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Texas Instruments SN74ABT821ANT
- Part No.:
- SN74ABT821ANT
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 24-DIP (0.300", 7.62mm)
- Datasheet:
-
SN74ABT821ANT.pdf
- Description:
- IC FF D-TYPE SNGL 10BIT 24DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,477
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Product details
Overview
SN74ABT821ANT 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 control and data acquisition systems. It operates at 5 V, delivers ±32 mA/±64 mA output drive, supports 125 MHz clock frequency, and features power-up/down high-impedance state for hot-swap compatibility.
For engineers reviewing the SN74ABT821ANT datasheet, SN74ABT821ANT pinout, SN74ABT821ANT application, or SN74ABT821ANT equivalent, key selection criteria include guaranteed 3-state behavior below 2.1 V VCC, latch-up immunity >500 mA, ground bounce <1 V, and compatibility with 5-V TTL/CMOS logic families in legacy backplane and I/O expansion designs.
Technical Context
This device implements ten independent D-type latches synchronized to the rising edge of CLK, with asynchronous 3-state control via OE. All outputs enter high-impedance when VCC is between 0–2.1 V, eliminating bus contention during power sequencing.
Its EPIC-IIB BiCMOS process enables low static current (≤250 µA in disabled state) while sustaining high-speed switching (tPLH/tPHL ≤6.2 ns at 5 V, CL = 50 pF) and robust ESD protection (>2000 V per MIL-STD-883 Method 3015).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Type | 10-bit positive-edge-triggered D flip-flop with 3-state outputs |
| Supply Voltage | 4.5 V to 5.5 V - ensures compatibility with standard 5-V TTL/CMOS systems |
| Output Drive | –32 mA IOH / +64 mA IOL - drives heavy capacitive loads without external buffers |
| Max Clock Frequency | 125 MHz - supports high-throughput data latching in real-time I/O interfaces |
| Propagation Delay | tPLH/tPHL ≤6.2 ns (VCC = 5 V, CL = 50 pF) - enables tight timing margins in synchronous bus architectures |
| Power-Up Behavior | High-impedance state when VCC < 2.1 V - prevents bus contention during power ramp-up/down |
| ESD Rating | >2000 V HBM - meets MIL-STD-883 requirements for rugged industrial deployment |
Pinout & Package
SN74ABT821ANT uses a 24-pin plastic DIP (NT) package with 0.6-inch body width and through-hole mounting. Pin 1 is marked by a notch or dot; pin numbering follows standard dual-in-line convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 | Data inputs (1D–10D) | Asynchronous D inputs for each of ten flip-flops; sampled on CLK↑ |
| 11 | GND | Ground reference for all internal circuitry and output drivers |
| 12 | VCC | 5-V supply input; powers BiCMOS core and output stages |
| 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 | Q outputs (1Q–10Q) | True outputs reflecting latched D values; tri-stated when OE is high |
| 23 | CLK | Global clock input; rising-edge sensitive for synchronous capture |
| 24 | OE | Active-low output-enable; controls 3-state mode independently of clock or latch state |
Key Features
| Feature | Design Value |
|---|---|
| EPIC-IIB BiCMOS process | Reduces dynamic power vs. pure bipolar while retaining high drive strength and speed |
| High-impedance on power ramp | Guaranteed Hi-Z when VCC ∈ [0, 2.1] V - eliminates bus glitches during cold-start or brownout |
| Output ground bounce (VOLP) | <1 V at VCC = 5 V - minimizes noise coupling into adjacent signal lines |
| Latch-up immunity | >500 mA per JEDEC JESD17 - ensures survivability under transient overcurrent events |
| Input clamp current rating | –18 mA - protects against negative transients without external diodes |
Applications
| Industrial Backplane Interface | Legacy I/O Expansion Module |
|---|---|
Use Scenario: Interfacing microcontroller GPIOs to a 10-bit parallel backplane in programmable logic controllers. IC Role / Device Role / Timing Role: Synchronizing and buffering bidirectional data transfers between CPU and peripheral cards using shared address/data bus. Use Value: High-drive outputs eliminate need for discrete bus transceivers; 3-state control allows seamless arbitration among multiple masters. | Use Scenario: Adding isolated digital I/O capability to an aging PLC rack via DIN-rail mounted expansion module. IC Role / Device Role / Timing Role: Latching sensor inputs and driving relay outputs with precise clock-aligned sampling and output update. Use Value: Power-up Hi-Z prevents spurious actuation during system boot; latch-up immunity ensures reliability in electrically noisy factory environments. |
| Test Equipment Data Capture | Avionics Signal Conditioning |
Use Scenario: Capturing parallel digital waveforms from multi-channel ADCs in automated test equipment. IC Role / Device Role / Timing Role: Simultaneously latching 10-bit sample words on system clock edge before serializing to FPGA controller. Use Value: 125 MHz max clock supports ≥100 MSPS sampling rates; low propagation skew ensures channel-to-channel timing alignment. | Use Scenario: Isolating and conditioning discrete status signals (e.g., landing gear position, flap angle) in legacy avionics subsystems. IC Role / Device Role / Timing Role: Buffering and level-shifting 28 V DC switch inputs to 5 V logic-compatible levels with EMI-hardened interface. Use Value: >2000 V HBM ESD rating withstands aircraft static discharge; wide operating temperature (–40°C to 85°C) satisfies DO-160 environmental requirements. |
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 |
|---|---|---|---|
| SN74ABT821ADW | SOIC-24 package (surface-mount), identical electrical specs and timing | Requires PCB rework for SMT assembly; no through-hole footprint compatibility | Select for new designs prioritizing board space and automated assembly. |
| SN74ABT821ADWR | Same SOIC-24 package, supplied in tape-and-reel (2000 pcs) instead of tube | Optimized for high-volume production; not suitable for hand-soldered prototypes | Select when sourcing for volume manufacturing with pick-and-place equipment. |
Compared with SN74ABT821ANT, the DW and DWR variants offer identical logic functionality and performance but differ in packaging and delivery format-making them functionally interchangeable where mechanical fit and procurement method permit.
