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Home > Products > Integrated Circuits (ICs) > Logic > Flip Flops

Texas Instruments SN54ALS109AJ

Name: SN54ALS109AJ
Brand: Texas Instruments
SKU: SN54ALS109AJ
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SN54ALS109AJ

Manufacturer:: Texas Instruments

Category:: Flip Flops

Package:: -

Datasheet:: SN54ALS109AJ.pdf

Description:: 54ALS109A DUAL J-K POSITIVE-EDGE

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Product details

Overview

SN54ALS109AJ from Texas Instruments is a dual J-K positive-edge-triggered flip-flop IC designed for synchronous logic control in military-grade digital systems. It operates across −55°C to 125°C, features 30 MHz maximum clock frequency, 6 mW typical power dissipation per flip-flop, and TTL-compatible input/output levels. It is used in critical timing, state-machine, and register applications requiring high-reliability edge-triggered storage.

For engineers reviewing the SN54ALS109AJ datasheet, SN54ALS109AJ pinout, SN54ALS109AJ application, or SN54ALS109AJ equivalent, key selection criteria include military temperature range compliance, J-K toggle/D-type reconfiguration capability, preset/clear asynchronous control, propagation delays under 21 ns, and CDIP (J) package suitability for ruggedized PCB layouts.

Technical Context

The SN54ALS109AJ implements two independent J-K flip-flops with asynchronous active-low preset (PRE) and clear (CLR) inputs that override clocked operation. Each flip-flop triggers on the positive-going edge of CLK, with setup time (tsu) of 15 ns and hold time (th) of 0 ns for J/K inputs relative to CLK↑.

It supports multiple functional modes: toggle (J=H, K=L), set/reset (asynchronous PRE/CLR), and D-type (J=K tied), all within a single 16-pin ceramic dual in-line package (CDIP-J). Its ALS logic family delivers improved speed-power product over standard TTL while maintaining pin compatibility with legacy 74LS/74S families.

Key Specifications

Parameter	Value and Actual Design Meaning
Logic Family	Advanced Low-Power Schottky (ALS), ensuring 6 mW/flop at 5 V and compatibility with TTL voltage thresholds.
Clock Frequency	30 MHz max - enables reliable operation in high-speed synchronous counters and control sequencers.
Propagation Delay	tPLH/tPHL ≤ 21 ns - guarantees tight timing margins for state transitions in real-time logic circuits.
Supply Voltage	4.5 V to 5.5 V - supports stable operation across military-grade power rail tolerances.
Operating Temperature	−55°C to 125°C - validated for deployment in aerospace, defense, and downhole electronics environments.
Output Drive	IOL = 4 mA / IOH = −0.4 mA - sufficient to drive standard TTL loads without external buffering.
Input Thresholds	VIL = 0.8 V, VIH = 2.0 V - ensures noise immunity and robust interfacing with other TTL/ALS devices.

Pinout & Package

Ceramic Dual In-Line Package (CDIP), 16-pin, 300-mil body, hermetically sealed for military reliability and moisture resistance.

Pin/Terminal	Circuit Role	Design Meaning
1	1CLR	Asynchronous active-low clear for first flip-flop; forces Q = L, Q̅ = H regardless of clock or data.
2	1J	Data input J for first flip-flop; controls set behavior when CLK↑ occurs and PRE/CLR inactive.
3	1K	Data input K for first flip-flop; controls reset behavior on CLK↑; J=K=H enables toggle mode.
4	1CLK	Positive-edge-triggered clock input for first flip-flop; edge-sensitive, not rise-time dependent.
5	1PRE	Asynchronous active-low preset for first flip-flop; forces Q = H, Q̅ = L independently of clock.
6	1Q	True output of first flip-flop; reflects stored state after CLK↑ and satisfies setup/hold timing.
7	1Q̅	Complementary output of first flip-flop; provides inverted logic for differential signaling or feedback.
8	GND	Ground reference for all internal circuitry and I/O; must be low-impedance for noise immunity.
9	VCC	+5 V supply pin; requires local 0.1 µF bypass capacitor to suppress switching transients.
10	2Q̅	Complementary output of second flip-flop; electrically isolated but shares same VCC/GND rails.
11	2PRE	Asynchronous active-low preset for second flip-flop; independent control from first section.
12	2CLK	Positive-edge-triggered clock input for second flip-flop; may be driven from same or separate source.
13	2K	Data input K for second flip-flop; identical function and timing to 1K.
14	2J	Data input J for second flip-flop; identical function and timing to 1J.
15	2CLR	Asynchronous active-low clear for second flip-flop; independent of first section's CLR.
16	2Q	True output of second flip-flop; fully functional duplicate of 1Q with independent control inputs.

