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Texas Instruments SN74ALS29821DWRG4
- Part No.:
- SN74ALS29821DWRG4
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74ALS29821DWRG4.pdf
- Description:
- IC FF D-TYPE SNGL 10BIT 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,343
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Product details
Overview
SN74ALS29821DWRG4 from Texas Instruments is a 10-bit edge-triggered D-type flip-flop with 3-state outputs, designed for driving highly capacitive or low-impedance bus loads. It operates at 5 V, supports 48 mA sink / −24 mA source output drive, features power-up high-impedance state, and is qualified for 0°C to 70°C industrial operation in SOIC-24 package.
For engineers reviewing the SN74ALS29821DWRG4 datasheet, SN74ALS29821DWRG4 pinout, SN74ALS29821DWRG4 application, or SN74ALS29821DWRG4 equivalent, key selection criteria include 10-bit synchronous data latching, OE-controlled 3-state bus interface capability, undershoot-protection circuitry, and compatibility with wider address/data paths requiring parity support.
Technical Context
This device implements ten independent D-type flip-flops, each triggered on the positive edge of CLK. Output-enable (OE) controls all ten Q outputs simultaneously, placing them in high-impedance without affecting internal latch states - enabling data retention during bus arbitration.
It uses ALS (Advanced Low-Power Schottky) logic technology, delivering TTL-compatible input thresholds (VIL = 0.8 V, VIH = 2.0 V), guaranteed 2 ns minimum hold time, 4 ns setup time, and propagation delays as low as 2 ns (CL = 50 pF) for both CLK→Q and OE→Q transitions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | ALS (Advanced Low-Power Schottky) - ensures TTL compatibility with reduced power vs standard LS. |
| Supply Voltage | 4.75 V to 5.25 V - tight regulation required; not rated for 5.5 V continuous operation. |
| Output Drive | 48 mA sink / −24 mA source - sufficient to drive 50-pF bus loads directly without external buffers. |
| Propagation Delay | 2 ns (min) to 10 ns (max) CLK→Q at CL = 50 pF - enables timing-critical bus register applications. |
| Enable/Disable Time | 1 ns (min) to 14 ns (max) OE→Q transition at CL = 50 pF - supports fast bus turnaround in multiplexed systems. |
| Operating Temperature | 0°C to 70°C - industrial-grade qualification; excludes extended or military temperature ranges. |
| Input Thresholds | VIL ≤ 0.8 V, VIH ≥ 2.0 V - compatible with standard TTL and 5-V CMOS logic interfaces. |
Pinout & Package
SN74ALS29821DWRG4 is housed in a 24-pin SOIC (DW) package, 300-mil body width, with standard pin pitch (1.27 mm) and gull-wing leads. The package is RoHS-compliant, moisture sensitivity level 1, and rated for peak reflow at 260°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | OE | Active-low output enable - disables all Q outputs to high-impedance; does not affect internal flip-flop state. |
| 2–11 | 1D–10D | Data inputs - sampled on rising CLK edge; asynchronous to OE control. |
| 12 | GND | Ground reference - must be low-impedance connection for noise immunity and output drive integrity. |
| 13 | VCC | Positive supply - requires local 0.1 µF ceramic decoupling adjacent to pin. |
| 14–23 | 1Q–10Q | 3-state buffered outputs - reflect D-input state when OE is low; high-Z when OE is high. |
| 24 | CLK | Positive-edge clock - synchronous trigger for all 10 flip-flops; no internal synchronization delay. |
Key Features
| Feature | Design Value |
|---|---|
| Power-up High-Impedance State | Prevents bus contention at power-on/off - outputs remain tri-stated until VCC stabilizes and OE is asserted. |
| Undershoot-Protection Circuitry | Clamps negative transients below GND to −1.2 V - protects against signal reflections on long PCB traces or unterminated buses. |
| Buffered Control Inputs | Reduces DC loading on OE and CLK lines - allows fan-out to multiple devices without signal degradation. |
| 10-Bit Bus Width Extension | Supports parity-enabled 11-bit buses (10 data + 1 parity) - used in legacy memory controllers and I/O port expansion. |
| Functionally Equivalent to AM29821 | Drop-in replacement for AMD's AM29821 - identical pinout, timing, and electrical behavior per TI and AMD documentation. |
Applications
| Memory Address Latch | Parallel I/O Port Buffer |
|---|---|
|
Use Scenario: Latching 10-bit address segments in 8086/8088-based systems with parity checking. IC Role / Device Role / Timing Role: Edge-triggered register holding upper/lower address bits during bus cycle; synchronized to CPU CLK. Use Value: Enables clean separation of address and data phases on multiplexed AD bus while supporting parity validation. |
Use Scenario: Bidirectional parallel interface between microcontroller and peripheral (e.g., printer, display controller). IC Role / Device Role / Timing Role: 3-state bus driver providing direction-controlled data flow; OE tied to microcontroller port control line. Use Value: Eliminates need for external bus transceivers - reduces component count and layout complexity in legacy embedded designs. |
| Parity Generator/Checker Interface | Legacy Backplane Data Register |
|
Use Scenario: Interfacing parity generator ICs (e.g., SN74ALS29820) to system data bus with 10-bit width + parity bit. IC Role / Device Role / Timing Role: Synchronizing parity-augmented data before transmission onto shared backplane bus. Use Value: Ensures timing-aligned delivery of full 11-bit word (10 data + 1 parity), meeting strict setup/hold requirements of bus receivers. |
Use Scenario: Registering data across modular backplane slots in industrial PLC or test equipment chassis. IC Role / Device Role / Timing Role: Isolating slot-specific data paths using OE-controlled 3-state outputs to prevent bus conflicts. Use Value: Provides deterministic, glitch-free bus arbitration in multi-slot systems where modules power up asynchronously. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 10-bit 3-state register applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ALS29821DW | Same die, identical DW package, same marking - differs only in tape-and-reel vs tube packaging (RG4 denotes tube). | No functional difference; RG4 suffix indicates tube packaging (25 pcs/tube), while bare DW is reel-packaged. | Select SN74ALS29821DWRG4 for low-volume prototyping or small-batch production requiring tube delivery. |
| AM29821 | Pin- and function-compatible with identical timing, drive strength, and ALS logic family - documented by AMD and TI as direct replacement. | Identical use in bus register, I/O port, and parity interface roles; validated in same military and industrial systems. | Choose AM29821 only if dual-sourcing or legacy BOM compliance requires AMD-branded part; otherwise SN74ALS29821DWRG4 offers full TI support. |
Compared with SN74ALS29821DWRG4, the SN74ALS29821DW offers identical functionality in reel format for automated assembly, while AM29821 provides second-source assurance with no design or layout changes needed - both preserve the same 10-bit synchronous register behavior, 3-state control, and industrial temperature range.
