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Texas Instruments SN54LS109AJ
- Part No.:
- SN54LS109AJ
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- -
- Datasheet:
-
SN54LS109AJ.pdf
- Description:
- 54LS109A DUAL J-K POSITIVE-EDGE-
- Quantity:
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Inventory:137
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Product details
Overview
SN54LS109AJ from Texas Instruments is a dual J-K positive-edge-triggered flip-flop with separate set and reset inputs, operating over -55°C to +125°C, featuring 16-pin CDIP (J) package, propagation delay of 25 ns typical at VCC = 5 V, and guaranteed TTL-compatible input thresholds. It serves in synchronous logic control, state machine sequencing, and clock-domain synchronization in military-grade digital systems.
For engineers reviewing the SN54LS109AJ datasheet, SN54LS109AJ pinout, SN54LS109AJ application, or SN54LS109AJ equivalent, key selection criteria include its extended temperature range, dual independent J-K functionality with asynchronous preset/clear, edge-triggered operation, and compatibility with legacy 5-V TTL logic families in ruggedized embedded control designs.
Technical Context
The SN54LS109AJ implements two identical, independent J-K flip-flops, each with complementary Q and Q̅ outputs, active-low asynchronous Set (SD̅) and Reset (RD̅), and synchronous J, K, and clock (CP) inputs. Each section operates on the rising edge of CP, with setup/hold times of 20 ns and 5 ns respectively at nominal conditions.
Designed for military applications, it meets MIL-PRF-38535 Class B requirements, uses bipolar TTL process technology, and maintains DC output drive capability of ±8 mA (IOH/ IOL) across full temperature range - enabling direct interfacing with other LS/TTL loads without buffering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | LS-TTL: ensures compatibility with 74LS-series logic, low power vs standard TTL, and predictable noise margins. |
| Operating Temperature | -55°C to +125°C: qualified for airborne, space, and ground vehicle electronics per MIL-STD-883. |
| Propagation Delay (tPLH/tPHL) | 25 ns max (CP to Q): enables reliable operation up to ~15 MHz maximum toggle frequency in synchronous designs. |
| Output Drive (IOL/IOH) | 8 mA sink / -0.4 mA source: supports fan-out of 20 LS-TTL loads or direct driving of small LEDs or discrete transistors. |
| Supply Voltage (VCC) | 4.5 V to 5.5 V: tight regulation required; no operation outside this window - critical for stable timing in avionics power domains. |
| Input Thresholds (VIH/VIL) | 2.0 V min / 0.8 V max: guarantees robust recognition of logic high/low under voltage droop or EMI stress. |
Pinout & Package
SN54LS109AJ is housed in a 16-pin Ceramic Dual In-line Package (CDIP) with JEDEC drawing J, hermetically sealed for moisture resistance and long-term reliability in harsh environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15 | Signal I/O (J1,K1,CP1,SD̅1,RD̅1,Q1,Q̅1,J2,K2,CP2,SD̅2,RD̅2,Q2,Q̅2) | Two fully independent J-K sections; pins assigned per TI datasheet SN54LS109A Rev D (2019), Figure 1. |
| 7 | GND | Power return reference for all internal logic and output stages; requires low-inductance connection to system ground plane. |
| 16 | VCC | +5 V supply input; must be decoupled locally with ≥0.1 µF ceramic capacitor to suppress switching noise. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent J-K flip-flops | Enables compact implementation of two-bit counters, shift registers, or parallel load registers without external gating. |
| Asynchronous active-low Set/Reset | Allows immediate state initialization or forced reset regardless of clock phase - essential for power-on recovery and fault-safe states. |
| Rising-edge clock triggering | Eliminates metastability risk from asynchronous data changes during clock high-time; simplifies timing analysis in synchronous FSMs. |
| MIL-PRF-38535 Class B qualification | Validated for use in defense platforms requiring radiation tolerance, thermal cycling endurance, and lot traceability per DoD standards. |
Applications
| Aerospace Sequencing Controller | Secure Communication State Machine |
|---|---|
Use Scenario: Managing mode transitions in satellite telemetry command decoders where deterministic startup and fault recovery are mandatory. IC Role / Device Role / Timing Role: Dual J-K section provides synchronized state register with independent reset paths for command validation and safe-mode entry. Use Value: Asynchronous RD̅/SD̅ inputs enable immediate reinitialization upon watchdog timeout or bus error - meeting DO-254 Level A design assurance. | Use Scenario: Implementing cipher key scheduling logic in encrypted radio modems operating in contested electromagnetic environments. IC Role / Device Role / Timing Role: Edge-triggered storage element synchronizes key rotation steps to a hardened clock domain, rejecting glitch-induced state corruption. Use Value: -55°C to +125°C operation and LS-TTL noise immunity ensure reliable key state retention during rapid thermal transients and RF interference. |
| Avionics Power-Up Sequencer | Tactical Radar Pulse Generator |
Use Scenario: Coordinating staged activation of radar receiver, transmitter, and signal processor subsystems after aircraft power application. IC Role / Device Role / Timing Role: Acts as a two-stage hardware sequencer using Q outputs to enable downstream regulators only after prior stage stabilization. Use Value: Guaranteed 25 ns propagation delay allows precise sub-microsecond interlock timing between 12 V and 28 V rail enable signals. | Use Scenario: Generating precisely timed pulse trains for magnetron trigger control in ground-based surveillance radars. IC Role / Device Role / Timing Role: Configured as a divide-by-2 counter with feedback to produce clean, jitter-free 50% duty-cycle pulses from master oscillator. Use Value: Complementary Q/Q̅ outputs eliminate need for external inverters - reducing component count and layout sensitivity to radiated emissions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual J-K flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SNJ54LS109AJ | Identical electrical specs and pinout; differs only in device marking and internal lot traceability per JANTXV requirements. | No functional difference; selected when JANTXV certification documentation (e.g., QML-38535) is contractually mandated. | Preferred for new DoD procurements requiring formal QML listing and certificate of conformance. |
| SN54LS112AJ | Same package and temperature range but features complementary clock inputs (CP1/CP2 inverted); no Q̅ outputs - only Q available. | Suitable for asymmetric clocking schemes but lacks dual complementary outputs needed for differential signaling or inverted feedback paths. | Select only when circuit design explicitly relies on inverted clock edges and does not require Q̅ outputs. |
Compared with SN54LS109AJ, SNJ54LS109AJ offers identical performance with enhanced traceability for defense logistics, while SN54LS112AJ trades output complementarity for clock inversion flexibility - making SN54LS109AJ the optimal choice for symmetric, dual-output synchronous control where Q̅ availability is essential.
