Texas Instruments CY74FCT240CTSOCTE4

Overview

CY74FCT240CTSOCTE4 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, 4.3-ns maximum propagation delay (tPLH/tPHL), TTL-compatible input thresholds, and Ioff partial-power-down support.

For engineers reviewing the CY74FCT240CTSOCTE4 datasheet, CY74FCT240CTSOCTE4 pinout, CY74FCT240CTSOCTE4 application, or CY74FCT240CTSOCTE4 equivalent, key selection criteria include 3-state bus isolation capability, industrial temperature range (–40°C to 85°C), SOIC-20 package compatibility, and FCT-family logic-level interoperability with TTL, CMOS, and NMOS devices.

Technical Context

The CY74FCT240CTSOCTE4 implements dual independent 4-bit noninverting buffers, each controlled by a separate 3-state enable (OEA/OEB). Its edge-rate control circuitry limits slew rate to reduce switching noise, while matched rise/fall times ensure clean signal integrity in high-speed digital buses.

It supports Ioff functionality: when VCC = 0 V, input/output terminals are high-impedance and leakage current is limited to ±1 µA, enabling safe back-drive prevention during partial power-down. Input thresholds (VIH = 2 V min, VIL = 0.8 V max) and output levels (VOH = 2.4 V min at –32 mA, VOL = 0.55 V max at 64 mA) guarantee direct interface with standard TTL logic without level-shifting components.

Key Specifications

Pinout & Package

Package: SOIC-20 (DW), 7.5 mm × 12.8 mm body, 1.27 mm pitch, 2.65 mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1 (unlimited reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74FCT240CTSOCT, CY74FCT240CTSOCTE4 shares identical timing, drive, and package but reflects TI's legacy military/aerospace-qualified ordering suffix (E4); versus 74ACT240SCX, it delivers superior noise control, Ioff protection, and 2× faster propagation - critical for industrial bus integrity.

Availability

CY74FCT240CTSOCTE4 is available at Aetrix Electronics and suitable for industrial control systems, memory subsystems, clock distribution networks, and embedded backplane interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CY74FCT240CTSOCTE4 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 decades of heritage in high-reliability logic families including FCT, ACT, and LVC.

The CY74FCT240CTSOCTE4 belongs to TI's military- and industrial-grade FCT logic series, designed specifically for noise-critical, high-drive, and partial-power-down applications in avionics, test equipment, and programmable logic controllers.

FAQ

What is the maximum operating frequency supported by CY74FCT240CTSOCTE4?

CY74FCT240CTSOCTE4 does not specify a maximum clock frequency directly, but its 4.3-ns maximum propagation delay (tPLH/tPHL) and 5-ns enable/disable times support reliable operation up to approximately 233 MHz in ideal conditions (1/4.3 ns). Real-world bus frequency depends on load capacitance, trace length, and termination - typical use cases operate at ≤50 MHz for robust margin. The device is optimized for address, control, and strobe signaling rather than continuous high-frequency clocking.

Does CY74FCT240CTSOCTE4 support hot-swap or live-insertion?

Yes, CY74FCT240CTSOCTE4 supports safe hot-swap via its Ioff feature: when VCC = 0 V, all I/O pins enter high-impedance state with leakage limited to ±1 µA, preventing damaging back-current flow from powered system traces into the unpowered device. This allows insertion/removal in live backplanes or modular systems - provided that GND and signal pins make contact before VCC during mating, per standard hot-plug sequencing guidelines.

Can CY74FCT240CTSOCTE4 drive multiple TTL inputs directly?

Yes, CY74FCT240CTSOCTE4 can directly drive multiple standard TTL inputs without external components. With 32-mA source and 64-mA sink capability, it meets or exceeds the DC loading requirements of up to 20 standard TTL unit loads (each requiring 40 µA high / 1.6 mA low). Its VIH/VIL thresholds (2.0 V / 0.8 V) and VOH/VOL levels (2.4 V min / 0.55 V max) are fully compatible with TTL logic families, eliminating need for level shifters or pull-up resistors.

What is the meaning of the "E4" suffix in CY74FCT240CTSOCTE4?

The "E4" suffix in CY74FCT240CTSOCTE4 denotes Texas Instruments' legacy packaging and testing option: it indicates the device is supplied in SOIC-20 tape-and-reel format (2000 units per reel), with NiPdAu lead finish, RoHS-compliant, and tested to industrial temperature range (–40°C to +85°C). It does not indicate enhanced reliability or military qualification - those are designated by prefixes like "CY54" or "5962-". CY74FCT240CTSOCTE4 is a commercial-industrial grade part.

How does the edge-rate control in CY74FCT240CTSOCTE4 improve system noise performance?

CY74FCT240CTSOCTE4 incorporates internal edge-rate control circuitry that intentionally limits output slew rate, reducing di/dt and dv/dt transients. This significantly lowers simultaneous switching noise (SSN) on shared power/ground planes and minimizes crosstalk-induced jitter on adjacent signal traces. Measured improvements include >10 dB reduction in radiated emissions at harmonics above 100 MHz and improved signal integrity on 50-pF loaded buses - critical for mixed-signal systems where digital noise couples into analog or RF sections.