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Texas Instruments SN74ALVTH16821GR

Name: SN74ALVTH16821GR
Brand: Texas Instruments
SKU: SN74ALVTH16821GR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SN74ALVTH16821GR

Manufacturer:: Texas Instruments

Category:: Flip Flops

Package:: 56-TFSOP (0.240", 6.10mm Width)

Datasheet:: SN74ALVTH16821GR.pdf

Description:: IC FF D-TYPE DUAL 10BIT 56TSSOP

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Product details

Overview

SN74ALVTH16821 from Texas Instruments is a 20-bit bus-interface D-type flip-flop with 3-state outputs, designed for 2.5-V/3.3-V operation and mixed-mode (5-V input-tolerant) interfacing. It features edge-triggered storage on CLK↑, ±32/64 mA drive at 3.3 V, bus-hold on all data inputs, and auto-3-state detection. It is used in high-speed backplane and memory interface buffering where level translation and bus contention prevention are critical.

For engineers reviewing the SN74ALVTH16821 datasheet, SN74ALVTH16821 pinout, SN74ALVTH16821 application, or SN74ALVTH16821 equivalent, key selection criteria include its dual 10-bit configurable operation, power-off output disable, high-impedance state during power-up/down, and compatibility with both 2.5-V and 3.3-V system domains while accepting 5-V inputs.

Technical Context

The SN74ALVTH16821 implements two independent 10-bit D-type flip-flop sections, each with separate clock (1CLK/2CLK) and output-enable (1OE/2OE) controls. Data is latched on the positive edge of CLK, and outputs enter high-impedance when OE is high - without affecting internal register state.

Its Advanced BiCMOS Technology (ABT) delivers low static power dissipation and high-speed performance (150 MHz max clock), while distributed VCC/GND pins and flow-through architecture minimize switching noise. Bus-hold circuitry eliminates external pullup/pulldown resistors on all 20 data inputs, and auto-3-state disables outputs when VO exceeds VCC + 0.5 V.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage	2.3 V to 3.6 V - supports dual-voltage system interfacing with stable operation across 2.5-V and 3.3-V rails.
Input Voltage Range	–0.5 V to 5.5 V - enables direct connection to 5-V TTL buses without level-shifting components.
Output Drive Strength	–32 mA / +64 mA at 3.3 V - drives heavily loaded PCB traces or multiple CMOS inputs without signal degradation.
Max Clock Frequency	150 MHz - suitable for high-bandwidth data capture in memory controllers and FPGA I/O expansion.
Propagation Delay	1 ns (min) to 3.5 ns (max) at 3.3 V - ensures tight timing margins in synchronous bus designs.
Bus-Hold Current	±75 µA at VIH/VIL thresholds - actively holds floating inputs at valid logic levels, preventing metastability.
Power-Up High-Impedance	Active below 1.2 V VCC - prevents bus conflicts during hot-insertion or uncontrolled power sequencing.

Pinout & Package

TSSOP-56 (DGG) package: 12.0 mm × 6.1 mm × 1.2 mm body, 0.5-mm pitch, lead-free, RoHS-compliant, moisture sensitivity level (MSL) not specified per TI documentation.

Pin/Terminal	Circuit Role	Design Meaning
1CLK, 2CLK	Clock input (positive-edge triggered)	Controls latching for respective 10-bit section; asynchronous to OE and independent between sections.
1OE, 2OE	Output-enable control (active-low)	Places corresponding 10 outputs in high-impedance state; does not affect internal register operation.
1D1–1D10, 2D1–2D10	Data inputs	Each has integrated bus-hold circuitry; no external resistors required to prevent floating states.
1Q1–1Q10, 2Q1–2Q10	Registered 3-state outputs	Driven by internal flip-flops; auto-3-state activates if output voltage exceeds VCC + 0.5 V.
VCC, GND	Power supply and ground	Distributed across package (multiple VCC/GND pins) to reduce simultaneous switching noise and improve signal integrity.

Key Features

Feature	Design Value
Mixed-mode signal operation	Accepts 5-V inputs while powered from 2.5-V/3.3-V rails - eliminates need for external level translators in legacy-to-modern bus interfaces.
Auto-3-state output protection	Automatically disables outputs when VO > VCC + 0.5 V - prevents latch-up and overvoltage stress during hot-swap or bus contention events.
Live insertion support	Outputs disabled when VCC = 0 V - allows safe insertion/removal into powered backplanes without disrupting bus operation.
Power-up/power-down high-impedance	Guaranteed Hi-Z state when VCC ≤ 1.2 V - avoids bus conflicts during uncontrolled power sequencing or brownout conditions.
Flow-through pinout architecture	Input and output pins arranged on opposite sides of package - simplifies PCB routing and reduces trace crossovers in dense layouts.

