Diodes Incorporated PI74FCT574ATQ

Overview

PI74FCT574ATQ 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 ≤ 6.5 ns (max) at CL = 50 pF.

For engineers reviewing the PI74FCT574ATQ datasheet, PI74FCT574ATQ pinout, PI74FCT574ATQ application, or PI74FCT574ATQ equivalent, this device is selected for synchronous data capture in industrial control backplanes, memory address latching, and bidirectional bus isolation where low ground bounce, hysteresis-enabled noise immunity, and pin compatibility with FAST™ logic are critical.

Technical Context

This device implements eight independent D-type flip-flops sharing a common clock (CP) and 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 200 mV hysteresis for robust noise rejection.

The built-in 25Ω series termination on each output eliminates external resistors in point-to-point or short-bus configurations. It uses advanced 0.6/0.8 µm CMOS technology to achieve lower static power (ICC ≤ 500 µA) and higher speed than bipolar FAST™ equivalents while maintaining TTL input thresholds (VIH = 2.0 V, VIL = 0.8 V).

Key Specifications

Pinout & Package

PI74FCT574ATQ is housed in a 20-pin 150 mil wide plastic TQSOP (Thin Quad Small Outline Package), designated "Q" suffix per Pericom's packaging nomenclature. The package provides compact footprint and improved thermal performance over SOIC for dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74F574PC and SN74ACT574N, PI74FCT574ATQ uniquely combines low-power CMOS efficiency, integrated signal integrity features (25Ω termination + 200 mV hysteresis), and industrial temperature qualification - making it optimal for new designs prioritizing reliability, layout simplicity, and EMI resilience.

Availability

PI74FCT574ATQ is available at Aetrix Electronics and suitable for industrial PLC backplanes, memory address latching circuits, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for PI74FCT574ATQ 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 was a fabless provider of high-performance interface, timing, and logic ICs, acquired by Diodes Incorporated in 2016. Its products targeted noise-sensitive, high-speed digital systems in industrial and communications infrastructure.

The PI74FCT family was engineered specifically for 5V TTL-compatible bus interface applications demanding low ground bounce, fast propagation, and robust noise immunity - bridging performance gaps between bipolar FAST™ and early CMOS logic.

FAQ

Is PI74FCT574ATQ compatible with 3.3V logic systems?

No. PI74FCT574ATQ is strictly a 5V-only device with TTL input thresholds (VIH = 2.0 V, VIL = 0.8 V) and 4.5–5.5V supply requirement. Direct connection to 3.3V logic may cause unreliable switching or excessive input current due to VIH exceeding 3.3V rail. Level translation is required for mixed-voltage interfacing.

What is the purpose of the 25Ω series resistor on each output?

The 25Ω resistor is monolithically integrated into each output driver to match typical PCB trace impedance (50–75Ω) in point-to-point or short-bus configurations. It damps signal reflections that cause ringing and timing uncertainty, eliminating discrete termination resistors and saving board space and cost.

Can OE be left unconnected or tied to VCC through a pull-up resistor?

No. OE must be actively driven - either to GND (to enable outputs) or VCC (to disable them). Leaving OE floating risks metastability and unintended output states. A pull-up to VCC is acceptable only if the driving source guarantees a clean, fast-rising edge to avoid momentary glitches during power-up.

Does PI74FCT574ATQ support hot-swap or live-insertion?

No. PI74FCT574ATQ lacks hot-swap protection features such as power-up 3-state, Ioff partial power-down, or bus-hold. Applying VCC before GND, or inserting into a live backplane, may cause latch-up or excessive current flow. Power sequencing per datasheet (GND first, then VCC) is mandatory.