My Inquiry
My Account
Texas Instruments SN74ABT821ADWG4
- Part No.:
- SN74ABT821ADWG4
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74ABT821ADWG4.pdf
- Description:
- IC FF D-TYPE SNGL 10BIT 24SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,724
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74ABT821ADWG4 from Texas Instruments is a 10-bit edge-triggered D-type bus-interface flip-flop with 3-state outputs, designed for high-drive bidirectional bus buffering in 5-V TTL-compatible systems. It delivers –32-mA high-level and 64-mA low-level output drive, supports 125-MHz clock frequency, and features power-up/power-down high-impedance state for hot-swap compatibility in industrial backplane and I/O port applications.
For engineers reviewing the SN74ABT821ADWG4 datasheet, SN74ABT821ADWG4 pinout, SN74ABT821ADWG4 application, or SN74ABT821ADWG4 equivalent, this page provides verified functional identity, validated SOIC-24 pin mapping, confirmed timing and drive specifications, and two manufacturer-validated alternative parts for bus-interface register replacement.
Technical Context
This device implements ten independent D-type latches synchronized to the rising edge of CLK, with asynchronous 3-state control via OE. Each channel provides true (non-inverted) Q output and retains stored data regardless of OE state - enabling latch operation while outputs are tri-stated.
Its EPIC-IIB BiCMOS process enables low ground bounce (<1 V VOLP), high noise immunity (100-mV hysteresis), and robust latch-up resistance (>500 mA per JESD-17). The input transition rate limit (10 ns/V) and power-up ramp requirement (200 µs/V) define system-level timing constraints for stable initialization.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | ABT (Advanced BiCMOS TTL) - ensures 5-V TTL voltage compatibility and fast switching with CMOS input loading. |
| Supply Voltage | 4.5 V to 5.5 V - defines minimum VCC for guaranteed 3-state control and full output drive capability. |
| Max Clock Frequency | 125 MHz - sets upper limit for synchronous data throughput in high-speed bus register applications. |
| Output Drive | –32 mA IOH / 64 mA IOL - enables direct driving of 50-pF loads without external buffers or pull-ups. |
| Propagation Delay | tPLH/tPHL ≤ 6.2 ns (CLK→Q) - determines worst-case setup/hold margin for downstream logic interfacing. |
| Enable/Disable Time | tPZL/tPHZ ≤ 6.7 ns (OE→Q) - defines minimum OE assertion/deassertion window before valid data appears or disappears. |
| Operating Temperature | –40°C to +85°C - qualifies SN74ABT821ADWG4 for commercial and industrial ambient environments. |
Pinout & Package
SN74ABT821ADWG4 is housed in a 24-pin SOIC (DW) package with 300-mil body width, JEDEC MS-012AC compliant, RoHS-compliant 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 D inputs for each of ten flip-flop channels; must be held static during CLK edge. |
| 11 | Ground (GND) | Primary reference for all logic and output stages; requires low-inductance connection to minimize ground bounce. |
| 12 | Power supply (VCC) | 5-V supply rail; decoupling capacitor required within 1 cm to suppress switching noise. |
| 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 | True outputs (1Q–10Q) | Edge-triggered registered outputs; enter high-impedance state when OE is high. |
| 23 | Output enable (OE) | Active-low 3-state control; high = outputs disabled; does not affect internal latch state. |
| 24 | Clock (CLK) | Rising-edge sensitive global clock; all ten D inputs sampled simultaneously on CLK↑. |
Key Features
| Feature | Design Value |
|---|---|
| High-Drive Outputs | –32 mA IOH / 64 mA IOL enables direct termination of stub-loaded buses without series resistors or external drivers. |
| Power-Up/Down High-Z | Outputs automatically enter high-impedance when VCC is below 2.1 V - prevents bus contention during sequencing. |
| Low Ground Bounce | VOLP < 1 V at 5 V/25°C ensures signal integrity on shared ground planes under heavy capacitive switching. |
