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onsemi 74LVTH16646MTD
- Part No.:
- 74LVTH16646MTD
- Manufacturer:
- onsemi
- Package:
- 56-TFSOP (0.240", 6.10mm Width)
- Datasheet:
-
74LVTH16646MTD.pdf
- Description:
- IC TXRX NON-INVERT 3.6V 56TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,172
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Product details
Overview
74LVTH16646MTD from ON Semiconductor is a low-voltage 16-bit registered transceiver with 3-STATE outputs, bushold inputs, and dual-directional data flow control via DIR pins. It operates at 2.7–3.6 V, supports 5 V-tolerant I/O, delivers ±32 mA/±64 mA drive strength, and features 150 MHz maximum clock frequency in TSSOP-56 package for high-speed bus interfacing.
For engineers reviewing the 74LVTH16646MTD datasheet, pinout, applications, or equivalent options, this device is selected for bidirectional registered bus transfer in mixed-voltage systems requiring glitch-free power-up/down behavior, real-time or stored-mode operation, and elimination of external pull-ups on unused inputs.
Technical Context
The 74LVTH16646MTD implements two independent 8-bit register banks (A and B) with separate clock (CPAB/CPBA), select (SAB/SBA), and direction (DIR1/DIR2) controls - enabling four distinct bus management modes: real-time A↔B transfer, A-register-to-B output, B-register-to-A output, and isolated register loading. Its bushold circuitry actively maintains input logic state without external resistors.
It uses advanced BiCMOS technology to achieve ABT-class speed (tPLH/tPHL ≤ 5.9 ns) while maintaining LVT-level power efficiency (ICCZ = 0.19 mA in 3-STATE), and meets JEDEC JED78 latch-up immunity and >2000 V HBM ESD rating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.7 V to 3.6 V - Ensures compatibility with 3.3 V system rails while tolerating supply variation. |
| I/O Voltage Tolerance | 0 V to 5.5 V - Allows direct interface to legacy 5 V logic without level shifters. |
| Output Drive | −32 mA / +64 mA - Supports heavy capacitive loads and fan-out to multiple TTL inputs. |
| Max Clock Frequency | 150 MHz - Enables high-throughput synchronous bus multiplexing in real-time mode. |
| Propagation Delay | 1.0–5.9 ns - Guarantees timing closure in sub-7 ns critical paths at 3.3 V. |
| Bushold Current | ±75 µA at VI = 0.8 V/2.0 V - Maintains valid logic levels on floating inputs without external bias. |
| Power-Up High-Z | Active - Prevents bus contention during power sequencing in hot-plug applications. |
Pinout & Package
74LVTH16646MTD is housed in a 56-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 6.1 mm wide, with 0.5 mm lead pitch and exposed thermal pad (not electrically connected).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A15 | Data Register A I/O | Bidirectional port: inputs load A register on CPAB↑; outputs reflect A register or real-time A bus when enabled. |
| B0–B15 | Data Register B I/O | Bidirectional port: inputs load B register on CPBA↑; outputs reflect B register or real-time B bus when enabled. |
| CPAB, CPBA | Register Clock Inputs | Edge-triggered clocks: LOW-to-HIGH transition latches data into A or B register respectively. |
| SAB, SBA | Register Select Inputs | Control whether output reflects register content (SAB=LOW enables A→B) or real-time bus (SAB=HIGH enables A↔B transparent mode). |
| DIR1, DIR2 | Direction Control | Determines bus direction: DIR=HIGH enables A→B; DIR=LOW enables B→A. |
| OE1, OE2 | Output Enable | Active-low enables 3-STATE outputs; HIGH forces high-impedance regardless of DIR or clock state. |
Key Features
| Feature | Design Value |
|---|---|
| Bushold inputs | Eliminates need for 10–100 kΩ external pull-up resistors on all 32 data pins, reducing BOM count and board space. |
| Registered + transparent modes | Supports both synchronous (clocked register) and asynchronous (real-time pass-through) data routing within same device. |
| Independent byte control | Two sets of DIR/OE/SAB/SBA allow 8-bit segments to operate in different modes simultaneously (e.g., A0–7 stored, A8–15 transparent). |
