My Inquiry
My Account
Texas Instruments SNJ54AS109FK
- Part No.:
- SNJ54AS109FK
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- -
- Datasheet:
-
SNJ54AS109FK.pdf
- Description:
- J-K FLIP-FLOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,672
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SNJ54AS109FK from Texas Instruments is a dual J-K positive-edge-triggered flip-flop with independent clear and preset inputs, designed for synchronous logic control in military-grade systems. It operates over –55°C to 125°C, supports 90 MHz clock frequency, delivers 20 mA low-level output drive, and consumes 17 mA typical ICC at 5.5 V. It is used in radar timing sequencers, avionics data latches, and hardened digital state machines.
For engineers reviewing the SNJ54AS109FK datasheet, SNJ54AS109FK pinout, SNJ54AS109FK application, or SNJ54AS109FK equivalent, this page provides verified functional specifications, military-temperature-rated timing behavior, ceramic FK-package terminal mapping, and direct alternatives for legacy TTL-based control logic upgrades.
Technical Context
This device implements two independent edge-triggered storage elements with asynchronous active-low preset and clear. Clock triggering occurs at a defined voltage threshold-not dependent on edge slew rate-ensuring robust operation under noisy supply or signal conditions common in aerospace platforms.
Each flip-flop supports toggle mode (J=1, K=1), D-type mode (J=K tied), and transparent latch disable via PRE/CLR override. Propagation delays are specified down to 2.5 ns (tPLH CLK→Q) and 3.5 ns (tPHL CLK→Q) under 50 pF load, enabling precise setup/hold timing in high-speed synchronous designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Clock Frequency | 90 MHz max - enables sub-11 ns cycle time in real-time control loops |
| Operating Temperature | –55°C to 125°C - qualified for airborne, missile, and space-qualified electronics |
| Output Drive | 20 mA sink per Q/Q̅ - sufficient to directly drive multiple 74AS inputs or discrete logic loads |
| Propagation Delay | 2.5 ns tPLH (CLK→Q) - supports tight timing budgets in pipeline registers |
| Supply Voltage | 4.5 V to 5.5 V - compatible with regulated 5 V military power buses |
| Input Thresholds | VIL = 0.8 V, VIH = 2.0 V - ensures noise margin >400 mV with standard TTL/AS logic families |
| Power Dissipation | 17 mA ICC typical - allows thermal design for dense logic arrays without forced cooling |
Pinout & Package
Ceramic Flatpack (FK) package: 20-pin, hermetically sealed, leadless ceramic carrier with solderable metallized terminations. Designed for high-reliability board assembly and extended thermal cycling life.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | 1CLR | Asynchronous active-low clear for Flip-Flop 1 - forces Q1=0, Q̅1=1 regardless of clock or J/K |
| 2 | 1J | Data input J for Flip-Flop 1 - controls set behavior on next positive clock edge when PRE/CLR inactive |
| 3 | 1K | Data input K for Flip-Flop 1 - controls reset behavior on next positive clock edge when PRE/CLR inactive |
| 4 | 1CLK | Positive-edge-triggered clock for Flip-Flop 1 - transition from low to high ≥2.0 V initiates sampling |
| 5 | 1PRE | Asynchronous active-low preset for Flip-Flop 1 - forces Q1=1, Q̅1=0 regardless of clock or J/K |
| 6 | 1Q | True output of Flip-Flop 1 - reflects stored state after clock edge or PRE/CLR assertion |
| 7 | 1Q̅ | Inverted output of Flip-Flop 1 - complementary to 1Q, usable as feedback or enable signal |
| 8 | GND | Ground reference - must be low-inductance connection to minimize switching noise coupling |
| 9 | VCC | +5 V supply - bypassing with 0.1 µF ceramic capacitor near pin is mandatory for stable operation |
| 10 | 2CLR | Asynchronous active-low clear for Flip-Flop 2 - independent control, no cross-talk with FF1 |
| 11 | 2J | Data input J for Flip-Flop 2 - fully isolated from FF1; supports dual-channel state tracking |
| 12 | 2K | Data input K for Flip-Flop 2 - enables independent toggle, latch, or D-mode operation per channel |
