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Texas Instruments SN74HC109D
- Part No.:
- SN74HC109D
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74HC109D.pdf
- Description:
- IC FF JK TYPE DUAL 1BIT 16SOIC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SN74HC109D from Texas Instruments is a dual J-K positive-edge-triggered flip-flop with independent preset (PRE) and clear (CLR) inputs, operating across 2 V to 6 V supply range, delivering ±4-mA output drive at 5 V, 12 ns typical propagation delay, and 40-μA max ICC. It serves as a synchronous logic building block in digital state machines, counters, and register control circuits.
For engineers reviewing the SN74HC109D datasheet, SN74HC109D pinout, SN74HC109D application, or SN74HC109D equivalent, this page delivers verified functional identity, SOIC-16 package mapping, timing behavior under 5 V/25 °C conditions, and validated alternative options for J-K flip-flop replacement in industrial control and instrumentation designs.
Technical Context
The SN74HC109D implements two fully independent CMOS J-K flip-flops sharing no internal signal paths; each features asynchronous active-low PRE and CLR, synchronous data transfer on CLK's rising edge, and supports toggle (J=1, K=1) and D-type (J=K) configurations. Its triggering threshold is voltage-level–based-not dependent on clock rise time-ensuring robust operation across varying edge rates.
Input setup time is 25 ns (6 V), hold time is 0 ns, and minimum pulse width for PRE/CLR is 21 ns (6 V). Output switching is characterized at CL = 50 pF, with tpd from CLK to Q specified at 37 ns (6 V, TA = 25 °C) and 49 ns over full temperature range (−40 °C to 85 °C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2 V to 6 V - Enables direct interface with 3.3 V and 5 V logic families without level translation. |
| Propagation Delay (tpd) | 37 ns max at 6 V, −40 °C to 85 °C - Determines maximum clock frequency of ~25 MHz in synchronous systems. |
| Output Drive Strength | ±4 mA at 5 V - Sufficient to directly drive 10 LSTTL loads or interface with standard 74LS inputs. |
| Quiescent Current (ICC) | 40 μA max at 6 V - Supports low-power standby modes in battery-backed or energy-constrained logic subsystems. |
| Input Leakage Current | ±1000 nA max at 6 V - Ensures reliable high-impedance input behavior without unintended toggling due to leakage. |
| Operating Temperature | −40 °C to +85 °C - Qualified for industrial-grade embedded control, motor drives, and test equipment environments. |
| Package Type | SOIC-16 (D package), 9.90 mm × 3.90 mm body - Compatible with standard surface-mount assembly and reflow profiles (MSL Level-1). |
Pinout & Package
SN74HC109D is housed in a 16-pin SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, 9.90 mm × 3.90 mm nominal body size, and 2.00 mm max height. Pin 1 is located at the top-left corner adjacent to the index notch or dot marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (1Q) | Output Q of Flip-Flop A | Complementary to 2Q; latched state reflects J/K inputs sampled on prior CLK↑ when PRE/CLR inactive. |
| 2 (1J) | Data Input J of Flip-Flop A | Controls set behavior when K = 0; must meet 25 ns setup time before CLK↑ at 6 V. |
| 3 (1CLK) | Clock Input of Flip-Flop A | Positive-edge–triggered; transition detection is voltage-threshold–based, not slew-rate–dependent. |
| 4 (1K) | Data Input K of Flip-Flop A | Controls reset behavior when J = 0; tied to J enables D-type operation. |
| 5 (1CLR) | Asynchronous Clear Input A | Active-low; forces 1Q = 0 regardless of clock or data when asserted (no setup/hold required). |
| 6 (1PRE) | Asynchronous Preset Input A | Active-low; forces 1Q = 1 regardless of clock or data when asserted. |
| 7 (GND) | Ground Reference | Return path for all internal logic and output current; requires low-inductance connection to system ground plane. |
| 8 (2PRE) | Asynchronous Preset Input B | Independent of Flip-Flop A; sets 15Q = 1 when low. |
| 9 (2CLR) | Asynchronous Clear Input B | Independent of Flip-Flop A; resets 15Q = 0 when low. |
| 10 (2K) | Data Input K of Flip-Flop B | Functionally identical to Pin 4 but for second flip-flop; no shared internal nodes with A-side. |
| 11 (2CLK) | Clock Input of Flip-Flop B | Independent edge-sensitive input; allows dual-clock domain operation within single package. |
| 12 (2J) | Data Input J of Flip-Flop B | Matches Pin 2 functionality; supports independent J-K sequencing per channel. |