Availability
SN74ALS29821DWRG4 is available at Aetrix Electronics and suitable for industrial control panels, legacy PC/PLC motherboard repair, and aerospace avionics spares programs requiring stable component supply over extended product lifecycles.
Supply support for SN74ALS29821DWRG4 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 company founded in 1930, specializing in analog, embedded processing, and logic solutions with broad industrial and defense heritage.
The SN74ALS29821DWRG4 belongs to TI's legacy ALS logic portfolio, engineered for robustness in high-noise, bus-intensive environments such as industrial backplanes and military computing systems.
FAQ
What is the operating voltage range for SN74ALS29821DWRG4?
The SN74ALS29821DWRG4 operates within a recommended supply range of 4.75 V to 5.25 V. Absolute maximum VCC is 5.5 V, but sustained operation above 5.25 V risks parametric shift or reliability degradation. This range ensures stable ALS logic thresholds and output drive performance across the full 0°C to 70°C temperature span.
Does SN74ALS29821DWRG4 support hot insertion or live bus swapping?
SN74ALS29821DWRG4 supports controlled bus isolation via its OE input but is not hot-swap rated. Its power-up high-impedance state prevents initial contention, and undershoot protection mitigates transient stress - however, it lacks dedicated hot-swap circuitry (e.g., slew-rate limiting, VCC sequencing detection), so system-level safeguards are required for live insertion.
Can SN74ALS29821DWRG4 replace SN74ALS29821DW in an existing design?
Yes - SN74ALS29821DWRG4 is functionally and electrically identical to SN74ALS29821DW, differing only in packaging format (tube vs reel). Pinout, timing, drive strength, and thermal characteristics are fully matched. No PCB or schematic changes are needed when substituting SN74ALS29821DWRG4 for SN74ALS29821DW.
What is the maximum capacitive load SN74ALS29821DWRG4 can drive reliably?
SN74ALS29821DWRG4 is characterized up to 300 pF load capacitance, with propagation delays specified at both 50 pF and 300 pF. At 300 pF, tPLH/tPHL remains ≤21 ns, and output drive maintains 48 mA sink capability - making it suitable for driving long traces, multiple TTL inputs, or unterminated stubs in legacy backplane architectures.
Is SN74ALS29821DWRG4 RoHS compliant?
Yes - SN74ALS29821DWRG4 carries NIPDAU (nickel-palladium-gold) lead finish and is RoHS-compliant per TI's Package Option Addendum. It meets JEDEC Level-1 moisture sensitivity rating and is qualified for peak reflow at 260°C, supporting standard lead-free assembly processes without derating.
SN74ALS29821DWRG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ALS
- Package/Case:
- 24-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Standard
- Type:
- D-Type
- Output Type:
- Tri-State, Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 10
- Clock Frequency:
- -
- Max Propagation Delay @ V, Max CL:
- 16ns @ 5V, 300pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 24mA, 48mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Current - Quiescent (Iq):
- 115 mA
- Input Capacitance:
- -
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SOIC
SN74ALS29821DWRG4 FAQ
1.How can I place an order for SN74ALS29821DWRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS29821DWRG4 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 SN74ALS29821DWRG4 reliable?
The price and inventory of SN74ALS29821DWRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS29821DWRG4 is usually 5 days.
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Once your SN74ALS29821DWRG4 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 SN74ALS29821DWRG4?
For technical support, including SN74ALS29821DWRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS29821DWRG4 requirements.
6.How does Aetrix verify that SN74ALS29821DWRG4 is sourced from the original manufacturer or authorized distributors?
All SN74ALS29821DWRG4 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 SN74ALS29821DWRG4 meets industry standards.
7.What is the process for return or replacement of SN74ALS29821DWRG4?
All SN74ALS29821DWRG4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS29821DWRG4, 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 SN74ALS29821DWRG4 part is unused and in its original packaging.
Return procedure for SN74ALS29821DWRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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