Texas Instruments SNJ54LVT574FK

Overview

SNJ54LVT574FK from Texas Instruments is a military-grade 3.3-V ABT octal edge-triggered D-type flip-flop with 3-state outputs, designed for bus-interface applications in mixed-voltage systems (3.3-V V_CC, 5-V tolerant I/O), operating from −55°C to 125°C, featuring bus-hold inputs and low ground bounce (<0.8 V).

For engineers reviewing the SNJ54LVT574FK datasheet, SNJ54LVT574FK pinout, SNJ54LVT574FK application, or SNJ54LVT574FK equivalent, key selection criteria include its military temperature rating, ceramic flat (W/FK) package, 150-MHz max clock frequency, 3-state output enable timing (t_PZH/t_PLZ ≤ 7.1 ns), and compatibility with 5-V input signaling while powered at 3.3 V.

Technical Context

This device implements eight independent positive-edge-triggered D flip-flops with asynchronous 3-state output control via OE. Its Advanced BiCMOS Technology (ABT) enables simultaneous 3.3-V core operation and 5-V-tolerant I/O, supporting live insertion and unregulated battery operation down to 2.7 V.

Bus-hold circuitry actively retains logic states on unused D inputs without external pullups. OE is fully decoupled from internal latch operation-data can be latched or held while outputs remain in high-impedance mode, enabling safe bus sharing in backplane or modular systems.

Key Specifications

Pinout & Package

Ceramic Flat (FK) package: 20-pin, 0.300-inch wide, hermetically sealed, leaded, with dual in-line footprint compatible with MIL-STD-883 Class B screening.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SNJ54ACT574FK and SNJ54LVTH162374FK, the SNJ54LVT574FK uniquely balances 3.3-V operation, 5-V I/O tolerance, military temperature range, and compact 20-pin FK packaging - making it the sole option for new designs requiring mixed-voltage register interfacing in ruggedized platforms.

Availability

SNJ54LVT574FK is available at Aetrix Electronics and suitable for avionics data bus interface, military test equipment, secure communication modules, and tactical vehicle control units requiring stable component supply across extended temperature and long product lifecycles.

Supply support for SNJ54LVT574FK 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 components, with decades of heritage in military and aerospace-grade IC development.

The SN54LVT series was engineered specifically for high-speed, mixed-signal military systems requiring 3.3-V logic with 5-V interoperability, low power, and guaranteed operation across extreme temperatures.

FAQ

What is the maximum clock frequency supported by SNJ54LVT574FK?

The SNJ54LVT574FK supports a maximum clock frequency of 150 MHz across its full military temperature range (−55°C to +125°C) when operated at V_CC = 3.3 V ± 0.3 V. This specification is verified per the SCBS139D datasheet timing tables and applies to both data capture and output enable/disable transitions. The SNJ54LVT574FK maintains this performance without derating, making it suitable for high-throughput digital instrumentation and real-time control loops.

Does SNJ54LVT574FK require external pullup resistors on its data inputs?

No, the SNJ54LVT574FK does not require external pullup resistors on its D inputs because it integrates active bus-hold circuitry on all eight data pins. This feature maintains valid logic levels on floating or unterminated inputs, preventing metastability and reducing BOM count. The bus-hold current is specified as ±75 μA at V_CC = 3 V, and the function remains active regardless of OE or CLK state - a key advantage confirmed in the device's functional description and electrical characteristics table.

Can SNJ54LVT574FK operate with a 2.7-V supply voltage?

Yes, the SNJ54LVT574FK is fully specified to operate at V_CC = 2.7 V, the minimum recommended supply voltage. At this level, it maintains 150-MHz clock capability, 5-V input tolerance, and guaranteed timing margins (t_su = 2.4 ns, t_h = 0.9 ns). This low-voltage support enables use with aging batteries or unregulated power sources in portable military gear - a design requirement explicitly called out in the "Support Unregulated Battery Operation Down to 2.7 V" feature statement.

What package type is used for SNJ54LVT574FK?

The SNJ54LVT574FK uses a ceramic flat (FK) package: a 20-pin, 0.300-inch wide, hermetically sealed dual in-line package with tin-lead leads. It is distinct from plastic SOIC (DW) or TSSOP (PW) variants and is qualified to MIL-STD-883 for high-reliability applications. The FK package provides superior thermal stability, moisture resistance, and mechanical robustness - critical for aerospace, missile, and naval deployments where long-term reliability under shock/vibration is mandatory.

How does the output-enable (OE) pin affect internal flip-flop operation in SNJ54LVT574FK?

The OE pin in the SNJ54LVT574FK has no effect on internal flip-flop operation: clocking, data latching, and state retention occur independently of OE status. When OE is high, outputs enter high-impedance (Z) mode without altering stored Q values; old data remains intact and new D inputs can still be captured on subsequent CLK edges. This decoupling - explicitly stated in the datasheet's description ("OE does not affect the internal operations") - enables glitch-free bus arbitration and dynamic reconfiguration in mission-critical systems.