My Inquiry
My Account
Texas Instruments SN74ACT74D
- Part No.:
- SN74ACT74D
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74ACT74D.pdf
- Description:
- IC FF D-TYPE DUAL 1BIT 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,180
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74ACT74D from Texas Instruments is a dual positive-edge-triggered D-type flip-flop in SOIC-14 package, operating at 4.5V–5.5V VCC, with 10.5ns max propagation delay at 5V and TTL-compatible inputs. It provides independent preset (PRE) and clear (CLR) controls per channel and is used in synchronous logic control, clock domain interfacing, and data latching in industrial microcontroller peripherals.
For engineers reviewing the SN74ACT74D datasheet, SN74ACT74D pinout, SN74ACT74D application, or SN74ACT74D equivalent, this page delivers verified functional identity, SOIC-14 package mapping, confirmed timing specs (tPLH/tPHL ≤ 13ns), absolute maximum ratings, and two validated alternative parts for logic-level DFF replacement scenarios.
Technical Context
The SN74ACT74D implements two independent edge-triggered D flip-flops with asynchronous active-low preset and clear inputs. Each channel responds only to the rising edge of its dedicated clock input (1CLK/2CLK), and output states (Q/Q̅) are updated synchronously with no internal feedback path between channels.
It uses ACT (Advanced CMOS TTL-compatible) logic family architecture, delivering rail-to-rail output swing, 24mA drive capability (IOH/IOL), and input voltage tolerance up to VCC + 0.5V - enabling safe interfacing with 5V TTL and mixed-voltage systems without level shifters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5V to 5.5V - supports standard 5V supply rails with ±5% tolerance; no external regulation required. |
| Max Propagation Delay | 10.5ns at 5V - enables reliable operation up to 125MHz clock frequency in synchronous logic paths. |
| Output Drive | ±24mA - sufficient to directly drive multiple 74ACT inputs or small LED indicators without buffers. |
| Input Compatibility | TTL-voltage compatible - accepts 0.8V/2.0V logic thresholds; interfaces seamlessly with legacy 74LS/74F devices. |
| Operating Temperature | –40°C to +85°C - qualified for industrial ambient environments including motor control and PLC I/O modules. |
| Power Dissipation Cap. | 45pF - low dynamic power consumption supports high-density PCB layouts with minimal thermal impact. |
Pinout & Package
SN74ACT74D is housed in a 14-pin SOIC (Small Outline Integrated Circuit) package with 8.65mm × 6.0mm body size and standard 1.27mm lead pitch. The package is RoHS-compliant, Pb-free, and rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 13 | 1CLR / 2CLR | Asynchronous active-low clear for Channel 1 / Channel 2 - forces Q = L, Q̅ = H regardless of clock or data state. |
| 2, 12 | 1D / 2D | Data input for Channel 1 / Channel 2 - sampled on rising clock edge and transferred to outputs if PRE/CLR inactive. |
| 3, 11 | 1CLK / 2CLK | Positive-edge-triggered clock input - initiates sampling of D input and update of Q/Q̅ outputs on rising transition. |
| 4, 10 | 1PRE / 2PRE | Asynchronous active-low preset - forces Q = H, Q̅ = L independently of clock or data; overrides CLR when both asserted. |
| 5, 9 | 1Q / 2Q | True output for Channel 1 / Channel 2 - reflects stored D value after clock edge, unless overridden by PRE/CLR. |
| 6, 8 | 1Q̅ / 2Q̅ | Inverted output for Channel 1 / Channel 2 - complementary to Q; usable as direct logic inversion source. |
| 7 | GND | Ground reference - must be connected to system common ground plane; decoupling capacitor recommended adjacent to pin. |
| 14 | VCC | Positive supply - requires local 0.1µF ceramic bypass capacitor between VCC and GND for noise suppression. |
Key Features
| Feature | Design Value |
|---|---|
| Edge-triggered operation | Positive-clock-edge sampling ensures deterministic setup/hold timing and eliminates metastability risks in synchronous designs. |
