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Texas Instruments SN74ALS74ADRE4
- Part No.:
- SN74ALS74ADRE4
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74ALS74ADRE4.pdf
- Description:
- IC FF D-TYPE DUAL 1BIT 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,244
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Product details
Overview
SN74ALS74ADRE4 from Texas Instruments is a dual positive-edge-triggered D-type flip-flop IC operating at 0°C to 70°C, with 34 MHz maximum clock frequency (CL = 50 pF), 6 mW typical power dissipation per flip-flop, and TTL-compatible input/output levels. It features independent preset (PRE) and clear (CLR) inputs that asynchronously set or reset outputs, and is used in synchronous logic control, data latching, and clock-domain synchronization in industrial control systems.
For engineers reviewing the SN74ALS74ADRE4 datasheet, SN74ALS74ADRE4 pinout, SN74ALS74ADRE4 application, or SN74ALS74ADRE4 equivalent, key selection considerations include its ALS family propagation delay (tPLH/tPHL ≤ 16 ns), guaranteed setup/hold timing (tsu = 15 ns, th = 0 ns), low-power TTL compatibility, and SOIC-14 package suitability for space-constrained PCB layouts.
Technical Context
The SN74ALS74ADRE4 implements two independent edge-triggered D flip-flops with asynchronous active-low PRE and CLR inputs. Its clock triggering responds to voltage threshold crossing-not edge slew rate-ensuring robust operation across varying signal rise times. Each flip-flop transfers D-input data to Q/Q outputs on the positive-going CLK transition when PRE and CLR are high.
It belongs to the 74ALS logic family, optimized for lower power than standard TTL while maintaining compatible voltage thresholds (VIH = 2 V min, VIL = 0.8 V max) and drive strength (IOL = 8 mA, IOH = −0.4 mA). The device is characterized for commercial temperature range only and does not support 3-state or open-collector outputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | 74ALS - Low-power Schottky TTL with 6 mW/flop typical consumption and 34 MHz max clock |
| Max Clock Frequency | 34 MHz at CL = 50 pF - supports medium-speed synchronous logic in control and interface circuits |
| Propagation Delay | tPLH/tPHL ≤ 16 ns (CLK→Q) - enables reliable timing in 25–30 MHz system clocks with margin |
| Supply Voltage Range | 4.5 V to 5.5 V - compatible with standard 5 V rail; absolute max 7 V prevents overvoltage damage |
| Input Thresholds | VIH ≥ 2 V, VIL ≤ 0.8 V - ensures interoperability with legacy TTL and LSTTL logic families |
| Output Drive | IOL = 8 mA, IOH = −0.4 mA - sufficient to drive 10+ standard TTL loads or one LS-TTL input |
| Operating Temperature | 0°C to 70°C - qualified for commercial-grade embedded and instrumentation applications |
Pinout & Package
SN74ALS74ADRE4 is packaged in a 14-pin SOIC (D) package, 3.9 mm wide, 1.75 mm max height, with 1.27 mm pitch and RoHS-compliant NiPdAu lead finish (Level-1 MSL rating).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | 1CLR | Active-low asynchronous clear for first flip-flop; forces 1Q = L, 1Q = H when asserted |
| 2 | 1D | Data input for first flip-flop; sampled on rising CLK edge if PRE/CLR inactive |
| 3 | 1CLK | Clock input for first flip-flop; positive-edge sensitive with voltage-threshold triggering |
| 4 | 1PRE | Active-low asynchronous preset for first flip-flop; forces 1Q = H, 1Q = L when asserted |
| 5 | 1Q | True output of first flip-flop; complements 1Q and follows D after CLK↑ when PRE/CLR inactive |
| 6 | 1Q | Inverted output of first flip-flop; complements 1Q and maintains state between CLK edges |
| 7 | GND | Ground reference for all internal circuitry and I/O; must be low-impedance connection |
| 8 | VCC | +5 V supply input; bypassing with 0.1 µF ceramic capacitor near pin recommended |
| 9 | 2CLR | Active-low asynchronous clear for second flip-flop; independent of first section |
| 10 | 2D | Data input for second flip-flop; electrically isolated from 1D path |
| 11 | 2CLK | Clock input for second flip-flop; no internal coupling to 1CLK |
| 12 | 2PRE | Active-low asynchronous preset for second flip-flop; independent control |
| 13 | 2Q | True output of second flip-flop; identical timing behavior to 1Q |
| 14 | 2Q | Inverted output of second flip-flop; matches 2Q phase relationship |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent D flip-flops | Enables compact implementation of paired storage elements without inter-stage coupling or shared control |
