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Texas Instruments 74ACT11821DW
- Part No.:
- 74ACT11821DW
- Manufacturer:
- Texas Instruments
- Package:
- -
- Datasheet:
-
74ACT11821DW.pdf
- Description:
- BUS DRIVER, ACT SERIES, 10-BIT
- Quantity:
- Payment:
- Shipping:
Inventory:700
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Product details
Overview
74ACT11821 from Texas Instruments is a 10-bit bus-interface D-type flip-flop with 3-state outputs, designed for high-capacitance bus driving in wide data/address paths. It operates at 5 V (±0.5 V), supports 125 MHz clock frequency, features ±24 mA output drive, and is rated for –40°C to 85°C industrial temperature range.
For engineers reviewing the 74ACT11821 datasheet, 74ACT11821 pinout, 74ACT11821 application, or 74ACT11821 equivalent, key selection criteria include 3-state bus-driving capability, TTL-compatible inputs, flow-through pinout for PCB layout optimization, latch-up immunity (500 mA at 125°C), and EPIC™ 1-µm CMOS process reliability.
Technical Context
This device implements ten edge-triggered D-type flip-flops with synchronous positive-edge clocking and independent buffered output enable (OE). Each flip-flop retains stored data during OE assertion, enabling concurrent data latching and bus isolation.
Its flow-through architecture places inputs on one side (pins 1–10, 16–27) and outputs on the opposite side (pins 11–15, 18–28), with center-aligned VCC (pins 19, 20) and GND (pins 6–9) to suppress switching noise. The EPIC™ process ensures rail-to-rail output swing and low input capacitance (4.5 pF).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | ACT (Advanced CMOS TTL-compatible), ensuring interoperability with 74TTL and 74LS systems without level shifters. |
| Supply Voltage | 4.5 V to 5.5 V - supports stable operation across industrial voltage tolerances and brown-out margins. |
| Max Clock Frequency | 125 MHz - enables high-speed data capture in wide parallel buses (e.g., 16/32-bit address/data paths with parity). |
| Output Drive | ±24 mA - sufficient to drive 50-pF loads at full speed while maintaining VOH ≥ 3.94 V and VOL ≤ 0.44 V at VCC = 4.5 V. |
| Propagation Delay | tPLH/tPHL ≤ 12.6 ns - ensures timing closure in sub-10 ns cycle-time systems when combined with 2.5 ns setup/1.5 ns hold. |
| Latch-Up Immunity | 500 mA typical at 125°C - meets stringent reliability requirements for industrial control and instrumentation environments. |
| Input Compatibility | TTL-voltage compatible (VIH = 2 V, VIL = 0.8 V) - allows direct interfacing with legacy 74LS/74F logic without pull-ups or translators. |
Pinout & Package
74ACT11821DW uses a 28-pin SOIC (Small-Outline Integrated Circuit) package (DW suffix), with 300-mil body width and gull-wing leads. Pin spacing is 0.050 inch (1.27 mm), compliant with JEDEC MS-013.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–5, 16–27 | Data Inputs (1D–10D) | Asynchronous D inputs for each of ten flip-flops; TTL-compatible thresholds allow direct connection to LS/F-series outputs. |
| 11–15, 18–28 | Q Outputs (1Q–10Q) | 3-state buffered outputs; high-impedance state (Z) fully isolates bus lines during OE high, eliminating need for external pull-ups. |
| CLK (Pin 10) | Clock Input | Positive-edge-triggered global clock; synchronizes all ten flip-flops simultaneously with ≤1.5 ns hold time requirement. |
| OE (Pin 17) | Output Enable | Active-low buffered control; does not affect internal latch state - data may be updated or held while outputs are disabled. |
| VCC (Pins 19, 20) | Power Supply | Dual center-placed VCC pins reduce power supply inductance and minimize simultaneous switching noise in high-speed operation. |
| GND (Pins 6–9) | Ground | Four adjacent ground pins provide low-inductance return path and improve signal integrity for all 10-bit channels. |
Key Features
| Feature | Design Value |
|---|---|
| Flow-through pinout | Input and output terminals arranged on opposite sides of package to enable straight PCB trace routing, reducing crosstalk and layer count. |
| Center-pin VCC/GND | Dual VCC and quad GND pins centrally located to lower power delivery impedance and suppress ground bounce in multi-bit switching events. |
| EPIC™ 1-µm CMOS process | Delivers rail-to-rail output swing, low static current (ICC ≤ 80 µA), and robust latch-up immunity without requiring special handling or guard rings. |
| 3-state output control | OE pin disables all outputs simultaneously to high-impedance without affecting internal register state - supports bidirectional bus arbitration and hot-swap readiness. |
| TTL-input compatibility | Accepts standard TTL logic levels (0.8 V/2.0 V thresholds) directly, eliminating interface components in mixed-logic-system designs. |
Applications
| Memory Interface Buffers | Industrial I/O Port Expansion |
|---|---|
|
Use Scenario: Buffering 10-bit parity-augmented address/data bus between microcontroller and SRAM or EPROM. IC Role / Device Role / Timing Role: Synchronous latch and 3-state bus driver; captures data on CLK↑ and isolates bus during OE high to prevent contention. Use Value: Enables clean separation of read/write cycles in shared-memory architectures with no external pull-up resistors or bus transceivers required. |
Use Scenario: Expanding GPIO count in PLC backplane modules using parallel bus protocols. IC Role / Device Role / Timing Role: Bidirectional bus interface register; holds output states during OE assertion while accepting new data on D inputs. Use Value: Supports hot-insertion of I/O cards by allowing bus drivers to enter high-Z before physical connection, preventing signal contention. |
| Test Equipment Data Capture | Legacy System Bus Arbitration |
|
Use Scenario: Capturing parallel test vectors from pattern generators into high-speed digital logic analyzers. IC Role / Device Role / Timing Role: High-fidelity 10-bit data sampler with 125 MHz clock support and sub-3 ns setup time. Use Value: Maintains signal integrity across 50-pF probe-loaded traces due to low output impedance (≤15 Ω) and fast edge rates. |