| Glitch-free power sequencing | Outputs remain in high-impedance during VCC ramp-up/down, preventing bus conflicts in hot-swap or multi-rail systems. |
| 5 V tolerant I/O | Enables direct connection to 5 V microcontrollers, FPGAs, or legacy peripherals without voltage translation circuitry. |
Applications
| PCI Bus Interface | Memory Expansion Subsystem |
|---|---|
Use Scenario: Interfacing a 3.3 V FPGA to a 5 V PCI slot for add-in card design. IC Role / Device Role / Timing Role: Bidirectional registered transceiver buffering address/data lines with synchronized sampling and direction control. Use Value: Eliminates external level shifters and pull-ups while meeting PCI timing requirements via 150 MHz clock support and sub-6 ns propagation delay. | Use Scenario: Expanding DRAM or SRAM capacity in industrial controller with mixed 3.3 V core and 5 V memory modules. IC Role / Device Role / Timing Role: Registered bus transceiver isolating CPU data bus from memory module, supporting burst reads/writes with clock-aligned latching. Use Value: Enables reliable data capture at memory access speeds using CPAB/CPBA edge-triggered registers, avoiding metastability in asynchronous handshakes. |
| Hot-Swappable Backplane Module | Test Equipment Data Acquisition |
Use Scenario: Inserting/removing line cards in telecom backplane without disrupting active data traffic. IC Role / Device Role / Timing Role: Isolation and direction-controlled data path between backplane and module local bus, with live-insertion tolerance. Use Value: Power-up high-impedance and bushold inputs prevent bus glitches or floating states during mechanical insertion, ensuring system stability. | Use Scenario: Capturing parallel sensor data streams (e.g., ADC outputs) into a 3.3 V test instrument with 5 V signal sources. IC Role / Device Role / Timing Role: Synchronized sampling node registering incoming 5 V parallel data before forwarding to internal processor bus. Use Value: CPAB/CPBA clocks align acquisition windows across all 16 bits; bushold prevents invalid readings from unterminated sensor lines. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar registered transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVTH16646DGGR | TSSOP-56 package, identical bushold, 3.3 V VCC, same pinout per TI datasheet. | No functional deviation; validated for same 16-bit registered bus roles in TI reference designs. | Select when sourcing from Texas Instruments' distribution channels or requiring TI-specific qualification documentation. |
| 74ALVCH16646PAG | 64-pin TQFP, no bushold, higher ICCZ (0.5 mA), 2.3–3.6 V VCC range. | Lacks bushold - requires external pull-ups; wider VCC range suits ultra-low-power systems but increases layout complexity. | Prefer only if TQFP footprint is mandatory and bushold is not required; verify pull-up resistor placement and power budget impact. |
Compared with SN74LVTH16646DGGR, the 74LVTH16646MTD offers identical functionality and pinout but differs in manufacturer qualification and traceability; versus 74ALVCH16646PAG, it trades package size and bushold capability for lower static current and simplified layout - making it optimal for space-constrained, mixed-voltage PCBs where input termination must be minimized.
Availability
74LVTH16646MTD is available at Aetrix Electronics and suitable for PCI interface design, memory expansion subsystems, hot-swappable backplane modules, and test equipment data acquisition requiring stable component supply across extended production lifecycles.
Supply support for 74LVTH16646MTD 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
ON Semiconductor (formerly Fairchild Semiconductor) is a global supplier of energy-efficient semiconductor components for automotive, industrial, cloud computing, and IoT applications.
The 74LVTH16646MTD belongs to ON Semiconductor's LVT/LVTH logic family, engineered for high-speed, low-voltage bus interfacing in mixed-supply systems where signal integrity, power efficiency, and input robustness are critical.
FAQ
What is the function of the bushold feature in the 74LVTH16646MTD?