| Asynchronous PRE/CLR | Allows immediate initialization or forced state reset independent of clock timing-critical for power-up sequencing and fault recovery |
| Positive-edge clock triggering | Ensures deterministic sampling aligned to rising transitions, simplifying timing analysis in synchronous designs |
| ALS family low power | 6 mW per flip-flop reduces thermal load and enables higher gate density in logic-intensive PCBs |
| TTL-compatible I/O | Direct interfacing with legacy 74xx, 74LS, and microcontroller GPIO without level-shifting components |
Applications
| Industrial PLC Input Latching | Digital Signal Sampling |
|---|---|
Use Scenario: Capturing momentary sensor signals (e.g., limit switches, emergency stops) in programmable logic controllers where transient pulses must be held until scan cycle processing. IC Role / Device Role / Timing Role: SN74ALS74ADRE4 acts as an edge-synchronized latch, converting asynchronous mechanical switch closures into clean, clock-aligned register bits. Use Value: Prevents metastability and bounce-related glitches by enforcing strict setup/hold timing (15 ns tsu, 0 ns th) and providing deterministic state capture on CLK↑. | Use Scenario: Sampling parallel digital bus data (e.g., ADC output, encoder position words) synchronized to a system master clock in test equipment or data acquisition modules. IC Role / Device Role / Timing Role: SN74ALS74ADRE4 serves as a dual-channel input register, capturing two independent 1-bit data streams on each rising clock edge. Use Value: Enables simultaneous, skew-controlled capture of related signals (e.g., direction + step) with matched tPLH/tPHL ≤ 16 ns propagation delay. |
| State Machine Control Register | Bus Interface Synchronization |
Use Scenario: Implementing finite-state machine (FSM) next-state registers in glue logic for FPGA-to-microcontroller handshaking or protocol translation engines. IC Role / Device Role / Timing Role: SN74ALS74ADRE4 provides two dedicated state bits with independent asynchronous reset (CLR) and preset (PRE) for known startup conditions. Use Value: Guarantees deterministic initial state (via PRE/CLR) and stable hold time (th = 0 ns) eliminates need for external delay circuits in critical FSM paths. | Use Scenario: Isolating and synchronizing control signals (e.g., chip select, write enable) crossing between clock domains in mixed-speed peripheral interfaces. IC Role / Device Role / Timing Role: SN74ALS74ADRE4 functions as a dual-stage synchronizer, using cascaded flip-flops to reduce metastability risk in asynchronous signal transfer. Use Value: Leverages proven ALS timing margins (tsu = 15 ns) and low jitter to achieve >99.99% synchronization reliability at 34 MHz clock rates. |
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 |
|---|---|---|---|
| SN74ALS74AN | Same electrical specs and logic function; PDIP-14 through-hole package instead of SOIC-14 | Suitable for prototyping, breadboarding, or legacy through-hole assembly; lacks surface-mount thermal and density advantages | Select SN74ALS74AN for manual soldering, educational labs, or legacy board rework where SOIC footprint is unavailable |
| SN74AS74ADR | Higher speed (105 MHz fmax), higher power (16 mA ICC), tighter timing (tsu = 4.5 ns), AS-family process | Better suited for high-frequency clock distribution or fast data-path latching where ALS timing margins are insufficient | Choose SN74AS74ADR only when >34 MHz operation or sub-5 ns setup is required; otherwise SN74ALS74ADRE4 offers optimal power/performance trade-off |
Compared with SN74ALS74AN, SN74ALS74ADRE4 provides identical logic functionality in a smaller, reflow-compatible SOIC package ideal for automated production; versus SN74AS74ADR, it delivers adequate speed for most industrial control applications at half the power consumption and lower cost.
Availability
SN74ALS74ADRE4 is available at Aetrix Electronics and suitable for industrial control systems, test instrumentation, and legacy digital logic upgrades requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.
Supply support for SN74ALS74ADRE4 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 delivering analog, embedded processing, and logic solutions since 1930, with deep expertise in industrial, automotive, and communications markets.
