Texas Instruments CY74FCT240ATQCT

Overview

CY74FCT240ATQCT from Texas Instruments is an octal noninverting 3-state buffer/line driver IC used for memory address driving, clock distribution, and bus transceiver applications. It features 64-mA sink / 32-mA source output drive, 4.8-ns max propagation delay (tPLH/tPHL), Ioff partial-power-down support, and TTL-compatible input/output voltage levels.

For engineers reviewing the CY74FCT240ATQCT datasheet, CY74FCT240ATQCT pinout, CY74FCT240ATQCT application, or CY74FCT240ATQCT equivalent, key selection criteria include 3-state bus isolation capability, industrial temperature range (–40°C to 85°C), QSOP-20 package compatibility, and FCT-family logic-level interoperability with TTL/NMOS/CMOS systems.

Technical Context

The CY74FCT240ATQCT implements dual 4-bit noninverting buffers with independent 3-state enable controls (OEA and OEB), enabling selective bus segment isolation. Its edge-rate control circuitry reduces switching noise while maintaining matched rise/fall times.

It supports partial-power-down via Ioff, which disables outputs and limits reverse current when VCC = 0 V. Input thresholds (VIH = 2 V min, VIL = 0.8 V max) and output voltage specs (VOH = 2.4 V min at –32 mA, VOL = 0.55 V max at 64 mA) ensure direct interface with TTL, NMOS, and CMOS logic without level-shifting components.

Key Specifications

Pinout & Package

Package: QSOP-20 (DBQ), 0.635 mm 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 SN74FCT240ATQCT, CY74FCT240ATQCT offers identical performance and form factor but reflects TI's original part numbering convention; versus 74AC240SCX, it delivers superior noise immunity, higher drive, and essential Ioff functionality for modern industrial power management.

Availability

CY74FCT240ATQCT is available at Aetrix Electronics and suitable for memory address drivers, clock distribution networks, and industrial backplane interfaces requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for CY74FCT240ATQCT 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 development.

The CY74FCT240ATQCT belongs to the FCT logic family, designed specifically for high-speed, low-noise bus interfacing in industrial, telecom, and computing infrastructure where TTL compatibility and robust 3-state control are mandatory.

FAQ

What is the maximum propagation delay for CY74FCT240ATQCT under industrial conditions?

The maximum propagation delay (tPLH/tPHL) for CY74FCT240ATQCT is 4.8 ns at VCC = 5 V, TA = –40°C to +85°C, and CL = 50 pF. This value is guaranteed across the full operating temperature range and reflects worst-case timing for design margining in real-world industrial environments where CY74FCT240ATQCT is deployed.

Does CY74FCT240ATQCT support hot-swap or partial-power-down operation?

Yes, CY74FCT240ATQCT includes Ioff circuitry that disables outputs and limits reverse current to ±1 µA when VCC = 0 V. This feature enables safe hot-insertion into live backplanes and supports system-level power sequencing - a core requirement validated in CY74FCT240ATQCT's specification table and functional description.

What package type and dimensions does CY74FCT240ATQCT use?

CY74FCT240ATQCT uses the QSOP-20 (DBQ) package: 7.2 mm × 5.3 mm body size, 2.0 mm maximum height, 0.635 mm lead pitch, and NiPdAu lead finish. Its MSL Level-2 rating (260°C peak reflow, 1-year floor life) is documented in TI's official packaging addendum for CY74FCT240ATQCT.

Can CY74FCT240ATQCT directly interface with TTL and CMOS logic families?

Yes, CY74FCT240ATQCT is fully compatible with TTL, NMOS, and CMOS inputs and outputs. Its VIH = 2 V min and VIL = 0.8 V max match TTL thresholds, while VOH ≥ 2.4 V and VOL ≤ 0.55 V meet both TTL and CMOS output requirements - confirmed in the "Recommended Operating Conditions" and "Electrical Characteristics" sections of the CY74FCT240ATQCT datasheet.

How many independent 3-state control inputs does CY74FCT240ATQCT provide?

CY74FCT240ATQCT provides two independent active-low 3-state enable inputs: OEA (Pin 11) controls outputs OA0–OA3, and OEB (Pin 18) controls outputs OB0–OB3. This dual-enable architecture allows granular bus segmentation - a defining feature explicitly shown in the logic diagram and function table of the CY74FCT240ATQCT datasheet.