Onsemi MC74AC00DR2G Quad 2-Input NAND Gate: Datasheet, Pinout, and Application Circuit Overview
The MC74AC00DR2G from Onsemi is a highly reliable and widely used integrated circuit belonging to the Advanced CMOS (AC) logic family. This IC encapsulates four independent 2-input NAND gates in a single compact package, making it a fundamental building block for a vast array of digital logic applications. Its key advantages include high-speed operation, low power consumption, and robust noise immunity, bridging the gap between older 74HC series and faster 74F series devices.
This article provides a detailed overview of its datasheet specifications, pinout configuration, and a typical application circuit.
Datasheet Overview and Key Specifications
The datasheet for the MC74AC00DR2G outlines its electrical characteristics and absolute maximum ratings, which are critical for ensuring safe and reliable operation within a circuit design.
Technology: Advanced CMOS (AC)
Supply Voltage Range (VCC): 2.0V to 6.0V. This wide range allows for compatibility with both 3.3V and 5V systems.
High-Speed Performance: Features a typical propagation delay (tPD) of 5ns at 5V VCC, enabling its use in high-frequency circuits.
Low Power: Has very low static power consumption due to its CMOS design.
Output Drive: Capable of sourcing/sinking up to 24mA at the output, allowing it to drive relatively high loads like LEDs or other IC inputs.
Noise Immunity: The AC family is known for its high noise margin, typically around 1.5V at 5V VCC, making it suitable for electrically noisy environments.
Package: The "DR2G" suffix denotes a SOIC-14 package, which is surface-mount and common for automated PCB assembly.
Pinout Configuration
The MC74AC00DR2G is housed in a 14-pin package. The pinout is standard for most quad 2-input NAND gate ICs.
Pins 1, 2, 5, 6, 8, 9, 12, 13: These are the input pins for the four gates. Each gate has two inputs (e.g., Input A1, Input B1 for Gate 1).
Pins 3, 4, 10, 11: These are the output pins for the four gates (e.g., Output Y1 for Gate 1).
Pin 7 (GND): This is the ground pin (0V reference).
Pin 14 (VCC): This is the positive power supply pin. Voltage applied here powers all four internal gates.
Application Circuit Overview: A Simple LED Pulse Indicator
A common use for a NAND gate is as a controlled inverter or in oscillator circuits. The following circuit creates a simple astable multivibrator (oscillator) using two of the four gates inside the MC74AC00DR2G.
Components Required:
IC1: MC74AC00DR2G
R1: Resistor (e.g., 10kΩ)
R2: Resistor (e.g., 220Ω)
C1: Capacitor (e.g., 10µF)
LED1: Light Emitting Diode
Circuit Operation:
1. Oscillator Formation: The first NAND gate (using pins 1, 2, and 3) is configured as an oscillator by connecting its output (pin 3) back to one of its inputs (pin 2) through an RC network (R1 and C1). The other input (pin 1) is tied to VCC to enable the gate.
2. Buffering and Inversion: The second NAND gate (using pins 4, 5, and 6) acts as a buffer/inverter. It takes the oscillating signal from the first gate and ensures a clean, sharp output waveform. Both its inputs are tied together to form a single input.
3. Output Drive: The output of the second gate (pin 6) is connected to an LED through a current-limiting resistor (R2). The LED will blink at a frequency determined by the formula f ≈ 1 / (1.2 R1 C1).
This circuit demonstrates the IC's ability to function not just in pure logic but also in simple analog-timing applications.
The Onsemi MC74AC00DR2G is an exceptionally versatile and robust logic IC. Its optimal blend of speed, low power, and noise tolerance ensures its continued relevance in modern digital design, from basic educational projects to complex industrial control systems. Its standardized pinout and functionality make it a perfect substitute for older 7400 series parts in upgrade and new design scenarios.
Keywords:
1. CMOS Logic Gate
2. NAND Gate
3. Pinout Configuration
4. Propagation Delay
5. Application Circuit
