SN74LS109ADRG4 Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
SN74LS109ADRG4 is a dual positive-edge-triggered J-K flip-flop from Texas Instruments in the LS logic family, featuring an inverted K input (J-Kbar configuration), 16-pin SOIC package, and up to 25 MHz toggle frequency for use in counters, registers, and clocked sequential logic circuits.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 16
- Lifecycle
- OBSOLETE
- Datasheet
- SN74LS109ADRG4 Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Dual J-Kbar flip-flop with positive edge-triggered clocking
- Maximum toggle frequency of 25 MHz for sequential logic applications
- Inverted K input (active-low Kbar) for direct J-K flip-flop implementations
- LS family logic with 8 mA output sink current per output
- 16-pin SOIC package compatible with standard small-outline footprints
- RoHS-compliant (JESD-609 e4) and Pb-free
Applications
SN74LS109ADRG4 is used in synchronous counter chains, shift registers, and state-machine implementations in digital logic designs operating up to 25 MHz. The dual flip-flop configuration allows two independent storage elements in a single 16-pin SOIC package, reducing component count in clock dividers, binary counters, and toggle-mode latch circuits. It is also found in legacy industrial logic boards, FPGA emulation prototypes, and educational digital design lab kits requiring standard LS-family sequential logic.
Specifications
| Pbfree Code | Yes |
| YTEOL | 0 |
| Additional Feature | INVERTED K INPUT |
| Family | LS |
| JESD-30 Code | R-PDSO-G16 |
| JESD-609 Code | e4 |
| Logic IC Type | J-KBAR FLIP-FLOP |
| Max Frequency@Nom-Sup | 25000000Hz |
| Max I(ol) | 0.008A |
| Number of Bits | 2 |
| Number of Functions | 2 |
| Output Polarity | COMPLEMENTARY |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP16,.25 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Packing Method | TR |
| Peak Reflow Temperature (Cel) | 260 |
| Power Supply Current-Max (ICC) | 8mA |
| Prop. Delay@Nom-Sup | 40ns |
| Propagation Delay (tpd) | 40ns |
| Qualification Status | Not Qualified |
| Supply Voltage-Max (Vsup) | 5.25V |
| Supply Voltage-Min (Vsup) | 4.75V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | YES |
| Technology | TTL |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | NICKEL PALLADIUM GOLD |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Trigger Type | POSITIVE EDGE |
| fmax-Min | 25MHz |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| HTS Code | 8542.39.00.60 |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN74LS109ADRG4:
J-Kbar Flip-Flop, LS Series, 2-Func, Positive Edge Triggered, 2-Bit, Complementary Output, TTL, PDSO16
J-Kbar Flip-Flop, LS Series, 2-Func, Positive Edge Triggered, 2-Bit, Complementary Output, TTL, PDSO16
Frequently Asked Questions
At what maximum frequency can SN74LS109ADRG4 operate as a toggle flip-flop?
SN74LS109ADRG4 supports a maximum clock frequency of 25 MHz in toggle mode, making it suitable for counter and divider circuits in systems where the clock domain does not exceed this limit. For applications requiring higher speeds, AHCT or ACT family flip-flops operating above 100 MHz would be a better choice.
How does the inverted K input (Kbar) in SN74LS109ADRG4 affect flip-flop operation compared to a standard JK device?
The Kbar (active-low K) input in SN74LS109ADRG4 means that asserting K low is equivalent to asserting K high on a standard JK flip-flop. When both J is high and Kbar is low (equivalent to K high), the output toggles on the rising clock edge. This inversion simplifies interfacing with active-low control signals from bus logic without requiring an external inverter gate.
How many independent flip-flop elements does SN74LS109ADRG4 provide, and how does that help in counter designs?
SN74LS109ADRG4 contains 2 independent positive-edge-triggered J-Kbar flip-flops in a single 16-pin SOIC package. In a 2-bit binary counter, both flip-flops are used from one IC, halving the IC count compared to single flip-flop packages. Cascading additional SN74LS109ADRG4 devices extends the counter to 4, 6, or more bits while keeping board area compact.
Is SN74LS109ADRG4 appropriate for new designs, or is it mainly a replacement part for legacy boards?
SN74LS109ADRG4 is most commonly specified as a drop-in replacement for legacy LS-family logic on maintenance and repair boards, since its 25 MHz speed limit and 8 mA sink current per output are modest by modern standards. New designs typically prefer faster, lower-power logic families like 74LVC or 74AHC, but for exact pin-compatible substitution in 16-pin SOIC through-hole or surface-mount legacy applications, this device remains widely available.
Related Guides
1206 100 uF MLCC Design Guide for Compact Bulk Decoupling
Design guidance for applying CL31A107MQHNNNE and related 1206 MLCCs in compact bulk decoupling networks.
Jul 3, 2026
0402 10 nF MLCC Design Guide for High-Speed Decoupling
Practical design guidance for using CL05B103KB5NNNC and related 0402 MLCCs in high-speed decoupling networks.
Jul 3, 2026
CL31A107MQHNNNE 1206 100 uF MLCC Selection Guide
How to choose CL31A107MQHNNNE and related 1206 MLCCs for low-voltage bulk capacitance and regulator stability.
Jul 2, 2026
CL05B103KB5NNNC 0402 10 nF X7R MLCC Selection Guide
How to choose CL05B103KB5NNNC and related 0402 MLCCs for bypassing, filtering, voltage derating, and sourcing.
Jul 2, 2026
Why Buy from FindMyChip
About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“Their engineering team helped us find a pin-compatible alternative when our original MCU went EOL.”