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Texas Instruments SNJ54LS670J
- Part No.:
- SNJ54LS670J
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-CDIP (0.300", 7.62mm)
- Datasheet:
-
SNJ54LS670J.pdf
- Description:
- 4-BY-4 REGISTER FILES WITH 3-STA
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SNJ54LS670J from Texas Instruments is a military-grade 4×4 register file IC with three-state outputs, designed for synchronous data storage and selective bus interfacing in TTL-based control logic systems. It provides 16-bit total storage (four 4-bit words), operates over –55°C to +125°C, supports dual read/write addressing via A0–A1 and B0–B1, and features independent output enable (OE) control for bus isolation.
For engineers reviewing the SNJ54LS670J datasheet, SNJ54LS670J pinout, SNJ54LS670J application, or SNJ54LS670J equivalent, key selection considerations include its CDIP-16 package, military temperature range, TTL-compatible input thresholds, 3-state output drive capability, and discrete address decoding architecture-critical for legacy aerospace, test equipment, and industrial controller designs requiring deterministic timing and radiation-tolerant packaging.
Technical Context
The SNJ54LS670J implements a fully static, dual-port register file using bipolar TTL circuitry, with separate address inputs (A0/A1 for write port, B0/B1 for read port) and independent write enable (WE) and output enable (OE) controls. Its internal structure avoids internal latches or clocks-data is written on WE assertion and read on OE assertion, with no internal synchronization.
It uses standard LS-TTL logic levels and drive strengths: VIH = 2.0 V min, VIL = 0.8 V max, IOH = –0.4 mA at VOH = 2.7 V, IOL = 8 mA at VOL = 0.5 V. Propagation delays are specified as tPLH/tPHL ≤ 35 ns (address-to-data) and ≤ 25 ns (OE-to-output enable), measured under defined load conditions (RL = 2.7 kΩ to VCC, CL = 15 pF).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Storage capacity | 4 words × 4 bits = 16-bit total; enables compact state storage without external memory interface |
| Operating temperature | –55°C to +125°C; qualified for extended-range military applications per MIL-PRF-38535 |
| Supply voltage | VCC = 4.5 V to 5.5 V; compatible with standard TTL power rails and noise margins |
| Addressing scheme | Dual independent 2-bit address buses (A0/A1 for write, B0/B1 for read); allows concurrent write/read of different registers |
| Output type | Three-state TTL outputs with common OE pin; permits direct connection to shared data buses without external bus transceivers |
| Propagation delay | tPD ≤ 35 ns (address-to-Q); ensures predictable timing in synchronous control state machines |
| Input compatibility | LS-TTL input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V); interoperable with 74LS, 74S, and 74F families |
Pinout & Package
SNJ54LS670J is supplied in a 16-pin Ceramic Dual In-line Package (CDIP-J), hermetically sealed with tin-lead (SNPB) leads, rated for military temperature operation and high-reliability environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (A0) | Write address bit 0 | Selects LSB of 2-bit write address; low = 0, high = 1 |
| 2 (A1) | Write address bit 1 | Selects MSB of 2-bit write address; defines one of four write locations |
| 3 (WE) | Write enable | Active-high signal enabling data capture on D0–D3 into selected register |
| 4 (D0) | Data input 0 | LSB of 4-bit parallel data word written when WE = high and address valid |
| 5 (D1) | Data input 1 | Second bit of 4-bit parallel input word |
| 6 (D2) | Data input 2 | Third bit of 4-bit parallel input word |
| 7 (D3) | Data input 3 | MSB of 4-bit parallel input word |
| 8 (GND) | Ground reference | Signal and power return path; must be low-impedance for TTL noise immunity |
| 9 (Q0) | Data output 0 | LSB of 4-bit read word; tri-stated when OE = low |
| 10 (Q1) | Data output 1 | Second bit of read word; driven only when OE = high and B0/B1 select valid register |
| 11 (Q2) | Data output 2 | Third bit of read word; synchronized to OE assertion, not clocked |
| 12 (Q3) | Data output 3 | MSB of read word; enables full 4-bit parallel output on demand |
| 13 (OE) | Output enable | Active-high control for all Q0–Q3 outputs; isolates device from data bus when low |
| 14 (B0) | Read address bit 0 | LSB of 2-bit read address; independent of write address bus |
| 15 (B1) | Read address bit 1 | MSB of 2-bit read address; allows simultaneous read/write to different registers |
