7409 Quad 2-Input AND Gate Open Collector IC (DIP)

7409 Quad 2-Input AND Gate Open Collector IC (DIP) — Overview

The 7409 is a TTL logic IC that integrates four independent 2-input AND gates with open-collector outputs. Because the outputs are open collector, the chip sinks current and requires external pull-up resistors to produce a high level. This design enables direct interfacing to LEDs, relays, higher-voltage circuits, and wired-AND configurations.

Key Benefits

• Open-collector outputs for flexible interfacing and level shifting.
• TTL-compatible 5V operation ensures broad compatibility with legacy and modern digital circuits.
• DIP-14 package for easy breadboard and through-hole PCB use.
• Supports wired-AND logic and simple signal mixing without additional gates.

Features

• Four independent 2-input AND gates in one IC.
• Open-collector outputs for direct driving of loads with external pull-ups.
• High noise immunity and fast switching (typical propagation delay ~12ns).
• Low power consumption and reliable TTL operation.
• Standard DIP-14 (Dual Inline Package) for prototyping and hobbyist use.

Specifications

• IC Type: Quad 2-Input AND Gate (Open Collector)
• Logic Family: 7400 Series TTL
• Number of Gates: 4
• Inputs per Gate: 2
• Output Type: Open Collector
• Package Type: DIP-14 (Dual Inline Package)
• Operating Voltage (Vcc): 4.75V to 5.25V
• Output Voltage (Max): 30V (with external pull-up)
• Output Current (Max): 16mA per output
• Input Voltage (Max): 5.5V
• Propagation Delay: ~12ns (typical)
• Power Dissipation: 500mW (maximum)
• Operating Temperature: 0°C to +70°C
• Pin Count: 14

Typical Applications

• Logic control circuits requiring AND gate functionality.
• Driving external devices such as LEDs, buzzers, and relays using external pull-ups.
• Wired-AND logic and signal combination for bus arbitration or shared lines.
• Voltage level shifting between 5V TTL logic and higher-voltage components.
• Digital signal processing, timing control, and microcontroller-based projects that need open-collector outputs.

Usage Notes and Best Practices

• Because outputs are open collector, always provide an appropriate pull-up resistor to the required voltage. Choose resistor values to limit current to safe levels (respecting the 16mA max output current).
• When driving LEDs or relays, calculate the pull-up resistor to match the load and desired current, or use a transistor driver for larger currents.
• Use wired-AND configurations carefully: multiple open-collector outputs can be tied together, but ensure combined loading does not exceed ratings.
• Keep Vcc stable at 5V and avoid input voltages above the specified 5.5V maximum to prevent damage.

Why Choose the 7409 for Your Project

The 7409 combines the simplicity of standard TTL AND logic with the flexibility of open-collector outputs, making it a versatile choice for prototyping, education, and interfacing tasks. Its DIP-14 format and TTL compatibility mean it plugs easily into breadboards and works cleanly with microcontrollers and legacy TTL systems.

Note: Images are for illustration purposes only.