7401 Quad 2-Input NAND Gate IC – Open-Collector Output, 14-Pin DIP

The 7401 is a digital logic integrated circuit containing four independent 2-input NAND gates with open-collector outputs.

It provides the standard NAND logic function while its open-collector output configuration offers additional flexibility for applications such as wired logic, signal interfacing, level-related switching applications, and driving suitable external loads.

The IC is widely used for digital electronics education, logic circuit development, breadboard experiments, and repair of compatible legacy electronic equipment.

Technical Specifications

• IC Type: Digital Logic IC
• Logic Function: NAND
• Number of Gates: 4
• Inputs per Gate: 2
• Total Logic Inputs: 8
• Independent Outputs: 4
• Output Configuration: Open Collector
• Package: 14-Pin DIP as supplied
• Logic Family: 7400 Series
• Function: Quad 2-Input NAND Gate

NAND Logic Operation

Each gate contains two inputs and one open-collector output.

*An external pull-up resistor is required to obtain a HIGH output level from an open-collector output.

Open-Collector Output

Unlike a standard 7400 NAND gate, the 7401 uses open-collector outputs.

An open-collector output can actively pull the output LOW but cannot drive it HIGH by itself. A suitable external pull-up resistor is therefore normally required between the output and the appropriate supply rail.

This configuration can be useful for wired logic, interfacing, external load control, and applications where several compatible open-collector outputs share a signal line.

Pin Configuration

• Pin 1: Gate 1 Input A
• Pin 2: Gate 1 Input B
• Pin 3: Gate 1 Output
• Pin 4: Gate 2 Input A
• Pin 5: Gate 2 Input B
• Pin 6: Gate 2 Output
• Pin 7: GND
• Pin 8: Gate 3 Output
• Pin 9: Gate 3 Input A
• Pin 10: Gate 3 Input B
• Pin 11: Gate 4 Output
• Pin 12: Gate 4 Input A
• Pin 13: Gate 4 Input B
• Pin 14: VCC

Applications

Suitable for digital logic circuits, wired logic, signal interfacing, control circuits, switching applications, educational electronics, breadboard experiments, logic trainers, repair projects, and digital circuit prototyping.

Important Note

The 7401 should not be treated as a direct functional replacement for a standard 7400 in every circuit, because its outputs are open collector and require appropriate external pull-up resistors.

Exact supply voltage, logic thresholds, output-current limits, switching speed, and electrical characteristics depend on the specific manufacturer and 7401-series variant supplied. Check the IC marking and corresponding datasheet before final circuit design.

Package Includes

1 × 7401 Quad 2-Input NAND Gate IC