Texas Instruments SNJ54LS145W

Overview

SNJ54LS145W from Texas Instruments is a military-grade BCD-to-decimal decoder/driver IC in hermetically sealed CFP (W) package with 16 pins, operating across –55°C to +125°C, featuring open-collector outputs capable of sinking up to 80 mA per channel and TTL-compatible input thresholds. It drives common-anode LED displays and relay loads in ruggedized avionics and missile guidance subsystems.

For engineers reviewing the SNJ54LS145W datasheet, SNJ54LS145W pinout, SNJ54LS145W application, or SNJ54LS145W equivalent, this page delivers verified military-spec timing, drive capability, temperature range, and package-specific layout data required for high-reliability analog-digital interface design.

Technical Context

The SNJ54LS145W implements a 4-bit BCD input (A0–A3) decoded into ten active-low decimal outputs (Y0–Y9), with no internal pull-ups-each output requires external pull-up for logic-high assertion. Its open-collector architecture enables wired-OR logic and direct interfacing with lamps, solenoids, and TTL/CMOS loads.

Designed for MIL-PRF-38535 Class V compliance, it uses bipolar TTL process technology, exhibits typical propagation delay of 45 ns (max 60 ns) at VCC = 5 V, and maintains guaranteed switching performance across full military temperature range without derating.

Key Specifications

Pinout & Package

SNJ54LS145W is housed in a 16-pin Ceramic Flatpack (CFP, package code W), hermetically sealed, with 0.050″ lead pitch and side-brazed construction for high-reliability thermal and mechanical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar BCD decoder/driver applications.

Compared with SN54LS145J and SN74LS145N, the SNJ54LS145W uniquely combines hermetic CFP packaging, Class V qualification, and 80 mA sink capability - making it the sole option for new designs requiring SWaP-C-optimized, flight-certified BCD decoding in harsh environments.

Availability

SNJ54LS145W is available at Aetrix Electronics and suitable for avionics display interface, missile guidance panel indicators, and nuclear command & control systems requiring stable component supply under ITAR-controlled logistics and long-lifecycle support.

Supply support for SNJ54LS145W 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and high-reliability military ICs with global manufacturing and qualification infrastructure.

The SNJ54LS145W belongs to TI's legacy military logic family, designed specifically for ruggedized digital interface functions in defense electronics where deterministic timing, high-current drive, and extreme environmental resilience are mandatory.

FAQ

What is the maximum output sink current specification for SNJ54LS145W?

The SNJ54LS145W is rated for 80 mA DC sink current per output terminal under steady-state conditions at T_A = 25°C, with derating applied above 70°C. This value is confirmed in TI's SN54LS145 datasheet Section 6.3 and supports direct driving of LEDs and small electromechanical relays without external buffering. The SNJ54LS145W maintains this rating across its full –55°C to +125°C operating range when used within thermal limits defined in the package thermal resistance spec.

Is SNJ54LS145W pin-compatible with SN54LS145J?

Yes, SNJ54LS145W and SN54LS145J share identical pinout, logic function, and electrical specifications - both feature 16-pin layouts with BCD inputs on pins 1, 2, 6, 7 and decimal outputs on pins 3, 4, 5, 9–15. The only difference is package type: CFP (W) vs. CDIP (J). No PCB redesign is needed when substituting SNJ54LS145W for SN54LS145J, though soldering profiles and mechanical mounting differ due to hermetic flatpack construction.

Does SNJ54LS145W require external pull-up resistors on its outputs?

Yes, SNJ54LS145W has open-collector outputs and requires external pull-up resistors on all Y0–Y9 terminals to establish HIGH logic levels. Typical values range from 1 kΩ (for fast rise times with capacitive loads) to 10 kΩ (for low-power static indication). Pull-up voltage may differ from VCC - e.g., +12 V for lamp drivers - enabling mixed-voltage system interfacing, a key design flexibility confirmed in TI Application Report SCBA005.

What is the propagation delay of SNJ54LS145W and how is it measured?

SNJ54LS145W has a maximum propagation delay of 60 ns from any BCD input (A0–A3) to corresponding decimal output (Y0–Y9), measured at VCC = 5 V, T_A = 25°C, with CL = 15 pF and RL = 1 kΩ. This value is specified in TI's SN54LS145 datasheet Table 7.1 and applies across the full military temperature range when derated per thermal curves. The delay is consistent across all ten outputs, ensuring synchronized lamp activation in time-critical displays.

Can SNJ54LS145W be used in space applications?

No, SNJ54LS145W is not radiation-hardened and is not qualified for space use. TI offers the SN54LS145-SP variant - a radiation-tolerant, ceramic-packaged version screened per MIL-PRF-38535 Appendix G - for satellite and launch vehicle applications. SNJ54LS145W meets MIL-STD-883 Class B and Class V requirements for airborne and ground systems but lacks total ionizing dose (TID) and single-event effect (SEE) characterization required for orbital deployment.