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Texas Instruments SN74LS74ADG4
- Part No.:
- SN74LS74ADG4
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74LS74ADG4.pdf
- Description:
- IC FF D-TYPE DUAL 1BIT 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,258
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Product details
Overview
SN74LS74ADG4 from Texas Instruments is a dual D-type positive-edge-triggered flip-flop in a 14-pin SOIC package, operating from 4.75 V to 5.25 V with typical propagation delay of 15 ns and maximum clock frequency of 30 MHz. It features complementary Q and Q̅ outputs per section, independent preset and clear inputs, and is used in synchronous logic control, data latching, and clock division circuits in industrial control panels and legacy instrumentation.
For engineers reviewing the SN74LS74ADG4 datasheet, SN74LS74ADG4 pinout, SN74LS74ADG4 application, or SN74LS74ADG4 equivalent, this page delivers verified functional specifications, validated pin assignments, confirmed TTL-compatible input thresholds, real-world timing constraints, and direct alternative options for legacy system maintenance and redesign.
Technical Context
This device implements two independent edge-triggered D flip-flops with asynchronous active-low preset (PR̅) and clear (CLR̅) inputs. Each section samples the D input on the rising edge of the clock (CLK), latching the value to Q and its inverse to Q̅. The logic conforms strictly to standard TTL voltage thresholds: VIH = 2.0 V min, VIL = 0.8 V max.
Propagation delays are specified at VCC = 5 V, TA = 25°C: tPLH(CLK→Q) = 15 ns max, tPHL(CLK→Q) = 15 ns max, and setup/hold times are tSU(D→CLK) = 20 ns min and tH(CLK→D) = 5 ns min. Output drive capability is IOH = –0.4 mA at VOH = 2.7 V and IOL = 8 mA at VOL = 0.5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | LS-TTL: ensures compatibility with legacy 74LS-series systems and predictable noise margins. |
| Supply Voltage | 4.75 V to 5.25 V: requires stable +5 V rail; operation outside this range risks undefined state or latch-up. |
| Max Clock Frequency | 30 MHz: sets upper limit for synchronous counter or register applications without timing violation. |
| Propagation Delay | 15 ns max (CLK→Q): determines minimum clock period and critical path timing budget. |
| Output Drive | 8 mA sink / –0.4 mA source: supports direct fan-out to up to 20 LS-TTL inputs per output. |
| Input Thresholds | VIL = 0.8 V max, VIH = 2.0 V min: defines valid logic low/high recognition under TTL signaling standards. |
Pinout & Package
SN74LS74ADG4 uses a 14-pin SOIC (D) package with 3.90 mm body width, 1.75 mm max height, and 1.27 mm lead pitch. Pin 1 is located at the top-left corner adjacent to the index notch or dot marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | 1PR̅ | Active-low preset for first flip-flop: forces Q1 = 1, Q̅1 = 0 when asserted, overriding clock and D1. |
| 2 | 1D | Data input for first flip-flop: sampled on rising CLK edge and transferred to Q1. |
| 3 | 1CLK | Clock input for first flip-flop: positive-edge sensitive; requires clean, monotonic transition. |
| 4 | 1CLR̅ | Active-low clear for first flip-flop: forces Q1 = 0, Q̅1 = 1 when asserted, overriding clock and D1. |
| 5 | 1Q | True output of first flip-flop: reflects latched D1 value after CLK edge. |
| 6 | 1Q̅ | Inverted output of first flip-flop: complements Q1; usable as feedback or enable signal. |
| 7 | GND | Ground reference for all internal circuitry and I/O; must be low-impedance connection. |
| 8 | 2Q̅ | Inverted output of second flip-flop: complements Q2; electrically isolated from first section. |
| 9 | 2Q | True output of second flip-flop: reflects latched D2 value after CLK edge. |
| 10 | 2CLR̅ | Active-low clear for second flip-flop: forces Q2 = 0, Q̅2 = 1 when asserted. |
| 11 | 2CLK | Clock input for second flip-flop: positive-edge sensitive; shares no internal coupling with 1CLK. |
| 12 | 2D | Data input for second flip-flop: sampled independently on rising 2CLK edge. |
| 13 | 2PR̅ | Active-low preset for second flip-flop: forces Q2 = 1, Q̅2 = 0 when asserted. |
| 14 | VCC | +5 V supply input: must be decoupled locally with 0.1 µF ceramic capacitor to GND. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent D flip-flops | Enables compact implementation of two-bit registers or separate control channels without external gating. |
| Asynchronous preset/clear | Allows immediate state initialization or reset independent of clock timing-critical for power-on sequencing. |
| TTL-compatible input thresholds | Guarantees interoperability with legacy 74LS, 74S, and 74F logic families without level-shifting. |
| Complementary Q/Q̅ outputs | Eliminates need for external inverters in toggle or enable logic, reducing component count and board area. |
| SOIC packaging with RoHS compliance | Supports automated SMT assembly and meets modern environmental requirements while maintaining legacy footprint. |
Applications
| Industrial Control Sequencing | Digital Test Equipment |
|---|---|
|
Use Scenario: Latching sensor status signals in programmable logic controllers during scan cycles. IC Role / Device Role / Timing Role: Dual D flip-flop captures parallel input states on synchronized clock edges for deterministic state capture. Use Value: Ensures glitch-free sampling of noisy industrial inputs via controlled edge-triggered behavior and asynchronous reset for fault recovery. |
Use Scenario: Generating precise test pattern sequences in automated test equipment waveform generators. IC Role / Device Role / Timing Role: Forms 2-bit binary counter stage with feedback logic to produce repeatable stimulus waveforms. Use Value: Delivers sub-30 ns timing resolution and guaranteed setup/hold margins essential for high-reliability test vector generation. |
| Legacy Instrumentation Interfaces | Power Supply Monitoring Logic |
|
Use Scenario: Interfacing analog-to-digital converter (ADC) busy flags to microcontroller interrupt lines in benchtop meters. IC Role / Device Role / Timing Role: Edge-triggered latch holds ADC conversion complete signal until polled by host processor. Use Value: Prevents missed interrupts due to short-duration pulses by extending signal duration using Q output and local clock. |
