Diodes Incorporated PI74FCT244TQE

Overview

PI74FCT244TQE 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 PI74FCT244TQE datasheet, PI74FCT244TQE pinout, PI74FCT244TQE application, or PI74FCT244TQE equivalent, key selection criteria include its integrated 25Ω output termination, low ground bounce, hysteresis-enabled noise immunity, and QSOP-20 package compatibility with high-density PCB 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. All inputs feature hysteresis (200 mV typical) and TTL-level thresholds (VIH = 2.0 V, VIL = 0.8 V).

Each output integrates a 25Ω series resistor to suppress transmission-line reflections-eliminating external termination-and supports 64 mA sink (VOL = 0.55 V) and 15 mA source (VOH = 2.4 V) drive under 5.0 V ±5% supply conditions.

Key Specifications

Pinout & Package

PI74FCT244TQE is housed in a Pb-free, green 20-pin plastic QSOP (150-mil width), with 0.65 mm lead pitch and standard JEDEC MO-137AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PI74FCT541TQE and SN74F244N, PI74FCT244TQE uniquely supports dual-nibble bus isolation via separate OEA/OEB enables and eliminates external termination-reducing component count and improving signal fidelity in dense industrial backplanes.

Availability

PI74FCT244TQE is available at Aetrix Electronics and suitable for industrial backplane bus drivers, memory address buffering, system clock distribution, and legacy ISA bus interfacing requiring stable component supply and long-term lifecycle support.

Supply support for PI74FCT244TQE 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 FCT logic portfolio remains widely deployed in industrial and communications infrastructure.

PI74FCT244TQE belongs to the FCT2XXX family of fast CMOS octal buffers designed specifically for noise-immune, high-drive 5 V bus interfacing in space-constrained industrial and telecom systems.

FAQ

What is the function of the OEA and OEB pins on PI74FCT244TQE?

OEA and OEB are independent active-low 3-state enable inputs: OEA controls outputs OB0–OB3, and OEB controls outputs OA0–OA3. When asserted (LOW), each enables its respective 4-bit output group; when HIGH, those outputs enter high-impedance state. This allows selective bus isolation for nibble-level control in multiplexed systems.

Does PI74FCT244TQE require external termination resistors?

No. Each output includes an integrated 25Ω series resistor optimized for 50 pF loads and typical PCB trace impedances. This eliminates the need for discrete 22–33 Ω resistors, reducing component count and layout complexity while suppressing reflections on unterminated lines up to ~10 cm.

Can PI74FCT244TQE operate with a 3.3 V input signal while powered at 5 V?

Yes. Its TTL-compatible inputs accept VIH ≥ 2.0 V and VIL ≤ 0.8 V, so 3.3 V logic HIGH signals (typically 3.3 V) exceed the 2.0 V threshold. The device is not 3.3 V tolerant on VCC, but input voltage levels are fully compatible with mixed-voltage 3.3 V/5 V system interfaces.

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

PI74FCT244TQE is characterized for CL = 50 pF, with guaranteed 6.5 ns max propagation delay and 0.55 V VOL at 64 mA sink. For heavier loads (>75 pF), rise/fall times increase and VOH/VOL margins degrade; use IBIS simulation or empirical testing to verify timing closure in >100 pF applications.