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Texas Instruments SN74ALS574BDBR
- Part No.:
- SN74ALS574BDBR
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- -
- Datasheet:
-
SN74ALS574BDBR.pdf
- Description:
- FLIP FLOP D-TYPE BUS INTERFACE P
- Quantity:
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Inventory:9,345
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Product details
Overview
SN74ALS574B from Texas Instruments is an octal D-type edge-triggered flip-flop with 3-state noninverting outputs, designed for bus driving in digital systems. It operates at 0°C to 70°C, supports 35 MHz clock frequency, features 12 mA low-level output drive, and uses a 20-pin SOIC (DW) package. It is used in I/O port expansion and bidirectional data bus buffering.
For engineers reviewing the SN74ALS574B datasheet, SN74ALS574B pinout, SN74ALS574B application, or SN74ALS574B equivalent, key selection criteria include its 3-state bus-compatible output architecture, edge-triggered synchronous data capture on CLK↑, and compatibility with 5-V TTL logic families in industrial control and legacy computing interfaces.
Technical Context
The SN74ALS574B implements eight independent D-type latches triggered on the rising edge of CLK, with separate 3-state output-enable (OE) control that does not affect internal state retention. Its buffered OE and CLK inputs reduce loading and improve noise immunity in high-density bus environments.
It lacks synchronous clear (CLR), distinguishing it from SN74ALS575A and AS-series variants. The device adheres to ALS (Advanced Low-Power Schottky) logic family characteristics - lower power than standard TTL while maintaining compatible voltage thresholds and drive strength.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | ALS (Advanced Low-Power Schottky) - ensures TTL-compatible voltage levels with reduced power vs. standard TTL. |
| Supply Voltage | 4.5 V to 5.5 V - supports standard 5-V digital rails with ±10% tolerance for robust operation. |
| Max Clock Frequency | 35 MHz - enables reliable data latching in medium-speed bus applications such as ISA-style peripherals. |
| Output Drive | IOL = 12 mA / IOH = –1 mA - sufficient to drive multiple TTL loads directly without external buffers. |
| Propagation Delay | tPLH/tPHL ≤ 14 ns (VCC = 4.5–5.5 V, CL = 50 pF) - ensures tight timing margins in synchronous bus designs. |
| Operating Temperature | 0°C to 70°C - qualified for commercial-grade embedded and industrial control equipment. |
| Package | SOIC-20 (DW) - surface-mount footprint compatible with automated assembly and space-constrained PCB layouts. |
Pinout & Package
SN74ALS574B is housed in a 20-pin SOIC (DW) package with 0.300-inch body width and 1.27 mm pitch. Pin 1 is marked by a beveled corner or notch; pins are numbered counterclockwise from top-left.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | OE (Output Enable) | Active-low 3-state control: drives outputs high-Z when high; no effect on internal latch state. |
| 2–9 | 1D–8D | Data inputs for each of eight D-type flip-flops; sampled on CLK↑ transition. |
| 10 | GND | Ground reference for all logic and output circuitry. |
| 11 | VCC | Positive supply (4.5–5.5 V); powers internal logic and output drivers. |
| 12–19 | 1Q–8Q | Noninverting 3-state outputs; reflect latched D-input values when OE is low. |
| 20 | CLK | Clock input; rising-edge sensitive; triggers simultaneous capture of all eight D inputs. |
Key Features
| Feature | Design Value |
|---|---|
| 3-State Noninverting Outputs | Enables direct connection to shared data buses without contention; OE allows dynamic bus arbitration. |
| Bus-Structured Pinout | D- and Q-pins arranged in parallel order (e.g., D1/Q1 adjacent), simplifying PCB trace routing and reducing crosstalk. |
| Buffered Control Inputs | OE and CLK inputs include Schottky-clamped buffers, improving noise rejection and fan-out capability. |
| ALS Logic Compatibility | Matches input thresholds and output drive of TTL/LS families, enabling drop-in replacement in legacy 5-V systems. |
| No Internal Clear Function | Omits CLR pin - simplifies control logic where asynchronous reset is unnecessary or handled externally. |
Applications
| Industrial PLC I/O Expansion | Legacy Computer Bus Interface |
|---|---|
Use Scenario: Adding parallel digital input/output capability to programmable logic controllers using ISA or STD bus architectures. IC Role / Device Role / Timing Role: Acts as an 8-bit output latch and input buffer, synchronizing host CPU writes/reads with peripheral timing via CLK and OE. Use Value: Provides deterministic, edge-triggered data capture and high-drive 3-state outputs compatible with TTL bus loading requirements. |
Use Scenario: Interfacing microprocessor address/data buses to peripheral devices like EPROMs, RAMs, or UARTs in vintage PC or embedded x86 designs. IC Role / Device Role / Timing Role: Buffers and latches address or data lines during bus cycles, isolating CPU from peripheral delays using OE-controlled tri-state. Use Value: Ensures signal integrity across long traces with 12 mA drive and <14 ns propagation delay, meeting ISA timing budgets. |
| Test Equipment Digital Pattern Generator | Automated Test Fixture Control |
Use Scenario: Generating synchronized multi-bit stimulus patterns for IC functional testing in ATE systems. IC Role / Device Role / Timing Role: Stores pattern words from controller memory and releases them in parallel on CLK edges under OE gating. Use Value: Enables precise, repeatable timing alignment across all 8 bits with sub-15 ns setup/hold windows. |
