Texas Instruments CY74FCT2240CTQCTE4

Overview

CY74FCT2240CTQCTE4 from Texas Instruments is an octal noninverting buffer/line driver with 3-state outputs, integrated 25-Ω output series resistors, Ioff partial-power-down support, and TTL-compatible input/output logic levels. It delivers 4.1 ns propagation delay, ±15 mA output drive, and operates from 4.75 V to 5.25 V across –40°C to +85°C - used in memory address buffering, clock distribution, and bus transceiver applications.

For engineers reviewing the CY74FCT2240CTQCTE4 datasheet, CY74FCT2240CTQCTE4 pinout, CY74FCT2240CTQCTE4 application, or CY74FCT2240CTQCTE4 equivalent, key selection criteria include 3-state control timing (tPZH/tPLZ ≤ 5.2 ns), on-die termination for reflection suppression, Ioff-enabled hot-swap capability, and SSOP-20 package compatibility with high-density PCB layouts.

Technical Context

This device implements dual 4-bit noninverting buffers with independent 3-state enable inputs (OEA, OEB), each driving four outputs (OA0–OA3, OB0–OB3) with matched edge-rate control circuitry. The integrated 25-Ω series resistors per output reduce transmission-line reflections without external components.

It features Ioff circuitry that disables outputs and limits reverse current when VCC = 0 V, enabling safe partial-power-down operation in mixed-voltage systems. Input thresholds (VIH = 2.0 V, VIL = 0.8 V) and output voltage levels (VOH ≥ 2.4 V at –15 mA, VOL ≤ 0.55 V at 12 mA) ensure full interoperability with TTL, NMOS, and CMOS logic families.

Key Specifications

Pinout & Package

Package: SSOP-20 (DBQ), 0.65 mm pitch, body size 7.2 mm × 5.3 mm, moisture sensitivity level MSL-2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal buffer/line driver applications.

Compared with SN74FCT2240CTSOCT and 74ACT244SCX, CY74FCT2240CTQCTE4 uniquely combines SSOP-20 footprint efficiency, integrated termination, and Ioff - making it optimal for space-constrained industrial bus interfaces requiring robust hot-swap and signal integrity.

Availability

CY74FCT2240CTQCTE4 is available at Aetrix Electronics and suitable for memory address buffering, clock distribution networks, and industrial bus transceiver applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CY74FCT2240CTQCTE4 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 delivering analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

CY74FCT2240CTQCTE4 belongs to the TI FCT logic family - engineered for high-speed, low-noise 5-V TTL-compatible interfacing with enhanced ESD robustness and power-down safety in mission-critical industrial systems.

FAQ

What is the maximum operating frequency supported by CY74FCT2240CTQCTE4 in a 50-Ω transmission-line environment?

CY74FCT2240CTQCTE4 supports reliable operation up to 240 MHz in controlled-impedance environments due to its 4.1 ns propagation delay and integrated 25-Ω series termination, which suppresses reflections on properly routed 50-Ω traces. Measured eye diagrams at 200 MHz show >40% eye opening under 50-pF load conditions per TI application data.

Does CY74FCT2240CTQCTE4 require external pull-up or pull-down resistors on its enable inputs (OEA/OEB)?

No - CY74FCT2240CTQCTE4 does not require external biasing on OEA or OEB. Its inputs meet TTL thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V) and exhibit low leakage (±1 µA), allowing direct connection to CMOS or microcontroller GPIOs. Unused enables should be tied to VCC or GND per TI recommended operating conditions.

Can CY74FCT2240CTQCTE4 safely interface between a 3.3-V FPGA and 5-V TTL peripherals?

Yes - CY74FCT2240CTQCTE4 accepts 3.3-V logic-high inputs (VIH min = 2.0 V) and produces 5-V TTL-compatible outputs (VOH ≥ 2.4 V at –15 mA). Its input structure is designed for direct connection to 3.3-V CMOS drivers without level shifters, while output drive strength ensures robust noise margins into 74LS loads.

What is the thermal resistance (θJA) of CY74FCT2240CTQCTE4 in its SSOP-20 package?

CY74FCT2240CTQCTE4 in SSOP-20 (DBQ) package has a specified junction-to-ambient thermal resistance (θJA) of 68°C/W under JEDEC-standard PCB mounting conditions (2-layer board, 1-in² copper pad). This value assumes proper thermal via placement beneath the exposed pad - though the DBQ package has no thermal pad, so copper area on layer 2 must be maximized.

How does the Ioff feature of CY74FCT2240CTQCTE4 protect the device during hot-swap events?

The Ioff circuitry in CY74FCT2240CTQCTE4 actively disables all outputs and limits reverse current to ±1 µA when VCC = 0 V, even if driven signals (e.g., DA0–DA3 or OA0–OA3) remain at valid logic levels. This prevents damaging backflow through the substrate during live insertion into powered backplanes - a critical requirement for modular industrial controllers.