Texas Instruments CY74FCT244DTSOCT

Overview

CY74FCT244DTSOCT from Texas Instruments is an octal noninverting 3-state buffer/line driver IC used for memory address driving, clock distribution, and bus transceiver applications in TTL- and CMOS-compatible systems. It features 64-mA sink / 32-mA source output drive, 3.6-ns typical propagation delay (tPLH/tPHL), Ioff partial-power-down support, and edge-rate control for noise reduction.

For engineers reviewing the CY74FCT244DTSOCT datasheet, CY74FCT244DTSOCT pinout, CY74FCT244DTSOCT application, or CY74FCT244DTSOCT equivalent, key selection criteria include 3-state bus isolation capability, 5-V TTL/CMOS interoperability, industrial temperature range (–40°C to 85°C), SOIC-20 package compatibility, and Ioff-enabled system power sequencing.

Technical Context

The CY74FCT244DTSOCT implements dual independent 4-bit noninverting buffers with separate 3-state enable controls (OEA and OEB), enabling selective activation of two 4-bit data paths. Its FCT logic family delivers bipolar-equivalent speed with CMOS-level static power consumption.

Edge-rate control circuitry limits slew rate to suppress simultaneous switching noise, while Ioff protection disables outputs and blocks current flow when VCC = 0 V-critical for hot-swap and partial-power-down operation in multi-rail systems.

Key Specifications

Pinout & Package

Package: SOIC-20 (DW), 7.5 mm × 12.8 mm body, 1.27 mm pitch, 2.65 mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1 (unlimited reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74FCT244DWR and 74ACT244SCX, CY74FCT244DTSOCT uniquely combines industrial-grade timing (3.6 ns), integrated Ioff protection, and edge-rate control-making it the optimal choice for robust, hot-pluggable, or mixed-rail embedded systems requiring guaranteed 3-state isolation and noise immunity.

Availability

CY74FCT244DTSOCT is available at Aetrix Electronics and suitable for industrial automation, test equipment, and legacy-system upgrades requiring stable component supply, long-lifecycle support, and RoHS-compliant SOIC packaging.

Supply support for CY74FCT244DTSOCT 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 since 1930.

CY74FCT244DTSOCT belongs to TI's FCT logic family-designed specifically for high-speed, low-power 5-V TTL/CMOS interoperability in industrial control, instrumentation, and legacy system modernization.

FAQ

What is the maximum operating frequency supported by CY74FCT244DTSOCT?

CY74FCT244DTSOCT does not specify a maximum clock frequency directly, but its 3.6-ns propagation delay (tPLH/tPHL) and 4.8-ns disable time (tPZL) support reliable operation in bus systems with data rates up to approximately 270 MHz under ideal loading conditions. Actual usable frequency depends on trace capacitance, termination, and fanout-designers should verify timing margins using the provided switching characteristics table and load circuit (CL = 50 pF).

Does CY74FCT244DTSOCT support mixed-voltage operation between 3.3-V and 5-V domains?

CY74FCT244DTSOCT is a 5-V-only device with VCC range 4.75 V to 5.25 V and TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max). It accepts 3.3-V logic inputs reliably, but its outputs swing to 5-V levels. For bidirectional 3.3-V/5-V translation, external level-shifting circuitry or a dedicated voltage-tolerant transceiver is required-CY74FCT244DTSOCT itself does not provide level conversion.

How does the Ioff feature of CY74FCT244DTSOCT protect the system during power sequencing?

When VCC = 0 V, CY74FCT244DTSOCT's Ioff circuitry limits input/output leakage to ±1 µA-even if driven by live signals from other powered sections. This prevents damaging current backflow through the IC, avoids unintended logic states on shared buses, and eliminates latch-up risk. It enables safe power-up/down sequencing in modular systems and hot-swap architectures without requiring external isolation components.

Can CY74FCT244DTSOCT replace older 74LS244 devices in existing designs?

Yes-CY74FCT244DTSOCT is pin-compatible with 74LS244 in SOIC-20 and offers superior performance: 10× lower ICC (0.2 mA vs. ~20 mA), 3× faster propagation (3.6 ns vs. 15–20 ns), full 3.3-V/5-V input compatibility, and Ioff support. No PCB changes are needed, but decoupling and layout best practices for high-speed logic should be followed to realize full noise and timing benefits.

What thermal considerations apply to CY74FCT244DTSOCT in continuous operation?

CY74FCT244DTSOCT has a θJA of 58°C/W in SOIC-20. At worst-case 64-mA sink per output (8 channels active), total power dissipation can reach ~120 mW. With ambient at 85°C, junction temperature stays below 155°C-within absolute max rating. For sustained high-drive operation, maintain ≥2 cm² copper pour under the package and avoid stacking heat-generating components nearby.