Texas Instruments SNJ54F153FK

Overview

SNJ54F153FK from Texas Instruments is a dual 4-line to 1-line data selector/multiplexer with independent strobe (enable) inputs per section, operating across −55°C to 125°C, featuring 7 ns typical propagation delay (tPLH/tPHL), 20 mA low-level output drive, and TTL-compatible input thresholds. It enables parallel-to-serial conversion and N-line multiplexing in military-grade digital control logic.

For engineers reviewing the SNJ54F153FK datasheet, SNJ54F153FK pinout, SNJ54F153FK application, or SNJ54F153FK equivalent, key selection criteria include its LCCC-20 package, dual-section independent gating, full military temperature range, and compatibility with F-series TTL system timing budgets.

Technical Context

The SNJ54F153FK implements two independent 4:1 multiplexer sections sharing common select lines A and B, each with dedicated active-low strobe inputs (1G, 2G). Its internal architecture uses binary-decoded AND-OR logic with inverters and drivers for full decoding and signal routing.

Each section selects one of four data inputs (C0–C3) based on A/B state and passes it to the corresponding output (1Y or 2Y) only when its strobe is asserted. Propagation delays are specified separately for select (A/B), strobe (G), and data (C) inputs to output (Y), supporting cascaded multiplexing and synchronous data routing.

Key Specifications

Pinout & Package

LCCC (FK) package: 20-pin leadless ceramic chip carrier, 8.89 mm × 8.89 mm body, 1.27 mm pitch, 2.03 mm max height, hermetically sealed, suitable for high-reliability military and space applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 4:1 multiplexer applications.

Compared with SNJ54F153J, SNJ54F153FK offers superior thermal performance and hermetic reliability in surface-mount high-density layouts; compared with 5962-9758301Q2A, SNJ54F153FK is functionally identical but carries distinct TI-specific orderable branding for commercial/mixed-sourcing programs.

Availability

SNJ54F153FK is available at Aetrix Electronics and suitable for avionics data consolidation, military radar signal routing, secure crypto module addressing, and hardened industrial PLC I/O expansion requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for SNJ54F153FK 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, with decades of heritage in military-grade component development.

The SNJ54F153FK belongs to TI's 54F TTL logic family, designed specifically for high-speed, temperature-resilient digital control in defense, aerospace, and critical infrastructure systems.

FAQ

What is the maximum clock frequency supported by SNJ54F153FK?

The SNJ54F153FK does not operate on a clock signal - it is a combinational logic device. Its usable switching rate is determined by propagation delay: with a maximum tPHL/tPLH of 14 ns (G→Y, VCC = 4.5 V, TA = min/max), it supports data selection events up to approximately 35 MHz in repetitive use, assuming clean setup/hold margins and proper load termination. SNJ54F153FK performance remains stable across its full −55°C to 125°C range.

Does SNJ54F153FK require external pull-up resistors on its outputs?

Yes, SNJ54F153FK outputs (1Y and 2Y) are standard TTL totem-pole outputs - not open-collector - but they do not source significant current (IOH = −1 mA). For reliable high-level signaling into standard TTL fan-in loads, a pull-up resistor (typically 1–4.7 kΩ to VCC) is recommended to ensure VIH ≥ 2.0 V under capacitive or multi-load conditions. SNJ54F153FK output voltage specifications assume this configuration per recommended operating conditions.

Can SNJ54F153FK be used in place of SN74F153N in commercial designs?

No - SNJ54F153FK is rated for −55°C to 125°C and packaged in hermetic LCCC-20, whereas SN74F153N operates from 0°C to 70°C and uses plastic DIP-16. While logic function and pinout (for shared pins) are identical, SNJ54F153FK is not a drop-in replacement due to different package footprint, thermal characteristics, and qualification level. Using SNJ54F153FK in a commercial design is permissible but incurs cost and layout overhead without functional benefit unless extended temperature or reliability is required.

What is the meaning of "NC" pins on SNJ54F153FK, and how should they be handled?

SNJ54F153FK has four NC (No Connection) pins: pins 10, 11, 19, and 20. These pins have no internal bond wires or circuit connections and must remain unconnected - neither tied to VCC nor GND. Leaving them floating is safe and required per TI's datasheet guidance. PCB layout should avoid routing traces or copper pours beneath these pads to prevent parasitic coupling. This applies strictly to SNJ54F153FK and differs from other variants like SN74F153D which lack NC pins.

Is SNJ54F153FK compliant with RoHS or lead-free assembly requirements?

No - SNJ54F153FK uses SNPB (tin-lead) lead finish and is explicitly marked "No" for RoHS compliance in TI's packaging documentation. It is intended for legacy military/aerospace applications where tin-lead soldering is mandated for reliability and whisker mitigation. For RoHS-compliant alternatives, consider modern replacements such as SN74LV153 (SOIC-16, 1.65–5.5 V, −40°C to 125°C), though functionality and pinout differ. SNJ54F153FK remains a non-RoHS, tin-lead solution per its QML-38535 qualification.