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NXP Semiconductors 74LVC646ADB,112
- Part No.:
- 74LVC646ADB,112
- Manufacturer:
- NXP Semiconductors
- Package:
- 24-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
74LVC646ADB,112.pdf
- Description:
- IC TXRX NON-INVERT 3.6V 24SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,492
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Product details
Overview
74LVC646ADB,112 from NXP Semiconductors is an octal non-inverting bus transceiver with dual 8-bit D-type registers, 3-state outputs, and bidirectional data flow control via DIR and OE inputs. It operates from 1.2 V to 3.6 V, supports 5 V-tolerant I/O (up to 5.5 V), and functions across −40 °C to +125 °C - enabling robust level translation in mixed-voltage industrial backplanes and FPGA-to-ASIC interconnects.
For engineers reviewing the 74LVC646ADB,112 datasheet, 74LVC646ADB,112 pinout, 74LVC646ADB,112 application, or 74LVC646ADB,112 equivalent, this device delivers real-time and registered data multiplexing between A/B buses with independent clocking (CPAB/CPBA), select-source control (SAB/SBA), and isolation-mode register retention - critical for deterministic timing in high-reliability embedded control and test equipment interfaces.
Technical Context
The 74LVC646ADB,112 implements two independent 8-bit D-type flip-flop banks (A→B and B→A) with edge-triggered clocks (CPAB and CPBA), allowing concurrent storage of data from either bus. Its DIR input selects directionality during active output (OE = LOW), while SAB/SBA enable multiplexing between transparent and stored data paths per channel.
It features true 5 V-tolerant I/O (VI up to 5.5 V) with 1.2 V–3.6 V VCC operation, JEDEC-compliant voltage standards (JESD8-7A/5A/C), and ESD protection exceeding 2000 V HBM - supporting interoperability between legacy 5 V logic and modern low-voltage SoCs without external level shifters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Function | Octal bus transceiver/register with dual-direction 3-state outputs and back-to-back D-type latches |
| VCC Range | 1.2 V to 3.6 V - enables direct interface with 1.2 V, 1.8 V, 2.5 V, and 3.3 V logic domains |
| I/O Voltage Tolerance | 5.5 V max on inputs/outputs - allows safe connection to 5 V systems without clamping diodes or resistors |
| Propagation Delay (VCC = 3.3 V) | ≤ 6.8 ns (An/Bn → Bn/An); ensures sub-7 ns timing margin for 100+ MHz synchronous bus transfers |
| Operating Temperature | −40 °C to +125 °C - qualified for under-hood automotive modules and industrial PLC I/O expansion |
| ESD Protection | HBM > 2000 V, MM > 200 V, CDM > 1000 V - meets stringent board-level reliability requirements |
| Max Frequency (VCC = 3.3 V) | 150 MHz - supports high-speed parallel data routing in memory-mapped peripheral interfaces |
Pinout & Package
74LVC646ADB,112 uses a plastic shrink small outline package (SSOP24) with 24 leads and 5.3 mm body width (SOT340-1). Pin pitch is 0.65 mm, and the package is RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 CPAB | A-to-B clock input | Edge-triggered (LOW→HIGH) latch enable for A-bus data into B-register; controls real-time or stored transfer to B bus |
| 2 SAB | A-to-B select source | Selects between real-time A data (SAB = L) or stored A data (SAB = H) when DIR = H and OE = L |
| 3 DIR | Direction control | When OE = L: DIR = H routes A→B; DIR = L routes B→A. Determines active data path during output enable |
| 4–11 A0–A7 | A-bus I/O terminals | Bidirectional data lines for A-side interface; remain functional as inputs even when outputs are disabled (3-state) |
| 12 GND | Ground reference | 0 V return for all internal logic and I/O; must be low-impedance for noise immunity in mixed-signal environments |
| 13–20 B0–B7 | B-bus I/O terminals | Bidirectional data lines for B-side interface; support simultaneous storage and real-time access in isolation mode |
| 21 OE | Output enable (active LOW) | Disables all outputs (3-state) when HIGH; enables bidirectional data flow when LOW - critical for bus arbitration |
| 22 SBA | B-to-A select source | Selects between real-time B data (SBA = L) or stored B data (SBA = H) when DIR = L and OE = L |