Availability
SN74ABT821ANT is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy I/O expansion modules, and test equipment data capture systems requiring stable component supply across extended product lifecycles.
Supply support for SN74ABT821ANT 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 decades of heritage in industrial-grade logic families.
The ABT logic family-including SN74ABT821ANT-is engineered for high-noise industrial and instrumentation applications, emphasizing robustness, bus-driving capability, and power sequencing safety over consumer-grade speed or density.
FAQ
What is the operating temperature range for SN74ABT821ANT?
The SN74ABT821ANT is characterized for operation from –40°C to +85°C, meeting industrial-grade thermal requirements. This range is explicitly specified in the SCBS193E datasheet revision May 1997 and confirmed in TI's packaging addendum. The device maintains full electrical compliance-including setup/hold times, output drive, and 3-state behavior-across this entire span. Unlike the military-grade SN54ABT821 variant, SN74ABT821ANT does not support operation below –40°C or above +85°C.
Does SN74ABT821ANT support hot-plug or live-insertion into a powered bus?
Yes, SN74ABT821ANT supports safe live insertion due to its guaranteed high-impedance state when VCC is between 0 V and 2.1 V. During power-up or power-down, outputs remain Hi-Z regardless of OE or CLK state-preventing bus contention. However, to ensure Hi-Z above 2.1 V, OE must be tied to VCC via a pullup resistor (minimum value determined by driver sink capability). This behavior is documented in the "Power-Up/Down" section of the SCBS193E datasheet.
What is the maximum capacitive load SN74ABT821ANT can drive reliably?
SN74ABT821ANT is characterized with CL = 50 pF for timing measurements (tPLH, tPHL, etc.), and its high-drive outputs (–32 mA IOH / +64 mA IOL) enable reliable operation into loads exceeding 100 pF in many layouts. While no absolute maximum capacitance is specified, the device's low VOLP (<1 V) and fast edge rates (≤10 ns/V input transition) indicate robust driving capability for typical backplane traces and multi-drop buses. For loads >75 pF, layout optimization (short traces, proper termination) is recommended per TI application guidance.
Is SN74ABT821ANT RoHS compliant?
No, SN74ABT821ANT (NT package, plastic DIP) is not RoHS compliant. Per TI's Packaging Addendum, the NT package uses leaded solder (SNPB finish) and carries "No" in the RoHS column. It is intended for legacy industrial and aerospace applications where leaded through-hole assembly remains standard. For RoHS-compliant alternatives, consider SN74ABT821ADW (SOIC-24, NIPDAU finish) or SN74ABT821ADWR (same package, tape-and-reel).
How does the OE pin interact with internal latch operation in SN74ABT821ANT?
In SN74ABT821ANT, OE is purely an output control signal and has no effect on internal latch operation. Data can be captured on CLK↑ and retained in the flip-flops regardless of OE state. While outputs are in high-impedance (OE = high), new data may still be loaded, and previously stored data remains intact. This decoupling allows asynchronous data staging and synchronous output release-critical for pipelined bus protocols. This behavior is explicitly stated in the device description and function table of SCBS193E.
SN74ABT821ANT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ABT
- Package/Case:
- 24-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- 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:
- Through Hole
- Supplier Device Package:
- 24-PDIP
SN74ABT821ANT FAQ
1.How can I place an order for SN74ABT821ANT through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ABT821ANT 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 SN74ABT821ANT reliable?
The price and inventory of SN74ABT821ANT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ABT821ANT is usually 5 days.
3.What payment methods are accepted for SN74ABT821ANT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ABT821ANT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ABT821ANT?
SN74ABT821ANT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ABT821ANT 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 SN74ABT821ANT?
For technical support, including SN74ABT821ANT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ABT821ANT requirements.
6.How does Aetrix verify that SN74ABT821ANT is sourced from the original manufacturer or authorized distributors?
All SN74ABT821ANT 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 SN74ABT821ANT meets industry standards.
7.What is the process for return or replacement of SN74ABT821ANT?
All SN74ABT821ANT units undergo pre-shipment inspection (PSI). If there is an issue with SN74ABT821ANT, 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 SN74ABT821ANT part is unused and in its original packaging.
Return procedure for SN74ABT821ANT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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