NXP Semiconductors 74ALVT16821DGG512

Overview

74ALVT16821DGG512 from Nexperia is a 20-bit, positive-edge-triggered D-type flip-flop with 3-state outputs, designed for high-speed bus interface applications in industrial and telecom systems. It operates across 2.3 V to 3.6 V supply, supports 150 MHz maximum clock frequency, features dual independent 10-bit sections (each with dedicated clock and output enable), and includes bus-hold circuitry eliminating external pull-ups on unused inputs.

For engineers reviewing the 74ALVT16821DGG512 datasheet, 74ALVT16821DGG512 pinout, 74ALVT16821DGG512 application, or 74ALVT16821DGG512 equivalent, this device serves as a robust, overvoltage-tolerant (5.5 V) register for data latching, bus isolation, and level translation between 2.5 V/3.3 V logic domains in backplane, memory buffer, and FPGA I/O expansion designs.

Technical Context

The 74ALVT16821DGG512 implements two independent 10-bit synchronous registers, each controlled by its own rising-edge clock (1CP/2CP) and active-low output enable (1OE/2OE). Its BiCMOS architecture delivers TTL-compatible drive strength while maintaining low power consumption and fast propagation delays (as low as 0.5 ns tPLH at 3.3 V).

Bus-hold circuitry actively maintains valid logic states on un-driven data inputs, and IOFF functionality ensures minimal leakage during partial power-down. The device meets JESD78 Class II Level B latch-up immunity (>500 mA) and JEDEC ESD standards (HBM >2000 V, CDM >1000 V).

Key Specifications

Pinout & Package

TSSOP56 package (SOT364-1), plastic thin shrink small outline, 56 leads, body width 6.1 mm, lead pitch 0.5 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus interface register applications.

Compared with SN74ALVTH16821DGGR and 74LVT16821DGG, the 74ALVT16821DGG512 uniquely combines 5.5 V overvoltage tolerance, integrated bus-hold, and 64 mA output drive - making it optimal for mixed-voltage, high-reliability industrial bus interfaces where layout simplicity and robustness are critical.

Availability

74ALVT16821DGG512 is available at Aetrix Electronics and suitable for industrial control systems, telecom infrastructure equipment, and automated test instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for 74ALVT16821DGG512 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

Nexperia is a leading global semiconductor expert delivering high-performance, reliable components for automotive, industrial, and consumer electronics, with core expertise in logic, power, analog, and MOSFET technologies.

The 74ALVT16821DGG512 belongs to Nexperia's advanced ALVT logic family, engineered specifically for high-speed, low-power bus interface applications in mixed-voltage systems demanding robust ESD performance and signal integrity.

FAQ

What is the maximum clock frequency supported by the 74ALVT16821DGG512?

The 74ALVT16821DGG512 supports a maximum clock frequency of 150 MHz across its full operating temperature range (-40 °C to +85 °C) and supply voltage range (2.3 V to 3.6 V), as verified in the dynamic characteristics table of the official Nexperia datasheet Rev. 5.

Does the 74ALVT16821DGG512 include bus-hold functionality, and how does it affect system design?

Yes, the 74ALVT16821DGG512 integrates bus-hold circuitry on all 20 data inputs. This feature actively maintains valid logic states on un-driven inputs, eliminating the need for external pull-up or pull-down resistors - reducing BOM cost, PCB space, and potential signal integrity issues caused by resistor parasitics.

Can the 74ALVT16821DGG512 safely interface with 5 V logic signals?

Yes, the 74ALVT16821DGG512 features overvoltage-tolerant inputs rated to 5.5 V, allowing direct connection to 5 V TTL or CMOS outputs without level-shifting circuitry or external clamping diodes - a key advantage over standard LVT or LVTH devices.

How does the IOFF functionality of the 74ALVT16821DGG512 benefit hot-swap applications?

The IOFF circuitry in the 74ALVT16821DGG512 disables current flow through the device when VCC = 0 V, preventing back-driving of live backplanes or powered subsystems during card insertion/removal - ensuring safe hot-swap operation in modular telecom and industrial systems.

What is the purpose of having two separate clock and output-enable inputs on the 74ALVT16821DGG512?

The dual clock (1CP/2CP) and dual output-enable (1OE/2OE) inputs allow the 74ALVT16821DGG512 to operate as two independent 10-bit registers. This enables flexible partitioning of data paths - such as separating address and data lanes or managing redundant bus segments - without requiring two discrete devices.