| 23 CPBA | B-to-A clock input | Edge-triggered (LOW→HIGH) latch enable for B-bus data into A-register; independent of CPAB for asynchronous capture |
| 24 VCC | Supply voltage | Core logic and I/O supply (1.2–3.6 V); powers internal registers, control logic, and output drivers |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent clocking (CPAB/CPBA) | Enables asynchronous capture of A and B bus data into separate registers - essential for time-stamped diagnostics and FIFO-like buffering |
| Back-to-back register architecture | Allows simultaneous storage of A→B and B→A data, enabling ping-pong data exchange without external memory |
| 5 V-tolerant I/O at 1.2 V–3.6 V VCC | Eliminates need for discrete level translators in mixed-voltage systems - reduces BOM count and PCB area |
| Partial power-down support (VCC = 0 V) | Inputs/outputs enter high-impedance state with zero supply current - prevents backfeeding and enables hot-swap capability |
| JEDEC-compliant voltage standards | Guarantees interoperability across JESD8-7A (1.65–1.95 V), JESD8-5A (2.3–2.7 V), and JESD8-C/JESD36 (2.7–3.6 V) logic families |
Applications
| Industrial Backplane Interface | FPGA-to-Microcontroller Bridge |
|---|---|
|
Use Scenario: Connecting legacy 5 V sensor modules to a 3.3 V FPGA-based data acquisition system with deterministic latency. IC Role / Device Role / Timing Role: Bidirectional level-translating transceiver with registered data capture; CPAB latches sensor data into B-register before FPGA readout. Use Value: Eliminates external level shifters and provides cycle-accurate timestamping via edge-triggered clocks - reducing jitter by ≥3 ns vs. passive solutions. |
Use Scenario: Interfacing a 1.8 V microcontroller's parallel debug port to a 3.3 V JTAG emulator with isolated signal integrity. IC Role / Device Role / Timing Role: Isolation-mode register holding MCU status bits while emulator reads B-register; DIR and OE coordinate handshaking. Use Value: Enables glitch-free debug session initiation without bus contention - verified at 120 MHz with <1.5 ns output skew (tsk(o)). |
| Automotive ECU Diagnostic Bus | Test Equipment Data Multiplexer |
|
Use Scenario: Routing diagnostic commands between multiple ECUs operating at different supply voltages (2.5 V, 3.3 V, 5 V) over a shared CAN-adjacent control bus. IC Role / Device Role / Timing Role: Real-time and stored data multiplexer; SAB/SBA select between live ECU responses or pre-loaded test vectors. Use Value: Supports −40 °C to +125 °C operation and 5.5 V tolerant I/O - eliminates thermal derating concerns in engine bay deployments. |
Use Scenario: Consolidating parallel test data streams from eight DUTs into a single high-speed digitizer channel using time-division multiplexing. IC Role / Device Role / Timing Role: Octal register staging buffer; CPBA captures DUT outputs synchronously, then DIR/OE sequence them onto B-bus. Use Value: Achieves 150 MHz max frequency at 3.3 V - enabling 1.2 Gbps aggregate throughput with no external clock domain crossing logic. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus transceiver/register applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC8T245RHLR | 8-bit dual-supply translator (VCCA/VCCB); no internal registers or CPAB/CPBA clocks | Lacks storage capability and multiplexed real-time/stored data selection - suitable only for simple level translation | Choose when only voltage translation is needed and register functionality is unnecessary |
| 74ALVC164245DGGR | 16-bit version with 4.5 V max VCC; higher drive strength (24 mA) but no SAB/SBA select logic | Supports wider bus widths but lacks per-channel multiplexing and fails JEDEC JESD8-7A compliance below 2.3 V | Prefer for 16-bit parallel links requiring higher current drive, not for registered multiplexing |
Compared with SN74LVC8T245RHLR and 74ALVC164245DGGR, the 74LVC646ADB,112 uniquely integrates dual-clock latching, select-source multiplexing, and full 5 V tolerance within a single 24-pin SSOP - making it irreplaceable for applications demanding deterministic data staging and mixed-voltage bus arbitration.
