Nexperia USA Inc. 74ALVT16821DL,518

Overview

74ALVT16821DL,518 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 logic. It operates from 2.3 V to 3.6 V, supports 150 MHz clock frequency, and features independent clocks (1CP/2CP) and output enables (1OE/2OE) for each 10-bit bank. It is used in high-speed bus interface and data latching applications in industrial control backplanes and memory expansion modules.

For engineers reviewing the 74ALVT16821DL,518 datasheet, 74ALVT16821DL,518 pinout, 74ALVT16821DL,518 application, or 74ALVT16821DL,518 equivalent, key selection criteria include dual-clock timing control, overvoltage-tolerant 5.5 V inputs, bus-hold functionality eliminating external pull-ups, power-up 3-state behavior, and TSSOP56 package compatibility with high-density PCB layouts.

Technical Context

This device implements two independent 10-bit D-register banks sharing no internal signal paths-each with dedicated clock (nCP), output enable (nOE), and 10 data I/Os. The flip-flops capture input states only on LOW-to-HIGH transitions of nCP, with setup/hold times as low as 0.1 ns at 3.3 V.

Bus-hold circuitry actively maintains valid logic levels on unused data inputs without external resistors, while IOFF protection ensures low leakage (<±100 μA) during partial power-down. Output drive strength reaches 64 mA sink / 32 mA source at 3.3 V, enabling direct TTL interfacing.

Key Specifications

Pinout & Package

TSSOP56 plastic thin shrink small outline package (SOT364-1), 56-pin, body width 6.1 mm, 0.5 mm pitch, lead-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALVTH16821GR and 74LVC16374APAG, the 74ALVT16821DL,518 uniquely combines 5.5 V input tolerance, integrated bus-hold, and 150 MHz operation in a pin-compatible TSSOP56 package-making it the only option that eliminates external termination while supporting mixed-voltage, high-speed bus interfacing without redesign.

Availability

74ALVT16821DL,518 is available at Aetrix Electronics and suitable for industrial backplane interfaces, memory expansion modules, programmable logic I/O expansion, and test equipment digital pattern generators requiring stable component supply across extended product lifecycles.

Supply support for 74ALVT16821DL,518 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 delivering high-performance, reliable logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets with emphasis on efficiency and miniaturization.

The 74ALVT series targets high-speed, low-voltage bus interface applications-designed specifically for 2.3–3.6 V systems needing robust 5 V-tolerant I/O, fast propagation, and advanced power management features like IOFF and bus-hold.

FAQ

What is the maximum clock frequency supported by the 74ALVT16821DL,518?

The device 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 under recommended operating conditions with 50 pF load and 500 Ω termination.

Does the 74ALVT16821DL,518 require external pull-up resistors on unused data inputs?

No. All data inputs feature integrated bus-hold circuitry that actively maintains the last valid logic state without external components. At 3 V supply, bus-hold current ranges from ±75 μA to ±140 μA, ensuring stable HIGH or LOW levels on floating inputs.

Can the 74ALVT16821DL,518 safely interface with 5 V logic systems?

Yes. Its inputs are overvoltage tolerant up to 5.5 V regardless of VCC level (2.3–3.6 V), allowing direct connection to 5 V buses without level shifters. This is confirmed in Table 4 (Limiting Values) and Table 5 (Recommended Operating Conditions) of the datasheet.

What happens to the outputs during power-up?

The device features power-up 3-state behavior: all outputs remain in high-impedance until VCC stabilizes and valid clock/output-enable signals are applied. This prevents bus contention during power sequencing, as specified in Section 2 "Features and benefits" and validated in static characterization tests.