Use Scenario: Interfacing modern FPGA-based controllers with vintage 16-bit ISA or VMEbus peripherals. IC Role / Device Role / Timing Role: Level-shifting and bus-isolation bridge; translates 3.3 V FPGA outputs to 5 V TTL-compatible bus signals. Use Value: Eliminates need for discrete level shifters and bus buffers - single 74ACT11821DW handles 10-bit data + parity with guaranteed timing margins. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 10-bit bus-interface flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74ACT16374DGGR | 16-bit version in 48-pin TSSOP; identical ACT family specs but double width and higher ICC (160 µA max). | Used where full 16-bit bus width is required; not pin-compatible with 28-pin DW package. | Select when system requires >10-bit data path expansion without redesigning PCB layout for dual devices. |
| SN74ABT16374ADGGR | ABT-family (higher drive: ±64 mA), 16-bit, 48-pin TSSOP; TTL-compatible but higher power and different timing (tPLH ≤ 4.3 ns). | Suitable for heavier capacitive loads (>100 pF) or faster timing-critical buses; not drop-in due to pin count and voltage tolerance (5.5 V max). | Choose when driving long backplanes or high-fanout nets where 74ACT11821DW's ±24 mA is insufficient. |
Compared with 74ACT11821DW, the 74ACT16374DGGR offers doubled data width in a non-pin-compatible footprint, while SN74ABT16374ADGGR delivers higher drive strength and speed at the cost of increased power and layout incompatibility - both require PCB redesign but serve distinct scalability and loading requirements.
Availability
74ACT11821DW is available at Aetrix Electronics and suitable for memory interface buffers, industrial I/O port expansion, test equipment data capture, and legacy system bus arbitration requiring stable component supply across extended product lifecycles.
Supply support for 74ACT11821DW 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 U.S.-based semiconductor innovator founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The 74ACT11821DW belongs to TI's Advanced CMOS (ACT) logic family, engineered for high-speed, low-power, TTL-compatible bus interfacing in mission-critical industrial and instrumentation systems.
FAQ
What is the operating temperature range for the 74ACT11821DW?
The 74ACT11821DW is characterized for industrial operation from –40°C to +85°C. This range is validated per TI's SCAS156A datasheet and supports deployment in factory automation, motor drives, and outdoor instrumentation without derating. The military-grade 54ACT11821 variant extends to –55°C to +125°C, but the DW-packaged 74ACT11821DW strictly adheres to the industrial specification.
Does the 74ACT11821DW support true bidirectional bus operation?
The 74ACT11821DW is not inherently bidirectional - it is a unidirectional 10-bit D-type flip-flop with 3-state outputs. However, it enables bidirectional bus systems when paired with complementary devices (e.g., receivers or transceivers) and controlled via OE and direction logic. Its ability to retain internal state while outputs are in high-Z makes it ideal for master-side latching in such architectures.
What is the maximum capacitive load the 74ACT11821DW can drive reliably?
The 74ACT11821DW is specified to drive up to 50 pF loads while maintaining timing (tPLH/tPHL ≤ 12.6 ns) and DC levels (VOH ≥ 3.94 V, VOL ≤ 0.44 V at VCC = 4.5 V). Test conditions in the datasheet use CL = 50 pF, and performance degrades predictably beyond that - for >50 pF, consider the higher-drive SN74ABT16374ADGGR or add local buffering.
Is the 74ACT11821DW pin-compatible with older 74F or 74LS series devices?
No - the 74ACT11821DW has a unique 28-pin SOIC (DW) pinout optimized for flow-through layout and is not pin-compatible with any 74F or 74LS 10-bit register (e.g., 74F181, 74LS174). Its pin mapping (e.g., CLK on pin 10, OE on pin 17, dual VCC/GND clusters) is specific to the ACT family and requires dedicated PCB footprint design.
How does the EPIC™ process benefit the 74ACT11821DW in real-world applications?
The EPIC™ (Enhanced-Performance Implanted CMOS) 1-µm process used in the 74ACT11821DW delivers low input capacitance (4.5 pF), high noise immunity, and 500-mA latch-up immunity at 125°C. These traits directly translate to stable operation in electrically noisy industrial environments, reduced board-level filtering needs, and elimination of special handling precautions during assembly or field service.
74ACT11821DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Logic Type:
- -
- Number of Elements:
- -
- Number of Bits per Element:
- -
- Input Type:
- -
- Output Type:
- -
- Current - Output High, Low:
- -
- Voltage - Supply:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
74ACT11821DW FAQ
1.How can I place an order for 74ACT11821DW through Aetrix?
Please submit a Request for Quotation (RFQ) for 74ACT11821DW 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 74ACT11821DW reliable?
The price and inventory of 74ACT11821DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ACT11821DW is usually 5 days.
3.What payment methods are accepted for 74ACT11821DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ACT11821DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74ACT11821DW?
74ACT11821DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74ACT11821DW 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 74ACT11821DW?
For technical support, including 74ACT11821DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ACT11821DW requirements.
6.How does Aetrix verify that 74ACT11821DW is sourced from the original manufacturer or authorized distributors?
All 74ACT11821DW 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 74ACT11821DW meets industry standards.
7.What is the process for return or replacement of 74ACT11821DW?
All 74ACT11821DW units undergo pre-shipment inspection (PSI). If there is an issue with 74ACT11821DW, 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 74ACT11821DW part is unused and in its original packaging.
Return procedure for 74ACT11821DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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