Many digital devices rely on logic gates to process signals and perform logical operations. CD4012, a CMOS integrated circuit contains two independent 4-input NAND gates. Its ability to combine multiple input signals and produce a reliable logic output makes it useful in digital control, automation, and signal processing systems. This article will discuss the CD4012 CMOS logic IC basics, internal structure, technical specifications, working principle, and more.

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CD4012 CMOS Logic IC Basic

The CD4012 is a CMOS digital integrated circuit that contains two independent 4-input NAND gates in a single package. Each gate accepts four input signals and produces one output signal. Because it belongs to the CD4000-series CMOS logic family, the device offers low power consumption and stable operation across a wide supply voltage range.

In a 4-input NAND gate, the output becomes LOW only when all four inputs are HIGH. If any of the inputs is LOW, the output becomes HIGH. This behavior follows the Boolean expression Y = ¬(A · B · C · D), where the output is the inverted result of the four input signals.

The chip typically comes in a 14-pin package and contains two separate NAND gates that can operate independently. The CMOS design also provides high noise immunity and reliable digital switching.

An improved version called CD4012B offers better electrical performance and wider operating specifications compared to the original CD4012. If you are interested in purchasing, feel free to contact us for pricing and availability.

CD4012 CAD Models

CD4012BE symbol, footprint and 3d model.

CD4012 Symbol

CD4012 Footprint

CD4012 3D Models

CD4012 Pinout Details

Alternatives & Equivalent Model

• CD4012B

• MC14012

• HCF4012

• TC4012

• HEF4012

• CD4023

• CD4011

CD4012 Ordering Codes

Internal Structure of CD4012

The CD4012 is a CMOS logic IC that contains two independent 4-input NAND gates inside one package. Each gate receives four input signals labeled A, B, C, and D and produces a single output Q. The internal structure shown in the diagram illustrates how these four inputs are connected to a NAND logic stage. The IC operates when VDD (pin 14) is connected to the positive supply and VSS (pin 7) is connected to ground. Each group of four inputs controls one NAND gate, allowing the chip to perform two logic operations simultaneously.

In the internal circuit, the inputs are arranged so that the output depends on the combined logic state of all four signals. A NAND gate produces a LOW output only when all inputs are HIGH at the same time. In any other combination where at least one input is LOW, the output becomes HIGH. This behavior is represented by the logic expression Q = ¬(A·B·C·D), which means the output is the inverse of the AND result of the four inputs.

The truth table below the diagram demonstrates this logic behavior. It lists every possible combination of the four inputs and the resulting output. As shown in the table, the output Q remains HIGH for almost all input combinations. The output becomes LOW only when A, B, C, and D are all equal to 1. This confirms the NAND logic function implemented by the internal structure of the CD4012.

CD4012 Tech Specifications

CD4012 CMOS Logic IC Features

Low Propagation Delay

The CD4012 provides a typical propagation delay time of about 60 ns when the load capacitance is 50 pF and the supply voltage is 10 V. This allows the device to respond quickly in digital switching applications.

Buffered Inputs and Outputs

The IC includes buffered input and output stages, which improve signal stability and ensure reliable logic transitions within digital circuits.

Symmetrical Output Characteristics

The device is designed with standardized symmetrical output characteristics, meaning the source and sink capabilities are balanced for consistent performance.

Low Maximum Input Current

The CD4012 features very low input current, typically 1 µA at 18 V across the full temperature range and 100 nA at 25°C, helping reduce overall power consumption.

Wide Operating Voltage Range

It supports 5 V, 10 V, and 15 V parameter ratings, allowing flexible operation in various CMOS logic systems.

Low Noise Margin Performance

The IC provides stable noise margins of 1 V at 5 V, 2 V at 10 V, and 2.5 V at 15 V, ensuring reliable logic level detection.

JEDEC Standard Compliance

The CD4012 meets the requirements of JEDEC Tentative Standard No. 13B for B-series CMOS devices, ensuring consistent quality and performance.

CD4012 Working in Circuit

2N6107 as a Switching Transistor

The 2N6107 is commonly used as a power switching transistor in electronic circuits. In a typical application circuit, the transistor works by controlling the flow of current between the collector and emitter terminals. A small current applied to the base terminal allows a larger current to pass through the collector–emitter path. This makes the 2N6107 useful for controlling high-power loads such as motors, relays, or lamps using a low-power control signal.

In the application circuit, the input signal is applied to the base through a resistor that limits the base current and protects the transistor. When the base receives a sufficient voltage, the transistor enters saturation mode, allowing current to flow from the collector to the emitter and turning the connected load ON. When the base signal is removed, the transistor returns to the cutoff region, stopping the current flow and turning the load OFF.

The diagram also shows how the transistor acts as an electronic switch. The load is connected between the power supply and the collector, while the emitter is connected to ground. By controlling the base signal, the circuit can easily switch the load on and off. This simple configuration demonstrates how the 2N6107 transistor amplifies current and controls higher-power devices using a small input signal.