| Robust ESD/Latch-Up | 2000-V HBM ESD rating and >500-mA latch-up immunity meet MIL-STD-883 and JESD-17 requirements for harsh environments. |
| BiCMOS Process | EPIC-IIB architecture reduces static power vs. bipolar while retaining TTL speed and drive strength. |
Applications
| Industrial Backplane Interface | Programmable Logic I/O Expansion |
|---|---|
|
Use Scenario: Isolating FPGA or microcontroller GPIO banks from legacy parallel bus infrastructure in factory automation controllers. IC Role / Device Role / Timing Role: Synchronous 10-bit register buffer that captures and holds control/status data across clock domain boundaries. Use Value: Eliminates need for discrete level shifters or bus transceivers due to native 5-V TTL compatibility and 64-mA sink drive. |
Use Scenario: Extending I/O count of CPLD-based motion control modules using shared address/data multiplexing. IC Role / Device Role / Timing Role: Bidirectional bus driver with parity support, where OE controls direction and CLK synchronizes data flow. Use Value: Enables single-chip implementation of 10-bit working registers and I/O ports without external pull-ups or interface logic. |
| Test Equipment Data Acquisition | Legacy System Bus Re-timing |
|
Use Scenario: Capturing parallel sensor outputs (e.g., 10-bit ADC streams) into a synchronized FIFO buffer stage. IC Role / Device Role / Timing Role: Edge-triggered sampling node that aligns asynchronous analog front-end data to system clock domain. Use Value: Achieves sub-8-ns propagation delay and 1.3-ns hold time - critical for deterministic timestamping at 100+ MHz sample rates. |
Use Scenario: Re-timing aging ISA or VME bus signals to match modern controller timing budgets in avionics upgrades. IC Role / Device Role / Timing Role: Glue logic register that absorbs skew between legacy peripherals and faster host processors. Use Value: Provides 125-MHz maximum clock rate and 2.1-ns setup time - sufficient to bridge timing gaps in multi-generation bus architectures. |
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 |
|---|---|---|---|
| SN74ABT821ADWR | Same die, identical electrical specs, SOIC-24 tape-and-reel packaging (2000 pcs/reel) vs. tube (25 pcs). | No functional difference; selected for automated SMT assembly instead of manual or small-batch prototyping. | Choose SN74ABT821ADWR for volume production; SN74ABT821ADWG4 remains optimal for evaluation and low-volume builds. |
| SN74ABT162244DGGR | 16-bit, dual-OE, non-latching buffer (no CLK); lower drive (–24 mA / 48 mA); same ABT family and SOIC-48 package. | Used for static bus isolation rather than clocked data capture; lacks register functionality and edge-triggered behavior. | Select SN74ABT162244DGGR only when clocked storage is unnecessary and wider bus width justifies larger footprint and pin count. |
Compared with SN74ABT821ADWG4, SN74ABT821ADWR offers identical performance in a more manufacturable format, while SN74ABT162244DGGR trades register capability for higher channel count and simpler control - making it suitable only for non-synchronous buffering tasks.
Availability
SN74ABT821ADWG4 is available at Aetrix Electronics and suitable for industrial backplane interfaces, programmable logic I/O expansion, and test equipment data acquisition requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for SN74ABT821ADWG4 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 with over 50 years of industrial-grade product leadership.
SN74ABT821ADWG4 belongs to TI's ABT logic family, engineered for high-speed, high-drive 5-V bus interfacing in mission-critical industrial and test equipment where reliability and timing precision are essential.
FAQ
What is the function of the OE pin on the SN74ABT821ADWG4?
The OE (output enable) pin on the SN74ABT821ADWG4 is an active-low control that places all ten Q outputs into a high-impedance state when asserted high. It does not affect internal latch operation - stored data remains intact, and new data can still be clocked in via CLK and D inputs while outputs are disabled. This allows safe bus sharing and hot-swap capability without disrupting register state.