Applications

Memory Interface Buffering	FPGA I/O Expansion
Use Scenario: Buffering address/data lines between DDR SDRAM controller and memory module in embedded computing systems. IC Role / Device Role / Timing Role: Edge-triggered 20-bit register synchronizing burst transfers; provides level translation and bus isolation. Use Value: Enables reliable 150-MHz operation with deterministic setup/hold timing and eliminates external bus-hold resistors.	Use Scenario: Extending I/O count of Xilinx Artix-7 FPGA to drive industrial sensor array with 5-V tolerant inputs. IC Role / Device Role / Timing Role: Bidirectional bus interface translating between 3.3-V FPGA core and 5-V peripheral logic. Use Value: Supports live insertion into powered systems and prevents bus contention during partial reconfiguration cycles.
Backplane Data Latching	Industrial PLC I/O Module
Use Scenario: Capturing parallel status signals from multiple field devices onto a centralized control bus in telecom shelf management. IC Role / Device Role / Timing Role: Synchronized sampling node with independent 10-bit sections for time-aligned acquisition. Use Value: Delivers sub-4-ns propagation delay and 1.1-ns hold time margin at 3.3 V, ensuring robust timing closure.	Use Scenario: Isolating microcontroller GPIOs from noisy 24-V industrial field wiring in modular I/O racks. IC Role / Device Role / Timing Role: Input register with bus-hold and high-impedance fail-safe behavior during power faults. Use Value: Maintains known input state during brownouts and prevents false triggering due to floating inputs.

Memory Interface Buffering

FPGA I/O Expansion

Use Scenario: Buffering address/data lines between DDR SDRAM controller and memory module in embedded computing systems.

IC Role / Device Role / Timing Role: Edge-triggered 20-bit register synchronizing burst transfers; provides level translation and bus isolation.

Use Value: Enables reliable 150-MHz operation with deterministic setup/hold timing and eliminates external bus-hold resistors.

Use Scenario: Extending I/O count of Xilinx Artix-7 FPGA to drive industrial sensor array with 5-V tolerant inputs.

IC Role / Device Role / Timing Role: Bidirectional bus interface translating between 3.3-V FPGA core and 5-V peripheral logic.

Use Value: Supports live insertion into powered systems and prevents bus contention during partial reconfiguration cycles.

Backplane Data Latching

Industrial PLC I/O Module

Use Scenario: Capturing parallel status signals from multiple field devices onto a centralized control bus in telecom shelf management.

IC Role / Device Role / Timing Role: Synchronized sampling node with independent 10-bit sections for time-aligned acquisition.

Use Value: Delivers sub-4-ns propagation delay and 1.1-ns hold time margin at 3.3 V, ensuring robust timing closure.

Use Scenario: Isolating microcontroller GPIOs from noisy 24-V industrial field wiring in modular I/O racks.

IC Role / Device Role / Timing Role: Input register with bus-hold and high-impedance fail-safe behavior during power faults.

Use Value: Maintains known input state during brownouts and prevents false triggering due to floating inputs.

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus-interface flip-flop applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74ALVCH16821GR	No bus-hold circuitry; requires external pullups/pulldowns on all inputs; lower drive (–24/24 mA at 3.3 V).	Suitable only where board layout guarantees no floating inputs and lower drive suffices.	Select only if cost reduction outweighs reliability risk from missing bus-hold and reduced drive capability.
SN74LVC16373ADGGR	Non-latching 3-state transceiver (no clock); 3.3-V only; no 5-V input tolerance; no auto-3-state.	Applicable only for simple bidirectional bus buffering without timing synchronization requirements.	Choose only for non-critical, low-speed data transfer where clocked registration and 5-V compatibility are unnecessary.

Compared with SN74ALVCH16821GR and SN74LVC16373ADGGR, the SN74ALVTH16821 uniquely combines clocked 20-bit registration, 5-V input tolerance, integrated bus-hold, and auto-3-state - making it irreplaceable in mixed-voltage, high-reliability synchronous bus applications.