The bushold feature in the 74LVTH16646MTD actively holds unused or floating data inputs (A0–A15 and B0–B15) at their last-valid logic state using internal feedback circuitry, eliminating the need for external pull-up or pull-down resistors. This reduces bill-of-materials cost, saves PCB area, and improves noise immunity in high-density layouts - a key advantage over non-bushold variants like the 74LVT16646MTD. The 74LVTH16646MTD specifies ±75 µA minimum drive current to override bushold, ensuring reliable forced transitions when needed.
Does the 74LVTH16646MTD support live insertion and extraction?
Yes, the 74LVTH16646MTD supports live insertion and extraction due to its power-up/power-down high-impedance outputs and bushold inputs. During power ramp-up or ramp-down, all outputs remain in 3-STATE, preventing bus contention; bushold maintains defined logic levels on inputs even when VCC is absent or unstable. This behavior is explicitly verified in the datasheet under "Power Up/Down high impedance provides glitch-free bus loading" and makes the 74LVTH16646MTD suitable for hot-swap backplane and modular system applications.
What are the key timing differences between real-time and registered modes in the 74LVTH16646MTD?
In real-time (transparent) mode - activated by setting SAB/SBA to HIGH - data passes directly from A to B or B to A with typical propagation delay of 1.0–4.7 ns. In registered mode - activated by LOW SAB/SBA - data is latched on the rising edge of CPAB/CPBA and appears at outputs after an additional 1.0–5.9 ns register-to-output delay. The 74LVTH16646MTD allows mixing both modes per byte group, enabling simultaneous streaming and sampled data paths without external logic. These delays are guaranteed across −40°C to +85°C at 3.3 V.
Can the 74LVTH16646MTD interface directly with 5 V logic devices?
Yes, the 74LVTH16646MTD supports direct 5 V interface: its inputs tolerate up to 5.5 V regardless of VCC, and its outputs drive 5 V TTL loads with ±32 mA/±64 mA current capability. When powered at 3.3 V, it meets VOH ≥ 2.4 V and VOL ≤ 0.5 V under 24 mA load - satisfying standard TTL input thresholds. This eliminates level-shifting circuitry in mixed-voltage systems, and the 74LVTH16646MTD has been validated in reference designs connecting 3.3 V FPGAs to 5 V peripheral buses.
How does the 74LVTH16646MTD handle simultaneous read/write operations across A and B ports?
The 74LVTH16646MTD does not allow simultaneous driving of both A and B ports - only one direction is enabled at a time via DIR1/DIR2, and OE1/OE2 independently disable outputs. However, it supports concurrent register loading and output driving: for example, while DIR1=HIGH enables A→B real-time transfer, CPAB↑ can simultaneously load new data into the A register for next-cycle use. This pipelined operation enables efficient burst transfers in protocols like PCI or memory-mapped I/O, and the 74LVTH16646MTD's separate SAB/SBA controls let designers stage data in registers ahead of directional switching.
74LVTH16646MTD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74LVTH
- Package/Case:
- 56-TFSOP (0.240", 6.10mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Logic Type:
- Transceiver, Non-Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 8
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 32mA, 64mA
- Voltage - Supply:
- 2.7V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 56-TSSOP
74LVTH16646MTD FAQ
1.How can I place an order for 74LVTH16646MTD through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LVTH16646MTD 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 74LVTH16646MTD reliable?
The price and inventory of 74LVTH16646MTD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LVTH16646MTD is usually 5 days.
3.What payment methods are accepted for 74LVTH16646MTD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LVTH16646MTD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74LVTH16646MTD?
74LVTH16646MTD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LVTH16646MTD 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 74LVTH16646MTD?
For technical support, including 74LVTH16646MTD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LVTH16646MTD requirements.
6.How does Aetrix verify that 74LVTH16646MTD is sourced from the original manufacturer or authorized distributors?
All 74LVTH16646MTD 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 74LVTH16646MTD meets industry standards.
7.What is the process for return or replacement of 74LVTH16646MTD?
All 74LVTH16646MTD units undergo pre-shipment inspection (PSI). If there is an issue with 74LVTH16646MTD, 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 74LVTH16646MTD part is unused and in its original packaging.
Return procedure for 74LVTH16646MTD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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