Texas Instruments CY74FCT240CTQCTE4

Overview

CY74FCT240CTQCTE4 from Texas Instruments is an octal noninverting 3-state buffer/line driver IC used for memory address driving, clock distribution, and bus-oriented data transmission. It features 64-mA sink / 32-mA source output drive, 4.3-ns typical propagation delay (tPLH/tPHL), and operates over –40°C to 85°C with 4.75–5.25-V supply. Its Ioff circuitry enables partial-power-down mode in mixed-voltage systems.

For engineers reviewing the CY74FCT240CTQCTE4 datasheet, CY74FCT240CTQCTE4 pinout, CY74FCT240CTQCTE4 application, or CY74FCT240CTQCTE4 equivalent, key selection criteria include 3-state bus interface capability, TTL-compatible input thresholds, low-noise edge-rate control, and QSOP-20 packaging for high-density PCB layouts.

Technical Context

The CY74FCT240CTQCTE4 implements dual independent 4-bit noninverting buffer sections, each controlled by separate 3-state enable inputs (OEA and OEB). Its FCT-family architecture delivers bipolar-equivalent speed with CMOS power efficiency, supporting direct TTL/NMOS/CMOS interfacing without level-shifting components.

Edge-rate control circuitry limits dV/dt at outputs to suppress switching noise, while matched rise/fall times (typ. 3.5 ns) ensure clean signal integrity. The Ioff specification (±1 µA at VCC = 0 V) prevents backflow current during hot-insertion or partial system power-down scenarios.

Key Specifications

Pinout & Package

QSOP-20 (DBQ) package: 0.64-mm lead pitch, 7.2 mm × 5.3 mm body, 2.0 mm height, RoHS-compliant NiPdAu lead finish, MSL Level-2-260°C-1 year.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with SN74FCT240CTQCT, CY74FCT240CTQCTE4 offers identical performance and drop-in compatibility; versus 74ACT240SCX, it provides superior bus-driving strength, guaranteed Ioff, and lower noise-critical for industrial backplane interfaces.

Availability

CY74FCT240CTQCTE4 is available at Aetrix Electronics and suitable for memory subsystems, industrial communication interfaces, clock distribution networks, and legacy bus adapters requiring stable component supply across extended product lifecycles.

Supply support for CY74FCT240CTQCTE4 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 50 years of industrial-grade product experience.

The CY74FCT240CTQCTE4 belongs to the FCT logic family, engineered for high-speed, low-noise 5-V digital interfacing in mission-critical industrial, telecom, and computing infrastructure.

FAQ

What is the maximum operating temperature range for CY74FCT240CTQCTE4?

The CY74FCT240CTQCTE4 is rated for operation from –40°C to +85°C ambient temperature. This industrial temperature grade supports deployment in harsh environments such as factory automation controllers, outdoor telecom cabinets, and motor drive systems where thermal cycling and sustained elevated temperatures occur. The device's thermal resistance (θJA = 68°C/W in QSOP) ensures junction temperature remains within safe limits under typical 5-V/10-mA static loading conditions.

Does CY74FCT240CTQCTE4 support hot-swap or partial-power-down operation?

Yes, CY74FCT240CTQCTE4 includes Ioff circuitry that actively disables outputs and limits reverse current to ±1 µA when VCC = 0 V. This feature enables safe insertion into live backplanes or operation in systems where upstream/downstream sections may be powered independently-such as modular PLC I/O carriers or redundant power supply architectures. No external isolation components are required.

What is the pin configuration and package type of CY74FCT240CTQCTE4?

CY74FCT240CTQCTE4 uses a 20-pin QSOP (DBQ) package with 0.64-mm lead pitch, 7.2 mm × 5.3 mm body size, and 2.0 mm height. Pin 1 is located at the top-left corner with a notch or dot marker; the layout comprises two independent 4-bit channels (DA0–DA3/OA0–OA3 and DB0–DB3/OB0–OB3), dual 3-state enables (OEA, OEB), VCC, and GND. Full mechanical drawings are available in TI's DBQ package documentation.

Can CY74FCT240CTQCTE4 directly interface with 3.3-V microcontrollers?

CY74FCT240CTQCTE4 accepts 3.3-V logic-high inputs reliably due to its VIH minimum of 2.0 V at VCC = 4.75 V, satisfying the 3.3-V MCU's VOH spec (typically ≥2.4 V). However, its outputs swing to ~3.3 V (VOH typ) under 32-mA load-not sufficient to drive standard 5-V TTL inputs requiring ≥2.4 V at full load. For bidirectional 3.3-V ↔ 5-V interfacing, level-shifting buffers or series resistors are recommended.

What are the key timing parameters for CY74FCT240CTQCTE4 at 5-V operation?

At VCC = 5.0 V and TA = 25°C, CY74FCT240CTQCTE4 exhibits tPLH/tPHL ≤ 4.3 ns (max), tPZL/tPZH ≤ 5.0 ns (max), and tPHZ/tPLZ ≤ 4.5 ns (max). These values ensure sub-5-ns propagation and enable/disable transitions, supporting 100-MHz bus clocking with >2-ns timing margin. Matched rise/fall times (~3.5 ns typ) minimize duty-cycle distortion critical for clock fan-out applications.