onsemi MC74VHCT244ADTG

Overview

MC74VHCT244ADTG from onsemi is an octal non-inverting 3-state buffer/line driver with TTL-compatible inputs and CMOS outputs, operating at 4.5–5.5 V supply, featuring 8 mA output drive strength and ±24 mA peak bus-hold current, used in address/data bus interface and memory expansion circuits.

For engineers reviewing the MC74VHCT244ADTG datasheet, pinout, applications, or equivalent options, key selection criteria include 5 V TTL-level input compatibility, high-current 3-state outputs for bus contention control, propagation delay under 9 ns at 5 V, and SOIC-20 package suitability for industrial PCB layouts.

Technical Context

This device implements two independent 4-bit non-inverting buffers, each with separate 3-state enable controls (1OE̅, 2OE̅), supporting bidirectional bus isolation. Input thresholds are TTL-compatible (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V), while output swing reaches rail-to-rail under load.

Designed for mixed-voltage system interfacing, it provides noise immunity via hysteresis-free CMOS output stages and supports hot insertion when enabled with controlled slew rate-no internal clamping diodes are present, requiring external protection if needed.

Key Specifications

Pinout & Package

MC74VHCT244ADTG is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with 0.300-inch body width and 1.27 mm pitch, compliant with JEDEC MS-013AC and RoHS requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT244N and 74VHC244M, the MC74VHCT244ADTG delivers higher output drive (±8 mA vs. ±4 mA) and guaranteed 5 V-only operation, making it optimal for industrial bus loading where signal integrity under heavy capacitive load is critical.

Availability

MC74VHCT244ADTG is available at Aetrix Electronics and suitable for industrial automation, test equipment, and legacy system upgrades requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.

Supply support for MC74VHCT244ADTG 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

onsemi is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MC74VHCT244ADTG belongs to the VHCT logic family, engineered specifically for TTL-to-CMOS translation in industrial control and instrumentation systems where reliability and noise immunity are essential.

FAQ

What is the maximum operating temperature range for the MC74VHCT244ADTG?

The MC74VHCT244ADTG is rated for industrial temperature operation from −40 °C to +85 °C. This range is validated per onsemi's qualification standards and applies to continuous operation under specified supply and load conditions. The SOIC-20 package's thermal resistance (θ_JA ≈ 120 °C/W) supports this rating in typical 2-layer PCB layouts with moderate copper area.

Does the MC74VHCT244ADTG support hot swapping?

The MC74VHCT244ADTG does not include built-in hot-swap protection features such as power-on reset or slew-rate limiting. While its 3-state outputs reduce bus contention during insertion, external current-limiting resistors and sequencing controls are required to ensure safe hot insertion. The absence of input clamping diodes means transient voltage suppression must be implemented externally.

Can the MC74VHCT244ADTG drive a 50 pF load at 50 MHz?

Yes, the MC74VHCT244ADTG can drive a 50 pF load with less than 9 ns propagation delay at 5 V supply, supporting signal edges usable up to approximately 50 MHz fundamental frequency. Rise/fall times are typically 4.5 ns, meeting setup/hold timing for standard 5 V SRAM and latch interfaces at that rate.

Is the MC74VHCT244ADTG pin-compatible with the 74LS244?

Yes, the MC74VHCT244ADTG has identical pinout and function mapping to the 74LS244, including dual 4-bit non-inverting buffers with active-low 3-state enables. However, it replaces bipolar TTL output stages with CMOS outputs, delivering higher noise margin, lower static current, and rail-to-rail swing-no layout change is required for drop-in replacement.

What is the quiescent supply current of the MC74VHCT244ADTG?

The quiescent supply current (I_CC) for the MC74VHCT244ADTG is 4 μA maximum at V_CC = 5.5 V and T_A = 25 °C. This ultra-low static draw results from its CMOS core architecture and makes it suitable for always-on monitoring circuits where standby power is constrained.