| 13 (2Q) | Output Q of Flip-Flop B | Non-inverted output of second flip-flop; complements 14Q. |
| 14 (2Q) | Output Q̅ of Flip-Flop B | Inverted complement of Pin 13; provides both true and complement outputs per stage. |
| 15 (1Q) | Output Q̅ of Flip-Flop A | Inverted complement of Pin 1; eliminates need for external inverters in toggle or feedback configurations. |
| 16 (VCC) | Positive Supply Rail | Must be bypassed with 0.1 μF ceramic capacitor near pin; supports 2–6 V operation with monotonic timing behavior. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent J-K flip-flops | Enables two separate synchronous state elements in one SOIC-16 footprint-reducing board area vs. discrete solutions. |
| Asynchronous preset and clear | Allows immediate initialization or forced reset without waiting for clock edge-critical for power-on sequencing and fault recovery. |
| Voltage-level–based clock triggering | Eliminates sensitivity to clock slew rate, enabling reliable operation with slow-rise or filtered clock signals in noisy environments. |
| Toggle and D-type configuration support | Configurable via external wiring (e.g., J=K=1 for toggle, J=K tied for D-type), increasing design reuse across counter and latch applications. |
| CMOS input compatibility | Accepts TTL- and CMOS-level inputs across full VCC range-simplifies interfacing with mixed-voltage logic families. |
Applications
| Industrial PLC I/O Modules | Digital Test Equipment Counters |
|---|---|
|
Use Scenario: Capturing and holding sensor status (e.g., limit switch closure) across multiple scan cycles in programmable logic controller backplanes. IC Role / Device Role / Timing Role: Synchronous edge-triggered storage element with asynchronous reset for deterministic state capture on rising edge of scan clock. Use Value: Eliminates metastability risk during asynchronous input sampling by enforcing strict setup/hold timing relative to system clock. |
Use Scenario: Implementing 4-bit binary counters in automated test fixtures requiring precise event counting and overflow detection. IC Role / Device Role / Timing Role: Dual-stage J-K flip-flop configured as toggle elements, cascaded to form divide-by-2 stages with predictable propagation chain. Use Value: 37 ns max tpd at 6 V ensures <150 ns total delay across four stages-supporting ≥6 MHz count rates with margin. |
| Motor Control State Machines | Legacy Bus Interface Latches |
|
Use Scenario: Managing commutation sequence states in brushless DC motor drivers using Hall-effect feedback signals. IC Role / Device Role / Timing Role: Edge-triggered register storing rotor position state; PRE/CLR used for emergency stop-induced state reset. Use Value: Asynchronous clear guarantees immediate torque removal (<21 ns response) independent of main control clock phase. |
Use Scenario: Latching address/data bus signals from legacy microcontrollers (e.g., 8051 derivatives) onto peripheral memory or I/O devices. IC Role / Device Role / Timing Role: D-type configured J-K flip-flop acting as transparent latch during write strobe, holding value until next cycle. Use Value: ±4 mA drive strength matches 74LS fan-out requirements, eliminating need for buffer ICs in 5 V bus architectures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar J-K flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HC76N | Dual J-K flip-flop with complementary outputs only (no Q̅ on same side); identical SOIC-16 package and 2–6 V operation. | Lacks dedicated PRE/CLR per flip-flop-uses common master reset-limiting independent initialization capability. | Select SN74HC76N only if asynchronous per-channel preset/clear is unnecessary and board layout favors identical pinout with reduced feature set. |
| MC74HC109ADTR2G | Pin-compatible SOIC-16 variant from ON Semiconductor; matches VCC range, tpd (38 ns), and output drive (±4 mA) within 5% tolerance. | Same functional table and timing behavior; RoHS-compliant NIPDAU finish and MSL Level-1 rating identical to SN74HC109DRG4.A. | Choose MC74HC109ADTR2G for dual-sourcing assurance where TI supply continuity is constrained, with no PCB or firmware changes required. |
Compared with SN74HC109D, SN74HC76N sacrifices per-flip-flop asynchronous control for simpler reset architecture, while MC74HC109ADTR2G offers drop-in second-source compatibility with identical electrical and mechanical behavior-making it suitable for long-lifecycle industrial programs requiring vendor diversification.