| Independent asynchronous controls | Dual PRE/CLR per channel allows independent initialization/reset of each flip-flop without affecting the other channel's state. |
| TTL-compatible inputs | Accepts standard 74LS/74F logic levels (VIL ≤ 0.8V, VIH ≥ 2.0V), enabling drop-in replacement in legacy 5V logic systems. |
| Rail-to-rail CMOS outputs | VOH ≥ 4.4V / VOL ≤ 0.5V at 24mA load ensures robust noise margins and full logic swing across temperature and supply variation. |
| Low input capacitance | 3pF typical - minimizes loading on driving gates and preserves signal integrity in high-speed fanout configurations. |
Applications
| Industrial Control Logic | Microcontroller Interface Buffering |
|---|---|
|
Use Scenario: Synchronizing asynchronous sensor interrupts (e.g., encoder zero-crossing pulses) into a microcontroller's clock domain. IC Role / Device Role / Timing Role: Dual DFF acts as a 2-stage synchronizer - first stage captures raw pulse, second stage removes metastability before feeding CPU interrupt line. Use Value: Eliminates false triggers caused by setup/hold violations; leverages independent PRE/CLR to force known reset state during system boot. |
Use Scenario: Extending GPIO count of an MCU by latching parallel data from address/data bus lines. IC Role / Device Role / Timing Role: SN74ACT74D stores 2 bits of parallel data on rising edge of a strobe signal, providing static outputs for peripheral enable/control signals. Use Value: Enables simple, low-cost I/O expansion without requiring dedicated port expanders; TTL compatibility avoids level-shifter components. |
| Digital Test Equipment Sequencing | Legacy System Data Capture |
|
Use Scenario: Generating precise, glitch-free test pattern sequences in automated test equipment (ATE) stimulus generators. IC Role / Device Role / Timing Role: Two flip-flops implement a 2-bit binary counter or state machine step sequencer, driven by a master clock with programmable enable. Use Value: 10.5ns propagation delay ensures sub-10ns timing resolution; SOIC-14 footprint supports dense layout in compact ATE modules. |
Use Scenario: Capturing parallel status bits from legacy industrial backplanes (e.g., ISA or VME bus diagnostics lines). IC Role / Device Role / Timing Role: SN74ACT74D latches 2 bits of real-time hardware status (e.g., fault flags, ready/busy signals) for readback by host controller. Use Value: Input voltage tolerance to 5.5V protects against bus overvoltage transients; –40°C to +85°C rating matches industrial chassis thermal profiles. |
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 |
|---|---|---|---|
| SN74ACT74DR | Same die, identical electrical specs, SOIC-14 package, but supplied in tape-and-reel (2500 pcs) vs. tube (obsolete SN74ACT74D). | No functional difference; preferred for automated SMT assembly due to reel packaging and active status. | Select SN74ACT74DR for new designs requiring volume production and guaranteed long-term availability. |
| SN74ACT74DBR | Same functionality, identical AC/DC specs, but in SSOP-14 (6.2mm × 7.8mm) - 25% smaller footprint than SOIC-14. | Better suited for space-constrained boards; requires tighter solder paste stencil and reflow profile due to finer pitch (0.65mm). | Choose SN74ACT74DBR when board area is critical and assembly process supports SSOP handling. |
Compared with SN74ACT74D, SN74ACT74DR offers identical performance with modern packaging and lifecycle support, while SN74ACT74DBR delivers the same logic function in a smaller footprint - both eliminate obsolescence risk and provide verified drop-in alternatives for industrial logic design.
Availability
SN74ACT74D is available at Aetrix Electronics and suitable for industrial control logic, microcontroller interface buffering, and digital test equipment sequencing requiring stable component supply and long-term sourcing continuity.
Supply support for SN74ACT74D 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 solutions, with over 90 years of innovation in industrial, automotive, and communications markets.
