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Texas Instruments SN74ABT646ADWR
- Part No.:
- SN74ABT646ADWR
- Manufacturer:
- Texas Instruments
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74ABT646ADWR.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 24SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,360
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Product details
Overview
SN74ABT646ADWR from Texas Instruments is a 16-bit bus transceiver with dual D-type registers, direction control (DIR), output enable (OE), and clocked multiplexing (CLKAB/CLKBA, SAB/SBA). It supports high-drive outputs (−32 mA IOH, 64 mA IOL), Ioff partial-power-down operation, and operates from 4.5 V to 5.5 V across −40°C to 85°C. It enables real-time or registered data transfer between A and B buses in industrial backplane and memory interface applications.
For engineers reviewing the SN74ABT646ADWR datasheet, SN74ABT646ADWR pinout, SN74ABT646ADWR application, or SN74ABT646ADWR equivalent, this page delivers verified functional architecture, timing-critical switching parameters (e.g., tPLH ≤ 5.6 ns, fmax = 125 MHz), bus-isolation behavior under OE high, and confirmed SOIC-24 (DW) package compatibility for PCB layout and thermal design.
Technical Context
The SN74ABT646ADWR integrates two independent 8-bit register banks (A1–A8 and B1–B8), edge-triggered clock inputs (CLKAB and CLKBA), and select-control logic (SAB/SBA) to support four bus-management modes: real-time A→B/B→A transfer, storage from either bus, and simultaneous stored-data output to both buses. Its DIR input determines data flow direction when OE is active low.
It implements Ioff circuitry to disable outputs during power-down, preventing backflow current, and features robust ESD protection (2000-V HBM, 200-V MM) and latch-up immunity (>500 mA per JESD-17). The device uses ABT logic family characteristics including TTL-compatible inputs, 5-V supply-only operation, and ground-bounce mitigation (VOLP < 1 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - Ensures compatibility with standard 5-V digital systems and tolerance against rail droop. |
| Max Clock Frequency | 125 MHz - Supports high-speed synchronous bus bridging without external timing constraints. |
| Output Drive Strength | −32 mA IOH / 64 mA IOL - Drives heavy capacitive loads and multiple TTL inputs without external buffers. |
| Ioff Current | ±100 µA at VCC = 0 - Enables safe hot-insertion and partial-power-down in modular backplane systems. |
| Propagation Delay | tPLH/tPHL ≤ 5.6 ns (CL = 50 pF) - Guarantees sub-8-ns worst-case path timing for 125-MHz operation. |
| Operating Temperature | −40°C to +85°C - Qualified for industrial-grade embedded control and communications equipment. |
| ESD Rating | 2000-V HBM, 200-V MM - Meets JEDEC JESD22-A114/A115 for robust handling in manufacturing and field service. |
Pinout & Package
SN74ABT646ADWR is packaged in a 24-pin SOIC (DW) body measuring 15.4 mm × 7.5 mm × 2.35 mm, with 1.27-mm pitch, RoHS-compliant NiPdAu lead finish, and moisture sensitivity level (MSL) 1 (unlimited floor life at ≤30°C/60% RH).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 4–10, 12–19, 21–24 | A1–A8, B1–B8 bidirectional data terminals | Eight parallel A-side and eight parallel B-side I/Os supporting registered or transparent data paths. |
| 3 | DIR (Direction Control) | When OE = L, sets bus direction: DIR = L → B→A transfer; DIR = H → A→B transfer. |
| 11 | OE (Output Enable) | Active-low; OE = H places all A/B outputs in high-impedance state while preserving internal register contents. |
| 20 | GND | Power return reference for logic and output stages; requires low-inductance connection to minimize ground bounce. |
| 22 | VCC | 5-V supply input; decoupling capacitor (0.1 µF ceramic) required within 10 mm of pin for noise suppression. |
| 23, 1 | CLKBA, CLKAB | Low-to-high edge-triggered clocks: CLKAB latches A-port data into B-register; CLKBA latches B-port into A-register. |