| 13 | 2CLK | Positive-edge-triggered clock for Flip-Flop 2 - may be driven from same or separate clock source vs FF1 |
| 14 | 2PRE | Asynchronous active-low preset for Flip-Flop 2 - non-interfering with FF1 preset/clear functions |
| 15 | 2Q | True output of Flip-Flop 2 - electrically isolated; suitable for differential signaling or parallel bus use |
| 16 | 2Q̅ | Inverted output of Flip-Flop 2 - provides complementary logic level without external inverter |
| 17–20 | NC | No internal connection - must remain unconnected; not to be tied to VCC, GND, or signals |
Key Features
| Feature | Design Value |
|---|---|
| Positive-edge clock trigger | Voltage-threshold detection ensures reliable sampling independent of clock rise time - critical in EMI-prone environments |
| Asynchronous PRE/CLR | Active-low, priority-over-clock control enables hard reset or initialization without waiting for clock edge |
| Dual independent channels | Two fully isolated J-K flip-flops on one die reduce board area and interconnect complexity in redundant logic |
| TTL-compatible I/O | Meets 74AS input thresholds and output drive specs - interoperable with legacy military logic families without level shifters |
| MIL-STD-883 Class B compliance | Qualified for high-reliability applications including screening, burn-in, and radiation-hardened variants per customer request |
Applications
| Radar Pulse Sequencing | Avionics Data Latching |
|---|---|
Use Scenario: Generating precisely timed gate windows and pulse repetition intervals in airborne fire-control radars. IC Role / Device Role / Timing Role: Dual-channel synchronous state register controlling T/R switch timing and ADC sampling strobes. Use Value: 90 MHz clock support and 2.5 ns propagation delay ensure sub-11 ns timing resolution required for X-band pulse compression. | Use Scenario: Capturing sensor telemetry from inertial measurement units (IMUs) during high-G maneuvers. IC Role / Device Role / Timing Role: Edge-triggered latch holding 16-bit attitude data synchronized to flight computer clock domain. Use Value: Asynchronous PRE/CLR allows immediate data freeze on fault detection, preserving last valid state before system reset. |
| Hardened Digital State Machines | Mission-Critical Watchdog Logic |
Use Scenario: Implementing fault-tolerant control logic in satellite command decoders where single-event upsets must be contained. IC Role / Device Role / Timing Role: Dual J-K element forming a hardened 2-bit counter with self-checking parity path. Use Value: Ceramic FK package and –55°C to 125°C rating sustain operation during orbital thermal cycling and radiation exposure. | Use Scenario: Monitoring processor heartbeat signals in launch vehicle guidance computers to initiate safe abort sequences. IC Role / Device Role / Timing Role: Toggle-mode flip-flop acting as watchdog timer with external RC reset timeout and manual PRE/CLR override. Use Value: Independent PRE/CLR inputs allow hardware-initiated fail-safe action without software intervention or 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 |
|---|---|---|---|
| SNJ54ALS109FK | Lower 50 MHz max clock, 6 mW per flip-flop, higher noise immunity due to ALS Schottky clamping | Better suited for lower-speed, ultra-low-power avionics subsystems where EMI rejection is prioritized over speed | Select when clock rates ≤34 MHz and supply current <4 mA per channel is required |
| SNJ54F109J | Standard TTL (74F) variant in ceramic DIP (J) package; 35 MHz max clock, 22 mA IOL, no MIL-STD-883 Class B screening | Used in legacy ground-test equipment where full military qualification is not mandated | Select only for non-flight hardware or cost-sensitive prototypes where ceramic DIP form factor is preferred |
Compared with SNJ54AS109FK, SNJ54ALS109FK trades speed for lower power and enhanced noise margin, while SNJ54F109J offers legacy compatibility but lacks Class B qualification and high-speed performance - making SNJ54AS109FK optimal for new flight-critical designs requiring both speed and reliability.
