Nexperia USA Inc. 74ALVT16821DGGS

Overview

74ALVT16821DGGS from Nexperia is a 20-bit positive-edge-triggered D-type flip-flop with dual 10-bit sections, 3-state outputs, bus-hold inputs, and BiCMOS output drive. It operates from 2.3 V to 3.6 V, supports 5.5 V-tolerant inputs, and delivers sub-4 ns propagation delay at 3.3 V - used in high-speed bus interface buffering and data synchronization between asynchronous logic domains in industrial control backplanes.

For engineers reviewing the 74ALVT16821DGGS datasheet, 74ALVT16821DGGS pinout, 74ALVT16821DGGS application, or 74ALVT16821DGGS equivalent, this page provides verified functional partitioning (dual 10-bit register blocks), real-world timing margins (setup/hold times down to 0.1 ns), bus-hold current specs (±140 μA), 3-state enable behavior, and TSSOP56 package-level thermal and routing constraints.

Technical Context

The device implements two independent 10-bit D-register banks, each controlled by its own clock (1CP/2CP) and output enable (1OE/2OE), enabling selective latching and tri-state control per bank. Its BiCMOS architecture combines bipolar speed with CMOS low power, delivering 64 mA sink and 32 mA source drive while maintaining TTL-compatible input thresholds.

Bus-hold circuitry actively maintains valid logic states on unused data inputs without external pull-ups, eliminating floating node risks. The IOFF partial power-down feature disables I/O leakage when VCC = 0 V, supporting hot-swap and power-gating scenarios in modular systems.

Key Specifications

Pinout & Package

TSSOP56 (SOT364-1) plastic thin shrink small outline package, 56-pin, 6.1 mm body width, 0.5 mm pitch, 1.2 mm max height - optimized for high-density PCB layouts with thermal relief via exposed pad compatibility (not internally connected).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 20-bit bus interface register applications.

Compared with SN74ALVTH16821DGGR and 74LVC16374ADGG, the 74ALVT16821DGGS uniquely delivers 20-bit width, integrated bus-hold, and 5.5 V tolerance in one package - reducing component count, improving signal integrity on unterminated buses, and enabling mixed-voltage interoperability without translation circuitry.

Availability

74ALVT16821DGGS is available at Aetrix Electronics and suitable for industrial backplane buffering, high-speed data acquisition interfaces, modular I/O expansion modules, and TTL-to-ALVT logic translation bridges requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74ALVT16821DGGS 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 global semiconductor expert focused on high-volume, high-reliability logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets - with manufacturing rooted in process control and AEC-Q200 qualification rigor.

The 74ALVT series targets high-speed, mixed-voltage digital interface applications where speed, noise immunity, and voltage flexibility outweigh ultra-low-power requirements - designed specifically for robust bus buffering in industrial control and instrumentation.

FAQ

Does the 74ALVT16821DGGS support hot-swap operation?

Yes - its IOFF circuitry ensures negligible I/O leakage (< ±100 μA) when VCC = 0 V, preventing back-driving or latch-up during live insertion. Combined with power-up 3-state behavior, it safely enters high-impedance mode before power stabilization, making it suitable for modular backplane systems requiring field-replaceable units.

What is the maximum clock frequency supported at 2.5 V supply?

The device supports up to 150 MHz maximum clock frequency at both 2.5 V and 3.3 V supply conditions, as confirmed by dynamic characterization in Table 7. At 2.5 V, typical propagation delay is 2.6 ns (tPLH) and 2.7 ns (tPHL), with guaranteed worst-case values of 4.0 ns and 4.4 ns respectively - sufficient for reliable operation at 150 MHz with standard PCB trace lengths.

How does bus-hold functionality behave during power-up?

Bus-hold remains inactive until VCC exceeds ~1.2 V; below that threshold, inputs float but outputs stay in 3-state. Once powered, bus-hold draws ±130 μA (at 3 V) to maintain last-valid logic state on unconnected inputs - eliminating need for external biasing and preventing false triggering in partially populated systems.

Can 1OE and 2OE be tied together for unified 20-bit control?

Yes - connecting 1OE and 2OE enables simultaneous 20-bit output control, effectively operating the device as a single 20-bit register. However, doing so forfeits independent bank control; for applications requiring staggered data release or isolation between data groups, separate OE routing preserves full functional flexibility and timing decoupling.