Diodes Incorporated PI74FCT574ATS

Overview

PI74FCT574ATS from Pericom Semiconductor is an octal D-type transparent latch with 3-state outputs, designed for high-speed data buffering and bus interface applications in 5V TTL-compatible systems. It features 25Ω series output resistors to suppress signal reflections, operates across –40°C to +85°C, supports 4.5–5.5V supply, and delivers tPLH/tPHL ≤ 4.5ns (at 5V, 50pF load) with 2ns setup/1ns hold timing.

For engineers reviewing the PI74FCT574ATS datasheet, PI74FCT574ATS pinout, PI74FCT574ATS application, or PI74FCT574ATS equivalent, key selection criteria include its 20-pin TSSOP package, active-low 3-state output enable (OE), edge-triggered clock (CP), low ground bounce, and integrated 25Ω series termination-critical for noise-sensitive backplane and memory address/data bus designs.

Technical Context

This device implements eight independent D-type flip-flops sharing a common clock (CP) and a single active-low output enable (OE). Data on D0–D7 is latched on the LOW-to-HIGH transition of CP, and outputs O0–O7 enter high-impedance state when OE is HIGH. All inputs exhibit hysteresis (200mV) for noise immunity.

The 25Ω series resistor on each output terminal reduces transmission-line reflections without requiring external termination, enabling clean signal integrity at up to 100MHz clock rates. Its CMOS process achieves TTL-compatible input thresholds (VIH = 2.0V, VIL = 0.8V) and rail-to-rail output swing (VOH ≥ 2.4V, VOL ≤ 0.50V at 12mA).

Key Specifications

Pinout & Package

PI74FCT574ATS is housed in a 20-pin 173-mil wide plastic TSSOP (Thin Shrink Small Outline Package), pin-compatible with industry-standard SOIC-20 footprints using adapter boards. The package supports fine-pitch surface-mount assembly and thermal performance suitable for dense logic layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal D-latch applications.

Compared with 74F574PC and SN74ACT574N, PI74FCT574ATS uniquely combines sub-5ns speed, integrated 25Ω termination, and <500µA quiescent current-making it optimal for noise-sensitive, space-constrained 5V bus interfaces where signal integrity and component count reduction are design priorities.

Availability

PI74FCT574ATS is available at Aetrix Electronics and suitable for memory address latching, microprocessor bus isolation, backplane signal conditioning, and industrial I/O expansion requiring stable component supply and long-term industrial temperature support.

Supply support for PI74FCT574ATS 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

Pericom Semiconductor (now part of Diodes Incorporated) specialized in high-speed interface and timing solutions, with expertise in CMOS logic, clock distribution, and signal integrity optimization.

PI74FCT574ATS belongs to the FCT logic family-designed specifically for 5V TTL-compatible, low-noise, high-speed data path applications in computing, communications, and industrial control systems.

FAQ

What is the function of the OE pin on PI74FCT574ATS?

The OE (Output Enable) pin is an active-low control input that determines whether the O0–O7 outputs are actively driven (OE = LOW) or placed in high-impedance state (OE = HIGH). This allows multiple devices to share a common bus without contention. OE has hysteresis (200mV) for noise immunity and supports direct connection to microcontroller GPIO or decoder outputs without additional buffering.

Does PI74FCT574ATS require external termination resistors?

No. Each output (O0–O7) integrates a precise 25Ω series resistor optimized for impedance matching with standard 50Ω PCB traces, eliminating the need for discrete termination components. This reduces BOM count, PCB area, and potential layout-induced signal integrity issues-verified under 100MHz toggle conditions with 50pF load.

Can PI74FCT574ATS operate at 3.3V supply?

No. PI74FCT574ATS is specified only for 4.5V to 5.5V operation. Its TTL-compatible input thresholds (VIH = 2.0V, VIL = 0.8V) and internal gate design require nominal 5V biasing. Attempting 3.3V operation results in undefined logic states, excessive propagation delay, and potential functional failure per DC electrical specifications.

How does the 25Ω series resistor affect drive capability?

The integrated 25Ω resistor limits peak output current but maintains full TTL-compatibility: VOL remains ≤ 0.50V at 12mA sink, and VOH stays ≥ 2.4V at 15mA source. It trades minor voltage drop (<0.3V at 12mA) for significant reduction in edge-induced ringing-enabling robust operation on unterminated 4-inch traces without sacrificing fanout (up to 10 TTL loads).