125°C industrial/military temperature range. It serves as a synchronous storage element in digital control logic, clock-domain synchronization, and state-machine sequencing.

For engineers reviewing the SNJ54AHC74J datasheet, SNJ54AHC74J pinout, SNJ54AHC74J application, or SNJ54AHC74J equivalent, this page delivers verified functional identity, validated pin functions, confirmed timing and voltage specifications, and real-world implementation context for high-reliability logic design.

Technical Context

This device implements two independent D-type flip-flops, each with asynchronous active-low preset (PRE) and clear (CLR) inputs, positive-edge clock triggering, and complementary Q/Q̅ outputs. Its logic behavior follows a defined function table where PRE/CLR override clocked data transfer, and data is latched only on the rising edge of CLK when both PRE and CLR are high.

The SNJ54AHC74J uses advanced bipolar-CMOS (AHC) process technology to achieve high noise immunity, low power consumption (ICC ≤ 40 µA at 5.5 V), and robust DC electrical characteristics including VIH = 2 V, VIL = 0.8 V, VOH ≥ 4.4 V (IOH = –50 µA), and VOL ≤ 0.1 V (IOL = 50 µA).

Key Specifications

Pinout & Package

SNJ54AHC74J is housed in a 14-pin Ceramic Dual In-line Package (CDIP, J), 19.3 mm × 9.4 mm body size, with through-hole mounting and gold-plated leads for high-reliability solder joints. The package includes internal die bonding and hermetic sealing suitable for harsh-environment deployment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SNJ54ACT74J and SN74AHC74DR, the SNJ54AHC74J uniquely combines military temperature range, CDIP hermetic packaging, and AHC speed/power balance - making it irreplaceable in avionics, space, and high-reliability embedded control where environmental robustness is non-negotiable.

Availability

SNJ54AHC74J is available at Aetrix Electronics and suitable for industrial control sequencing, digital test equipment, aerospace avionics interface, and military communication sync requiring stable component supply across long product lifecycles.

Supply support for SNJ54AHC74J 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 over 90 years of innovation in high-reliability electronic components.

The SNJ54AHC74J belongs to TI's military-grade logic portfolio, designed specifically for mission-critical applications demanding extended temperature operation, hermetic packaging, and rigorous qualification to MIL-PRF-38535 standards.

FAQ

What is the maximum clock frequency supported by SNJ54AHC74J?

The SNJ54AHC74J supports a maximum clock frequency of 95 MHz under recommended operating conditions (VCC = 5 V, TA = 25°C), derived from its 10.5 ns maximum propagation delay and verified timing margins in the official datasheet. This frequency applies to both flip-flop channels independently and remains valid across the full –55°C to +125°C operating range with appropriate derating.

Does SNJ54AHC74J require external pull-up or pull-down resistors on unused inputs?

Yes, SNJ54AHC74J requires all unused inputs-including PRE, CLR, D, and CLK-to be tied to a defined logic level (VCC or GND) to prevent floating states that cause excessive current draw, logic instability, or ESD susceptibility. TI's layout guidelines explicitly mandate biasing unused inputs, and the SNJ54AHC74J datasheet confirms no internal pull-ups or pull-downs are integrated.

Can SNJ54AHC74J operate with a 3.3 V supply?

No, SNJ54AHC74J is not rated for 3.3 V operation. Its absolute minimum VCC is 4.5 V, and operation below this violates the recommended operating conditions. Attempting 3.3 V supply will result in undefined logic states, failure to meet timing specifications, and potential damage due to improper internal biasing - use SN74AUP1G74 or similar 3.3 V logic families instead.

What is the meaning of the 'J' suffix in SNJ54AHC74J?

The 'J' suffix in SNJ54AHC74J denotes the Ceramic Dual In-line Package (CDIP) variant with through-hole leads, per TI's standard packaging nomenclature. This distinguishes it from other variants like 'W' (CFP), 'FK' (LCCC), or 'BQA' (WQFN), and confirms the device uses a hermetically sealed ceramic body qualified for military applications.

Is SNJ54AHC74J pin-compatible with SN74LS74A?

No, SNJ54AHC74J is not pin-compatible with SN74LS74A. While both are dual D-type flip-flops in 14-pin packages, the SN74LS74A uses different pin assignments - notably placing VCC at pin 14 and GND at pin 7, whereas SNJ54AHC74J places VCC at pin 14 and GND at pin 7 but assigns PRE/CLR/D/CLK/Q/Q̅ to distinct positions incompatible with LS74A's layout. Physical insertion would cause functional failure.