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Texas Instruments SN74ABT821ADBR
- Part No.:
- SN74ABT821ADBR
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 24-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
SN74ABT821ADBR.pdf
- Description:
- IC FF D-TYPE SNGL 10BIT 24SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,773
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Product details
Overview
SN74ABT821ADBR from Texas Instruments is a 10-bit edge-triggered D-type bus-interface flip-flop with 3-state outputs, designed for high-capacitance bus driving in industrial and embedded systems. It operates at 4.5–5.5 V, delivers ±32-mA/64-mA drive strength, supports up to 125 MHz clock frequency, and features power-up/power-down high-impedance state - enabling safe hot-insertion in backplane and I/O port applications.
For engineers reviewing the SN74ABT821ADBR datasheet, SN74ABT821ADBR pinout, SN74ABT821ADBR application, or SN74ABT821ADBR equivalent, key selection criteria include guaranteed 3-state behavior below 2.1 V VCC, sub-7 ns propagation delay (tPLH/tPHL), low ground bounce (<1 V VOLP), latch-up immunity (>500 mA), and ESD protection exceeding 2000 V per MIL-STD-883.
Technical Context
This device implements ten independent positive-edge-triggered D flip-flops with a shared clock (CLK) and buffered output-enable (OE) control. All outputs enter high-impedance state when OE is high or when VCC is between 0–2.1 V - ensuring bus isolation during power sequencing without external pullups.
Its EPIC-IIB BiCMOS architecture enables high-drive capability while maintaining TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V) and low static current (ICC < 250 µA in disabled state). Timing parameters are specified at CL = 50 pF and TA = 25°C, with setup/hold times of 2.1 ns / 1.3 ns respectively.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Type | 10-bit positive-edge-triggered D-type flip-flop with 3-state outputs |
| Supply Voltage | 4.5 V to 5.5 V - ensures compatibility with 5-V TTL and mixed-voltage system rails |
| Output Drive | –32 mA IOH / +64 mA IOL - drives heavy capacitive buses without external buffers or termination |
| Max Clock Frequency | 125 MHz - supports high-speed data latching in memory interfaces and bus transceivers |
| Propagation Delay | tPLH/tPHL ≤ 6.2 ns (typ. 4.1/4.6 ns) - enables tight timing margins in synchronous designs |
| Power-Up Behavior | High-impedance outputs when VCC < 2.1 V - prevents bus contention during power ramp-up/down |
| ESD Rating | >2000 V HBM - meets MIL-STD-883 Method 3015 for robust handling in manufacturing and field service |
Pinout & Package
SN74ABT821ADBR is packaged in a 24-pin Shrink Small-Outline (DB) package with 300-mil body width and gull-wing leads. Pin pitch is 0.025 inch (0.65 mm), and the package is RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 | Data inputs (1D–10D) | Asynchronous parallel data inputs synchronized on CLK rising edge |
| 11 | GND | Ground reference for all internal circuitry and output drivers |
| 12 | VCC | Positive supply rail (4.5–5.5 V); powers both logic core and output drivers |
| 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 | Q outputs (1Q–10Q) | Registered true outputs; placed in high-Z when OE = high or VCC < 2.1 V |
| 23 | CLK | Global clock input - positive-edge sensitive; triggers simultaneous latching of all 10 bits |
| 24 | OE | Active-low output-enable - high disables all outputs into high-impedance state |
Key Features
| Feature | Design Value |
|---|---|
| BiCMOS EPIC-IIB process | Reduces dynamic power vs. pure bipolar while retaining TTL-level drive and speed |
| Bus-friendly 3-state control | OE-independent power sequencing: outputs auto-enter high-Z below 2.1 V VCC |
| High-current drive capability | 64-mA sink / 32-mA source per output - eliminates need for external bus drivers |
| Low ground bounce | VOLP < 1 V at VCC = 5 V - minimizes noise coupling into adjacent signal lines |
| Latch-up immunity | Exceeds 500 mA per JEDEC JESD17 - ensures reliability in noisy industrial environments |
Applications
| Backplane Data Latching | I/O Port Expansion |
|---|---|
Use Scenario: Latching address/data signals across modular chassis backplanes with long trace lengths and high capacitance. IC Role / Device Role / Timing Role: Synchronizes and buffers 10-bit parallel data streams between plug-in cards and main controller under strict timing constraints. Use Value: High drive strength and sub-7 ns propagation delay ensure signal integrity across >100 pF loads without added termination or repeaters. | Use Scenario: Expanding microcontroller GPIO count for industrial PLC I/O modules requiring bidirectional data flow. IC Role / Device Role / Timing Role: Acts as configurable 10-bit bidirectional I/O register with independent OE control for direction management. Use Value: 3-state outputs allow shared bus operation; power-up high-Z prevents glitches during MCU boot sequence. |
| Memory Interface Buffering | Parity-Enabled Bus Driving |
Use Scenario: Interfacing FPGA-based memory controllers to external SRAM or FIFO devices with wide data buses. IC Role / Device Role / Timing Role: Provides registered, level-shifted, and driven data path between logic domain and memory array. Use Value: 125 MHz max clock rate and 2.1 ns setup time support high-bandwidth burst transfers without timing closure issues. | Use Scenario: Implementing parity-checked data paths in telecom line cards where error detection is mandatory. IC Role / Device Role / Timing Role: Latches 10-bit data plus parity bit (using one spare D/Q pair) before transmission over differential bus. Use Value: Simultaneous edge-triggered capture of data and parity ensures temporal alignment critical for ECC validation. |
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 |
|---|---|---|---|
| SN74ABT824ADBR | Same pinout and function but includes separate master reset (MR) input; otherwise identical timing and drive specs | Required where synchronous global reset of all 10 bits is needed alongside OE control | Select SN74ABT824ADBR only if MR functionality is essential; SN74ABT821ADBR offers simpler control for OE-only use cases |
| SN74LVTH162374DGGR | 16-bit, dual-rail (3.3 V core / 5 V tolerant I/O), lower drive (–24/+24 mA), slower max clock (100 MHz) | Suitable for mixed-voltage systems needing 3.3-V logic compatibility and higher channel density | Choose SN74LVTH162374DGGR for 3.3-V domains or space-constrained layouts; SN74ABT821ADBR remains optimal for legacy 5-V bus systems demanding full drive |
Compared with SN74ABT824ADBR, SN74ABT821ADBR simplifies control by omitting MR - reducing external logic and PCB routing overhead. Against SN74LVTH162374DGGR, SN74ABT821ADBR delivers higher drive, faster timing, and native 5-V operation - making it preferable for industrial backplanes and legacy embedded buses where voltage translation adds cost and complexity.
