Texas Instruments CY74FCT2541ATQCT

Overview

CY74FCT2541ATQCT from Texas Instruments is an octal noninverting 3-state buffer/line driver with edge-rate control and 25-Ω output series resistors, designed for memory-address driving, clock distribution, and bus-oriented transmitter/receiver applications in 5-V TTL/CMOS systems. It features 4.8-ns typical propagation delay, ±15-mA output drive, Ioff partial-power-down support, and reduced transmission-line reflection noise.

For engineers reviewing the CY74FCT2541ATQCT datasheet, CY74FCT2541ATQCT pinout, CY74FCT2541ATQCT application, or CY74FCT2541ATQCT equivalent, key selection criteria include 3-state enable timing (tPZH/tPLZ ≤ 5.6 ns), matched rise/fall times, 25-Ω integrated output termination, and compatibility with legacy FCT/F logic designs requiring low-noise bus interfacing.

Technical Context

This device implements dual active-low 3-state enable inputs (OEA and OEB) controlling eight noninverting buffered outputs, supporting independent or combined output gating. Its edge-rate control circuitry shapes output transitions to minimize EMI while maintaining TTL-compatible VOH (3.3 V typ) and VOL (0.55 V max) levels at 12-mA sink/15-mA source drive.

The Ioff feature disables all outputs when VCC = 0 V, limiting backflow current to ±1 µA and enabling safe partial-power-down operation in mixed-voltage systems. Input thresholds (VIH = 2 V min, VIL = 0.8 V max) ensure direct interoperability with standard TTL and CMOS logic without level-shifting components.

Key Specifications

Pinout & Package

Package: 20-pin SSOP (DBQ), 0.65-mm pitch, 7.4–7.6 mm width, 12.6–13.0 mm length, 2.65-mm max height - optimized for high-density board layouts with improved thermal dissipation vs. SOIC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY74FCT2541CTQCT, the CY74FCT2541ATQCT trades 0.7 ns of speed for broader availability and lower unit cost; versus SN74FCT2541ATPWR, it offers superior thermal performance in high-ambient industrial settings due to larger SSOP copper exposure.

Availability

CY74FCT2541ATQCT is available at Aetrix Electronics and suitable for memory subsystems, industrial bus interfaces, clock distribution networks, and legacy system upgrades requiring stable component supply across extended product lifecycles.

Supply support for CY74FCT2541ATQCT 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 industrial and automotive ICs.

The CY74FCT2541ATQCT belongs to TI's FCT logic family, engineered for noise-immune 5-V digital interfacing in mission-critical industrial control, test equipment, and communications infrastructure.

FAQ

What is the maximum operating frequency supported by the CY74FCT2541ATQCT?

The CY74FCT2541ATQCT does not specify a maximum operating frequency in its datasheet, as it is a combinational buffer-not a registered device. Its 4.8-ns propagation delay supports reliable operation in systems with clock periods ≥10 ns (i.e., ≤100 MHz fundamental frequency), assuming proper PCB layout, load capacitance ≤50 pF, and clean power delivery. For sustained high-speed data bus use, derate based on measured eye diagram opening.

Does the CY74FCT2541ATQCT require external pull-up or pull-down resistors on its enable pins?

No, the CY74FCT2541ATQCT does not require external pull-up or pull-down resistors on OEA or OEB. Its inputs meet TTL voltage thresholds (VIH ≥ 2 V, VIL ≤ 0.8 V), so they can be driven directly from microcontroller GPIOs or other logic outputs. However, per datasheet Note 2, unused inputs must be tied to VCC or GND-floating enables risk undefined output states and increased ICC.

Can the CY74FCT2541ATQCT safely interface with 3.3-V logic devices?

The CY74FCT2541ATQCT is a 5-V-only device with TTL-compatible inputs (VIH min = 2 V), so it can accept 3.3-V logic HIGH signals reliably. However, its outputs swing to 3.3 V (typ) at 15-mA source, which may fall below the VIH threshold of some 3.3-V CMOS receivers. For guaranteed interoperability, use a level-shifter or verify receiver VIH spec; direct connection is acceptable only if the 3.3-V device specifies VIH ≤ 2.0 V.

How does the 25-Ω output series resistor in the CY74FCT2541ATQCT improve signal integrity?

The 25-Ω output series resistor in the CY74FCT2541ATQCT forms a controlled-impedance source termination that matches typical PCB trace impedances (50–75 Ω) when combined with load capacitance. This dampens signal reflections caused by impedance discontinuities-especially at stubs or unterminated ends-reducing overshoot, undershoot, and ringing. Measured result: >15 dB reduction in radiated emissions at harmonics above 100 MHz in bus applications.

Is the CY74FCT2541ATQCT RoHS compliant and lead-free?

Yes, the CY74FCT2541ATQCT is RoHS compliant and lead-free. Per TI's Packaging Information Addendum, it carries "Yes" for RoHS and uses NIPDAU (nickel/palladium/gold) lead finish. It is rated MSL Level-2-260°C-1 year, qualifying for standard Pb-free reflow profiles. The part marking "FCT2541A" and tape-and-reel packaging (2500 units per reel) align with TI's green manufacturing standards.