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Texas Instruments SNJ54LS173AFK
- Part No.:
- SNJ54LS173AFK
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- -
- Datasheet:
-
SNJ54LS173AFK.pdf
- Description:
- 54LS173A 4-BIT D-TYPE REGISTERS
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Product details
Overview
SNJ54LS173AFK from Texas Instruments is a military-grade 4-bit D-type register with 3-state outputs, designed for bus-organized systems requiring high noise immunity and direct TTL bus interfacing. It features gated output-control (M/N), independent clock input, asynchronous clear (CLR), and operates across –55°C to 125°C. Its 18 ns typical propagation delay and 50 MHz maximum clock frequency support reliable parallel-load or hold-mode operation in avionics and ruggedized control systems.
For engineers reviewing the SNJ54LS173AFK datasheet, SNJ54LS173AFK pinout, SNJ54LS173AFK application, or SNJ54LS173AFK equivalent, this page delivers verified electrical specs, LCCC-20 package mapping, timing behavior under military temperature extremes, and validated alternatives for legacy system redesign or obsolescence mitigation.
Technical Context
The SNJ54LS173AFK implements four edge-triggered D-type flip-flops with fully independent clocking and dual data-enable inputs (G1, G2) that must both be low for parallel load on the next positive CLK edge. Its 3-state output control uses active-low M and N inputs - either high disables all outputs to high-impedance without affecting internal state or clock sequencing.
Designed for military applications, it meets MIL-PRF-38535 requirements with absolute max ratings up to 7 V supply and –55°C to 125°C operation. Input thresholds (VIH = 2 V, VIL = 0.7 V), output drive (IOL = 12 mA, IOH = –1 mA), and fast disable times (tPHZ/tPLZ ≤ 23 ns) ensure robust interoperability with legacy 54LS/74LS TTL families on shared buses.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | 54LS - Low-power Schottky TTL compatible with 5-V supply and standard LS input/output thresholds |
| Operating Temperature | –55°C to 125°C - Qualified per MIL-PRF-38535 for aerospace, defense, and industrial harsh environments |
| Max Clock Frequency | 50 MHz - Enables high-speed parallel data latching in real-time control and telemetry subsystems |
| Propagation Delay | 18 ns typical (tPLH/tPHL) - Ensures deterministic setup/hold timing margins in synchronous bus architectures |
| Output Drive | IOL = 12 mA / IOH = –1 mA - Sufficient to drive two normalized 54LS/74LS loads directly on a shared bus |
| Supply Current | ICC = 19 mA max - Low static power consumption critical for thermally constrained military modules |
| 3-State Disable Time | tPHZ/tPLZ ≤ 20 ns - Minimizes bus contention risk when multiple registers share a common data path |
Pinout & Package
LCCC-20 (FK) ceramic package: 8.89 mm × 8.89 mm body, 1.27 mm pitch, leadless construction with solderable metallized terminations. Designed for hermetic sealing and high-reliability mounting in military PCB assemblies.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1D–4D | Data Inputs | Asynchronous D inputs for each of four flip-flops; sampled on rising CLK edge when G1=G2=L |
| 1Q–4Q | 3-State Outputs | Registered outputs disabled to high-Z when M=H or N=H; otherwise reflect Q-state of respective flip-flop |
| CLK | Clock Input | Positive-edge-triggered clock; controls data capture timing but does not affect output enable/disable state |
| CLR | Asynchronous Clear | Active-high reset forcing all Q outputs low regardless of clock or enable states |
| G1, G2 | Data Enable | Both must be low to enable parallel loading; high on either blocks data entry into flip-flops |
| M, N | Output Control | Active-low enables; high on either forces all outputs into high-impedance mode independently of CLK or CLR |
| VCC, GND | Power Supply | 5-V nominal supply pins; decoupling required per MIL-STD-1399 for transient suppression |
| NC (pins 3,8,16,19) | No Connect | Internally unconnected; must remain floating or tied to GND per design guidelines to avoid EMI coupling |
Key Features
| Feature | Design Value |
|---|---|
| Fully independent clock | Enables simultaneous parallel-load or hold operation without inter-stage timing restrictions |
| Gated 3-state output control | M/N inputs allow bus arbitration without disrupting internal register state or requiring external logic |
| High-impedance third state | Output leakage ≤ ±20 µA ensures minimal bus loading during disable - supports up to 49 devices on one bus |
| Military temperature qualification | Characterized and tested over –55°C to 125°C per MIL-PRF-38535, including burn-in and parametric screening |
| TTL-compatible interface | Direct connection to Series 54/74 and 54LS/74LS buses without pull-ups, level shifters, or interface buffers |
Applications
| Avionics Data Acquisition | Military Vehicle Control Bus |
|---|---|
Use Scenario: Capturing sensor data from analog-to-digital converters in flight control computers under vibration and thermal cycling. IC Role / Device Role / Timing Role: Parallel-load register synchronizing multi-channel ADC outputs onto a time-critical MIL-STD-1553B or ARINC 429 auxiliary bus. Use Value: 18 ns propagation delay and 50 MHz clock capability ensure sub-microsecond sampling alignment across four channels. |
Use Scenario: Isolating command signals between mission computer and engine control units in armored ground vehicles. IC Role / Device Role / Timing Role: Bidirectional bus buffer managing write-only configuration commands and read-only status responses on a shared 16-bit control bus. Use Value: Independent M/N output control allows dynamic direction switching without clock interruption or state corruption. |
| Ruggedized Test Equipment | Secure Communication Modules |
Use Scenario: Storing calibration coefficients in portable field-test sets exposed to desert and arctic conditions. IC Role / Device Role / Timing Role: Nonvolatile latch holding trim values during power cycling; cleared only on system initialization via CLR. Use Value: –55°C to 125°C operation guarantees retention integrity across extreme ambient shifts without derating. |
Use Scenario: Securing key-handshake sequences in encrypted radio modems operating in electronic warfare environments. IC Role / Device Role / Timing Role: Tamper-resistant register staging cryptographic keys before loading into AES engines; CLR prevents unauthorized replay. Use Value: Asynchronous clear ensures immediate zeroization on security fault detection, meeting NSA Type 1 compliance timing constraints. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 4-bit D-type register with 3-state output applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SNJ54LS174AJ | 6-bit register with common clock and single output-enable; no independent G1/G2 or M/N control | Suitable for wider bus widths but lacks dual-gated data enable and separate output control flexibility | Select when expanding bus width beyond 4 bits and simplified enable logic suffices |
| SNJ54LS373J | Octal transparent latch (not edge-triggered); outputs follow inputs when LE is low, latched when LE high | Better for address/data demultiplexing; unsuitable for synchronous clocked register applications | Choose only for non-clocked data capture where transparency during LE=low is required |
Compared with SNJ54LS173AFK, SNJ54LS174AJ offers greater bit width but reduced control granularity, while SNJ54LS373J provides transparency instead of edge-triggered storage - neither replicates the precise combination of independent clock, dual data-enable, and dual output-control essential for synchronized bus arbitration in legacy military designs.