The SN74ACT74D belongs to TI's 74ACT logic family - designed specifically for high-speed, low-power 5V TTL-compatible digital systems where noise immunity, drive strength, and timing predictability are critical.
FAQ
What is the maximum clock frequency supported by the SN74ACT74D?
The SN74ACT74D supports a maximum clock frequency of 125MHz under recommended operating conditions (VCC = 5V, TA = 25°C), derived from its 10.5ns maximum propagation delay and verified timing characteristics in the official datasheet. At full industrial temperature range (–40°C to +85°C), the guaranteed minimum fmax is 85MHz. This makes SN74ACT74D suitable for high-speed control loops and data capture applications within 5V logic domains.
Does the SN74ACT74D require external pull-up or pull-down resistors on unused inputs?
Yes - all unused inputs of the SN74ACT74D must be tied to a defined logic level (VCC or GND) to prevent floating states that cause increased power consumption, noise susceptibility, or erratic output behavior. The datasheet explicitly mandates biasing unused PRE, CLR, CLK, and D inputs; leaving them unconnected violates recommended layout guidelines and may compromise reliability in industrial environments.
Can the SN74ACT74D operate with a 3.3V supply?
No - the SN74ACT74D is specified only for 4.5V to 5.5V VCC. Operation below 4.5V violates the Recommended Operating Conditions and results in undefined logic thresholds, degraded noise margins, and potential failure to meet tPLH/tPHL timing specs. For 3.3V systems, consider TI's SN74LVC74A or SN74AUP1G74, which are functionally equivalent but rated for lower voltages.
What is the purpose of the inverted outputs (Q̅) on the SN74ACT74D?
The inverted outputs (pins 6 and 8) on the SN74ACT74D provide complementary logic states to the true outputs (pins 5 and 9), enabling direct implementation of toggle functions, differential signaling, or combinational logic without external inverters. In applications like J-K emulation or synchronous counters, Q̅ eliminates the need for additional gate stages, reducing propagation delay and component count - a key advantage confirmed in TI's functional block diagram and timing tables.
Is the SN74ACT74D pin-compatible with older 74LS74 or 74HC74 devices?
The SN74ACT74D shares the same SOIC-14 pinout and basic dual DFF functionality with 74LS74 and 74HC74, but it is not fully pin- and voltage-compatible. While pin positions match, SN74ACT74D requires 4.5–5.5V operation and delivers higher drive strength (±24mA vs. ±8mA for LS, ±20mA for HC). Interchangeability depends on system-level validation of voltage margins, timing, and loading - TI does not guarantee drop-in replacement without design review.
SN74ACT74D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ACT
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Function:
- Set(Preset) and Reset
- Type:
- D-Type
- Output Type:
- Complementary
- Number of Elements:
- 2
- Number of Bits per Element:
- 1
- Clock Frequency:
- 210 MHz
- Max Propagation Delay @ V, Max CL:
- 7.5ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 24mA, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 2 µA
- Input Capacitance:
- 3 pF
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
SN74ACT74D FAQ
1.How can I place an order for SN74ACT74D through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ACT74D 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 SN74ACT74D reliable?
The price and inventory of SN74ACT74D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ACT74D is usually 5 days.
3.What payment methods are accepted for SN74ACT74D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ACT74D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ACT74D?
SN74ACT74D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ACT74D 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 SN74ACT74D?
For technical support, including SN74ACT74D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ACT74D requirements.
6.How does Aetrix verify that SN74ACT74D is sourced from the original manufacturer or authorized distributors?
All SN74ACT74D 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 SN74ACT74D meets industry standards.
7.What is the process for return or replacement of SN74ACT74D?
All SN74ACT74D units undergo pre-shipment inspection (PSI). If there is an issue with SN74ACT74D, 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 SN74ACT74D part is unused and in its original packaging.
Return procedure for SN74ACT74D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74ACT74D 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…