| 2, 22 | SAB, SBA | Select controls: SAB = L enables stored B-data to A bus; SBA = L enables stored A-data to B bus. |
Key Features
| Feature | Design Value |
|---|---|
| Dual 8-bit registered transceivers | Enables independent storage and synchronized transfer of two 8-bit data streams without external flip-flops. |
| Ioff partial-power-down support | Prevents damaging current flow when VCC = 0, enabling safe insertion/removal in live backplanes or hot-swap modules. |
| High-drive ABT outputs | −32 mA source / 64 mA sink capability drives ≥10 standard TTL loads or long traces with minimal signal degradation. |
| Four-mode bus management | Supports real-time pass-through, register storage, isolation, and mixed-mode transfer via combinational control of DIR/OE/SAB/SBA. |
| Ground-bounce suppression | VOLP < 1 V at 5 V/25°C ensures stable logic thresholds during simultaneous output switching, critical for noise-sensitive systems. |
Applications
| Industrial Backplane Interface | Memory Subsystem Buffering |
|---|---|
|
Use Scenario: Isolating CPU address/data bus from peripheral expansion slots in programmable logic controllers (PLCs) with hot-swap capability. IC Role / Device Role / Timing Role: Bidirectional registered transceiver managing synchronous data handoff between master and slave modules using CLKAB/CLKBA edges. Use Value: Ioff support prevents backfeed during slot insertion; 125-MHz timing allows full-speed bus utilization without wait states. |
Use Scenario: Interfacing microcontroller parallel bus to external SRAM or Flash memory with separate address and data latching requirements. IC Role / Device Role / Timing Role: Dual-register function stores address on one clock edge and data on another, eliminating external latch components. Use Value: Reduces component count by integrating 16-bit register + transceiver; tPLH ≤ 5.6 ns meets 125-MHz memory access timing. |
| Test Equipment Data Acquisition | Legacy Bus Protocol Translation |
|
Use Scenario: Capturing parallel sensor data streams in automated test equipment (ATE) where timing alignment and glitch-free sampling are critical. IC Role / Device Role / Timing Role: Real-time or registered capture of 16-bit analog-to-digital converter outputs synchronized to system clock domain. Use Value: Low ground bounce (<1 V) prevents sampling errors; setup/hold times (tsu = 3 ns, th = 0 ns) simplify timing closure. |
Use Scenario: Bridging ISA or PCI-X legacy control signals to modern FPGA-based host interfaces requiring voltage-level and timing adaptation. IC Role / Device Role / Timing Role: Direction-controlled bus isolator with register hold capability to resolve asynchronous protocol handshaking delays. Use Value: DIR/OE/SAB/SBA logic enables flexible mode selection without firmware changes; 5-V only operation matches legacy rail requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ABT245DW | Octal (8-bit), no internal registers; lacks CLKAB/CLKBA, SAB/SBA, and DIR-controlled dual-direction logic. | Used only for simple unidirectional/bidirectional level translation without storage - not suitable for clocked bus arbitration. | Select SN74ABT245DW only when register functionality is unnecessary and board space or cost reduction is prioritized over timing control. |
| SN74LVTH16245ADGGR | 16-bit, 3.3-V only (2.7–3.6 V); LVTH logic family with lower drive (−32/64 mA same, but at 3.3 V), no Ioff support. | Requires level-shifting for 5-V systems; unsuitable for partial-power-down or mixed-voltage backplanes. | Choose SN74LVTH16245ADGGR only in pure 3.3-V designs where lower power and smaller TSSOP-48 package are mandatory. |
Compared with SN74ABT245DW and SN74LVTH16245ADGGR, the SN74ABT646ADWR uniquely combines 5-V operation, integrated dual-register storage, Ioff safety, and full 125-MHz bus management - making it irreplaceable in registered, hot-swap-capable industrial backplane designs.
