Texas Instruments CY74FCT2240TSOC

Overview

CY74FCT2240TSOC from Texas Instruments is an octal noninverting buffer/line driver with 3-state outputs, 25-Ω on-chip series termination resistors, 8 ns propagation delay (max), ±15 mA output drive, and I_off support for partial-power-down operation. It serves as a memory address driver, clock driver, or bus transmitter/receiver in TTL-, CMOS-, and NMOS-interfaced systems.

For engineers reviewing the CY74FCT2240TSOC datasheet, CY74FCT2240TSOC pinout, CY74FCT2240TSOC application, or CY74FCT2240TSOC equivalent, key selection criteria include 3-state control timing (t_PZH/t_PLZ ≤ 9.5 ns), 25-Ω output impedance matching, I_off current ≤ ±1 µA at V_CC = 0 V, and SOIC-20 package compatibility with legacy FCT logic families.

Technical Context

This device implements dual 4-bit noninverting buffers with independent 3-state enable controls (OEA and OEB), each driving four outputs (OA0–OA3 and OB0–OB3). Its edge-rate control circuitry limits slew rate to suppress transmission-line reflections without external components.

The integrated 25-Ω series resistors per output eliminate need for discrete termination, reducing board space and improving signal integrity in high-speed bus applications. I_off protection ensures safe backflow prevention when V_CC = 0 V and I/O pins are biased to 4.5 V.

Key Specifications

Pinout & Package

Package: SOIC-20 (SO), 7.5 mm × 12.8 mm body, 1.27 mm pitch, 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 SN74FCT240NSR and 74ACT240SCX, CY74FCT2240TSOC uniquely integrates 25-Ω series resistors and I_off protection in a drop-in SOIC-20 footprint - reducing BOM count by 16 resistors and enabling safe partial-power-down without redesign.

Availability

CY74FCT2240TSOC is available at Aetrix Electronics and suitable for memory address driving, clock distribution, and industrial I/O expansion requiring stable component supply across extended temperature ranges (–40°C to +85°C) and long-lifecycle industrial programs.

Supply support for CY74FCT2240TSOC 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 innovation in high-reliability logic families.

CY74FCT2240TSOC belongs to the TI FCT logic family designed for high-speed, low-noise, TTL-compatible interfacing in industrial, communications, and computing systems where signal integrity and power-down safety are critical.

FAQ

What is the maximum operating temperature range for CY74FCT2240TSOC?

CY74FCT2240TSOC is rated for operation from –40°C to +85°C ambient temperature, validated per TI's recommended operating conditions. This range supports deployment in industrial control cabinets, outdoor telecom equipment enclosures, and automotive under-hood auxiliary modules where thermal cycling and sustained elevated temperatures occur. The SOIC-20 package's 58°C/W θ_JA ensures thermal stability within this envelope when proper PCB copper pour and airflow are maintained.

Does CY74FCT2240TSOC support hot-swap or partial-power-down operation?

Yes, CY74FCT2240TSOC includes I_off circuitry that disables outputs and limits reverse current to ±1 µA when V_CC = 0 V and I/O pins are biased up to 4.5 V. This feature enables safe insertion and removal in live backplanes or modular systems without damaging the device or upstream logic. The specification is verified across temperature and confirmed in TI's absolute maximum ratings table and functional description.

What is the purpose of the 25-Ω on-chip series resistors in CY74FCT2240TSOC?

The 25-Ω on-chip series resistors in CY74FCT2240TSOC are integrated at each output to match typical PCB trace impedances (40–70 Ω) and suppress transmission-line reflections that cause ringing, overshoot, and timing violations. They eliminate the need for 16 external 0402/0603 resistors, reduce board area, improve signal integrity on unterminated buses, and are specified as 20–40 Ω across process/voltage/temperature per TI's electrical characteristics table.

Can CY74FCT2240TSOC directly interface with 3.3-V CMOS logic?

CY74FCT2240TSOC accepts 3.3-V CMOS logic levels at its inputs (V_IH = 2.0 V min, V_IL = 0.8 V max), but its outputs swing to TTL levels (VOH ≥ 2.4 V at –15 mA, VOL ≤ 0.55 V at +12 mA) - not full 3.3-V rail-to-rail. Direct connection to 3.3-V CMOS inputs is acceptable if those inputs tolerate TTL-high (≥2.0 V) and TTL-low (≤0.8 V), which most 3.3-V tolerant CMOS devices do. For guaranteed 3.3-V output compliance, a level translator is required.

What are the enable timing parameters for CY74FCT2240TSOC's 3-state outputs?

CY74FCT2240TSOC specifies t_PZH (enable time from OE low to valid high output) and t_PLZ (enable time from OE low to valid low output) both at ≤9.5 ns max, and t_PHZ/t_PLZ (disable times) also ≤9.5 ns max, measured at V_CC = 4.75 V with 50 pF load. These values ensure fast bus turnaround in multiplexed address/data systems and meet timing budgets for 100-MHz synchronous protocols when combined with its 8 ns propagation delay.