Use Scenario: Controlling solenoids, relays, or LED indicators in manufacturing test jigs requiring isolated, noise-immune digital outputs. IC Role / Device Role / Timing Role: Serves as a buffered, latch-based output port driven by microcontroller GPIO, with OE enabling safe power-up sequencing. Use Value: Delivers 12 mA per channel to drive indicator LEDs or small relay coils directly, eliminating discrete driver stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal D-type latch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ALS574BN | Same ALS logic, identical function and timing, but in 20-pin PDIP (N) package instead of SOIC (DW). | Used where through-hole prototyping or legacy board repair is required; not suitable for SMT-only production. | Select SN74ALS574BN for hand-soldering, breadboarding, or backward compatibility with through-hole PCB footprints. |
| SN74AS574N | AS-family variant: higher speed (100 MHz fmax), stronger drive (32 mA IOL), but higher ICC (78–116 mA vs. 17–28 mA). | Suitable for high-speed bus applications needing faster timing, but requires more power and thermal management. | Choose SN74AS574N only when >35 MHz operation or >12 mA drive is mandatory; otherwise SN74ALS574B offers better power efficiency. |
Compared with SN74ALS574BN, SN74ALS574B provides identical logic behavior in a smaller, surface-mount package ideal for modern production; versus SN74AS574N, it trades peak speed for significantly lower static and dynamic power consumption in cost- and thermally constrained systems.
Availability
SN74ALS574B is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy computer bus interface, and automated test fixture control requiring stable component supply and long-term obsolescence support.
Supply support for SN74ALS574B 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 SN74ALS574B belongs to TI's legacy 74-series ALS logic family, engineered for reliable 5-V TTL-compatible operation in industrial control, instrumentation, and retro-computing applications where power efficiency and noise immunity are critical.
FAQ
What is the maximum clock frequency supported by SN74ALS574B?
The SN74ALS574B supports a maximum clock frequency of 35 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C, CL = 50 pF). This value is specified in the switching characteristics table of the SDAS165B datasheet and reflects guaranteed timing performance across temperature and voltage extremes. Exceeding 35 MHz may result in setup/hold violations or metastability.
Does SN74ALS574B include a synchronous clear (CLR) input?
No, SN74ALS574B does not include a synchronous clear input. Unlike SN74ALS575A or SN74AS575, the SN74ALS574B has only CLK, OE, eight D inputs, and eight Q outputs - totaling 20 pins with no dedicated CLR terminal. Reset functionality must be implemented externally using OE to place outputs in high-impedance state or by cycling power/logic to the system level.
What package types are available for SN74ALS574B?
SN74ALS574B is offered in SOIC-20 (DW) and PDIP-20 (N) packages. The active tape-and-reel version is SN74ALS574BDWR (SOIC, 2000 pcs/reel), while SN74ALS574BN is the through-hole PDIP variant. Both share identical electrical specifications and pinout. Ceramic or military-grade FK/J/W packages apply only to SN54-series (–55°C to 125°C) versions, not SN74ALS574B.
Can SN74ALS574B drive standard TTL loads directly?
Yes, SN74ALS574B can drive standard TTL loads directly. Its IOL = 12 mA and IOH = –1 mA meet or exceed the TTL input current requirements (IIL = –1.6 mA, IIH = 40 µA), allowing one SN74ALS574B output to fan out to at least 10 standard TTL inputs. This eliminates the need for additional buffer stages in most 5-V bus applications.
Is SN74ALS574B RoHS compliant?
Yes, SN74ALS574BDWR and SN74ALS574BN variants are RoHS compliant, as confirmed in TI's Package Option Addendum. SN74ALS574BDWR features NiPdAu (NIPDAU) lead finish and Level-1 MSL rating; SN74ALS574BN uses the same finish and is rated for unlimited floor life. Lead-free compliance applies to all currently active production lots shipped by TI.
SN74ALS574BDBR 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:
- -
SN74ALS574BDBR FAQ
1.How can I place an order for SN74ALS574BDBR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS574BDBR 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 SN74ALS574BDBR reliable?
The price and inventory of SN74ALS574BDBR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS574BDBR is usually 5 days.
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Once your SN74ALS574BDBR 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 SN74ALS574BDBR?
For technical support, including SN74ALS574BDBR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS574BDBR requirements.
6.How does Aetrix verify that SN74ALS574BDBR is sourced from the original manufacturer or authorized distributors?
All SN74ALS574BDBR 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 SN74ALS574BDBR meets industry standards.
7.What is the process for return or replacement of SN74ALS574BDBR?
All SN74ALS574BDBR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS574BDBR, 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 SN74ALS574BDBR part is unused and in its original packaging.
Return procedure for SN74ALS574BDBR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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