Texas Instruments CY74FCT2240TSOCTE4

Overview

CY74FCT2240TSOCTE4 from Texas Instruments is an octal noninverting buffer/line driver with 3-state outputs, on-chip 25-Ω series output resistors, I_off partial-power-down support, and TTL-compatible input/output logic levels. It delivers 8 ns max 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 transceivers.

For engineers reviewing the CY74FCT2240TSOCTE4 datasheet, CY74FCT2240TSOCTE4 pinout, CY74FCT2240TSOCTE4 application, or CY74FCT2240TSOCTE4 equivalent, key selection criteria include 3-state enable timing (t_PZH/t_PLZ ≤ 9.5 ns), integrated termination for reflection suppression, I_off protection during power sequencing, and SOIC-20 package compatibility with legacy FCT logic families.

Technical Context

This device implements dual independent 4-bit noninverting buffers, each with separate active-low 3-state enable inputs (OEA and OEB). Its edge-rate control circuitry shapes output transitions to reduce EMI and transmission-line ringing without external components.

The 25-Ω on-die series resistors are integrated per output and function only during active driving - not in high-impedance state - enabling clean signal integrity on unterminated PCB traces. I_off limits current flow when V_CC = 0 V and input/output pins are biased to 4.5 V, supporting hot-insertion and mixed-voltage system power sequencing.

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 buffer applications.

Compared with SN74FCT2240NSR and 74AC240M, CY74FCT2240TSOCTE4 uniquely combines on-die termination, I_off, and industrial temp range in a drop-in SOIC-20 package - reducing design risk in legacy-replacement and mixed-power-system applications.

Availability

CY74FCT2240TSOCTE4 is available at Aetrix Electronics and suitable for memory subsystems, clock distribution networks, industrial bus interfaces, and legacy logic upgrades requiring stable component supply and long-term manufacturability.

Supply support for CY74FCT2240TSOCTE4 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.

CY74FCT2240TSOCTE4 belongs to the 74FCT logic family - engineered for high-speed, low-noise, TTL-compatible digital interfacing in industrial control and computing infrastructure.

FAQ

What is the maximum operating temperature range for CY74FCT2240TSOCTE4?

CY74FCT2240TSOCTE4 is rated for continuous operation from –40°C to +85°C ambient temperature. This range is validated per TI's production testing and applies to all electrical specifications in the datasheet, including propagation delay, output drive, and I_off performance. The SOIC-20 package's 58°C/W thermal resistance ensures safe junction temperatures under typical industrial load conditions.

Does CY74FCT2240TSOCTE4 support hot-swap or partial-power-down operation?

Yes, CY74FCT2240TSOCTE4 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 into live backplanes and supports controlled power sequencing in multi-rail systems - a capability not present in standard 74LS or AC logic variants.

What is the purpose of the 25-Ω on-chip series resistors in CY74FCT2240TSOCTE4?

The 25-Ω on-chip series resistors in CY74FCT2240TSOCTE4 are placed at each output to match typical PCB trace impedance and suppress signal reflections on unterminated lines. They operate only during active driving (not in 3-state), reducing EMI and improving signal integrity without requiring eight discrete SMT resistors - lowering BOM cost and layout complexity.

Is CY74FCT2240TSOCTE4 pin-compatible with older 74LS240 devices?

CY74FCT2240TSOCTE4 is functionally and pinout-compatible with 74LS240 and 74F240, but uses different enable logic: OEA/OEB are active-low versus LS240's active-high G̅ inputs. Direct replacement requires inverting the enable signals or adding inverters. Electrical compatibility is maintained via TTL-level VOH/VOL and 12/15 mA drive strength.

What are the key timing parameters for 3-state enable/disable in CY74FCT2240TSOCTE4?

CY74FCT2240TSOCTE4 specifies t_PZH and t_PLZ ≤ 9.5 ns (enable-to-output-high-impedance), and t_PHZ and t_PLZ ≤ 9.5 ns (disable-to-output-active). These values ensure fast bus turnaround in shared-data applications - critical for avoiding contention in multi-master systems like ISA or custom parallel buses.