Availability
SN74ABT646ADWR is available at Aetrix Electronics and suitable for industrial backplane interface, memory subsystem buffering, and test equipment data acquisition requiring stable component supply, long-term lifecycle support, and guaranteed SOIC-24 tape-and-reel packaging.
Supply support for SN74ABT646ADWR 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 expertise in high-reliability industrial and automotive ICs.
The SN74ABT646ADWR belongs to TI's ABT logic family, engineered for high-speed, low-noise 5-V bus interfacing in demanding industrial control, instrumentation, and communications infrastructure applications.
FAQ
What is the maximum operating frequency of the SN74ABT646ADWR?
The SN74ABT646ADWR supports a maximum clock frequency of 125 MHz under recommended conditions (VCC = 5 V, TA = 25°C, CL = 50 pF). This is validated by timing specifications including tPLH ≤ 5.6 ns and fmax = 125 MHz in the official datasheet SCBS069H. The SN74ABT646ADWR maintains this performance across its full industrial temperature range (−40°C to +85°C) with appropriate derating.
Does the SN74ABT646ADWR support partial-power-down operation?
Yes, the SN74ABT646ADWR includes Ioff circuitry that disables outputs when VCC = 0 V, limiting Ioff to ±100 µA. This feature prevents damaging current backflow during hot-swap or partial-system power-down events. The SN74ABT646ADWR is explicitly specified for such applications in Section 1 of the datasheet, and its Ioff compliance exceeds JEDEC standards for safe operation in modular systems.
What package type and dimensions does the SN74ABT646ADWR use?
The SN74ABT646ADWR uses a 24-pin SOIC (DW) package: 15.4 mm × 7.5 mm × 2.35 mm body size, 1.27-mm lead pitch, and RoHS-compliant NiPdAu surface finish. It is supplied in tape-and-reel format (2000 units/reel) with MSL Level-1 rating. This exact package is confirmed in TI's Packaging Information document and ordering table for SN74ABT646ADWR.
Can the SN74ABT646ADWR operate at 3.3 V?
No, the SN74ABT646ADWR is specified exclusively for 4.5 V to 5.5 V operation. Its ABT logic family requires 5-V supply rails to meet guaranteed timing, drive strength, and noise margin specifications. Attempting 3.3-V operation results in undefined behavior, failure to meet tPLH/tPHL specs, and potential violation of VIH/VIL thresholds. For 3.3-V systems, consider TI's LVTH or LVC families instead of the SN74ABT646ADWR.
How does the SN74ABT646ADWR handle bus isolation when OE is high?
When OE is high, all A- and B-side outputs enter high-impedance state, effectively isolating both buses. Critically, internal register contents remain preserved - allowing stored data to be retained and later retransmitted upon OE assertion. This behavior is defined in the FUNCTION TABLE and "Isolation, hold storage" mode of Figure 1 in the SN74ABT646ADWR datasheet, and is essential for glitch-free bus arbitration in multi-master systems.
SN74ABT646ADWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ABT
- Package/Case:
- 24-SOIC (0.295", 7.50mm 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-SOIC
SN74ABT646ADWR FAQ
1.How can I place an order for SN74ABT646ADWR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ABT646ADWR 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 SN74ABT646ADWR reliable?
The price and inventory of SN74ABT646ADWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ABT646ADWR is usually 5 days.
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SN74ABT646ADWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ABT646ADWR 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 SN74ABT646ADWR?
For technical support, including SN74ABT646ADWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ABT646ADWR requirements.
6.How does Aetrix verify that SN74ABT646ADWR is sourced from the original manufacturer or authorized distributors?
All SN74ABT646ADWR 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 SN74ABT646ADWR meets industry standards.
7.What is the process for return or replacement of SN74ABT646ADWR?
All SN74ABT646ADWR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ABT646ADWR, 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 SN74ABT646ADWR part is unused and in its original packaging.
Return procedure for SN74ABT646ADWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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