Diodes Incorporated PI74FCT244CTQE

Overview

PI74FCT244CTQE from Pericom Semiconductor is a fast CMOS non-inverting octal buffer/line driver with dual 3-state output enables (OEA, OEB), TTL-compatible I/O levels, 25Ω series output termination, and industrial temperature range (–40°C to +85°C). It delivers 64mA sink current per output, 3.6ns max propagation delay (CL = 50pF), and operates at 5.0V ±5%. Used in high-speed bus driving for memory address/data paths in embedded control systems.

For engineers reviewing the PI74FCT244CTQE datasheet, PI74FCT244CTQE pinout, PI74FCT244CTQE application, or PI74FCT244CTQE equivalent, key selection criteria include output drive strength (64mA), integrated 25Ω series termination, dual active-low/high enable logic, low ground bounce, and QSOP-20 packaging for space-constrained PCB layouts.

Technical Context

The PI74FCT244CTQE implements two independent 4-bit non-inverting buffer sections, each controlled by separate 3-state enable inputs (OEA active-low, OEB active-high). Its internal 25Ω series resistors on all eight outputs suppress transmission-line reflections without external termination.

It uses Fast CMOS technology to achieve TTL-compatible input thresholds (VIH = 2.0V, VIL = 0.8V) and output voltage levels (VOH ≥ 2.4V at –15mA, VOL ≤ 0.55V at 64mA), while maintaining quiescent ICC ≤ 500μA and dynamic ICCD ≤ 0.25mA/MHz.

Key Specifications

Pinout & Package

PI74FCT244CTQE is housed in a Pb-free and Green-compliant 20-pin plastic QSOP (150-mil width), with 0.65mm lead pitch and JEDEC MO-137AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PI74FCT244TQE, the 'C' grade offers tighter timing for high-speed buses; compared with PI74FCT541CTQE, it retains symmetrical I/O pin arrangement ideal for bidirectional bus mirroring but requires more careful routing for fan-out.

Availability

PI74FCT244CTQE is available at Aetrix Electronics and suitable for industrial control systems, memory subsystems, and embedded bus interface designs requiring stable component supply, RoHS compliance, and long-term lifecycle support.

Supply support for PI74FCT244CTQE 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 for computing, communications, and industrial electronics before its 2017 acquisition.

The PI74FCT2xxx family was designed to replace bipolar TTL buffers with CMOS efficiency while preserving pinout and electrical compatibility - targeting cost-sensitive, high-reliability embedded systems operating at 5V.

FAQ

What is the function of the OEA and OEB pins on PI74FCT244CTQE?

OEA is an active-low 3-state output enable; OEB is an active-high 3-state output enable. Both control all eight outputs simultaneously. When OEA = LOW and OEB = HIGH, outputs are enabled; any other combination places outputs in high-impedance state. This dual-enable scheme supports flexible bus arbitration and avoids floating-bus conditions during power-up or reset sequences.

Does PI74FCT244CTQE require external pull-up or pull-down resistors on its control inputs?

No external resistors are required. Inputs have built-in hysteresis (200mV) and TTL-compatible thresholds (VIH = 2.0V, VIL = 0.8V), ensuring robust logic recognition even with slow-rising or noisy enable signals. Pull-ups are only needed if the driving source cannot guarantee valid logic levels during power-up or standby states - not a requirement of the device itself.

Can PI74FCT244CTQE drive a 50Ω transmission line directly?

Yes - each output integrates a 25Ω series resistor. When paired with a typical PCB trace impedance of ~100Ω (differential) or ~50Ω (single-ended), this provides near-ideal source termination for point-to-point or short-stub topologies. For longer traces or multi-drop configurations, additional end termination may still be required, but the on-die resistor significantly reduces reflection magnitude and simplifies layout.

Is PI74FCT244CTQE compatible with 3.3V logic interfaces?

It is not 3.3V I/O tolerant. Designed for 5.0V ±5% operation, its inputs recognize 3.3V as a valid HIGH (since VIH = 2.0V min), but outputs swing rail-to-rail at 5V and may damage downstream 3.3V-only inputs. Use level-shifting buffers or resistive dividers if interfacing with 3.3V systems; direct connection is unsafe without voltage translation.