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Texas Instruments SNJ54ACT74J
- Part No.:
- SNJ54ACT74J
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- -
- Datasheet:
-
SNJ54ACT74J.pdf
- Description:
- 54ACT74 DUAL POSITIVE-EDGE-TRIGG
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Product details
Overview
SNJ54ACT74J from Texas Instruments is a dual positive-edge-triggered D-type flip-flop in a 14-pin CDIP (ceramic dual in-line package), operating over –55°C to +125°C with 4.5V–5.5V supply, 10.5ns max propagation delay at 5V, and TTL-compatible inputs-used in military-grade synchronous logic control, clock domain synchronization, and data latching in avionics timing circuits.
For engineers reviewing the SNJ54ACT74J datasheet, SNJ54ACT74J pinout, SNJ54ACT74J application, or SNJ54ACT74J equivalent, this page delivers verified functional identity, validated pin functions, confirmed military-temperature operation, and precise timing parameters for high-reliability digital system design.
Technical Context
The SNJ54ACT74J implements two independent D-type flip-flops, each with asynchronous active-low preset (PRE) and clear (CLR) inputs, positive-edge clock triggering, and complementary Q/Q̅ outputs. Its TTL-voltage-compatible inputs accept up to 5.5V regardless of VCC level.
It operates under MIL-PRF-38535 Class B requirements, supports full military temperature range (–55°C to +125°C), and features low input current (±1 µA max), 24 mA output drive capability, and 45 pF typical power dissipation capacitance at 5V/1 MHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5V to 5.5V - Enables robust operation across wide supply tolerances in ruggedized systems. |
| Max Propagation Delay (tPLH/tPHL) | 10.5ns at 5V - Supports >95 MHz clock frequency in synchronous logic paths. |
| Operating Temperature | –55°C to +125°C - Qualified for military and aerospace applications per SN54ACT series. |
| Output Drive (IOL/IOH) | ±24mA - Sufficient to directly drive multiple TTL loads or interface with legacy bus structures. |
| Input Voltage Tolerance | Up to 5.5V - Allows interfacing with higher-voltage logic without level-shifting circuitry. |
| Power Dissipation Capacitance (Cpd) | 45pF - Predictable dynamic power consumption for thermal modeling in sealed enclosures. |
Pinout & Package
SNJ54ACT74J uses a 14-pin Ceramic Dual In-Line Package (CDIP, J package), 19.3mm × 9.4mm body size, with through-hole mounting and hermetic sealing suitable for high-reliability environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 CLR | Channel 1 Clear Input | Asynchronous active-low reset; forces Q=0, Q̅=1 independent of clock or data. |
| 2 D | Channel 1 Data Input | Stores logic state on rising edge of CLK when PRE and CLR are inactive (high). |
| 3 CLK | Channel 1 Clock Input | Positive-edge-triggered; sampling occurs at voltage threshold crossing, not edge slew rate. |
| 4 PRE | Channel 1 Preset Input | Asynchronous active-low set; forces Q=1, Q̅=0 independent of clock or data. |
| 5 Q | Channel 1 True Output | Non-inverted registered output; synchronized to CLK edge and subject to setup/hold timing. |
| 6 Q̅ | Channel 1 Complementary Output | Inverted copy of Q; enables differential signaling or direct NAND/NOR logic fanout. |
| 7 GND | Ground Reference | Primary return path for all internal logic and I/O; requires low-inductance connection in RF-sensitive layouts. |
| 8 Q̅ | Channel 2 Complementary Output | Independent inverted output for second flip-flop; no shared resources with Channel 1. |
| 9 Q | Channel 2 True Output | Second independent registered output; identical timing and loading behavior as Pin 5. |
| 10 PRE | Channel 2 Preset Input | Asynchronous set for Channel 2 only; electrically isolated from Channel 1 control lines. |
| 11 CLK | Channel 2 Clock Input | Dedicated clock input; allows independent clocking of each flip-flop in multi-phase designs. |
| 12 D | Channel 2 Data Input | Independent data path; no crosstalk or timing coupling with Channel 1 D input. |
| 13 CLR | Channel 2 Clear Input | Asynchronous reset for Channel 2 only; supports selective channel initialization. |
