Diodes Incorporated PI74FCT373ATQ

Overview

PI74FCT373ATQ from Pericom Semiconductor is an octal transparent latch with 3-state outputs, designed for bus-oriented digital systems requiring data latching and isolation. It features TTL-compatible input/output levels, 25Ω series output resistors to suppress signal reflections, a 3.8 ns maximum propagation delay (tPLH), 5.0 ns max output enable/disable times, and operates across –40°C to +85°C for industrial bus buffering in microprocessor data paths.

For engineers reviewing the PI74FCT373ATQ datasheet, PI74FCT373ATQ pinout, PI74FCT373ATQ application, or PI74FCT373ATQ equivalent, key selection criteria include latch enable timing (min 4.0 ns LE pulse width), output drive capability (64 mA sink), low static current (≤500 µA), hysteresis-enhanced noise immunity (200 mV), and TSSOP-20 package compatibility with high-density PCB layouts.

Technical Context

This device implements a parallel 8-bit transparent latch architecture where data passes through when Latch Enable (LE) is HIGH and is captured on the falling edge of LE. Output Enable (OE) controls tri-state output behavior independently, allowing bidirectional bus sharing without external bus transceivers.

Its 25Ω integrated series termination on all eight outputs eliminates discrete resistors while maintaining signal integrity at up to 100 MHz bus speeds. The design uses advanced 0.6/0.8 µm CMOS process, delivering faster switching than bipolar FAST™ logic while consuming less power and exhibiting lower ground bounce.

Key Specifications

Pinout & Package

PI74FCT373ATQ is housed in a 20-pin 173-mil wide plastic TSSOP (Thin Shrink Small Outline Package), optimized for automated assembly and thermal performance in compact industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74F573N and 74LCX373MTCX, PI74FCT373ATQ uniquely combines 5V TTL compatibility, integrated termination, industrial temperature support, and sub-4 ns speed-making it optimal for upgrading legacy 5V bus architectures without redesign.

Availability

PI74FCT373ATQ is available at Aetrix Electronics and suitable for industrial PLC backplanes, microprocessor data path latching, and automated test equipment requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for PI74FCT373ATQ 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 and timing solutions, acquired by Diodes Incorporated in 2016; its FCT logic portfolio remains widely deployed in industrial and communications infrastructure.

The PI74FCT series targets 5V bus-oriented digital systems needing TTL-compatible speed, low power, and noise resilience-specifically engineered for microprocessor co-processors, memory interfaces, and programmable logic interconnects.

FAQ

What is the minimum Latch Enable (LE) pulse width required for reliable operation of PI74FCT373ATQ?

The minimum LE pulse width is 4.0 ns for the 'AT' speed grade, verified across –40°C to +85°C and VCC = 4.75 V to 5.25 V. This specification ensures sufficient time for internal metastability resolution and guarantees data capture integrity even under worst-case voltage and temperature conditions.

Does PI74FCT373ATQ require external pull-up or pull-down resistors on OE or LE inputs?

No external biasing resistors are required. All inputs feature built-in hysteresis (200 mV) and TTL-compatible thresholds, enabling direct connection to microcontroller GPIOs or open-collector drivers without risk of floating states or oscillation.

Can PI74FCT373ATQ be used in mixed-voltage systems with both 3.3V and 5V logic?

It operates exclusively at 5.0 V ±5% and accepts 3.3V logic-high inputs (VIH = 2.0 V min), but its outputs swing to 5V levels. Interfacing with 3.3V-only receivers requires external level-shifting or clamping; it is not 3.3V-tolerant on outputs.

How does the integrated 25Ω series resistor affect signal rise/fall times on PI74FCT373ATQ outputs?

The 25Ω resistor, combined with typical PCB trace capacitance (~5–10 pF), limits edge rates to ~0.5–0.8 ns, reducing EMI and eliminating ringing on unterminated 50Ω traces. Measured tPLH/tPHL remain within datasheet specs because propagation delay is defined at 50% crossing, not edge rate.