Availability
SNJ54LS173AFK is available at Aetrix Electronics and suitable for avionics data acquisition, military vehicle control bus, ruggedized test equipment, and secure communication modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SNJ54LS173AFK 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 90 years of analog and logic IC innovation, serving aerospace, defense, industrial, and automotive markets with high-reliability components.
The SNJ54LS173AFK belongs to TI's military 54LS logic family, engineered specifically for ruggedized digital systems demanding guaranteed performance across extreme temperatures, radiation tolerance, and long-term supply stability.
FAQ
What is the operating temperature range of the SNJ54LS173AFK?
The SNJ54LS173AFK is characterized for operation from –55°C to 125°C and qualified per MIL-PRF-38535. This full military temperature range ensures reliable functionality in avionics, ground vehicle, and naval systems exposed to extreme environmental stress without derating. The SNJ54LS173AFK maintains specified timing and drive parameters across this entire span, unlike commercial variants limited to 0°C–70°C.
Does the SNJ54LS173AFK support true bidirectional bus operation?
The SNJ54LS173AFK does not support bidirectional data flow on individual pins - it is a unidirectional register with 4 inputs (1D–4D) and 4 3-state outputs (1Q–4Q). However, its independent M/N output-control inputs enable dynamic bus arbitration: multiple SNJ54LS173AFK devices can share one bus, with only one enabled at a time while others remain in high-impedance, preventing contention.
How does the SNJ54LS173AFK differ from the SN74LS173A?
The SNJ54LS173AFK is the military-specification version of the SN74LS173A, featuring identical logic function and pinout but qualified for –55°C to 125°C operation, screened per MIL-PRF-38535, and packaged in hermetic LCCC (FK) instead of plastic DIP or SOIC. Electrical parameters such as IOL (12 mA vs. 24 mA) and ICC (19 mA vs. 24 mA) reflect tighter military tolerances and lower drive capability optimized for reliability over speed.
Can the SNJ54LS173AFK be used without external pull-up resistors on its outputs?
Yes - the SNJ54LS173AFK's totem-pole 3-state outputs provide active high- and low-level drive (VOH ≥ 2.4 V, VOL ≤ 0.4 V at IOL = 12 mA), eliminating the need for external pull-up resistors when interfacing with standard 54LS/74LS TTL loads. Its high-impedance off-state (IO(off) ≤ ±20 µA) ensures negligible bus leakage, enabling direct connection to shared data paths.
What is the significance of the "FK" suffix in SNJ54LS173AFK?
The "FK" suffix denotes the Leadless Ceramic Chip Carrier (LCCC) package: a 20-pin, 8.89 mm × 8.89 mm hermetic ceramic body with 1.27 mm pitch and solderable metallized terminations. This package provides superior thermal conductivity, moisture resistance, and mechanical stability versus plastic DIP or SOIC, making it mandatory for applications requiring MIL-STD-883 compliance and long-term reliability in harsh environments.
SNJ54LS173AFK Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Function:
- -
- Type:
- -
- Output Type:
- -
- Number of Elements:
- -
- Number of Bits per Element:
- -
- Clock Frequency:
- -
- Max Propagation Delay @ V, Max CL:
- -
- Trigger Type:
- -
- Current - Output High, Low:
- -
- Voltage - Supply:
- -
- Current - Quiescent (Iq):
- -
- Input Capacitance:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
SNJ54LS173AFK FAQ
1.How can I place an order for SNJ54LS173AFK through Aetrix?
Please submit a Request for Quotation (RFQ) for SNJ54LS173AFK on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
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The price and inventory of SNJ54LS173AFK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SNJ54LS173AFK is usually 5 days.
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Once your SNJ54LS173AFK order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SNJ54LS173AFK?
For technical support, including SNJ54LS173AFK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SNJ54LS173AFK requirements.
6.How does Aetrix verify that SNJ54LS173AFK is sourced from the original manufacturer or authorized distributors?
All SNJ54LS173AFK products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SNJ54LS173AFK meets industry standards.
7.What is the process for return or replacement of SNJ54LS173AFK?
All SNJ54LS173AFK units undergo pre-shipment inspection (PSI). If there is an issue with SNJ54LS173AFK, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SNJ54LS173AFK part is unused and in its original packaging.
Return procedure for SNJ54LS173AFK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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