Availability

SN74ALVTH16821 is available at Aetrix Electronics and suitable for memory interface buffering, FPGA I/O expansion, backplane data latching, and industrial PLC I/O modules requiring stable component supply across extended temperature ranges (–40°C to 85°C).

Supply support for SN74ALVTH16821 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 heritage in high-reliability interface ICs.

The SN74ALVTH16821 belongs to TI's ALVTH advanced logic family, engineered for high-speed, mixed-voltage bus interfacing in telecom infrastructure, industrial automation, and computing systems demanding robust signal integrity and power sequencing resilience.

FAQ

What is the operating temperature range for the SN74ALVTH16821?

The SN74ALVTH16821 is characterized for operation from –40°C to 85°C. This commercial-grade temperature specification aligns with industrial system requirements and is explicitly defined in the SCES078E datasheet under recommended operating conditions. The SN54ALVTH16821 variant extends to –55°C to 125°C, but the SN74ALVTH16821 part number itself is rated only for the –40°C to 85°C range.

Does the SN74ALVTH16821 support 5-V input signals while powered at 3.3 V?

Yes, the SN74ALVTH16821 supports 5-V input signals with VCC = 3.3 V. Its absolute maximum input voltage is 7 V, and the recommended operating input voltage range is 0 to 5.5 V - enabling direct interfacing with legacy 5-V TTL logic without external level shifters. This is confirmed in the "Mixed-Mode Signal Operation" feature and electrical characteristics tables of the SCES078E datasheet.

How does the bus-hold function work on the SN74ALVTH16821 inputs?

The SN74ALVTH16821 integrates active bus-hold circuitry on all 20 data inputs. When an input floats, the bus-hold sinks or sources current (±75 µA at 3.3 V) to maintain the last-valid logic state - eliminating the need for external pullup or pulldown resistors. This behavior is verified in the IBHL/IBHH specifications and functional description of the SCES078E datasheet.

What is the maximum clock frequency supported by the SN74ALVTH16821?

The SN74ALVTH16821 supports a maximum clock frequency of 150 MHz under recommended operating conditions (VCC = 3.3 V ± 0.3 V, TA = –40°C to 85°C). This value is specified in the timing requirements table of the SCES078E datasheet and applies to both the SN74ALVTH16821 and SN54ALVTH16821 variants.

Is the SN74ALVTH16821 pin-compatible with other 20-bit ALVTH flip-flops?

The SN74ALVTH16821 shares identical pinout and functionality with the SN74ALVTH16821DLR (SSOP-56) and SN74ALVTH16821VR (TVSOP-56) variants - differing only in package type (TSSOP-56 for SN74ALVTH16821GR). All three share the same 56-pin mapping, electrical behavior, and timing specs per the SCES078E datasheet and TI packaging addendum.

SN74ALVTH16821GR Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Series:: 74ALVTH

Package/Case:: 56-TFSOP (0.240", 6.10mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Function:: Standard

Type:: D-Type

Output Type:: Tri-State, Non-Inverted

Number of Elements:: 2

Number of Bits per Element:: 10

Clock Frequency:: 150 MHz

Max Propagation Delay @ V, Max CL:: 3.5ns @ 3.3V, 50pF

Trigger Type:: Positive Edge

Current - Output High, Low:: 8mA, 24mA; 32mA, 64mA

Voltage - Supply:: 2.3V ~ 2.7V, 3V ~ 3.6V

Current - Quiescent (Iq):: 100 µA

Input Capacitance:: 3.5 pF

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 56-TSSOP

SN74ALVTH16821GR FAQ

1.How can I place an order for SN74ALVTH16821GR through Aetrix?

Please submit a Request for Quotation (RFQ) for SN74ALVTH16821GR 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 SN74ALVTH16821GR reliable?

The price and inventory of SN74ALVTH16821GR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALVTH16821GR is usually 5 days.

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4.How is shipping managed for SN74ALVTH16821GR?

SN74ALVTH16821GR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SN74ALVTH16821GR 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 SN74ALVTH16821GR?

For technical support, including SN74ALVTH16821GR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALVTH16821GR requirements.

6.How does Aetrix verify that SN74ALVTH16821GR is sourced from the original manufacturer or authorized distributors?

All SN74ALVTH16821GR 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 SN74ALVTH16821GR meets industry standards.

7.What is the process for return or replacement of SN74ALVTH16821GR?

All SN74ALVTH16821GR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALVTH16821GR, 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 SN74ALVTH16821GR part is unused and in its original packaging.

Return procedure for SN74ALVTH16821GR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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