Diodes Incorporated PI74FCT244ATQ

Overview

PI74FCT244ATQ from Pericom Semiconductor is an octal non-inverting 3-state buffer/line driver with TTL-compatible inputs and outputs, built-in 25Ω series output resistors, 3.6 ns max propagation delay (at 5V, CL=50pF), and industrial temperature range (–40°C to +85°C). It functions as a bidirectional bus interface driver in high-speed memory and address bus systems.

For engineers reviewing the PI74FCT244ATQ datasheet, PI74FCT244ATQ pinout, PI74FCT244ATQ application, or PI74FCT244ATQ equivalent, key selection criteria include output drive strength (64 mA sink), low ground bounce, hysteresis-enabled noise immunity, and TSSOP-20 (Q) package compatibility with dense PCB layouts.

Technical Context

The PI74FCT244ATQ implements dual 4-bit non-inverting buffers with independent active-low 3-state enable controls (OEA and OEB), allowing selective gating of two 4-bit data paths. Each output features an integrated 25Ω series resistor to suppress transmission-line reflections without external termination.

It operates at 5.0 V ±5%, supports TTL-level input thresholds (VIH = 2.0 V, VIL = 0.8 V), and delivers VOH ≥ 2.4 V at –15 mA and VOL ≤ 0.50 V at 12 mA - optimized for driving unterminated 50 Ω transmission lines in backplane and motherboard applications.

Key Specifications

Pinout & Package

PI74FCT244ATQ is housed in a 20-pin plastic TSSOP (Thin Shrink Small Outline Package), 173 mil wide (Q suffix), with 0.65 mm lead pitch and exposed pad not present. Pin numbering follows JEDEC MS-013AC standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74FCT244CTQ and SN74F244N, the PI74FCT244ATQ delivers the fastest propagation delay in the FCT family, lowest dynamic power, and eliminates external termination - making it optimal for new designs prioritizing signal integrity and space-constrained layouts.

Availability

PI74FCT244ATQ is available at Aetrix Electronics and suitable for memory bus drivers, address interfaces, backplane repeaters, and legacy system extenders requiring stable component supply across industrial product lifecycles.

Supply support for PI74FCT244ATQ 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 U.S.-based fabless semiconductor company specializing in high-speed interface, timing, and logic solutions before its acquisition by Diodes Incorporated in 2017.

The PI74FCT series targets industrial and telecom applications needing 5 V logic with superior speed-power-noise trade-offs versus legacy bipolar FAST logic.

FAQ

What is the function of the OEA and OEB pins on PI74FCT244ATQ?

OEA (pin 1) and OEB (pin 19) are independent active-low 3-state enable inputs. When pulled low, they enable the respective 4-bit output group (O0–O3 or O4–O7); when high, those outputs enter high-impedance state. This allows selective bus driving without external logic.

Does PI74FCT244ATQ require external termination resistors?

No. Each output integrates a 25Ω series resistor optimized for driving 50Ω transmission lines. This eliminates the need for discrete 25–33Ω resistors typically placed near the driver output, reducing component count and PCB area.

Can PI74FCT244ATQ interface directly with 3.3 V logic inputs?

Yes - its VIH threshold is 2.0 V minimum, so it reliably drives 3.3 V CMOS inputs. However, its outputs swing rail-to-rail (0–5 V), so interfacing with 3.3 V-only receivers requires level-shifting or clamping to avoid overvoltage damage.

What is the maximum capacitive load supported by PI74FCT244ATQ?

The device is characterized up to 50 pF load capacitance (per switching spec), but can drive heavier loads (e.g., 100 pF) at reduced speed. For sustained 64 mA sink capability, trace impedance and layout inductance must be controlled to limit ground bounce below 0.5 V peak.