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Texas Instruments SN74ABT646PWR
- Part No.:
- SN74ABT646PWR
- Manufacturer:
- Texas Instruments
- Package:
- 24-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74ABT646PWR.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 24TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,112
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Product details
Overview
SN74ABT646PWR from Texas Instruments is an octal bus transceiver and register IC with 3-state outputs, designed for bidirectional data flow control between A and B 8-bit buses in high-speed digital systems. It supports real-time and registered transfer modes, features ±32-mA high-drive outputs, operates at 5 V, and is rated for –40°C to 85°C industrial temperature range.
For engineers reviewing the SN74ABT646PWR datasheet, SN74ABT646PWR pinout, SN74ABT646PWR application, or SN74ABT646PWR equivalent, key selection considerations include its dual-clock (CLKAB/CLKBA) register control, DIR/OE/SAB/SBA logic interface, TSSOP-24 package footprint, and compatibility with 5-V TTL-level bus architectures requiring storage-enabled data routing.
Technical Context
The SN74ABT646PWR integrates eight independent bidirectional channels, each with D-type flip-flop registers clocked on low-to-high transitions of CLKAB or CLKBA. It implements four distinct bus-management functions-real-time A→B/B→A transfer, simultaneous A/B storage, and stored-data output-governed by OE, DIR, SAB, and SBA control inputs.
Its EPIC-IIB BiCMOS process enables high-output drive (–32 mA IOH, 64 mA IOL), low ground bounce (<1 V VOLP), and latch-up immunity (>500 mA per JESD-17), while maintaining TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V) and 125-MHz maximum clock frequency.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - ensures stable operation across standard 5-V rail tolerances without level-shifting. |
| Output Drive | –32 mA IOH / 64 mA IOL - drives heavy capacitive loads and multiple TTL inputs without external buffers. |
| Max Clock Frequency | 125 MHz - supports high-throughput data transfer in fast synchronous bus systems. |
| Propagation Delay | tPLH/tPHL ≤ 7.8 ns (CLK→bus) - enables sub-8-ns timing-critical path resolution in 125-MHz designs. |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded and communications equipment. |
| Package | TSSOP-24 (PW) - 6.95 mm × 4.4 mm footprint with 0.65-mm pitch, optimized for space-constrained PCB layouts. |
| 3-State Enable Time | tPZH ≤ 6.3 ns - ensures rapid bus release during dynamic direction switching. |
Pinout & Package
TSSOP-24 (PW) package: 7.9 mm × 4.4 mm body, 0.65 mm lead pitch, 1.2 mm max height, exposed pad not present, RoHS-compliant NiPdAu finish, MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 4–11, 13–20 | A1–A8, B1–B8 I/O | Octal bidirectional data ports - connect directly to A and B system buses; internally isolated when OE high. |
| 3 | DIR | Direction control - sets bus flow direction (A→B when high, B→A when low) during transceiver mode. |
| 21 | OE | Output enable - disables all outputs to high-impedance state when high; must be pulled up for power-up safety. |
| 1, 23 | CLKAB, CLKBA | Register clocks - latch data from A or B bus on rising edge; independent control enables asynchronous storage. |
| 2, 22 | SAB, SBA | Select controls - choose between real-time or registered data for output to opposite bus. |
| 12, 24 | GND, VCC | Power terminals - decoupling capacitor required near Pin 12 (GND) and Pin 24 (VCC) for noise suppression. |
Key Features
| Feature | Design Value |
|---|---|
| Dual-register architecture | Independent CLKAB/CLKBA inputs allow concurrent capture of A- and B-bus data without conflict. |
| High-drive 3-state outputs | –32 mA source / 64 mA sink capability eliminates need for external line drivers in dense backplane interfaces. |
| Bus isolation with storage | OE high disables outputs while preserving register contents - enables glitch-free bus arbitration and hold states. |
| Low ground bounce | VOLP < 1 V at 5 V/25°C - prevents signal corruption during simultaneous output switching in multi-bit transfers. |
| TTL-compatible control logic | VIH = 2 V / VIL = 0.8 V thresholds ensure interoperability with legacy 5-V microcontrollers and FPGAs. |
Applications
| Backplane Data Routing | Industrial PLC I/O Expansion |
|---|---|
Use Scenario: Bidirectional data exchange between CPU module and peripheral I/O cards across a shared 8-bit parallel backplane. IC Role / Device Role / Timing Role: SN74ABT646PWR acts as a registered bus transceiver, buffering and synchronizing data transfers between modules using CLKAB/CLKBA for deterministic sampling. Use Value: Enables reliable handshaking-free communication at up to 125 MHz while isolating fault domains via 3-state control during hot-swap events. | Use Scenario: Extending digital input/output capacity of a programmable logic controller using modular expansion slots. IC Role / Device Role / Timing Role: SN74ABT646PWR serves as a configurable I/O register, capturing sensor status or actuator commands on one bus and presenting them to the PLC CPU on the other. Use Value: Provides synchronized latching of field-side signals with DIR/SAB/SBA logic, eliminating metastability in noisy industrial environments. |
| Test Equipment Bus Interface | Legacy System Interfacing |