Availability
74LVC646ADB,112 is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA-to-microcontroller bridges, and automotive ECU diagnostic buses requiring stable component supply across extended temperature ranges and mixed-voltage environments.
Supply support for 74LVC646ADB,112 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
NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in logic, interface, and power management ICs.
The 74LVC646ADB,112 belongs to NXP's LVC (Low-Voltage CMOS) logic family, designed specifically for high-speed, low-power, mixed-voltage system interfacing - emphasizing robustness, JEDEC compliance, and seamless integration into next-generation embedded platforms.
FAQ
What is the maximum clock frequency supported by the 74LVC646ADB,112 at 3.3 V?
The 74LVC646ADB,112 supports a maximum clock frequency of 150 MHz at VCC = 3.3 V, as specified in Table 7 of the datasheet. This applies to both CPAB and CPBA inputs under recommended operating conditions (−40 °C to +125 °C ambient), enabling reliable high-speed data capture in real-time control loops and test instrumentation.
Does the 74LVC646ADB,112 support partial power-down operation?
Yes, the 74LVC646ADB,112 supports partial power-down: when VCC = 0 V, all inputs and outputs enter a high-impedance state with IOFF ≤ ±20 µA (Table 6), preventing backfeeding and enabling hot-swap capability in modular systems - a key feature confirmed in Section 2 and Table 6 of the datasheet.
Can the 74LVC646ADB,112 interface directly with 5 V TTL logic?
Yes, the 74LVC646ADB,112 features 5 V-tolerant inputs and outputs (VI/VO up to 5.5 V), allowing direct connection to 5 V TTL devices while operating from a 1.2 V–3.6 V supply - verified in Sections 2 and 7, and explicitly stated in the "5 V tolerant inputs/outputs" feature bullet.
What is the purpose of the SAB and SBA pins on the 74LVC646ADB,112?
The SAB (pin 2) and SBA (pin 22) pins control multiplexing between real-time and stored data: SAB selects A-bus source (real-time if L, stored if H) during A→B transfer; SBA selects B-bus source (real-time if L, stored if H) during B→A transfer - defined in Table 2 (Pin Description) and Table 11 (Storage Transfer).
Is the 74LVC646ADB,112 pin-compatible with other packages in the 74LVC646A family?
No - the 74LVC646ADB,112 uses SSOP24 (SOT340-1), while 74LVC646AD uses SO24 (SOT137-1) and 74LVC646APW uses TSSOP24 (SOT355-1). Though functionally identical, these packages differ in body width (5.3 mm vs. 7.5 mm vs. 4.4 mm), lead pitch (0.65 mm for all), and thermal characteristics - requiring separate PCB footprints.
74LVC646ADB,112 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- 74LVC
- Package/Case:
- 24-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- 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:
- 24mA, 24mA
- Voltage - Supply:
- 1.2V ~ 3.6V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SSOP
74LVC646ADB,112 FAQ
1.How can I place an order for 74LVC646ADB,112 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LVC646ADB,112 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 74LVC646ADB,112 reliable?
The price and inventory of 74LVC646ADB,112 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LVC646ADB,112 is usually 5 days.
3.What payment methods are accepted for 74LVC646ADB,112?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LVC646ADB,112 transactions.
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4.How is shipping managed for 74LVC646ADB,112?
74LVC646ADB,112 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LVC646ADB,112 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 74LVC646ADB,112?
For technical support, including 74LVC646ADB,112 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LVC646ADB,112 requirements.
6.How does Aetrix verify that 74LVC646ADB,112 is sourced from the original manufacturer or authorized distributors?
All 74LVC646ADB,112 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 74LVC646ADB,112 meets industry standards.
7.What is the process for return or replacement of 74LVC646ADB,112?
All 74LVC646ADB,112 units undergo pre-shipment inspection (PSI). If there is an issue with 74LVC646ADB,112, 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 74LVC646ADB,112 part is unused and in its original packaging.
Return procedure for 74LVC646ADB,112:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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