Availability
SN74ABT821ADBR is available at Aetrix Electronics and suitable for industrial backplane latching, PLC I/O expansion, memory interface buffering, and parity-enabled bus driving requiring stable component supply across extended product lifecycles.
Supply support for SN74ABT821ADBR 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 specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The SN74ABT821A series belongs to TI's ABT logic family - engineered for high-speed, high-drive 5-V bus interfacing with robust power sequencing behavior and military-grade reliability.
FAQ
What is the operating temperature range for SN74ABT821ADBR?
The SN74ABT821ADBR is characterized for operation from –40°C to +85°C, matching the SN74ABT821A specification. This industrial temperature grade ensures reliable performance in factory automation, networking equipment, and outdoor embedded systems where ambient conditions exceed commercial limits. The device maintains full timing and drive specifications across this entire range.
Does SN74ABT821ADBR support hot-swap or live-insertion?
Yes, SN74ABT821ADBR supports hot-swap via its inherent power-up/power-down high-impedance feature: outputs automatically enter high-Z when VCC is between 0–2.1 V. This prevents bus contention during insertion/removal. For guaranteed high-Z above 2.1 V, tie OE to VCC through a pullup resistor - minimum value determined by driver sink capability, typically 4.7 kΩ.
What is the maximum capacitive load SN74ABT821ADBR can drive reliably?
SN74ABT821ADBR is tested and specified with CL = 50 pF, but its ±32-mA/64-mA drive strength allows reliable operation into >100 pF loads typical of backplane traces and multi-drop buses. Ground bounce remains <1 V at 5 V, confirming signal integrity under heavy loading. For loads exceeding 150 pF, verify timing margins using actual board parasitics and worst-case VCC/temperature corners.
Is SN74ABT821ADBR pin-compatible with older SN74ABT821 variants?
Yes, SN74ABT821ADBR shares identical pinout and functionality with SN74ABT821ADW and SN74ABT821ADR - all use the same 24-pin DB/DW/D package footprint and logic behavior. The "A" suffix denotes improved AC/DC specs versus original SN74ABT821, including tighter timing and enhanced ESD/latch-up ratings, while maintaining full backward compatibility in layout and firmware.
How does the OE pin behave when left unconnected?
Leaving OE unconnected is not recommended: the internal structure lacks a default pullup, so OE may float near switching threshold and cause unpredictable output states. TI specifies that unused inputs must be held high or low. To ensure defined high-Z, connect OE to VCC via a pullup resistor (e.g., 4.7 kΩ); to enable outputs, tie OE to GND or drive it actively low with compatible logic.
SN74ABT821ADBR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ABT
- Package/Case:
- 24-SSOP (0.209", 5.30mm 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:
- 125 MHz
- Max Propagation Delay @ V, Max CL:
- 6.2ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 32mA, 64mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 250 µA
- Input Capacitance:
- 3.5 pF
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SSOP
SN74ABT821ADBR FAQ
1.How can I place an order for SN74ABT821ADBR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ABT821ADBR 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 SN74ABT821ADBR reliable?
The price and inventory of SN74ABT821ADBR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ABT821ADBR is usually 5 days.
3.What payment methods are accepted for SN74ABT821ADBR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ABT821ADBR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ABT821ADBR?
SN74ABT821ADBR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ABT821ADBR 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 SN74ABT821ADBR?
For technical support, including SN74ABT821ADBR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ABT821ADBR requirements.
6.How does Aetrix verify that SN74ABT821ADBR is sourced from the original manufacturer or authorized distributors?
All SN74ABT821ADBR 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 SN74ABT821ADBR meets industry standards.
7.What is the process for return or replacement of SN74ABT821ADBR?
All SN74ABT821ADBR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ABT821ADBR, 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 SN74ABT821ADBR part is unused and in its original packaging.
Return procedure for SN74ABT821ADBR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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