Toshiba Semiconductor and Storage TC74ACT244FTEL

Overview

TC74ACT244FTEL from Toshiba Electronic Devices & Storage Corporation is a non-inverting octal 3-state bus buffer IC used for memory address and data bus driving in 5 V TTL-compatible digital systems. It delivers 5.0 ns typical propagation delay, ±24 mA output drive at 4.5 V, and operates across -40°C to +85°C with 8.0 µA max quiescent current.

For engineers reviewing the TC74ACT244FTEL datasheet, TC74ACT244FTEL pinout, TC74ACT244FTEL application, or TC74ACT244FTEL equivalent, key selection criteria include non-inverting 3-state logic, dual active-low output enables, SOP20 package compatibility with 74F244, and guaranteed 24 mA sink/source capability under industrial temperature conditions.

Technical Context

This device implements two independent 4-bit non-inverting buffers, each controlled by its own active-low output enable (OE) signal. All inputs feature ESD protection, and outputs exhibit balanced tPLH/tPHL delays (≈5.7 ns typ. at VCC = 5.0 V, CL = 50 pF).

Designed using C2MOS silicon gate technology, TC74ACT244FTEL achieves bipolar-level speed while retaining CMOS power efficiency. Its input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V) ensure direct interfacing with TTL logic families without level shifting.

Key Specifications

Pinout & Package

SOP20 (Small Outline Package, 20-pin, 0.65 mm pitch, 12.8 mm × 7.6 mm body, 0.22 g typical weight).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal non-inverting buffer applications.

Compared with 74F244N and SN74ACT244N, TC74ACT244FTEL offers optimal balance of speed (5.7 ns), ultra-low static current (8 µA), and SOP20 surface-mount compatibility - making it preferred for modern industrial PCBs requiring thermal efficiency and automated assembly.

Availability

TC74ACT244FTEL is available at Aetrix Electronics and suitable for memory address driving, microcontroller bus expansion, and industrial PLC I/O interface applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for TC74ACT244FTEL 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

Toshiba Electronic Devices & Storage Corporation designs and manufactures discrete semiconductors, power devices, and logic ICs for industrial, automotive, and consumer applications with emphasis on reliability and energy efficiency.

The TC74ACT series targets high-speed, low-power 5 V logic interfacing - specifically engineered to replace bipolar TTL buffers while reducing system power and heat in embedded control and instrumentation platforms.

FAQ

What is the function of the two output enable (OE) pins on TC74ACT244FTEL?

The TC74ACT244FTEL features two active-low output enable pins: Pin 1 controls outputs Y0–Y3, and Pin 19 controls Y4–Y7. When either OE is high, its associated 4-bit output group enters high-impedance state, allowing independent bus segmentation. This enables selective driving of memory banks or peripheral groups without external logic, reducing signal contention and simplifying timing control in TC74ACT244FTEL-based systems.

Does TC74ACT244FTEL support operation at 4.5 V supply voltage?

Yes, TC74ACT244FTEL is fully specified for operation across 4.5 V to 5.5 V. At VCC = 4.5 V, it maintains ±24 mA minimum output drive, 9.0 ns maximum propagation delay (-40°C to +85°C), and meets VIH ≥ 2.0 V / VIL ≤ 0.8 V input thresholds. This ensures robust interoperability with marginally regulated 5 V rails and compatibility with mixed-voltage systems where TC74ACT244FTEL serves as a bridge between older TTL and newer low-dropout supplies.

Is TC74ACT244FTEL pin-compatible with the 74F244?

Yes, TC74ACT244FTEL is pin- and function-compatible with the 74F244, including identical SOP20 pinout, dual OE placement, and non-inverting 3-state behavior. This allows direct replacement in existing 74F244 designs to reduce power consumption (8 µA vs. ~25 mA quiescent) without PCB changes - provided timing margins accommodate the slightly longer 5.7 ns typical propagation delay of TC74ACT244FTEL versus 4.5 ns for 74F244.

What is the maximum capacitive load TC74ACT244FTEL can drive while maintaining timing specifications?

TC74ACT244FTEL AC characteristics are guaranteed with CL = 50 pF and RL = 500 Ω. While it can drive heavier loads (e.g., 100 pF), propagation delay increases linearly with capacitance - tPLH/tPHL rises to ~8.5 ns max at CL = 50 pF and may exceed 10 ns at CL = 100 pF. For reliable timing in TC74ACT244FTEL applications, keep total net capacitance ≤50 pF or validate timing margins with oscilloscope measurement under actual load conditions.

How does TC74ACT244FTEL handle unused inputs?

Unused inputs on TC74ACT244FTEL must be tied to either VCC or GND to prevent floating states that cause increased ICC, noise susceptibility, and potential latch-up. The datasheet explicitly requires this per operating range note. Leaving inputs unconnected violates the specified operating conditions and may result in unpredictable output behavior or elevated power dissipation - a critical design requirement for stable long-term operation of any TC74ACT244FTEL implementation.