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Texas Instruments SN74F109D
- Part No.:
- SN74F109D
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74F109D.pdf
- Description:
- IC FF JK TYPE DUAL 1BIT 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:629
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Product details
Overview
SN74F109D from Texas Instruments is a dual J-K positive-edge-triggered flip-flop with independent clear (CLR) and preset (PRE) inputs, operating over 0°C to 70°C. It features 16-pin SOIC packaging, 70 MHz maximum clock frequency, 3 ns setup time, 1 ns hold time, and TTL-compatible input/output levels (VOH ≥ 2.5 V, VOL ≤ 0.5 V at IOL = 20 mA). It is used in synchronous logic control, state machine design, and digital counter circuits.
For engineers reviewing the SN74F109D datasheet, SN74F109D pinout, SN74F109D application, or SN74F109D equivalent, key selection considerations include its edge-triggered J-K functionality, dual independent flip-flop architecture, TTL-level interface compatibility, and SOIC-16 thermal and layout constraints for industrial control and legacy digital systems.
Technical Context
The SN74F109D implements two fully independent J-K flip-flops sharing no internal resources-each with dedicated J, K, CLK, PRE, CLR, Q, and Q̅ terminals. Clock triggering responds to voltage threshold crossing-not edge rate-enabling robust operation across varying slew rates.
Its asynchronous PRE/CLR inputs override clocked behavior with priority, forcing Q to high or low regardless of J/K states. When both PRE and CLR are high, data transfers on the positive clock edge only if setup (3 ns) and hold (1 ns) timing requirements are met-ensuring deterministic metastability avoidance in synchronous designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | F-series TTL - ensures compatibility with legacy 5 V TTL systems and predictable noise margins |
| Max Clock Frequency | 70 MHz - supports high-speed sequential logic in control registers and pipeline stages |
| Propagation Delay | tPLH/tPHL ≤ 8 ns - enables tight timing closure in multi-stage synchronous circuits |
| Supply Voltage Range | 4.5 V to 5.5 V - requires stable 5 V rail; not tolerant of undervoltage or overvoltage operation |
| Input Thresholds | VIH = 2.0 V min, VIL = 0.8 V max - defines unambiguous logic-high/low recognition under TTL signaling |
| Output Drive | IOL = 20 mA, IOH = –1 mA - sufficient to drive multiple standard TTL loads (fan-out ≥ 10) |
| Operating Temperature | 0°C to 70°C - qualified for commercial-grade applications, not extended or industrial temperature ranges |
Pinout & Package
SN74F109D uses a 16-pin SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, 10.3 mm body width, and RoHS-compliant NiPdAu lead finish. MSL Level-1 rating allows unlimited floor life and reflow up to 260°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | 1CLR | Asynchronous active-low reset for first flip-flop; forces Q1 = 0, Q̅1 = 1 independently of clock |
| 2 | 1J | Data input controlling toggle/set behavior of first flip-flop on next clock edge |
| 3 | 1K | Data input controlling toggle/reset behavior of first flip-flop on next clock edge |
| 4 | 1CLK | Positive-edge-triggered clock input for first flip-flop; transitions >2.0 V recognized as valid edge |
| 5 | 1PRE | Asynchronous active-low preset for first flip-flop; forces Q1 = 1, Q̅1 = 0 independently of clock |
| 6 | 1Q | True output of first flip-flop; reflects stored state after clock edge or async assertion |
| 7 | 1Q̅ | Inverted output of first flip-flop; complementary to 1Q, useful for feedback or differential routing |
| 8 | GND | Power ground reference for all internal circuitry and I/O buffers |
| 9 | VCC | +5 V supply input; must be decoupled locally to suppress switching noise |
| 10 | 2CLR | Asynchronous active-low reset for second flip-flop; independent of first section |
| 11 | 2J | Data input for second flip-flop; enables independent J-K control per channel |
| 12 | 2K | Data input for second flip-flop; supports toggle, set, reset, or hold functions |
| 13 | 2CLK | Positive-edge-triggered clock for second flip-flop; electrically isolated from 1CLK |
| 14 | 2PRE | Asynchronous active-low preset for second flip-flop; no interaction with first section |
| 15 | 2Q | True output of second flip-flop; usable for cascaded counters or parallel register banks |
| 16 | 2Q̅ | Inverted output of second flip-flop; provides complementary signal without external inversion |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent J-K flip-flops | Enables two separate synchronous storage elements in one IC-reducing board space vs discrete solutions |
| Asynchronous preset and clear | Allows immediate initialization or forced state without waiting for clock edge-critical for power-up sequencing |
| TTL-compatible input thresholds | Guarantees interoperability with legacy 74LS/74F logic families without level-shifting components |
| Positive-edge clock triggering | Eliminates ambiguity from slow-rising clocks; triggers on voltage threshold, not slope-improving noise immunity |
| Configurable as D-type or toggle | J=K ties enable D-latch emulation; J=1/K=0 or J=0/K=1 enable set/reset modes-increasing functional flexibility |
Applications
| Counter Design | State Machine Control |
|---|---|
Use Scenario: Building binary or modulo-N counters using cascaded J-K outputs and feedback logic. IC Role / Device Role / Timing Role: Each SN74F109D flip-flop serves as a stage in a synchronous counter chain, with J/K tied for toggle mode and clocked by system timing. Use Value: Enables precise, glitch-free counting up to 70 MHz with deterministic propagation delay and no race conditions between stages. | Use Scenario: Implementing Moore or Mealy finite-state machines in industrial PLCs or protocol controllers. IC Role / Device Role / Timing Role: SN74F109D stores current state bits; PRE/CLR initializes known state on power-up or error recovery. Use Value: Asynchronous reset/preset ensures reliable state entry before clocking begins-eliminating undefined startup behavior. |
| Register File Interface | Legacy System Glue Logic |