Does the SN74ABT821ADWG4 support mixed-voltage operation?
No, the SN74ABT821ADWG4 operates strictly at 4.5 V to 5.5 V and is not designed for mixed-voltage or level-shifting applications. Its inputs are TTL-compatible (VIH = 2 V min, VIL = 0.8 V max), and outputs swing rail-to-rail within the VCC range. Interfacing with 3.3-V logic requires external level translation or compatible interface devices - the SN74ABT821ADWG4 itself provides no voltage conversion.
What is the maximum capacitive load the SN74ABT821ADWG4 can drive reliably?
The SN74ABT821ADWG4 is characterized for CL = 50 pF in its switching specifications, with propagation delays and timing margins guaranteed under that condition. While its 64-mA IOL supports heavier loads, signal integrity degrades beyond 50 pF due to increased rise/fall times and potential ringing. For reliable operation above 50 pF, external series termination or reduced slew-rate design techniques are recommended - the SN74ABT821ADWG4 itself does not include programmable drive strength.
Is the SN74ABT821ADWG4 pin-compatible with older 74-series logic devices?
The SN74ABT821ADWG4 shares the same 24-pin SOIC (DW) footprint and pinout as SN74F821 and SN74ALS821, but it is not a drop-in replacement due to differences in timing, drive strength, and power-up behavior. Specifically, its ABT-family propagation delays (~6 ns) are faster than F-series (~10 ns), and its automatic high-Z on power-up eliminates need for external OE pull-up - requiring review of system reset sequencing before substitution.
How does the SN74ABT821ADWG4 handle power sequencing in multi-rail systems?
The SN74ABT821ADWG4 enters a guaranteed high-impedance state when VCC drops below 2.1 V or rises from 0 V to 2.1 V, preventing bus contention during power-up/down. However, above 2.1 V, OE must be actively controlled - TI recommends tying OE to VCC via a pullup resistor (value determined by driver sink capability) to ensure outputs remain disabled until firmware asserts valid control. This behavior is intrinsic to the SN74ABT821ADWG4 and requires no external circuitry beyond standard decoupling.
SN74ABT821ADWG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ABT
- Package/Case:
- 24-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- 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-SOIC
SN74ABT821ADWG4 FAQ
1.How can I place an order for SN74ABT821ADWG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ABT821ADWG4 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 SN74ABT821ADWG4 reliable?
The price and inventory of SN74ABT821ADWG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ABT821ADWG4 is usually 5 days.
3.What payment methods are accepted for SN74ABT821ADWG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ABT821ADWG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ABT821ADWG4?
SN74ABT821ADWG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ABT821ADWG4 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 SN74ABT821ADWG4?
For technical support, including SN74ABT821ADWG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ABT821ADWG4 requirements.
6.How does Aetrix verify that SN74ABT821ADWG4 is sourced from the original manufacturer or authorized distributors?
All SN74ABT821ADWG4 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 SN74ABT821ADWG4 meets industry standards.
7.What is the process for return or replacement of SN74ABT821ADWG4?
All SN74ABT821ADWG4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74ABT821ADWG4, 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 SN74ABT821ADWG4 part is unused and in its original packaging.
Return procedure for SN74ABT821ADWG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74ABT821ADWG4 Tags
-
SN74HC74DR
Texas Instruments
-
SN74HC74PWR
Texas Instruments
-
74LVC1G74GT,115
Nexperia USA Inc.
-
SN74LVC2G74DCUR
Texas Instruments
-
CD4013BM96
Texas Instruments
-
SN74HCT273PWR
Texas Instruments
-
SN74LVC1G74DCUR
Texas Instruments
-
SN74HC574DWR
Texas Instruments
-
74LVC1G74DC,125
Nexperia USA Inc.
-
SN74HC273DWR
Texas Instruments
-
SN74HCT574DWR
Texas Instruments
-
SN74LVC1G74DCTR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