Use Scenario: Connecting automated test equipment (ATE) controller to device-under-test (DUT) boards with mismatched timing or voltage domains. IC Role / Device Role / Timing Role: SN74ABT646PWR functions as a timing-flexible bridge, storing test vectors from the controller and releasing them synchronously to the DUT using CLKBA-triggered output. Use Value: Resolves setup/hold violations between high-speed ATE and slower DUTs via register staging, improving test repeatability and yield. | Use Scenario: Integrating modern microcontroller-based subsystems into older 5-V TTL-based instrumentation or communication hardware. IC Role / Device Role / Timing Role: SN74ABT646PWR operates as a protocol-transparent bus coupler, translating between MCU GPIO timing and legacy parallel bus protocols (e.g., IEEE-488 subsets). Use Value: Maintains full 5-V drive strength and noise margin while enabling software-controlled direction and data staging - critical for backward compatibility. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal registered transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ABT245PWR | No internal registers; transparent-only transceiver; identical 3-state drive and pinout except missing CLKAB/CLKBA/SAB/SBA. | Suitable only for real-time bidirectional transfer - cannot store or time-align data between buses. | Select when register functionality is unnecessary and cost or propagation delay is prioritized. |
| SN74LVTH16245DGGR | 16-bit, dual-supply (1.65–3.6 V core / 3.3 V I/O), lower drive (–24 mA/24 mA), no register clocks. | Targets low-voltage mixed-signal systems; lacks storage capability and 5-V tolerance. | Choose for battery-powered or 3.3-V domain interfacing where SN74ABT646PWR's 5-V operation and register features are excessive. |
Compared with SN74ABT245PWR and SN74LVTH16245DGGR, the SN74ABT646PWR uniquely delivers synchronized dual-bus registration within a compact TSSOP-24 package - essential for applications requiring deterministic data capture, hold-and-release timing, or isolation during bus arbitration, without adding external flip-flops or logic.
Availability
SN74ABT646PWR is available at Aetrix Electronics and suitable for industrial PLCs, automated test equipment, backplane interconnects, and legacy system upgrades requiring stable component supply and long-term manufacturability.
Supply support for SN74ABT646PWR 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 over 90 years of innovation in industrial, automotive, and communications markets.
The SN74ABT646PWR belongs to TI's ABT logic family, engineered for high-speed, low-noise 5-V TTL-compatible bus interfacing in industrial control and instrumentation systems requiring robust registered data transfer.
FAQ
What is the maximum clock frequency supported by the SN74ABT646PWR?
The SN74ABT646PWR supports a maximum clock frequency of 125 MHz under recommended operating conditions (VCC = 5 V, TA = 25°C). This rating applies to both CLKAB and CLKBA inputs and is validated across the full industrial temperature range (–40°C to 85°C) per the SCBS068E datasheet. Timing margins must be verified in-system considering board-level capacitance and signal integrity.
How does the SN74ABT646PWR handle power-up sequencing to avoid bus contention?
To prevent undefined outputs during power-up, the OE pin of the SN74ABT646PWR must be tied to VCC through a pullup resistor - TI specifies the minimum value based on driver current-sinking capability. This ensures all outputs remain in high-impedance state until firmware asserts valid DIR and OE control, eliminating risk of bus conflicts at startup.
Can the SN74ABT646PWR operate with a 3.3-V supply?
No, the SN74ABT646PWR is specified only for 4.5 V to 5.5 V supply operation. Its input thresholds (VIH = 2 V, VIL = 0.8 V), output drive strength, and internal BiCMOS structure are optimized for 5-V TTL compatibility. Using 3.3 V violates recommended operating conditions and may result in unreliable register behavior, weak output drive, or increased static current.
What is the function of the NC pins on the SN74ABT646PWR TSSOP-24 package?
The SN74ABT646PWR TSSOP-24 package has no NC (no-connect) pins - all 24 pins are assigned functional roles per the DB/DW/PW package pinout. The datasheet references NC pins only in the FK (ceramic LCC) and JT (DIP) variants. For SN74ABT646PWR, every pin from 1 to 24 connects to a defined signal: A/B I/O, CLK, DIR, OE, SAB, SBA, VCC, or GND.
Does the SN74ABT646PWR support hot-swap operation?
The SN74ABT646PWR supports controlled hot-swap operation when OE is held high (via pullup) during insertion, ensuring outputs remain in high-impedance state until system firmware initializes control lines. Its ESD protection (>2000 V HBM) and latch-up immunity (>500 mA) further enhance robustness, but external current-limiting resistors on A/B lines are recommended for full hot-swap compliance in live-backplane environments.
SN74ABT646PWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ABT
- Package/Case:
- 24-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Logic Type:
- Transceiver, Non-Inverting
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 32mA, 64mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-TSSOP
SN74ABT646PWR FAQ
1.How can I place an order for SN74ABT646PWR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ABT646PWR 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 SN74ABT646PWR reliable?
The price and inventory of SN74ABT646PWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ABT646PWR is usually 5 days.
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SN74ABT646PWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ABT646PWR 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 SN74ABT646PWR?
For technical support, including SN74ABT646PWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ABT646PWR requirements.
6.How does Aetrix verify that SN74ABT646PWR is sourced from the original manufacturer or authorized distributors?
All SN74ABT646PWR 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 SN74ABT646PWR meets industry standards.
7.What is the process for return or replacement of SN74ABT646PWR?
All SN74ABT646PWR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ABT646PWR, 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 SN74ABT646PWR part is unused and in its original packaging.
Return procedure for SN74ABT646PWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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