74LS38 Quad 2-Input NAND Buffer IC DIP-14

74LS38 Quad 2-Input NAND Buffer IC DIP-14

The 74LS38 is a monolithic integrated circuit from the Mitsubishi Low-Power Schottky (LSTTL) family, configured as a quadruple two-input positive NAND buffer. This means a single 14-pin package contains four independent, identical logic gates. Each gate performs the fundamental NAND Boolean function, where the output is driven low only when both of its inputs are high. The “buffer” designation indicates that these gates are designed to provide higher output current capability compared to standard logic gates, making them suitable for driving heavier loads.

A defining characteristic of the M74LS38P is its use of open-collector outputs. Unlike standard totem-pole outputs which actively drive the signal both high and low, an open-collector output can only pull the signal line low to ground. When the output transistor is off, the line is left in a high-impedance state. This requires an external pull-up resistor to bring the output voltage high. This architecture is key to enabling specific system-level functions that are impossible with conventional gates.

The open-collector design allows multiple outputs to be connected together to a common bus line with a single pull-up resistor, forming a “wired-AND” configuration. This is useful for creating shared bus systems and simplifying logic. Furthermore, the outputs are characterized by a high breakdown voltage and can sink a significant amount of current, making the device versatile for interfacing with higher voltage circuits or for directly driving indicators like LEDs or small relays.

Features:

Footprint Diagram:

Applications:

• Interfacing with Higher Voltage Logic.
• Wired-AND Logic.
• Bus Drivers.
• Signal Amplification.
• Timing and Control Circuits.
• Digital Signal Processing.
• Memory Systems.

Package Contents:

• 1x 74LS38 Quad 2-Input NAND Buffer IC DIP-14

Datasheet