Diodes Incorporated PI74FCT244TLE

Overview

PI74FCT244TLE from Pericom Semiconductor is a fast CMOS non-inverting octal buffer/line driver with 25Ω series output resistors, TTL-compatible input/output levels, and dual active-low 3-state enable inputs (OEA/OEB). It delivers 6.5 ns max propagation delay at 50 pF load, supports 64 mA sink current per output, and operates across –40°C to +85°C for bus driving in industrial control backplanes.

For engineers reviewing the PI74FCT244TLE datasheet, PI74FCT244TLE pinout, PI74FCT244TLE application, or PI74FCT244TLE equivalent, key selection criteria include output drive strength, integrated termination, low ground bounce, hysteresis-enabled noise immunity, and Pb-free TSSOP-20 packaging compatibility with legacy Fast TTL layouts.

Technical Context

This device implements two independent 4-bit non-inverting buffer sections, each controlled by separate 3-state enables (OEA for outputs OB0–OB3; OEB for outputs OA0–OA3), enabling bidirectional bus isolation without external logic. All eight outputs feature built-in 25Ω series resistors to suppress transmission-line reflections.

It uses Fast CMOS process technology to achieve TTL-level interface compatibility while delivering 0.5 μA typical quiescent ICC and <4.0 ns max output disable time (tPLZ) - critical for high-speed address/data bus hold timing in memory-mapped systems.

Key Specifications

Pinout & Package

PI74FCT244TLE is housed in a 20-pin 173-mil wide Pb-free and Green plastic TSSOP (Thin Shrink Small Outline Package), optimized for high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74F244N and 74LCX244MTCX, PI74FCT244TLE uniquely combines 5 V TTL interoperability, integrated termination, industrial temperature range, and RoHS compliance - making it optimal for upgrading legacy industrial backplanes without layout changes.

Availability

PI74FCT244TLE is available at Aetrix Electronics and suitable for industrial backplane bus drivers, memory address buffering, and system clock distribution requiring stable component supply, long-term lifecycle support, and Pb-free compliance.

Supply support for PI74FCT244TLE 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-speed interface and signal integrity solutions, acquired by Diodes Incorporated in 2016; its timing, logic, and interface portfolio remains actively supported.

PI74FCT244TLE belongs to the FCT2XXX Fast CMOS logic family, engineered specifically for 5 V TTL-compatible bus interfacing with enhanced noise immunity, low power, and integrated termination - targeting industrial control, telecom infrastructure, and legacy system upgrades.

FAQ

Is PI74FCT244TLE compatible with 3.3 V input signals?

Yes - its TTL-input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) accept 3.3 V logic HIGH safely, and VIH is guaranteed down to 2.0 V across temperature and voltage. No level shifter is needed when driven by 3.3 V CMOS outputs, though output swing remains 5 V.

Can both OEA and OEB be asserted simultaneously?

Yes - asserting both OEA and OEB LOW enables all eight outputs (OA0–OA3 and OB0–OB3) concurrently. This configuration is explicitly supported in the truth table and used for full-bus drive; no contention or undefined state occurs.

What is the maximum capacitive load this device can drive reliably?

The datasheet specifies switching characteristics up to CL = 50 pF. With its 25Ω series resistor, it maintains signal integrity up to ~75 pF in practice, but for guaranteed timing compliance (e.g., tPLH ≤ 6.5 ns), keep total load ≤50 pF including trace and input capacitance of downstream devices.

Does PI74FCT244TLE require external pull-up or pull-down resistors on enable pins?

No - OEA and OEB have hysteresis and valid TTL thresholds; they may be driven directly from MCU GPIOs or open-collector logic. Pull-ups are unnecessary unless floating states must be avoided in unpowered subsystems - in which case 10 kΩ to VCC suffices.