Texas Instruments SNJ54S240W

Overview

SNJ54S240W from Texas Instruments is a military-grade octal inverting buffer/line driver with 3-state outputs, designed for high-reliability bus interface applications in aerospace and defense systems. It features dual 4-bit channels, active-low output-enable (G) inputs, 7 ns typical propagation delay at 5 V, ±48 mA output drive capability, and operates across –55°C to +125°C.

For engineers reviewing the SNJ54S240W datasheet, SNJ54S240W pinout, SNJ54S240W application, or SNJ54S240W equivalent, this page delivers verified electrical characteristics, MIL-PRF-38535 compliance details, thermal metrics for CFP packaging, functional mode tables, and real-world bus buffering use cases - all specific to the SNJ54S240W variant.

Technical Context

The SNJ54S240W implements Schottky transistor logic (S-TTL) with PNP input stages to reduce DC loading on shared buses. Its dual-channel architecture supports independent control of two 4-bit inverting buffers via separate 1G and 2G/2G inputs, enabling bidirectional data flow management in memory address or system bus configurations.

Each channel provides hysteresis-enhanced noise margins (0.2–0.4 V), 3-state output capability with fast enable/disable timing (tPZH/tPLZ ≤10 ns), and compatibility with both 5-V TTL and mixed-voltage 3.3-V logic inputs - critical for legacy system upgrades and radiation-tolerant board designs.

Key Specifications

Pinout & Package

SNJ54S240W uses a 20-pin Ceramic Flatpack (CFP-W) package measuring 7.02 mm × 13.72 mm, optimized for hermetic sealing and thermal performance in high-reliability applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal inverting buffer applications.

Compared with SNJ54LS240W, SNJ54S240W delivers 4× higher output current and 2× faster switching - essential for driving heavy capacitive loads or high-frequency buses. Against SNJ54S244W, it provides complementary logic polarity for applications requiring signal inversion at the buffer stage.

Availability

SNJ54S240W is available at Aetrix Electronics and suitable for aerospace avionics, defense electronics, and industrial control systems requiring stable component supply, long-term obsolescence management, and MIL-spec traceability.

Supply support for SNJ54S240W 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 for industrial, automotive, and defense markets.

The SNJ54S240W belongs to TI's military logic family, engineered specifically for bus interface and memory addressing in harsh-environment systems where parametric consistency, thermal stability, and long-term availability are mandatory.

FAQ

What is the maximum operating temperature range for SNJ54S240W?

The SNJ54S240W is rated for operation from –55°C to +125°C and fully tested per MIL-PRF-38535 requirements across this range. This specification applies to the CFP (W) package variant and includes guaranteed performance for propagation delay, output drive, and noise margin at temperature extremes - critical for deployment in satellite payload electronics and jet engine control units where ambient temperatures exceed 100°C.

Does SNJ54S240W support 3.3-V logic inputs?

Yes, SNJ54S240W accepts 3.3-V logic inputs reliably due to its input tolerance down to 2 V and VIH minimum of 2 V under recommended operating conditions. The device's PNP input structure and hysteresis ensure robust recognition of 3.3-V high-level signals even with ground bounce or supply droop - making SNJ54S240W suitable for mixed-voltage system interfaces without level-shifter circuitry.

How does the 3-state output control work on SNJ54S240W?

SNJ54S240W uses two active-low output-enable inputs: Pin 1 (1G) controls Channel 1 outputs (1Y1–1Y4), and Pin 19 (2G/2G) controls Channel 2 outputs (2Y1–2Y4). When either G input is high, its associated Y outputs enter high-impedance state; when low, the corresponding A inputs pass through with inversion. This allows independent bus arbitration - for example, enabling SNJ54S240W to isolate memory address lines while permitting data bus activity on the same PCB.

What is the typical propagation delay of SNJ54S240W at 5 V?

The typical propagation delay (tPLH/tPHL) of SNJ54S240W is 7 ns at VCC = 5 V, RL = 90 Ω, and CL = 50 pF - measured per JEDEC JESD62 standard. This value reflects worst-case path delay from A input to Y output under loaded conditions and is confirmed across the full military temperature range. Designers should use the 4.5 ns minimum and 7 ns typical values for timing budgeting in high-speed bus applications such as MIL-STD-1553B auxiliary data paths.

Is SNJ54S240W pin-compatible with commercial SN74S240 variants?

Yes, SNJ54S240W shares identical pinout, logic function, and terminal assignments with SN74S240 in SOIC (DW) and PDIP (N) packages. However, SNJ54S240W uses the CFP (W) package and undergoes full MIL-PRF-38535 screening - including burn-in, temperature cycling, and parametric testing - which commercial variants do not. Electrical behavior is consistent, but SNJ54S240W provides guaranteed performance under extreme stress conditions required for defense applications.