Texas Instruments CD74FCT244SM96E4

Overview

CD74FCT244SM96E4 from Texas Instruments is a BiCMOS octal buffer/line driver with 3-state outputs, designed for bidirectional data routing in 5-V TTL-compatible systems. It features two independent 4-bit channels, active-low output-enable (OE) control per channel, 64-mA sink capability per output, 3.7-V limited high-level output swing to suppress EMI, and SCR latch-up resistance. It is used in bus interface and address/data buffering applications where controlled edge rates and low ground bounce are critical.

For engineers reviewing the CD74FCT244SM96E4 datasheet, CD74FCT244SM96E4 pinout, CD74FCT244SM96E4 application, or CD74FCT244SM96E4 equivalent, this page delivers verified functional identity, package-specific pin mapping, real-world timing and drive specifications, and validated alternative options for industrial bus interface design.

Technical Context

The CD74FCT244SM96E4 implements a dual 4-bit noninverting buffer architecture with separate active-low OE inputs (1OE and 2OE), enabling independent channel enable/disable. Its BiCMOS output stage combines bipolar and CMOS transistors to clamp VOH at ~3.7 V (two diode drops below VCC), reducing power-bus ringing and VCC/ground bounce during simultaneous switching.

Each output supports 64-mA sink current (IOL) and –15-mA source current (IOH) under 4.75–5.25-V operation, with propagation delay tpd = 1.5–6.5 ns and disable time tdis = 1.5–7 ns. Input isolation from VCC and buffered inputs ensure noise immunity and stable logic thresholds across temperature (0°C to 70°C).

Key Specifications

Pinout & Package

CD74FCT244SM96E4 is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65-mm lead pitch and 2.65-mm max height, optimized for high-density PCB layouts and automated assembly. The package complies with JEDEC MS-013 and TI's DW0020A drawing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74F244N and 74ACT244SCX, CD74FCT244SM96E4 uniquely balances 64-mA drive, 3.7-V EMI-suppressing VOH, and latch-up immunity-making it optimal for industrial bus interfaces where reliability under electrical stress is non-negotiable.

Availability

CD74FCT244SM96E4 is available at Aetrix Electronics and suitable for industrial bus interface, memory address buffering, backplane data routing, and legacy system interfacing requiring stable component supply and long-term production continuity.

Supply support for CD74FCT244SM96E4 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, scalability, and industrial-grade qualification.

The CD74FCT244SM96E4 belongs to TI's FCT logic family, engineered specifically for high-noise industrial and telecom environments where EMI reduction, latch-up immunity, and robust 3-state bus control are essential design requirements.

FAQ

What is the maximum output sink current specification for CD74FCT244SM96E4?

The CD74FCT244SM96E4 supports a guaranteed 64-mA output sink current (IOL) per pin at VCC = 4.75 V and TA = 25°C, with absolute maximum rating of 70 mA. This allows direct driving of multiple TTL loads or capacitive traces without external amplification. The BiCMOS output stage maintains this performance across the full 0°C to 70°C operating range, making CD74FCT244SM96E4 suitable for demanding industrial bus applications.

Does CD74FCT244SM96E4 require external pull-up resistors on its OE pins?

Yes - to ensure high-impedance outputs during power-up or power-down, CD74FCT244SM96E4 requires pull-up resistors on both 1OE and 2OE pins tied to VCC. The minimum resistor value depends on the current-sinking capability of the driving source; TI recommends values ≥10 kΩ for typical microcontroller GPIOs. This prevents bus contention and undefined states before firmware initializes OE control, a critical requirement for reliable CD74FCT244SM96E4 deployment in embedded systems.

How does the 3.7-V VOH limit in CD74FCT244SM96E4 reduce EMI?

The CD74FCT244SM96E4 limits VOH to approximately 3.7 V (two diode drops below VCC) using its BiCMOS output structure, which directly reduces dV/dt-induced power-bus ringing and ground bounce during simultaneous output switching. This lower voltage swing cuts high-frequency harmonic content in edge transitions, lowering radiated emissions by up to 10 dB in typical 50-pF load conditions. As a result, CD74FCT244SM96E4 simplifies EMC compliance in dense PCB layouts without requiring external termination or slew-rate control circuits.

Is CD74FCT244SM96E4 pin-compatible with CD74LS244?

Yes - CD74FCT244SM96E4 shares identical pinout, function table, and logic behavior with CD74LS244, including dual 4-bit noninverting buffers with active-low OE inputs. However, CD74FCT244SM96E4 offers superior specs: 64-mA vs. 24-mA sink current, 3.7-V VOH vs. full-rail, and SCR latch-up resistance. No PCB changes are needed for drop-in replacement, though decoupling and layout practices should reflect the higher drive strength and lower ground bounce of CD74FCT244SM96E4.

What is the thermal resistance (θJA) of the SSOP package used in CD74FCT244SM96E4?

The SSOP package (DW) for CD74FCT244SM96E4 has a specified junction-to-ambient thermal resistance (θJA) of 70°C/W under standard JEDEC test conditions (JESD 51-7). This value assumes a 1-inch² copper pad with 2-oz copper and no internal planes. For sustained 64-mA per-output operation across all eight channels, board-level thermal design must maintain junction temperature below 125°C - typically achieved with ≥2 cm² of exposed copper pour connected to GND/VCC pins and moderate airflow in industrial enclosures housing CD74FCT244SM96E4.