Texas Instruments CY74FCT2541TQCTE4

Overview

CY74FCT2541TQCTE4 from Texas Instruments is an octal noninverting 3-state buffer/line driver with 25-Ω output series resistors, designed for memory-address driving, clock distribution, and bus-oriented transmitter/receiver applications. It operates at 5 V, delivers 12 mA sink / 15 mA source drive, features Ioff partial-power-down support, and achieves 8 ns max propagation delay (tPLH/tPHL) across –40°C to 85°C.

For engineers reviewing the CY74FCT2541TQCTE4 datasheet, CY74FCT2541TQCTE4 pinout, CY74FCT2541TQCTE4 application, or CY74FCT2541TQCTE4 equivalent, key selection criteria include its integrated 25-Ω output termination for reflection noise suppression, TTL/CMOS-compatible logic levels, matched rise/fall times, and Ioff-enabled safe power-down in mixed-voltage systems.

Technical Context

The CY74FCT2541TQCTE4 implements dual active-low 3-state enable controls (OEA and OEB), allowing independent gating of two 4-bit groups or combined 8-bit operation. Its edge-rate control circuitry shapes output transitions to minimize EMI while maintaining compatibility with FCT and F logic families.

It integrates on-die 25-Ω series resistors per output to damp transmission-line reflections without external components, and its Ioff specification (±1 µA at VCC = 0 V) ensures no backflow current during partial power-down - critical for hot-swap and multi-rail system integrity.

Key Specifications

Pinout & Package

Package: SSOP-20 (DBQ), 0.65 mm pitch, 7.4 mm × 5.3 mm body, 2.65 mm max height, RoHS-compliant NIPDAU 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 CY74FCT2541ATQCT and SN74FCT2541CTSOCT, the CY74FCT2541TQCTE4 offers the highest propagation delay tolerance (8 ns), making it optimal for cost-sensitive, noise-critical, or thermally constrained SSOP layouts where absolute speed is secondary to signal integrity and power-down safety.

Availability

CY74FCT2541TQCTE4 is available at Aetrix Electronics and suitable for memory subsystems, industrial bus interfaces, legacy clock distribution networks, and test equipment signal conditioning requiring stable component supply and long-term lifecycle continuity.

Supply support for CY74FCT2541TQCTE4 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 with emphasis on reliability, longevity, and industrial-grade performance.

The CY74FCT2541TQCTE4 belongs to TI's FCT logic family, engineered for noise-immune, low-power 5 V digital interfacing in industrial, telecom, and computing infrastructure where signal integrity and partial-power-down operation are mandatory.

FAQ

What is the maximum operating temperature range for CY74FCT2541TQCTE4?

The CY74FCT2541TQCTE4 is rated for continuous operation from –40°C to +85°C ambient temperature. This range is validated per TI's recommended operating conditions and applies to all electrical and switching specifications in the datasheet, including propagation delay, drive strength, and Ioff behavior. The SSOP-20 package's thermal impedance (68°C/W) supports this rating under typical PCB copper pour conditions.

Does CY74FCT2541TQCTE4 support hot-swap applications?

Yes, CY74FCT2541TQCTE4 supports hot-swap via its Ioff feature: when VCC = 0 V, leakage current is limited to ±1 µA even with input/output voltages up to 4.5 V. This prevents damaging backflow current during insertion into a live backplane or bus, satisfying key requirements for modular industrial controllers and telecom line cards.

Can CY74FCT2541TQCTE4 directly interface with 3.3 V logic devices?

No - CY74FCT2541TQCTE4 is a 5 V-only device with TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V) and 5 V output swing (VOH ≈ 3.3 V min). While 3.3 V outputs may safely drive its inputs, its 5 V outputs exceed 3.3 V logic high limits and require level translation or clamping for reliable interfacing with pure 3.3 V receivers.

What is the purpose of the dual enable pins (OEA and OEB) on CY74FCT2541TQCTE4?

OEA and OEB are independent active-low 3-state enables: OEA gates outputs O0–O3, OEB gates O4–O7. This allows flexible partitioning - e.g., using OEA for local peripheral addressing and OEB for global memory mapping, or combining both for full 8-bit bus control. The function table confirms that either enable low yields active outputs; both high forces all outputs to high-impedance.

How does the 25-Ω output series resistor in CY74FCT2541TQCTE4 improve signal integrity?

The integrated 25-Ω resistor per output damps high-frequency reflections on PCB traces by matching typical FR-4 microstrip characteristic impedance (50–75 Ω) in series-terminated configurations. This reduces ringing, overshoot, and timing uncertainty - especially critical for memory address and clock lines longer than 2 inches at >10 MHz, eliminating need for discrete 25-Ω SMD resistors and saving board space.