Use Scenario: Constructing small-scale register files (e.g., 4-bit × 2-word) in microcontroller peripheral interfaces. IC Role / Device Role / Timing Role: SN74F109D acts as edge-triggered data latch for write-enable-controlled storage of bus data. Use Value: Setup/hold times (3 ns/1 ns) allow safe capture of fast 5 V bus signals without external timing constraints. | Use Scenario: Replacing obsolete 74LS109 or 74S109 in repair or backward-compatible upgrades of vintage test equipment. IC Role / Device Role / Timing Role: Drop-in functional replacement for J-K flip-flop functions in existing schematics using SOIC footprint. Use Value: Pin-compatible with SN74F109N (PDIP), enabling direct PCB substitution when SOIC mounting is acceptable. |
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 |
|---|---|---|---|
| SN74F109N | Same electrical specs and logic function; differs only in 16-pin PDIP (through-hole) packaging | Suitable for prototyping, through-hole assembly, or legacy board rework where SOIC is not feasible | Select SN74F109N for hand-soldered development or socket-based testing; SN74F109D for surface-mount production |
| SN74LS109N | Lower speed (40 MHz max), higher propagation delay (25 ns), reduced drive strength (IOL = 8 mA), same pinout | Acceptable in lower-frequency systems where power efficiency or legacy LS compatibility is prioritized over speed | Choose SN74LS109N only if system clock <40 MHz and fan-out ≤ 4; otherwise SN74F109D delivers superior timing margin |
Compared with SN74F109N and SN74LS109N, the SN74F109D offers optimal balance of speed (70 MHz), drive capability (20 mA), and modern SOIC packaging-making it the preferred choice for new 5 V TTL designs requiring reliable edge-triggered storage without layout redesign.
Availability
SN74F109D is available at Aetrix Electronics and suitable for industrial control panels, legacy instrumentation upgrades, and 5 V TTL-based communication interface modules requiring stable component supply and long-term sourcing continuity.
Supply support for SN74F109D 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 logic solutions for industrial, automotive, and communications markets.
The SN74F109D belongs to TI's 74F logic family-designed specifically for high-speed, low-power 5 V TTL applications where performance and compatibility with legacy systems are critical.
FAQ
What is the maximum clock frequency supported by the SN74F109D?
The SN74F109D supports a maximum clock frequency of 70 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C). This value is verified per the official Texas Instruments SDFS047A datasheet, with timing measured at CL = 50 pF and RL = 500 Ω. Exceeding this frequency risks setup/hold violations and metastability in the SN74F109D flip-flop outputs.
Does the SN74F109D support asynchronous reset and preset functions?
Yes, the SN74F109D provides fully asynchronous active-low clear (CLR) and preset (PRE) inputs for each of its two independent J-K flip-flops. When asserted low, these inputs force the corresponding Q output high (PRE) or low (CLR) immediately-regardless of clock state or J/K values. This behavior is confirmed in the function table and timing diagrams of the SN74F109D datasheet.
Is the SN74F109D pin-compatible with the SN74LS109N?
Yes, the SN74F109D is pin-compatible with the SN74LS109N in the 16-pin SOIC (D) and PDIP (N) packages respectively-both follow identical pin numbering and terminal assignments per TI's logic symbol and top-view diagrams. However, SN74F109D offers higher speed (70 MHz vs 40 MHz) and stronger output drive (20 mA vs 8 mA), so electrical validation is required in high-speed designs.
What are the absolute maximum ratings for the SN74F109D supply voltage?
The absolute maximum supply voltage (VCC) for the SN74F109D is –0.5 V to +7.0 V, as specified in the "Absolute Maximum Ratings" section of the TI SDFS047A datasheet. Operation outside the recommended range of 4.5 V to 5.5 V may cause permanent damage or unpredictable behavior. The SN74F109D is not rated for 3.3 V operation and requires a regulated 5 V source.
Can the SN74F109D be used as a D-type flip-flop?
Yes, the SN74F109D can be configured as a D-type flip-flop by connecting the J and K inputs of each section together-using the combined node as the D input. When J = K = D, the flip-flop transfers D to Q on the next positive clock edge. This functional equivalence is explicitly documented in the SN74F109D datasheet description and confirmed by its truth table behavior.
SN74F109D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74F
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Function:
- Set(Preset) and Reset
- Type:
- JK Type
- Output Type:
- Complementary
- Number of Elements:
- 2
- Number of Bits per Element:
- 1
- Clock Frequency:
- 150 MHz
- Max Propagation Delay @ V, Max CL:
- 8ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 1mA, 20mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 17 mA
- Input Capacitance:
- -
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SN74F109D FAQ
1.How can I place an order for SN74F109D through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74F109D 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 SN74F109D reliable?
The price and inventory of SN74F109D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74F109D is usually 5 days.
3.What payment methods are accepted for SN74F109D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74F109D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74F109D?
SN74F109D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74F109D 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 SN74F109D?
For technical support, including SN74F109D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74F109D requirements.
6.How does Aetrix verify that SN74F109D is sourced from the original manufacturer or authorized distributors?
All SN74F109D 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 SN74F109D meets industry standards.
7.What is the process for return or replacement of SN74F109D?
All SN74F109D units undergo pre-shipment inspection (PSI). If there is an issue with SN74F109D, 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 SN74F109D part is unused and in its original packaging.
Return procedure for SN74F109D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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