Texas Instruments 74ACT16825DLR

Overview

74ACT16825DLR from Texas Instruments is an 18-bit noninverting 3-state buffer/driver IC designed for high-density memory address and bus interface applications. It operates at 4.5–5.5 V, delivers ±24 mA output drive, supports TTL-compatible inputs, and features dual 9-bit sections with independent 2-input NOR enable logic (OE1/OE2). It is used in wide data/address buses requiring flow-through pinout and low-noise distributed power/ground.

For engineers reviewing the 74ACT16825DLR datasheet, 74ACT16825DLR pinout, 74ACT16825DLR application, or 74ACT16825DLR equivalent, this device is selected for high-speed 3-state bus driving where PCB layout optimization, noise control via distributed V_CC/GND, and true-level buffering across 18 channels are critical design requirements.

Technical Context

The 74ACT16825DLR implements two independent 9-bit buffer sections, each with true A→Y signal path and a 2-input NOR gate controlling all nine outputs simultaneously. Output-enable logic ensures that either OE1 or OE2 high forces the corresponding nine outputs into high-impedance state.

It uses TI's EPIC™ 1-µm CMOS process and features flow-through architecture with input/output pins arranged on opposite sides of the SSOP package to minimize trace crossovers. Distributed V_CC and GND pins across the 56-pin DL package reduce simultaneous switching noise during high-speed operation.

Key Specifications

Pinout & Package

74ACT16825DLR is housed in a 56-pin Shrink Small-Outline Package (SSOP-DL), 300-mil body width, 25-mil pin pitch, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 18-bit 3-state buffer applications.

Compared with SN74ACT162244DLR and 74AC16825DLR, the 74ACT16825DLR uniquely provides exact 18-bit width with guaranteed TTL compatibility and optimized flow-through layout - critical for memory subsystems and industrial backplanes where bit-width alignment and noise control are non-negotiable.

Availability

74ACT16825DLR is available at Aetrix Electronics and suitable for memory subsystems, industrial backplane interfaces, and high-density bus transceivers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 74ACT16825DLR 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 company specializing in analog, embedded processing, and logic solutions, with decades of leadership in high-reliability logic families.

The 74ACT16825DLR belongs to TI's Widebus™ ACT logic family, engineered for high-speed, low-noise bus interface applications in memory, computing, and industrial control systems.

FAQ

What is the maximum clock frequency supported by the 74ACT16825DLR?

The 74ACT16825DLR is not a clocked device-it has no internal clock or register. Its usable frequency depends on system-level timing margins. With typical propagation delays of 4.1–10.5 ns and output enable times under 11.5 ns, it supports reliable operation in parallel bus systems up to ~50 MHz (based on worst-case round-trip delay and setup/hold windows). The 74ACT16825DLR is specified for DC to high-speed switching, not periodic clocking.

Does the 74ACT16825DLR support hot-swap or live-insertion?

No, the 74ACT16825DLR is not designed for hot-swap operation. Its absolute maximum ratings do not include powered insertion sequences, and the input clamp current (±20 mA) and lack of power-up/down protection circuitry make uncontrolled hot-plug risky. For hot-swap applications, dedicated hot-swap controllers or buffers with power sequencing support should be used instead of the 74ACT16825DLR.

Can the 74ACT16825DLR be used with 3.3-V logic systems?

The 74ACT16825DLR is rated for 4.5–5.5 V supply only and is not 3.3-V compatible. Its inputs require TTL thresholds (V_IH ≥ 2 V), but its outputs swing rail-to-rail (0–5 V), which may damage 3.3-V receivers. Using the 74ACT16825DLR with 3.3-V systems requires level-shifting on both inputs and outputs. For native 3.3-V operation, consider TI's AVC or LVC series alternatives instead of the 74ACT16825DLR.

How many 74ACT16825DLR devices can be driven by a single 74ACT04 inverter output?

A 74ACT04 output can drive up to 10–12 74ACT16825DLR inputs under typical conditions. Each 74ACT16825DLR input draws ≤ ±1 µA (I_I) at V_CC = 5.5 V, well within the 74ACT04's ±24 mA drive capability. However, capacitive loading (C_i = 4 pF per input) becomes dominant at high frequencies - total load capacitance should remain ≤ 50 pF for clean edge integrity. So for 12 inputs, total C_i = 48 pF, making the 74ACT16825DLR a practical fanout limit.

Is the 74ACT16825DLR pin-compatible with the 54ACT16825DW?

No, the 74ACT16825DLR (56-pin SSOP-DL) is not pin-compatible with the 54ACT16825DW (56-pin ceramic flat package). Although both share identical logic function, pin numbering, and signal assignment, the DW package uses different mechanical dimensions, lead form (gull-wing vs. J-bend), and thermal/mounting characteristics. PCB footprints, reflow profiles, and mechanical clearances differ - direct substitution requires board redesign. The 74ACT16825DLR is not a drop-in replacement for the 54ACT16825DW.