Texas Instruments SN74ALVC16721DL

Overview

SN74ALVC16721DL from Texas Instruments is a 20-bit edge-triggered D-type flip-flop optimized for 3.3-V operation, featuring bus-hold inputs, independent output-enable control, and qualified clock storage. It delivers 150-MHz maximum clock frequency, ±24-mA output drive at 3 V, and operates across −40°C to 85°C for industrial bus interface applications.

For engineers reviewing the SN74ALVC16721DL datasheet, SN74ALVC16721DL pinout, SN74ALVC16721DL application, or SN74ALVC16721DL equivalent, key selection criteria include bus-hold functionality, dual-control timing (CLKEN + OE), high-speed 20-bit data latching, and DL-package compatibility with space-constrained PCB layouts.

Technical Context

This device implements 20 independent D-type flip-flops with synchronous clock enable (CLKEN) and asynchronous output enable (OE). Each channel samples D-input on the rising edge of CLK only when CLKEN = L; OE controls all 20 Q-outputs simultaneously into high-impedance or active logic states without affecting internal storage.

It uses TI's EPIC™ submicron CMOS process, supports 2.3–3.6-V supply range, and integrates active bus-hold circuitry on all 20 data inputs-eliminating external pull resistors while maintaining valid logic levels on floating or unused lines.

Key Specifications

Pinout & Package

SN74ALVC16721DL is housed in a 56-pin plastic shrink small-outline (DL) package measuring 18.4 mm × 7.5 mm × 2.36 mm (JEDEC MO-153), with 0.5-mm lead pitch and exposed thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALVC16721DL, SN74LVC16374DGGR offers identical pinout and speed but lacks bus-hold, increasing design overhead; 74ALVCH162244TTR provides bus-hold and drive but no clocked storage - making it functionally incomplete for register applications.

Availability

SN74ALVC16721DL is available at Aetrix Electronics and suitable for industrial PLC backplanes, ATE digital I/O modules, and communications line card buffers requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SN74ALVC16721DL 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions with broad industrial and automotive reach.

SN74ALVC16721DL belongs to TI's ALVC Widebus™ family - engineered for high-density, low-voltage parallel bus interfacing in industrial automation, test instrumentation, and telecom infrastructure.

FAQ

What is the maximum clock frequency supported by the SN74ALVC16721DL?

The SN74ALVC16721DL supports a maximum clock frequency of 150 MHz at VCC = 3.3 V, as specified in the timing characteristics table under recommended operating conditions. This value is validated across the full −40°C to +85°C temperature range and applies to all 20 flip-flop channels simultaneously when CLKEN is asserted low and load capacitance is 50 pF.

Does the SN74ALVC16721DL require external pullup or pulldown resistors on its data inputs?

No, the SN74ALVC16721DL does not require external pullup or pulldown resistors on its D1–D20 inputs due to integrated bus-hold circuitry. This feature actively maintains the last valid logic state on each input, eliminating floating nodes and reducing BOM count - a key differentiator from standard LVC-family equivalents like SN74LVC16374DGGR.

How many power and ground pins does the SN74ALVC16721DL have in the DL package?

The SN74ALVC16721DL in the 56-pin DL package has six dedicated VCC pins (pins 7, 16, 26, 36, 43, 50) and eight dedicated GND pins (pins 4, 11, 18, 25, 33, 41, 44, 51), providing low-impedance supply distribution essential for clean switching of all 20 outputs simultaneously.

What is the purpose of the CLKEN pin on the SN74ALVC16721DL?

The CLKEN (Clock Enable) pin on the SN74ALVC16721DL is an asynchronous control that gates clock sampling: when CLKEN = H, the device holds current Q-output values regardless of CLK transitions; when CLKEN = L, data from D-inputs is captured on each rising CLK edge. This enables precise windowed data capture without altering clock distribution.

Can the SN74ALVC16721DL operate at 2.5 V supply voltage?

Yes, the SN74ALVC16721DL is fully characterized for operation at 2.5 V supply voltage, with timing and DC specifications guaranteed across the recommended 2.3–3.6-V range. At VCC = 2.5 V, it achieves 150-MHz maximum clock frequency and maintains bus-hold functionality with ±45 µA hold current, supporting mixed-voltage system integration.