Key Features

Feature	Design Value
Dual independent J-K flip-flops	Enables compact implementation of 2-bit registers, counters, or state elements without external gating.
Asynchronous PRE/CLR	Allows immediate initialization or reset of each flip-flop without waiting for clock edge-critical for fault recovery.
Reconfigurable as D-type	J and K inputs tied together provide D-latch functionality, simplifying migration from D-flip-flop designs.
TTL-compatible interface	Accepts standard TTL input voltages and drives TTL loads directly, eliminating level-shifting components.
Military temperature qualification	Characterized and screened per MIL-PRF-38535 for −55°C to 125°C operation-no derating required.

Applications

Avionics Flight Control Logic	Secure Communications Synchronization
Use Scenario: Storing and sequencing command states in triple-modular redundant (TMR) flight control units where deterministic timing and fail-safe reset are mandatory. IC Role / Device Role / Timing Role: SN54ALS109AJ serves as edge-triggered state register enabling synchronized sampling of sensor inputs and actuator commands. Use Value: Asynchronous PRE/CLR allows immediate state reset during fault detection, while 30 MHz clock tolerance supports real-time loop rates up to 15 MHz.	Use Scenario: Generating and aligning frame-synchronized enable signals in encrypted radio modems operating in harsh electromagnetic environments. IC Role / Device Role / Timing Role: SN54ALS109AJ acts as a programmable divider and phase-aligner for baseband clock domains using J-K toggle configuration. Use Value: Propagation delay ≤21 ns ensures sub-33 ns jitter accumulation across cascaded stages, meeting MIL-STD-188-110B timing budgets.
Nuclear Instrumentation Data Acquisition	Missile Guidance System Sequencing
Use Scenario: Capturing radiation pulse events with precise timestamping in neutron detection arrays deployed in reactor containment zones. IC Role / Device Role / Timing Role: SN54ALS109AJ functions as a metastability-hardened input synchronizer, latching fast pulses into slower system clocks. Use Value: −55°C to 125°C rating permits direct mounting near detectors; 0 ns hold time simplifies timing closure in multi-clock-domain interfaces.	Use Scenario: Managing stage ignition sequence logic in solid-propellant missile guidance computers where environmental survivability is non-negotiable. IC Role / Device Role / Timing Role: SN54ALS109AJ implements hardened finite-state machine registers controlling pyro-initiator firing order and interlock verification. Use Value: Ceramic DIP (J) package resists thermal shock and vibration; asynchronous clear enables emergency abort without clock dependency.

Avionics Flight Control Logic

Secure Communications Synchronization

Use Scenario: Storing and sequencing command states in triple-modular redundant (TMR) flight control units where deterministic timing and fail-safe reset are mandatory.

IC Role / Device Role / Timing Role: SN54ALS109AJ serves as edge-triggered state register enabling synchronized sampling of sensor inputs and actuator commands.

Use Value: Asynchronous PRE/CLR allows immediate state reset during fault detection, while 30 MHz clock tolerance supports real-time loop rates up to 15 MHz.

Use Scenario: Generating and aligning frame-synchronized enable signals in encrypted radio modems operating in harsh electromagnetic environments.

IC Role / Device Role / Timing Role: SN54ALS109AJ acts as a programmable divider and phase-aligner for baseband clock domains using J-K toggle configuration.

Use Value: Propagation delay ≤21 ns ensures sub-33 ns jitter accumulation across cascaded stages, meeting MIL-STD-188-110B timing budgets.

Nuclear Instrumentation Data Acquisition

Missile Guidance System Sequencing

Use Scenario: Capturing radiation pulse events with precise timestamping in neutron detection arrays deployed in reactor containment zones.

IC Role / Device Role / Timing Role: SN54ALS109AJ functions as a metastability-hardened input synchronizer, latching fast pulses into slower system clocks.

Use Value: −55°C to 125°C rating permits direct mounting near detectors; 0 ns hold time simplifies timing closure in multi-clock-domain interfaces.

Use Scenario: Managing stage ignition sequence logic in solid-propellant missile guidance computers where environmental survivability is non-negotiable.

