Texas Instruments SN74ACT564DW

Overview

SN74ACT564DW from Texas Instruments is an octal D-type edge-triggered flip-flop with 3-state inverted outputs, designed for bus-oriented applications requiring high drive strength and low propagation delay. It operates at 4.5–5.5 V, delivers 8.5 ns max tpd at 5 V, supports TTL-compatible inputs, and drives capacitive or low-impedance loads directly in I/O port and bidirectional bus driver roles.

For engineers reviewing the SN74ACT564DW datasheet, SN74ACT564DW pinout, SN74ACT564DW application, or SN74ACT564DW equivalent, this page provides verified functional identity, SOIC-20 package mapping, timing and drive specifications, real-world use cases in bus buffering and register storage, and validated alternative options for design continuity.

Technical Context

The SN74ACT564DW implements eight independent D-type latches triggered on the rising edge of CLK, with each Q output inverted relative to its D input. Its 3-state OE control enables simultaneous high-impedance output disable without affecting internal state retention.

It features flow-through pin architecture (D inputs on left, Q outputs on right, OE/CLK/GND/VCC centrally located), optimized for minimal PCB trace crossing. Input voltage tolerance up to 5.5 V allows interfacing with mixed-voltage systems while maintaining full 5-V logic compatibility.

Key Specifications

Pinout & Package

SN74ACT564DW is housed in a 20-pin SOIC (DW) package measuring 12.8 mm × 10.3 mm (including pins), with body size 12.8 mm × 7.5 mm and maximum height 2.65 mm. The package is RoHS-compliant, NIPDAU lead finish, MSL Level-1, and suitable for standard reflow processes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal D-type flip-flop with 3-state output applications.

Compared with SN74ACT564DW, SN74ACT574DW offers identical speed and drive in the same SOIC-20 package but with true (non-inverted) outputs-critical for polarity-sensitive latching. SN74LVC574APW trades 5-V compatibility for lower power and smaller footprint, limiting use to 3.3-V-only systems.

Availability

SN74ACT564DW is available at Aetrix Electronics and suitable for industrial I/O expansion, embedded bus buffering, and legacy 5-V system upgrades requiring stable component supply and long-term sourcing continuity.

Supply support for SN74ACT564DW 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 specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN74ACT564DW belongs to TI's ACT (Advanced CMOS Technology) logic family-designed for high-speed, 5-V-compatible digital interfacing with robust noise immunity and bus-driving capability.

FAQ

What is the function of the OE pin on the SN74ACT564DW?

The OE (Output Enable) pin on the SN74ACT564DW is an active-low control that places all eight Q outputs into a high-impedance state when asserted (OE = LOW), without affecting internal flip-flop states. This allows safe bus sharing and dynamic contention control. When OE is HIGH, outputs drive their inverted logic levels normally. The SN74ACT564DW retains stored data regardless of OE state, supporting seamless bus arbitration.

Does the SN74ACT564DW support mixed-voltage interfacing?

Yes, the SN74ACT564DW supports mixed-voltage interfacing: its inputs tolerate voltages up to 5.5 V independent of VCC, and it accepts TTL-level thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V) while operating from 4.5 V to 5.5 V. This enables direct connection to 3.3-V or 5-V microcontrollers and legacy logic families without level shifters-provided VCC remains within specification. The SN74ACT564DW maintains full timing and drive performance under these conditions.

What is the maximum clock frequency supported by the SN74ACT564DW?

The SN74ACT564DW supports a maximum clock frequency of 75 MHz over the full operating temperature range (–40 °C to +85 °C) and 85 MHz at TA = 25 °C. This is derived from its guaranteed maximum propagation delay (tpd) of 8.5 ns at 5 V and minimum clock pulse width (tw) of 3 ns. System-level timing must also account for setup (tsu = 2.5 ns min) and hold (th = 1 ns min) requirements relative to the CLK rising edge. The SN74ACT564DW achieves this performance while maintaining 5-V logic compatibility and bus-drive capability.

Can the SN74ACT564DW drive standard 50-pF PCB traces directly?

Yes, the SN74ACT564DW is explicitly characterized to drive highly capacitive loads-including standard 50-pF PCB traces-without external buffering. Its ±24 mA output drive capability (IOL/IOH), low 8.5 ns propagation delay, and 15 pF output capacitance (Co) ensure clean signal edges and minimal distortion. The SN74ACT564DW datasheet confirms suitability for "driving highly capacitive or relatively low-impedance loads," and application guidance recommends direct bus connection without pull-up components. Layout best practices (e.g., local bypassing, ground flooding) further enhance performance.

Is the SN74ACT564DW pin-compatible with other packages in the same family?

No, the SN74ACT564DW (SOIC-20) is not pin-compatible with other package variants like SN74ACT564N (PDIP-20) or SN74ACT564PW (TSSOP-20), despite identical logic functionality and pin numbering. While all share the same pinout order (e.g., Pin 1 = OE, Pin 11 = CLK, Pin 20 = VCC), physical dimensions, pitch, and thermal characteristics differ significantly-requiring separate PCB footprints. The SN74ACT564DW uses 1.27-mm pitch SOIC; PDIP uses 2.54-mm pitch; TSSOP uses 0.65-mm pitch. Migration between packages necessitates board redesign.