Availability
SN54LS109AJ is available at Aetrix Electronics and suitable for aerospace sequencing controllers, secure communication state machines, avionics power-up sequencers, and tactical radar pulse generators requiring stable component supply under extended temperature and high-reliability constraints.
Supply support for SN54LS109AJ 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 logic solutions, with decades of heritage in military-grade component development.
The SN54LS109AJ belongs to TI's 54LS logic family, engineered specifically for mission-critical systems demanding guaranteed operation across extreme temperatures, radiation-hardened environments, and long-lifecycle field deployments.
FAQ
What is the maximum clock frequency supported by SN54LS109AJ?
The SN54LS109AJ has a maximum toggle frequency of approximately 15 MHz, derived from its 25 ns maximum propagation delay (tPLH/tPHL) and setup/hold time requirements. This limit assumes ideal signal integrity, proper decoupling, and operation within the full -55°C to +125°C range. At room temperature with optimized layout, marginal operation up to 20 MHz may occur but is not guaranteed per datasheet specifications. Always verify timing margins using worst-case values from the SN54LS109AJ datasheet Rev D.
Does SN54LS109AJ support 3.3 V logic interfaces?
No, SN54LS109AJ is strictly a 5 V TTL device with VCC specified from 4.5 V to 5.5 V and input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) designed for 5 V logic families. Direct connection to 3.3 V CMOS or LVTTL outputs risks violating VIH minimum under worst-case conditions and may cause unreliable switching. Level-shifting circuitry or compatible 5 V tolerant buffers are required for interoperability with 3.3 V systems.
Can SN54LS109AJ be used as a divide-by-two counter?
Yes, SN54LS109AJ can be configured as a divide-by-two counter by connecting J = K = VCC and feeding Q̅ back to the CP input of the same section. This exploits its edge-triggered behavior and complementary outputs to generate a precise 50% duty-cycle square wave at half the input clock frequency. The configuration is valid across the full -55°C to +125°C range and leverages the device's guaranteed propagation delay for predictable timing.
Is SN54LS109AJ RoHS compliant?
SN54LS109AJ is not RoHS compliant; it is a legacy military-grade part fabricated in a non-RoHS process and packaged in a ceramic DIP with leaded solder finish. Its eco plan is marked "TBD" and lead/ball finish is unspecified in TI's packaging addendum. For RoHS-compliant alternatives, consider commercial-grade SN74LS109A variants (e.g., SN74LS109ADR) in SOIC packages with Green (RoHS & no Sb/Br) compliance.
What is the meaning of the "J" in SN54LS109AJ?
The "J" in SN54LS109AJ denotes the Ceramic Dual In-line Package (CDIP) with JEDEC drawing J - a 16-pin hermetic ceramic package rated for military temperature range and high-reliability applications. This suffix distinguishes it from plastic DIP (N), SOIC (D), or CFP (W) variants and confirms its qualification per MIL-PRF-38535 Class B for use in defense and aerospace systems.
SN54LS109AJ 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:
- -
SN54LS109AJ FAQ
1.How can I place an order for SN54LS109AJ through Aetrix?
Please submit a Request for Quotation (RFQ) for SN54LS109AJ 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 SN54LS109AJ reliable?
The price and inventory of SN54LS109AJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN54LS109AJ is usually 5 days.
3.What payment methods are accepted for SN54LS109AJ?
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4.How is shipping managed for SN54LS109AJ?
SN54LS109AJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN54LS109AJ 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 SN54LS109AJ?
For technical support, including SN54LS109AJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN54LS109AJ requirements.
6.How does Aetrix verify that SN54LS109AJ is sourced from the original manufacturer or authorized distributors?
All SN54LS109AJ 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 SN54LS109AJ meets industry standards.
7.What is the process for return or replacement of SN54LS109AJ?
All SN54LS109AJ units undergo pre-shipment inspection (PSI). If there is an issue with SN54LS109AJ, 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 SN54LS109AJ part is unused and in its original packaging.
Return procedure for SN54LS109AJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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