| 14 VCC | Positive Supply | 5V nominal supply; bypass capacitor (0.1µF) required adjacent to pin for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| TTL-Voltage-Compatible Inputs | Accepts 0–5.5V input signals regardless of VCC level-enables mixed-voltage board interfacing without translators. |
| Asynchronous Preset/Clear | Independent active-low PRE/CLR per channel allows deterministic initialization or fault recovery outside clock domain. |
| Military Temperature Range | –55°C to +125°C operation certified per SN54ACT family-supports deployment in uncontrolled environmental enclosures. |
| Low Input Current | ±1 µA max at VCC or GND-minimizes loading on upstream drivers and reduces static power in battery-backed systems. |
| High-Speed Switching | 10.5ns max tPLH/tPHL at 5V-meets timing budgets for 100+ MHz system clocks with margin for trace delays. |
Applications
| Avionics Data Latching | Secure Boot State Capture |
|---|---|
Use Scenario: Capturing sensor status or configuration bits during aircraft power-up sequencing where voltage ramps slowly and clock stability is delayed. IC Role / Device Role / Timing Role: SNJ54ACT74J acts as a metastability-hardened latch, using asynchronous CLR to force known state before clock stabilization, then capturing first valid data on earliest clean CLK edge. Use Value: Eliminates boot-time race conditions in flight control computers by guaranteeing deterministic initial register values prior to firmware execution. |
Use Scenario: Storing tamper-evident hardware flags (e.g., secure boot failure, debug port access) in encrypted storage controllers where power may be interrupted mid-operation. IC Role / Device Role / Timing Role: SNJ54ACT74J holds critical security state in non-volatile latch configuration, with PRE/CLR enabling immediate flag assertion upon detection event, independent of CPU clock. Use Value: Provides atomic, glitch-immune state capture that survives brownout events-essential for cryptographic key lifecycle enforcement. |
| Radar Pulse Timing Synchronization | Mission-Critical Watchdog Reset Logic |
Use Scenario: Aligning asynchronous radar echo returns with system clock domains in phased-array antenna beamforming units. IC Role / Device Role / Timing Role: SNJ54ACT74J synchronizes pulse edges across two independent channels-one for leading edge, one for trailing edge-using separate CLK inputs for phase offset control. Use Value: Enables sub-nanosecond pulse width measurement accuracy by eliminating inter-channel skew in time-of-flight processing. |
Use Scenario: Generating fail-safe reset pulses for radiation-hardened microcontrollers in satellite command & data handling subsystems. IC Role / Device Role / Timing Role: SNJ54ACT74J implements a dual-stage watchdog: first stage detects software hang via periodic PRE toggle; second stage triggers hard reset via CLR if first stage fails. Use Value: Delivers redundant, hardware-enforced reset escalation-preventing single-point failures from compromising spacecraft autonomy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual D-type flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SNJ54ACT74W | CFP (ceramic flatpack) package; same electrical specs, identical timing, but different mechanical footprint and lead form. | Preferred for surface-mount PCBs with space constraints; lacks through-hole mounting rigidity of CDIP. | Select SNJ54ACT74W when board assembly uses reflow-only processes and thermal cycling is less severe than in avionics vibration environments. |
| SN74ACT74N | Commercial-grade PDIP; rated –40°C to +85°C; RoHS-compliant NiPdAu finish; lower cost and wider availability. | Suitable for ground-based test equipment or non-mission-critical industrial controllers-not qualified for flight hardware. | Choose SN74ACT74N for prototyping, lab validation, or cost-sensitive terrestrial applications where extended temperature range is unnecessary. |
Compared with SNJ54ACT74W and SN74ACT74N, the SNJ54ACT74J uniquely provides hermetic CDIP packaging, full military temperature qualification, and SN54-series reliability screening-making it the sole option for deployed airborne and space-rated systems requiring guaranteed operation at –55°C.
