Texas Instruments SNJ54AC374FK

Overview

SNJ54AC374 from Texas Instruments is a military-grade octal D-type edge-triggered flip-flop with 3-state noninverting outputs, designed for bus-oriented systems requiring high-drive capability and precise timing control. It operates across 2V–6V V_CC, delivers 9.5ns max propagation delay at 5V, and supports −55°C to +125°C operation in LCCC (FK) package - ideal for aerospace data buffering and avionics I/O port expansion.

For engineers reviewing the SNJ54AC374 datasheet, SNJ54AC374 pinout, SNJ54AC374 application, or SNJ54AC374 equivalent, key selection criteria include its 20-pin LCCC thermal performance (no MSL rating), 3-state output enable timing (t_PZH/t_PLZ ≤ 8.5ns at 5V), and compatibility with legacy TTL/CMOS bus architectures without pull-up components.

Technical Context

The SNJ54AC374 implements eight independent positive-edge-triggered D flip-flops synchronized to CLK, with each Q output directly controllable via a shared active-low OE input. Its 3-state outputs drive highly capacitive loads up to 50pF while maintaining rail-to-rail logic levels across full V_CC range (2V–6V).

Internal logic retains stored data regardless of OE state, enabling concurrent data latching and bus isolation. Timing parameters are fully characterized at both 3.3V and 5V, with setup time as low as 4ns and clock frequency up to 100MHz at 5V - meeting MIL-PRF-38535 Class V requirements for high-reliability digital subsystems.

Key Specifications

Pinout & Package

LCCC (FK) package: 20-pin leadless ceramic chip carrier, 8.89mm × 8.89mm body, 1.27mm pitch, 2.03mm max height, no moisture sensitivity level (MSL) rating - suitable for hermetic sealing and high-reliability board assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SNJ54ACT374 and SNJ54F374, the SNJ54AC374 offers optimal balance of speed, power efficiency, and CMOS input compatibility for modern high-reliability digital systems - especially where 5V bus interoperability and sub-10ns timing precision are required.

Availability

SNJ54AC374 is available at Aetrix Electronics and suitable for aerospace data buffering, avionics I/O expansion, radar signal conditioning, and secure communication module design requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SNJ54AC374 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 high-reliability logic solutions for industrial, automotive, and defense markets.

The SNJ54AC374 belongs to TI's military logic family, engineered specifically for ruggedized digital subsystems demanding guaranteed performance under extreme environmental stress and long-term obsolescence mitigation.

FAQ

What is the maximum clock frequency supported by SNJ54AC374 at 5V operation?

The SNJ54AC374 supports a maximum clock frequency of 100MHz at V_CC = 5V ± 0.5V, as specified in Section 4.6 of the datasheet. This timing is validated across the full −55°C to +125°C operating range and enables use in high-speed data acquisition and real-time control applications where deterministic edge-triggered behavior is critical. The SNJ54AC374 achieves this performance with a typical propagation delay of 8ns and maximum of 9.5ns.

Does SNJ54AC374 require external pull-up resistors on its 3-state outputs?

No, the SNJ54AC374 does not require external pull-up resistors on its 3-state outputs. Its noninverting 3-state outputs provide rail-to-rail drive capability (±24mA at 5V) and can directly interface with standard bus loads. External pull-ups are unnecessary because the device maintains defined logic states (HIGH/LOW/Hi-Z) without passive termination - a key advantage confirmed in Section 2 and Figure 6-1 of the SNJ54AC374 datasheet.

What is the package type and lead finish for SNJ54AC374FK?

The SNJ54AC374FK uses an LCCC (Leadless Ceramic Chip Carrier) package with 20 pins, 8.89mm × 8.89mm body size, and 1.27mm pitch. Its lead finish is SNPB (tin-lead), as documented in the PACKAGE OPTION ADDENDUM. This non-RoHS-compliant finish is standard for military-grade devices requiring proven solder joint reliability under thermal cycling and mechanical shock - consistent with MIL-PRF-38535 Class V qualification requirements.

How does the OE pin function during power-up and power-down sequences?

During power-up or power-down, the OE pin of the SNJ54AC374 must be tied to V_CC through a pullup resistor to ensure defined high-impedance outputs, as stated in Section 6.1. The minimum resistor value depends on the current-sinking capability of the driving circuit. This prevents bus contention or undefined states when V_CC is ramping, making the SNJ54AC374 suitable for systems requiring controlled power sequencing - a requirement explicitly addressed in the functional description of the SNJ54AC374.

Is SNJ54AC374 compatible with 3.3V logic systems?

Yes, the SNJ54AC374 is fully compatible with 3.3V logic systems. It operates over a V_CC range of 2V to 6V and specifies timing parameters (e.g., 60MHz f_clock, 13.5ns t_PLH) at V_CC = 3.3V ± 0.3V in Section 4.5. Input thresholds scale with V_CC, ensuring reliable recognition of 3.3V logic levels. This dual-voltage capability makes the SNJ54AC374 suitable for mixed-signal boards integrating both legacy 5V and modern 3.3V subsystems.