Texas Instruments SN74AC564DWRE4

Overview

SN74AC564DWRE4 from Texas Instruments is an octal D-type edge-triggered flip-flop with inverting 3-state outputs, designed for bus interface and register applications. It operates across 2V–6V V_CC, delivers ≤9ns propagation delay at 5V, and supports rising-edge clock triggering with full parallel data loading. It is used in bidirectional bus drivers and I/O port buffering in industrial control and data acquisition systems.

For engineers reviewing the SN74AC564DWRE4 datasheet, SN74AC564DWRE4 pinout, SN74AC564DWRE4 application, or SN74AC564DWRE4 equivalent, key selection considerations include its 20-pin SOIC (DW) package, 3-state inverting output architecture, 5V/3.3V-compatible timing, flow-through pin arrangement for PCB layout optimization, and guaranteed operation from −40°C to +85°C.

Technical Context

The SN74AC564DWRE4 implements eight independent D-type flip-flops sharing a common rising-edge-triggered clock (CLK) and active-low output-enable (OE) control. Each Q output is the logical inverse of its corresponding D input on CLK's positive transition.

Its 3-state outputs drive high-capacitance or low-impedance bus lines directly without external pull-ups; OE disables outputs to high-impedance without affecting internal state retention or clock/data sampling - enabling hot-swappable bus arbitration and multi-drop signaling.

Key Specifications

Pinout & Package

SN74AC564DWRE4 is packaged in a 20-pin SOIC (DW) with 12.80 mm × 10.3 mm body size and standard 1.27 mm lead pitch. The package is RoHS-compliant, moisture sensitivity level 1, and rated for reflow up to 260°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AC564DWRE4, SN74ACT564DW offers superior 5 V DC performance but sacrifices 3.3 V interoperability, while 74LVC574APW,118 reduces voltage range and removes inversion - making SN74AC564DWRE4 the only choice supporting wide-voltage, inverting, bus-driven register functions in a standard SOIC package.

Availability

SN74AC564DWRE4 is available at Aetrix Electronics and suitable for industrial control systems, legacy bus adapters, automated test equipment, and digital pattern generators requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AC564DWRE4 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, with decades of experience in high-reliability industrial and automotive-grade components.

The SN74AC564DWRE4 belongs to TI's AC-series advanced CMOS logic family, engineered for robust noise immunity, wide supply voltage operation, and seamless integration into mixed-signal industrial control and data acquisition platforms.

FAQ

What is the maximum clock frequency supported by the SN74AC564DWRE4?

The SN74AC564DWRE4 supports up to 95 MHz at V_CC = 5 V ± 0.5 V and 75 MHz at V_CC = 3.3 V ± 0.3 V under recommended operating conditions. These values reflect guaranteed maximum frequencies derived from timing parameters including t_su, t_h, and t_pd; actual system-level frequency may be limited by PCB layout, load capacitance, and signal integrity.

Does the SN74AC564DWRE4 require external pull-up resistors on its outputs?

No, the SN74AC564DWRE4 does not require external pull-up resistors on its outputs because its 3-state outputs actively drive both logic high and low levels when enabled. Pull-ups are only needed on the OE input if it must be held high during power-up - TI recommends a pull-up resistor to V_CC to ensure defined high-impedance state at startup.

Can the SN74AC564DWRE4 operate with a 3.3 V supply while interfacing with 5 V logic inputs?

Yes, the SN74AC564DWRE4 can operate with a 3.3 V supply while accepting 5 V logic inputs because its inputs tolerate voltages up to 6 V regardless of V_CC. This allows direct connection to 5 V sources without level-shifting circuitry, provided output loading remains within the device's drive capability at 3.3 V.

What is the purpose of the flow-through pin architecture in the SN74AC564DWRE4?

The flow-through pin architecture places all D inputs on pins 2–9 (left side) and all Q outputs on pins 12–19 (right side), enabling straight, non-overlapping PCB traces between adjacent devices. This reduces crosstalk, minimizes parasitic inductance, and simplifies layout in high-density digital systems - a key advantage over traditional input-output interleaved packages.

Is the SN74AC564DWRE4 pin-compatible with other members of the '564 family?

Yes, the SN74AC564DWRE4 shares identical pinout and functionality with SN74ACT564DW, SN74ALS564N, and SN74F564N across all 20 pins. Differences lie in electrical characteristics (e.g., speed, drive strength, voltage range), not pin assignment or logic behavior - enabling drop-in substitution where timing and voltage requirements align.