Availability
SNJ54ACT74J is available at Aetrix Electronics and suitable for avionics data latching, secure boot state capture, radar pulse timing synchronization, and mission-critical watchdog reset logic requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SNJ54ACT74J 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 and embedded processing technologies, with over 90 years of innovation in high-reliability components for defense, aerospace, and industrial markets.
The SN54ACT74J belongs to TI's military-grade ACT logic family, designed specifically for applications demanding guaranteed performance across extreme temperatures, radiation tolerance, and long-term reliability in safety-critical systems.
FAQ
What is the operating temperature range of the SNJ54ACT74J?
The SNJ54ACT74J is specified for operation from –55°C to +125°C, meeting MIL-PRF-38535 Class B requirements. This full military temperature range is validated across all electrical parameters in the datasheet and distinguishes SNJ54ACT74J from commercial variants like SN74ACT74N. The SNJ54ACT74J maintains timing, drive strength, and noise margins across this entire range without derating.
Does the SNJ54ACT74J support 3.3V logic interfaces?
No, the SNJ54ACT74J does not support 3.3V logic interfaces natively. It requires a minimum VCC of 4.5V and is designed for 5V TTL/ACT logic families. Its inputs are TTL-voltage compatible (accepting 0–5.5V), but it cannot operate reliably below 4.5V. For 3.3V systems, level-shifting circuitry or a 3.3V-compatible alternative such as SN74LVC74A must be used instead of the SNJ54ACT74J.
How is the SNJ54ACT74J pinout different from SN74ACT74D?
The SNJ54ACT74J (CDIP, J package) and SN74ACT74D (SOIC, D package) share identical pin numbering and signal mapping per TI's standard 14-pin dual D-flip-flop layout-both follow the same pin 1–14 assignment for CLR, D, CLK, PRE, Q, Q̅, GND, VCC, etc. However, SNJ54ACT74J uses through-hole leads with 0.3-inch row spacing, while SN74ACT74D uses gull-wing surface-mount leads with 0.15-inch pitch-making them mechanically incompatible despite functional equivalence.
Can the SNJ54ACT74J be used without external bypass capacitors?
No, the SNJ54ACT74J requires a 0.1µF ceramic bypass capacitor placed as close as possible to the VCC–GND pins. TI's datasheet explicitly mandates this for stable operation, especially under fast switching conditions. Omitting the capacitor risks power rail collapse during simultaneous output transitions, leading to metastability, false clocking, or latch-up-particularly critical in the SNJ54ACT74J's high-reliability target applications.
Is the SNJ54ACT74J RoHS compliant?
No, the SNJ54ACT74J is not RoHS compliant. Its CDIP (J) package uses SnPb (tin-lead) lead finish, as confirmed in TI's Package Option Addendum. This is intentional for military/aerospace use where Pb-free finishes are disallowed due to tin whisker risk and solder joint reliability concerns. RoHS-compliant alternatives include SN74ACT74N (PDIP, NiPdAu) or SN74ACT74BQAR (WQFN, NiPdAu), but neither qualifies for –55°C operation like the SNJ54ACT74J.
SNJ54ACT74J 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:
- -
SNJ54ACT74J FAQ
1.How can I place an order for SNJ54ACT74J through Aetrix?
Please submit a Request for Quotation (RFQ) for SNJ54ACT74J 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 SNJ54ACT74J reliable?
The price and inventory of SNJ54ACT74J are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SNJ54ACT74J is usually 5 days.
3.What payment methods are accepted for SNJ54ACT74J?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SNJ54ACT74J transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SNJ54ACT74J?
SNJ54ACT74J orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SNJ54ACT74J 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 SNJ54ACT74J?
For technical support, including SNJ54ACT74J datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SNJ54ACT74J requirements.
6.How does Aetrix verify that SNJ54ACT74J is sourced from the original manufacturer or authorized distributors?
All SNJ54ACT74J 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 SNJ54ACT74J meets industry standards.
7.What is the process for return or replacement of SNJ54ACT74J?
All SNJ54ACT74J units undergo pre-shipment inspection (PSI). If there is an issue with SNJ54ACT74J, 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 SNJ54ACT74J part is unused and in its original packaging.
Return procedure for SNJ54ACT74J:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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