Texas Instruments 74ACT16821DL

Overview

74ACT16821DL from Texas Instruments is a 20-bit 3-state CMOS flip-flop IC designed for high-capacitance bus driving in wide data/address paths. It operates at 5 V, supports 70 MHz clock frequency, delivers ±24 mA output drive, features dual 10-bit sections with independent clock and output-enable inputs, and is used in parity bus interfacing and I/O port buffering.

For engineers reviewing the 74ACT16821DL datasheet, 74ACT16821DL pinout, 74ACT16821DL application, or 74ACT16821DL equivalent, this page provides verified functional identity, validated DL-package pin mapping, confirmed timing and drive specifications, and two technically documented alternative parts for industrial bus interface designs.

Technical Context

The 74ACT16821DL implements two independent 10-bit positive-edge-triggered D-type flip-flop sections, each with dedicated clock (1CLK/2CLK) and output-enable (1OE/2OE) controls. Its flow-through architecture places inputs and outputs on opposite sides of the 56-pin SSOP package to simplify PCB routing.

Each section retains internal state regardless of OE status-data can be latched or held while outputs remain in high-impedance-enabling non-disruptive bus arbitration. Distributed V_CC/GND pins and EPIC™ 1-µm CMOS process minimize switching noise and support stable 70 MHz operation across −40°C to 85°C.

Key Specifications

Pinout & Package

74ACT16821DL is housed in a 56-pin shrink small-outline package (SSOP-DL), 300-mil body width, 25-mil pin pitch, JEDEC MO-118 compliant, with gull-wing leads and exposed thermal pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74ACT16821DL, the 74ACT16374DL offers identical speed and package but removes dual-section configurability, while SN74ALVCH162244DL trades storage capability for 3.3 V compatibility and faster enable timing-neither is pin-compatible, and both require schematic and timing revalidation.

Availability

74ACT16821DL is available at Aetrix Electronics and suitable for memory interface buffering, parity bus management, and industrial backplane interfacing requiring stable component supply and long-term industrial temperature support.

Supply support for 74ACT16821DL 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 delivering analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The 74ACT16821DL belongs to TI's Widebus™ family of high-speed CMOS logic devices, engineered specifically for wide-bus applications demanding low-noise, high-drive, and flow-through PCB layout optimization.

FAQ

What is the maximum operating frequency of the 74ACT16821DL?

The 74ACT16821DL is characterized for reliable operation up to 70 MHz across its full temperature range (−40°C to +85°C). This maximum clock frequency is guaranteed under recommended conditions: V_CC = 5 V ± 0.5 V, with input rise/fall times ≤10 ns/V and load capacitance ≤50 pF. The 74ACT16821DL achieves this using TI's EPIC™ 1-µm CMOS process and distributed power/ground architecture to minimize jitter and propagation skew.

Does the 74ACT16821DL support independent control of its two 10-bit sections?

Yes, the 74ACT16821DL provides fully independent control: each 10-bit section has its own clock input (1CLK and 2CLK) and active-low output-enable signal (1OE and 2OE). This allows asynchronous latching and selective bus driving-for example, holding data in one section while updating the other. The 74ACT16821DL maintains internal state regardless of OE status, enabling non-intrusive bus arbitration without data loss.

What package type is used for the 74ACT16821DL, and what are its key mechanical features?

The 74ACT16821DL uses a 56-pin shrink small-outline package (SSOP-DL) with 25-mil center-to-center pin spacing and 300-mil body width. Key mechanical features include eight GND and four V_CC pins distributed across the perimeter to reduce switching noise, gull-wing leads for surface-mount assembly, and compliance with JEDEC MO-118. The 74ACT16821DL's flow-through pinout places all inputs on one side and outputs on the opposite side to optimize PCB routing density.

Can the 74ACT16821DL interface directly with TTL logic circuits?

Yes, the 74ACT16821DL features TTL-voltage-compatible inputs, meaning it accepts standard TTL logic thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V) while operating from a 5 V supply. No external pull-ups or level shifters are needed when driven by legacy 74LS or 74F series devices. The 74ACT16821DL's output levels (V_OH ≥ 3.8 V, V_OL ≤ 0.44 V at 24 mA) also meet TTL fan-out requirements, supporting direct connection to multiple TTL inputs.

Is the 74ACT16821DL still in active production, and what is its lifecycle status?

The 74ACT16821DL is marked as OBSOLETE by Texas Instruments per official packaging documentation. While no longer in active production, Aetrix Electronics maintains traceable inventory and supports legacy design continuity through controlled distribution, BOM lifecycle management, and cross-reference guidance. For new designs, TI recommends evaluating functionally aligned alternatives such as the 74ACT16374DL or newer ALVC-series equivalents-but the 74ACT16821DL remains available for repair, maintenance, and legacy system replenishment.