The SN74ALS74ADRE4 belongs to TI's legacy 74ALS logic product line, designed specifically for low-power, medium-speed TTL-compatible digital systems where reliability, noise immunity, and backward compatibility are essential.
FAQ
What is the maximum clock frequency supported by the SN74ALS74ADRE4?
The SN74ALS74ADRE4 supports a maximum clock frequency of 34 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, CL = 50 pF, TA = 0°C to 70°C). This value is measured at the CLK input and reflects guaranteed timing performance across the full commercial temperature range. Exceeding this frequency may result in setup/hold violations or metastability, especially with marginal trace routing or load capacitance.
Does the SN74ALS74ADRE4 support 3-state or open-collector outputs?
No, the SN74ALS74ADRE4 does not support 3-state or open-collector outputs. It features standard totem-pole TTL-compatible outputs with defined VOH (≥ VCC−2 V) and VOL (≤ 0.4 V) specifications. All outputs are always driven high or low; there is no output-enable (OE) control or high-impedance state. For bus-sharing applications, external isolation or a different logic family (e.g., 74ALS244) is required.
What are the absolute maximum ratings for SN74ALS74ADRE4 supply voltage and input voltage?
The absolute maximum supply voltage (VCC) for SN74ALS74ADRE4 is 7 V, and the absolute maximum input voltage (VI) is also 7 V. Operation beyond these limits-even momentarily-may cause permanent damage. Recommended operating VCC is 4.5 V to 5.5 V; inputs should remain within −0.5 V to VCC + 0.5 V during normal operation to avoid latch-up or excessive current draw. These ratings are specified in the SDAS143C datasheet Section "Absolute Maximum Ratings".
Can SN74ALS74ADRE4 operate at temperatures below 0°C or above 70°C?
No, SN74ALS74ADRE4 is characterized and guaranteed only for operation from 0°C to 70°C. It is a commercial-grade part and is not rated for extended temperature ranges. For −55°C to 125°C operation, the military-grade SN54ALS74AJ (CDIP-14) or SNJ54ALS74AFK (LCCC-20) variants must be used. Using SN74ALS74ADRE4 outside its specified range risks timing violations, increased propagation delay, or functional failure.
Is SN74ALS74ADRE4 pin-compatible with other 74xx74-series dual D flip-flops?
Yes, SN74ALS74ADRE4 is pin-compatible with all standard 14-pin dual D flip-flops in the 74xx74 family-including SN74LS74A, SN74F74, and SN74HC74-using the same SOIC-14 (D) package outline and identical pin assignments (1CLR, 1D, 1CLK, 1PRE, 1Q, 1Q, GND, VCC, 2CLR, 2D, 2CLK, 2PRE, 2Q, 2Q). However, electrical characteristics (speed, drive strength, power) differ significantly between families, so direct substitution requires verification of timing and loading requirements.
SN74ALS74ADRE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ALS
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Function:
- Set(Preset) and Reset
- Type:
- D-Type
- Output Type:
- Complementary
- Number of Elements:
- 2
- Number of Bits per Element:
- 1
- Clock Frequency:
- 34 MHz
- Max Propagation Delay @ V, Max CL:
- 18ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 400µA, 8mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 4 mA
- Input Capacitance:
- -
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
SN74ALS74ADRE4 FAQ
1.How can I place an order for SN74ALS74ADRE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS74ADRE4 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 SN74ALS74ADRE4 reliable?
The price and inventory of SN74ALS74ADRE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS74ADRE4 is usually 5 days.
3.What payment methods are accepted for SN74ALS74ADRE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ALS74ADRE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ALS74ADRE4?
SN74ALS74ADRE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ALS74ADRE4 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 SN74ALS74ADRE4?
For technical support, including SN74ALS74ADRE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS74ADRE4 requirements.
6.How does Aetrix verify that SN74ALS74ADRE4 is sourced from the original manufacturer or authorized distributors?
All SN74ALS74ADRE4 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 SN74ALS74ADRE4 meets industry standards.
7.What is the process for return or replacement of SN74ALS74ADRE4?
All SN74ALS74ADRE4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS74ADRE4, 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 SN74ALS74ADRE4 part is unused and in its original packaging.
Return procedure for SN74ALS74ADRE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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