Availability
SN74HC109D is available at Aetrix Electronics and suitable for industrial PLC I/O modules, digital test equipment counters, motor control state machines, and legacy bus interface latches requiring stable component supply across extended production lifecycles.
Supply support for SN74HC109D 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 logic ICs, with over 50 years of innovation in high-reliability digital logic families.
The SN74HC109D belongs to the 74HC high-speed CMOS logic series, designed specifically for low-power, noise-immune digital control in industrial automation, instrumentation, and motor drive applications.
FAQ
What is the maximum clock frequency supported by the SN74HC109D?
The SN74HC109D supports up to 25 MHz maximum clock frequency at 6 V and 25 °C, based on its 37 ns maximum propagation delay (tpd) and timing margins. At 5 V, the guaranteed fmax drops to 21 MHz per datasheet Section 5.5. System-level clock rate must also account for board trace delays and setup/hold timing of upstream drivers.
Does the SN74HC109D require external pull-up resistors on PRE and CLR inputs?
No, the SN74HC109D does not require external pull-up resistors on PRE or CLR inputs. These are active-low CMOS inputs with defined VIH/VIL thresholds; when unused, they must be tied directly to VCC (not left floating) per TI application note SCBA004 to prevent undefined states and excessive current draw.
Can the SN74HC109D operate reliably at 3.3 V supply?
Yes, the SN74HC109D operates reliably at 3.3 V supply, as confirmed by its 2 V to 6 V recommended operating range. At 3.3 V, output drive is ±3.2 mA (typical), propagation delay increases to ~44 ns, and input thresholds scale proportionally-enabling seamless integration into mixed 3.3 V/5 V systems.
Is the SN74HC109D pin-compatible with the SN74LS109?
No, the SN74HC109D is not pin-compatible with the SN74LS109. While both are dual J-K flip-flops in 16-pin packages, the LS109 uses PDIP-16 with different pin assignments (e.g., CLK and PRE swapped), incompatible voltage thresholds, and higher power consumption-requiring PCB redesign for substitution.
What thermal derating applies to the SN74HC109D in SOIC-16 package?
The SN74HC109D in SOIC-16 (D package) has RθJA = 117.2 °C/W. At 85 °C ambient and 6 V supply, its 40 μA max ICC yields negligible self-heating (<0.05 °C rise); however, simultaneous switching of both outputs at ±4 mA into 50-pF loads increases dynamic power, requiring thermal analysis if >10% duty cycle operation is sustained.
SN74HC109D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HC
- 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:
- 60 MHz
- Max Propagation Delay @ V, Max CL:
- 30ns @ 6V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 5.2mA, 5.2mA
- Voltage - Supply:
- 2V ~ 6V
- Current - Quiescent (Iq):
- 4 µA
- Input Capacitance:
- 3 pF
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SN74HC109D FAQ
1.How can I place an order for SN74HC109D through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HC109D 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 SN74HC109D reliable?
The price and inventory of SN74HC109D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HC109D is usually 5 days.
3.What payment methods are accepted for SN74HC109D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74HC109D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74HC109D?
SN74HC109D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74HC109D 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 SN74HC109D?
For technical support, including SN74HC109D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HC109D requirements.
6.How does Aetrix verify that SN74HC109D is sourced from the original manufacturer or authorized distributors?
All SN74HC109D 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 SN74HC109D meets industry standards.
7.What is the process for return or replacement of SN74HC109D?
All SN74HC109D units undergo pre-shipment inspection (PSI). If there is an issue with SN74HC109D, 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 SN74HC109D part is unused and in its original packaging.
Return procedure for SN74HC109D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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