Texas Instruments SNJ54BCT245W

Overview

SNJ54BCT245 from Texas Instruments is a military-grade octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between A and B buses in high-reliability systems. It operates over –55°C to 125°C, supports 5 V supply (4.5–5.5 V), delivers up to 64 mA sink current on B-port outputs, and features direction control (DIR) and output-enable (OE) logic for precise bus isolation-used in avionics backplane interfaces and radiation-tolerant memory address buffering.

For engineers reviewing the SNJ54BCT245 datasheet, SNJ54BCT245 pinout, SNJ54BCT245 application, or SNJ54BCT245 equivalent, this page delivers verified electrical specs, CFP package mechanical data, MIL-PRF-38535 compliance context, and real-world timing behavior under 50 pF load conditions-critical for deterministic bus arbitration and thermal-aware layout planning.

Technical Context

The SNJ54BCT245 implements TTL-compatible bipolar transistor-transistor logic (BCT) with totem-pole outputs and active-low 3-state control. Its DIR input selects data flow direction (A→B or B→A), while OE independently disables all outputs into high-impedance state-enabling true bus isolation without leakage paths.

All 16 I/O pins (A1–A8, B1–B8) are fully buffered with symmetric propagation delays (tPLH/tPHL ≤ 7.6 ns at VCC = 4.5 V), and the device meets JESD22-A114A ESD rating (>2000 V HBM). It is specified for full parameter testing per MIL-PRF-38535 requirements across its –55°C to 125°C operating range.

Key Specifications

Pinout & Package

SNJ54BCT245 is housed in a 20-pin Ceramic Flatpack (CFP-W) package with gull-wing leads, 0.050" lead pitch, and 26.16 mm × 12.06 mm body dimensions. The package is hermetically sealed, RoHS-exempt (SNPB finish), and rated for indefinite storage per MIL-STD-883.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal bus transceiver applications.

Compared with SNJ54ACT245W and SNJ54LS245J, SNJ54BCT245 uniquely balances high-speed (≤7.6 ns), high-drive (64 mA B-port), and full MIL-PRF-38535 qualification-making it the sole option for new designs requiring simultaneous speed, drive strength, and military reliability assurance.

Availability

SNJ54BCT245 is available at Aetrix Electronics and suitable for avionics data bus interface, military memory address buffering, secure communication backplane, and tactical radio baseband interconnect applications requiring stable component supply across extended temperature and long product lifecycles.

Supply support for SNJ54BCT245 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 with over 50 years of analog and military-grade logic innovation, headquartered in Dallas, Texas.

The SNJ54BCT245 belongs to TI's military logic family, engineered specifically for high-reliability defense and aerospace systems where deterministic timing, extreme temperature resilience, and full-parameter MIL-PRF-38535 compliance are non-negotiable design requirements.

FAQ

What is the maximum capacitive load SNJ54BCT245 can drive while maintaining guaranteed timing?

SNJ54BCT245 is characterized for CL = 50 pF in its switching specifications, with tPLH/tPHL ≤ 7.6 ns at VCC = 4.5 V. While it can physically drive >100 pF loads due to its 64 mA B-port sink capability, timing margins degrade beyond 50 pF. For designs exceeding 50 pF, derating analysis per TI application report SCBA004 is required. SNJ54BCT245 remains functional-but not specification-guaranteed-at higher loads.

Does SNJ54BCT245 require external pull-up or pull-down resistors on DIR and OE inputs?

No. SNJ54BCT245 has internal input hysteresis and defined VIH (2.0 V min) and VIL (0.8 V max) thresholds. DIR and OE may be driven directly from TTL/CMOS logic without external biasing. However, TI recommends tying unused control inputs to VCC or GND per SCBA004 to prevent floating states that could cause undefined output behavior. SNJ54BCT245 does not include internal pull resistors.

Is SNJ54BCT245 compatible with 3.3 V logic systems?

SNJ54BCT245 is a 5 V-only device with VCC range 4.5–5.5 V and input thresholds referenced to 5 V. Its VIH = 2.0 V min is compatible with 3.3 V CMOS high levels, but driving SNJ54BCT245 inputs from 3.3 V sources risks marginal noise margin. Outputs swing rail-to-rail (0–5 V), so interfacing with 3.3 V receivers requires external level translation. SNJ54BCT245 itself is not 3.3 V tolerant.

How does the thermal performance of SNJ54BCT245 in CFP-W compare to plastic SOIC versions?

The CFP-W package of SNJ54BCT245 exhibits superior thermal resistance (θJA ≈ 65°C/W typical) versus plastic SOIC (e.g., SN74BCT245DW: θJA = 58°C/W) due to its ceramic body and metal lid. Though numeric θJA appears higher, CFP-W maintains stable junction temperature under sustained 64 mA loads across –55°C to 125°C ambient-unlike plastic packages prone to parameter drift above 85°C. SNJ54BCT245 leverages hermetic sealing for consistent thermal behavior.

Can SNJ54BCT245 be used in hot-swap applications?

SNJ54BCT245 supports controlled hot-swap via its OE input: asserting OE HIGH before insertion isolates all I/O pins, preventing bus contention. However, it lacks built-in power sequencing or slew-rate control. TI recommends pairing SNJ54BCT245 with external current-limiting resistors and soft-start circuitry. Full hot-swap compliance requires system-level design per MIL-STD-1553 or IEEE 1101.10-not inherent to SNJ54BCT245 alone.