NXP HEF4071BT Quad 2-Input OR Gate: Datasheet, Pinout, and Application Circuit Guide
The NXP HEF4071BT is a member of the 4000 series CMOS logic family, renowned for its robust performance and low power consumption. This integrated circuit (IC) contains four independent 2-input OR gates in a single 14-pin package, making it a fundamental building block for numerous digital logic applications. Its design is optimized for wide supply voltage operation and features buffered outputs, ensuring high noise immunity and stable performance.
Datasheet Overview: Key Specifications
The HEF4071BT operates over a wide supply voltage range from 3V to 15V, providing flexibility for both TTL-level and higher voltage projects. Key electrical characteristics include:
Low Power Consumption: Typical quiescent current of just 4nA at 5V, making it ideal for battery-powered devices.
High Noise Immunity: Typically 45% of the supply voltage at 5V.
Symmetrical Output Sourcing and Sinking Capability: The outputs can drive up to 10 LS-TTL loads.
Operating Temperature Range: -40°C to +125°C, suitable for industrial and automotive environments.
Pinout Configuration
Understanding the pinout is crucial for circuit design. The HEF4071BT comes in a standard 14-pin DIP (Dual In-line Package) or SO package.
Pin 1: Input 1A (Gate 1)
Pin 2: Input 1B (Gate 1)
Pin 3: Output 1Y (Gate 1)
Pin 4: Output 2Y (Gate 2)
Pin 5: Input 2B (Gate 2)
Pin 6: Input 2A (Gate 2)
Pin 7: VSS (Ground)
Pin 8: Input 3A (Gate 3)
Pin 9: Input 3B (Gate 3)
Pin 10: Output 3Y (Gate 3)
Pin 11: Output 4Y (Gate 4)
Pin 12: Input 4B (Gate 4)
Pin 13: Input 4A (Gate 4)
Pin 14: VDD (Positive Supply Voltage)
Application Circuit Guide: A Basic Example
A classic use for an OR gate is in a simple logic controlled switch or an alarm circuit. The following example demonstrates a basic two-sensor alarm circuit.
Objective: Activate an output (e.g., an LED or buzzer) if either Sensor A or Sensor B is triggered (logic HIGH).
Components: HEF4071BT IC, two sensors (e.g., push buttons or digital sensors), one LED, one current-limiting resistor (e.g., 330Ω), and a power supply (e.g., 5V).
Circuit Connection:
1. Connect VDD (Pin 14) to the positive supply rail (+5V).
2. Connect VSS (Pin 7) to the ground rail (0V).
3. Connect Sensor A to Pin 1 (1A) of the HEF4071BT.
4. Connect Sensor B to Pin 2 (1B) of the HEF4071BT.
5. Connect the anode of the LED to Pin 3 (Output 1Y) through the 330Ω resistor.
6. Connect the cathode of the LED directly to ground.
Operation: Under normal conditions, both sensors are LOW (0V). The OR gate outputs a LOW signal, and the LED remains off. If any sensor goes HIGH, the OR gate’s output immediately goes HIGH, turning on the LED to indicate an alarm condition. This circuit effectively demonstrates the core OR logic function: Y = A + B.
The NXP HEF4071BT is a versatile, reliable, and low-power solution for implementing fundamental OR logic in digital systems. Its wide operating voltage range and high noise immunity make it a robust choice for hobbyists and engineers designing everything from simple educational projects to complex industrial control systems. By mastering its pinout and basic applications, designers can effectively integrate this essential logic gate into their circuits.
Keywords:
HEF4071BT
OR Gate
CMOS Logic
Datasheet
Pinout