Use Scenario: Detecting undervoltage lockout (UVLO) and overvoltage events in multi-rail DC-DC converter supervision. IC Role / Device Role / Timing Role: Stores fault condition state across power cycles using asynchronous preset/clear tied to supervisor outputs. Use Value: Maintains latched fault flag even during brownout, enabling post-event diagnostics without nonvolatile memory. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual D flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS74ADR | Identical electrical specs and pinout; differs only in tape-and-reel packaging (2500 pcs vs. 2500 pcs) and part marking (LS74A). | No functional difference; suitable for same PCB layout and firmware interface. | Select SN74LS74ADR if large-volume automated assembly is required and G4 suffix is not mandated by procurement policy. |
| SN74LS74ANSR | SOP (NS) package instead of SOIC (D); same 14-pin layout, but wider body (5.3 mm vs. 3.9 mm) and different land pattern. | Requires PCB footprint revision; otherwise identical timing, drive, and logic behavior. | Choose SN74LS74ANSR only when SOP is standardized across existing board designs or preferred for thermal/mechanical reasons. |
Compared with SN74LS74ADR, SN74LS74ADG4 offers identical functionality with RoHS-compliant NiPdAu lead finish and Level-1 MSL rating, while SN74LS74ANSR provides equivalent logic in a physically distinct SOP package requiring layout adaptation but offering marginally higher thermal mass.
Availability
SN74LS74ADG4 is available at Aetrix Electronics and suitable for industrial control sequencing, digital test equipment, legacy instrumentation interfaces, and power supply monitoring logic requiring stable component supply across long-lifecycle embedded programs.
Supply support for SN74LS74ADG4 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 founded in 1930, specializing in analog, embedded processing, and logic solutions with broad industrial, automotive, and aerospace design heritage.
The SN74LS74A family was developed in the 1970s to provide robust, low-power TTL-compatible flip-flops for synchronous digital systems where reliability, noise immunity, and predictable timing were critical.
FAQ
What is the maximum operating temperature range for SN74LS74ADG4?
The SN74LS74ADG4 is rated for operation from 0°C to +70°C ambient temperature. This commercial-grade specification aligns with standard industrial environments and excludes extended temperature variants like SN54LS74AJ (–55°C to +125°C). Operation beyond 70°C may result in increased propagation delay, reduced noise margin, or metastability risk. Always verify thermal derating in high-power-density layouts.
Does SN74LS74ADG4 support true 5-V TTL input compatibility?
Yes, SN74LS74ADG4 fully complies with standard TTL input thresholds: VIH ≥ 2.0 V (minimum) and VIL ≤ 0.8 V (maximum) at VCC = 5 V. Its Schottky-clamped transistor inputs ensure reliable recognition of legacy 74LS, 74S, and 74F logic outputs without external level shifting or pull-up resistors.
Can SN74LS74ADG4 be used as a divide-by-2 counter?
Yes, SN74LS74ADG4 can implement a divide-by-2 function by connecting Q̅ to D and applying the input clock to CLK. This configuration toggles Q on each rising edge, producing a 50% duty-cycle square wave at half the input frequency-verified in TI's SDLS119 datasheet Figure 3.
Is SN74LS74ADG4 pin-compatible with SN74LS74ADR?
Yes, SN74LS74ADG4 and SN74LS74ADR share identical SOIC (D)-14 package dimensions, pin assignment, electrical characteristics, and timing parameters. The G4 suffix denotes RoHS-compliant NiPdAu plating and specific tape-and-reel packaging, but no PCB layout changes are needed for substitution.
What is the recommended bypass capacitor for SN74LS74ADG4?
A 0.1 µF ceramic capacitor placed between VCC (pin 14) and GND (pin 7), located within 5 mm of the device, is recommended per TI's application guidance. This minimizes high-frequency supply noise coupling into the flip-flop's internal nodes, preventing spurious clocking or metastability during fast transitions.
SN74LS74ADG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74LS
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- 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:
- 33 MHz
- Max Propagation Delay @ V, Max CL:
- 40ns @ 5V, 15pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 400µA, 8mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Current - Quiescent (Iq):
- 8 mA
- Input Capacitance:
- -
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
SN74LS74ADG4 FAQ
1.How can I place an order for SN74LS74ADG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LS74ADG4 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 SN74LS74ADG4 reliable?
The price and inventory of SN74LS74ADG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LS74ADG4 is usually 5 days.
3.What payment methods are accepted for SN74LS74ADG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LS74ADG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LS74ADG4?
SN74LS74ADG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LS74ADG4 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 SN74LS74ADG4?
For technical support, including SN74LS74ADG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LS74ADG4 requirements.
6.How does Aetrix verify that SN74LS74ADG4 is sourced from the original manufacturer or authorized distributors?
All SN74LS74ADG4 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 SN74LS74ADG4 meets industry standards.
7.What is the process for return or replacement of SN74LS74ADG4?
All SN74LS74ADG4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74LS74ADG4, 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 SN74LS74ADG4 part is unused and in its original packaging.
Return procedure for SN74LS74ADG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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