IC Role / Device Role / Timing Role: SN54ALS109AJ implements hardened finite-state machine registers controlling pyro-initiator firing order and interlock verification.

Use Value: Ceramic DIP (J) package resists thermal shock and vibration; asynchronous clear enables emergency abort without clock dependency.

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
SNJ54ALS109AJ	Identical electrical specs and pinout; differs only in TI's internal part numbering convention and screening documentation.	No functional difference; both meet MIL-PRF-38535 Class B requirements for military use.	Select SNJ54ALS109AJ if procurement documentation requires TI's "SNJ" prefix per DoD standards.
JM38510/37102BEA	Same CDIP-J package, −55°C to 125°C rating, and J-K functionality; manufactured under QML Class V process flow.	Qualified to MIL-PRF-38535 Class V (higher reliability screening); preferred for space-grade or life-critical subsystems.	Choose JM38510/37102BEA when mission assurance level exceeds Class B, such as satellite attitude control or nuclear safety systems.

Compared with SN54ALS109AJ, SNJ54ALS109AJ offers identical performance with alternate documentation traceability, while JM38510/37102BEA adds QML Class V screening for extended reliability-neither is pin-compatible with AS-series variants due to differing AC characteristics and drive strength.

Availability

SN54ALS109AJ is available at Aetrix Electronics and suitable for avionics, secure communications, nuclear instrumentation, and missile guidance systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN54ALS109AJ 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 over 50 years of aerospace and defense component heritage.

The SN54ALS109AJ belongs to TI's military-grade ALS logic family, engineered for high-speed, low-power synchronous digital control in mission-critical systems where temperature resilience and timing predictability are essential.

FAQ

What is the maximum clock frequency supported by the SN54ALS109AJ?

The SN54ALS109AJ supports a maximum clock frequency of 30 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = −55°C to 125°C, CL = 50 pF). This value is verified across the full military temperature range and reflects guaranteed timing performance-not a typical or characterization-only figure.

Does the SN54ALS109AJ support asynchronous preset and clear functions?

Yes, the SN54ALS109AJ provides dedicated active-low asynchronous inputs: 1PRE/1CLR for the first flip-flop and 2PRE/2CLR for the second. These override clocked operation entirely, forcing Q and Q̅ to defined states regardless of J, K, or CLK levels-enabling immediate initialization or fault recovery.

What package type is used for the SN54ALS109AJ?

The SN54ALS109AJ is supplied in a 16-pin ceramic dual in-line package (CDIP), designated as the J package per TI's ordering nomenclature. It features a 300-mil body width, hermetic sealing, and lead finish compatible with military soldering processes.

Can the SN54ALS109AJ be configured as a D-type flip-flop?

Yes, the SN54ALS109AJ can operate as a D-type flip-flop by connecting the J and K inputs of each section together. When J = K, the device transfers the J/K logic level to Q on the next positive clock edge-providing transparent D-latch behavior without external gates or redesign.

Is the SN54ALS109AJ compatible with standard TTL logic levels?

Yes, the SN54ALS109AJ is fully TTL-compatible: its input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and output drive capability (IOL = 4 mA, IOH = −0.4 mA) meet standard TTL specifications, allowing direct interfacing with 74LS, 74S, and other TTL-family devices without level shifters.

SN54ALS109AJ 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:: -

SN54ALS109AJ FAQ

1.How can I place an order for SN54ALS109AJ through Aetrix?

Please submit a Request for Quotation (RFQ) for SN54ALS109AJ 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 SN54ALS109AJ reliable?

The price and inventory of SN54ALS109AJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN54ALS109AJ is usually 5 days.

3.What payment methods are accepted for SN54ALS109AJ?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN54ALS109AJ transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SN54ALS109AJ?

SN54ALS109AJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SN54ALS109AJ 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 SN54ALS109AJ?

For technical support, including SN54ALS109AJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN54ALS109AJ requirements.

6.How does Aetrix verify that SN54ALS109AJ is sourced from the original manufacturer or authorized distributors?

All SN54ALS109AJ 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 SN54ALS109AJ meets industry standards.

7.What is the process for return or replacement of SN54ALS109AJ?

All SN54ALS109AJ units undergo pre-shipment inspection (PSI). If there is an issue with SN54ALS109AJ, 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 SN54ALS109AJ part is unused and in its original packaging.

Return procedure for SN54ALS109AJ:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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