| 16 (VCC) | Positive supply | +5 V nominal supply; requires local 0.1 µF ceramic bypass near pin |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent address ports | Separate A0/A1 (write) and B0/B1 (read) allow non-blocking register access-enables pipelined control logic without arbitration |
| True three-state outputs | Q0–Q3 enter high-impedance state within 25 ns of OE deassertion, preventing bus contention in multi-device systems |
| Military temperature qualification | Qualified per MIL-PRF-38535 Class B; suitable for avionics, ground radar, and hardened embedded controllers |
| No internal clock or timing dependency | Operation is level-sensitive and asynchronous-eliminates setup/hold timing constraints on address or data edges |
| LS-TTL compatible I/O | Direct interface with 74LS-series logic without level-shifting; supports fan-out of 20 LS loads |
Applications
| Industrial Control Sequencers | Aerospace Avionics Data Buffers |
|---|---|
|
Use Scenario: Storing intermediate state values in programmable logic controllers managing sequential machine operations (e.g., stepper motor phase sequencing or valve timing). IC Role / Device Role / Timing Role: Register file providing deterministic, non-volatile (during power-on) 4-word scratchpad storage with zero-clock latency access. Use Value: Eliminates need for external RAM or microcontroller-based state management-reduces BOM count and improves real-time determinism. |
Use Scenario: Holding configuration parameters and sensor calibration offsets in airborne inertial measurement units (IMUs) where radiation tolerance and wide temperature operation are mandatory. IC Role / Device Role / Timing Role: Radiation-hardened (ceramic package), temperature-stable register bank used during cold-start initialization before FPGA or processor boot. Use Value: Provides immediate-access parameter storage without reliance on volatile SRAM or EEPROM write cycles-critical for fail-operational startup sequences. |
| Legacy Test Equipment Pattern Generators | Hardened Communication Protocol Controllers |
|
Use Scenario: Generating repeatable digital stimulus patterns in automated test systems for vintage microprocessor validation (e.g., Z80, 6502, or 8080-based boards). IC Role / Device Role / Timing Role: Static pattern register enabling precise, jitter-free waveform generation via parallel output toggling under external sequencer control. Use Value: Delivers sub-35 ns address-to-output timing consistency-essential for reproducing edge-aligned test vectors without microcontroller-induced jitter. |
Use Scenario: Managing command/response buffers in MIL-STD-1553B remote terminal interfaces where deterministic latency and EMI resilience are required. IC Role / Device Role / Timing Role: Isolated register staging area between bus transceiver and control logic-decouples timing domains while maintaining signal integrity. Use Value: Enables clean handoff of 4-bit command opcodes or status codes without metastability risk-supports guaranteed single-cycle transfer under worst-case temperature extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar register file applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SNJ54LS670W | Same functionality and specs, but in 16-pin CFP (ceramic flatpack) package; lower profile, different lead form, identical temperature range | Preferred for surface-mount or space-constrained military PCBs where CDIP socket mounting is impractical | Select SNJ54LS670W when board layout requires gull-wing or flatpack footprint and thermal/mechanical stress profiles differ from through-hole CDIP |
| SN74LS670N | Commercial version (0°C to +70°C), PDIP-16 package, RoHS-compliant NiPdAu finish; identical logic behavior and timing | Suitable for non-military industrial or lab equipment where extended temperature range is unnecessary | Choose SN74LS670N for cost-sensitive, non-radiation-hardened applications with standard ambient operating conditions |
Compared with SNJ54LS670W and SN74LS670N, the SNJ54LS670J offers through-hole CDIP packaging optimized for high-reliability socketed deployment in field-replaceable modules, while retaining full functional equivalence with the W and N variants-making it the preferred choice for maintainable, repairable military subsystems.
Availability
SNJ54LS670J is available at Aetrix Electronics and suitable for aerospace avionics, industrial control sequencers, and legacy test equipment requiring stable component supply across long product lifecycles and obsolescence-sensitive programs.