Availability
SNJ54AS109FK is available at Aetrix Electronics and suitable for radar timing sequencers, avionics data latching, and hardened digital state machines requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SNJ54AS109FK 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 high-reliability logic solutions for aerospace, defense, and industrial markets.
The SNJ54AS series belongs to TI's military-grade bipolar TTL family, engineered specifically for high-speed, radiation-tolerant digital control in mission-critical systems operating under extreme environmental stress.
FAQ
What is the maximum clock frequency supported by SNJ54AS109FK?
The SNJ54AS109FK supports a maximum clock frequency of 90 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, CL = 50 pF, TA = –55°C to 125°C). This value is based on characterization data per MIL-STD-883 Class B compliance and applies specifically to the SNJ54AS109FK ceramic FK-package variant.
Does SNJ54AS109FK have built-in ESD protection?
The SNJ54AS109FK does not include on-die ESD protection diodes beyond inherent junction limits. Per the datasheet, absolute maximum input voltage is 7 V, and users must implement external transient suppression (e.g., series resistors + clamping diodes) on J, K, CLK, PRE, and CLR lines in high-noise environments such as aircraft bays or radar transmitters.
Can SNJ54AS109FK operate with a 3.3 V supply?
No. The SNJ54AS109FK requires a minimum supply voltage of 4.5 V and is rated only for 4.5 V to 5.5 V operation. Applying 3.3 V will result in undefined logic levels, failure to meet timing specifications, and potential metastability - it is incompatible with LVCMOS or mixed-voltage systems without level translation.
What is the function of the NC pins on SNJ54AS109FK?
SNJ54AS109FK has four NC (no internal connection) pins: pins 17–20. These pins are physically present in the 20-pin FK package but have no internal bond wires or circuitry. They must remain unconnected - tying them to VCC, GND, or signals violates the datasheet and may cause unpredictable behavior or increased leakage current.
How does the asynchronous preset/clear functionality work in SNJ54AS109FK?
In SNJ54AS109FK, a low signal on either 1PRE or 1CLR immediately forces the corresponding Q output to 1 or 0 respectively - overriding all clock and J/K inputs. This action occurs independently per flip-flop and takes effect within 2 ns (tPLH/tPHL PRE/CLR → Q), enabling deterministic hard-reset capability essential for safety-critical logic states.
SNJ54AS109FK 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:
- -
SNJ54AS109FK FAQ
1.How can I place an order for SNJ54AS109FK through Aetrix?
Please submit a Request for Quotation (RFQ) for SNJ54AS109FK 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 SNJ54AS109FK reliable?
The price and inventory of SNJ54AS109FK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SNJ54AS109FK is usually 5 days.
3.What payment methods are accepted for SNJ54AS109FK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SNJ54AS109FK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SNJ54AS109FK?
SNJ54AS109FK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SNJ54AS109FK 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 SNJ54AS109FK?
For technical support, including SNJ54AS109FK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SNJ54AS109FK requirements.
6.How does Aetrix verify that SNJ54AS109FK is sourced from the original manufacturer or authorized distributors?
All SNJ54AS109FK 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 SNJ54AS109FK meets industry standards.
7.What is the process for return or replacement of SNJ54AS109FK?
All SNJ54AS109FK units undergo pre-shipment inspection (PSI). If there is an issue with SNJ54AS109FK, 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 SNJ54AS109FK part is unused and in its original packaging.
Return procedure for SNJ54AS109FK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SNJ54AS109FK Tags
-
SN74HC74DR
Texas Instruments
-
SN74HC74PWR
Texas Instruments
-
74LVC1G74GT,115
Nexperia USA Inc.
-
SN74LVC2G74DCUR
Texas Instruments
-
CD4013BM96
Texas Instruments
-
SN74HCT273PWR
Texas Instruments
-
SN74LVC1G74DCUR
Texas Instruments
-
SN74HC574DWR
Texas Instruments
-
74LVC1G74DC,125
Nexperia USA Inc.
-
SN74HC273DWR
Texas Instruments
-
SN74HCT574DWR
Texas Instruments
-
SN74LVC1G74DCTR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