Supply support for SNJ54LS670J 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 logic solutions for industrial, automotive, and defense markets.
The SNJ54LS670J belongs to TI's military-qualified TTL logic family, engineered for deterministic, clockless register storage in safety-critical and mission-essential systems where predictability and environmental robustness outweigh power efficiency.
FAQ
What is the function of the SNJ54LS670J in a digital system?
The SNJ54LS670J functions as a 4×4 static register file with independent read and write addressing. It stores four 4-bit words and allows simultaneous access to different registers via separate A0/A1 (write) and B0/B1 (read) address lines. Its three-state outputs enable direct connection to shared data buses, making it ideal for state-holding, buffering, and addressable scratchpad roles in TTL-based control logic-without requiring clocks or external memory controllers.
Does the SNJ54LS670J require a clock signal to operate?
No, the SNJ54LS670J is a fully static, asynchronous device with no internal clock. Data is written on assertion of the WE (write enable) signal and read on assertion of the OE (output enable) signal. Address transitions and data validity are level-sensitive-not edge-triggered-so timing depends solely on propagation delays (≤35 ns), not clock frequency. This makes the SNJ54LS670J especially suitable for systems where clock distribution is impractical or where deterministic, jitter-free access is required.
What is the significance of the "J" suffix in SNJ54LS670J?
Within Texas Instruments' military logic nomenclature, the "J" suffix denotes the Ceramic Dual In-line Package (CDIP) variant. The "SNJ" prefix identifies it as a military-specification part (per MIL-PRF-38535), and "54" indicates the extended –55°C to +125°C temperature grade. Thus, SNJ54LS670J specifically refers to the hermetically sealed, through-hole CDIP-16 packaged version of the 4×4 register file, distinct from the CFP ("W"), LCCC ("FK"), or commercial "74" variants.
Can SNJ54LS670J be used interchangeably with SN74LS670N in a design?
Functionally, yes-the SNJ54LS670J and SN74LS670N share identical logic behavior, pinout, and DC/AC electrical specifications. However, they differ in temperature range (–55°C to +125°C vs. 0°C to +70°C), package (CDIP-J vs. PDIP-N), lead finish (SNPB vs. NiPdAu), and qualification (military vs. commercial). Interchange is only safe if the application stays within the SN74LS670N's temperature limits and accepts its RoHS-compliant finish and non-hermetic package-otherwise, SNJ54LS670J remains necessary for full spec compliance.
How does the dual-address architecture of SNJ54LS670J improve system performance?
The SNJ54LS670J's separate A0/A1 (write) and B0/B1 (read) address buses enable true concurrent read and write operations to different registers-e.g., writing new data to register 2 while reading previously stored data from register 0. This eliminates bus arbitration delays and pipeline stalls common in single-port memory, improving throughput in real-time sequencers, pattern generators, and control state machines. Because access is asynchronous and level-triggered, this concurrency adds zero timing overhead beyond standard propagation delays.
SNJ54LS670J Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 54LS
- Package/Case:
- 16-CDIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Register File
- Circuit:
- 1 x 1:1
- Independent Circuits:
- 4
- Current - Output High, Low:
- 1mA, 4mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-CDIP
SNJ54LS670J FAQ
1.How can I place an order for SNJ54LS670J through Aetrix?
Please submit a Request for Quotation (RFQ) for SNJ54LS670J on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SNJ54LS670J reliable?
The price and inventory of SNJ54LS670J are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SNJ54LS670J is usually 5 days.
3.What payment methods are accepted for SNJ54LS670J?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SNJ54LS670J transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SNJ54LS670J?
SNJ54LS670J orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SNJ54LS670J 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 SNJ54LS670J?
For technical support, including SNJ54LS670J datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SNJ54LS670J requirements.
6.How does Aetrix verify that SNJ54LS670J is sourced from the original manufacturer or authorized distributors?
All SNJ54LS670J 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 SNJ54LS670J meets industry standards.
7.What is the process for return or replacement of SNJ54LS670J?
All SNJ54LS670J units undergo pre-shipment inspection (PSI). If there is an issue with SNJ54LS670J, 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 SNJ54LS670J part is unused and in its original packaging.
Return procedure for SNJ54LS670J:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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