Digital-electronics 简明教程
Implementation of NOT Gate using NAND Gate
在使用 NAND 门来实现 NOT 门之前，让我们对 NOT 门和 NAND gates 有一个基本的了解。
Before getting into implementing a NOT gate using NAND gate, let’s have a basic overview of NOT gates and NAND gates.
What is NOT Gate?
NOT 门是数字电子电路中使用的基本逻辑门。NOT 门有一个输入和一个输出。NOT 门的输出是对其输入的逻辑反转。因此，NOT 门也称为 inverter 。
NOT gate is a basic logic gate used in digital electronic circuits. The NOT gate has a single input and a single output. The output of the NOT gate is the logical inversion of its input. For this reason, the NOT gate is also known as inverter.
标准 NOT 门的符号是一个指向右方的三角形，其右端有一个圆圈，如图 1 所示。这个圆圈被称为反转气泡。NOT 门产生的输出是对其输入的补码或反转。例如，如果我们给一个 HIGH 输入单，那么它将提供一个 LOW 输出信号。类似地，当我们给一个 LOW 输入信号时，它会提供一个 HIGH 输出信号。
The symbol of the standard NOT gate has a triangle pointing to the right with a circle at its right end as shown in figure-1. This circle is referred to as an inversion bubble. The NOT gate produces an output which is the complement or inversion of its input. For example, if we give a HIGH input single, then it provides a LOW output signal. Similarly, when we give a LOW input signal, then it provides a HIGH output signal.
由于 NOT 门是一种单输入设备，因此它不作为逻辑电路中的决策组件使用。
Since, the NOT gate is a single input device, therefore, it is not used as a decision making component in the logic circuits.
What is NAND Gate?
NAND 是一个通用逻辑门。它是一个具有两个或更多个输入端的数字逻辑门，并根据输入信号的组合产生一个输出。NAND 表示 NOT + AND，即它产生的输出是对逻辑 AND 运算的反演或补码。
NAND is a universal logic gate. It is a digital logic gate having two or more input terminals and gives an output depending on the combination of the input signals. NAND represents NOT + AND, i.e. it produces an output which is the inversion or compliment of logic AND operation.
由于 NAND 是一个通用逻辑门，因此它可以用来实现各种逻辑运算，如 OR、AND、NOT。NAND 门的符号如图 2 所示。
Since, NAND is a universal logic gate, therefore, it can be used to implement all kinds of logic operations like OR, AND, NOT. The symbol of the NAND gate is shown in Figure-2.
从该符号中可以看出，它有一个带有圆圈的标准 AND 门的形状。这个圆圈被称为反转气泡。该符号给出了关于 NAND 门操作的想法，即它获取输入，执行 AND 运算，最后反转 AND 运算的结果以提供 NAND 门的最终输出。
From the symbol, it is clear that it has a shape of standard AND gate with a circle. This circle is known as inversion bubble. The symbol gives the idea about the operation of the NAND gate, i.e. it takes inputs, performs AND operations, and at last takes the inversion of the result of AND operation to provide the final output of the NAND gate.
Truth Table of NAND Gate
以下是 NAND 门的真值表 −
The following is the truth table of the NAND gate −
Inputs |
Output |
A |
B |
Y = (AB)’ |
0 |
0 |
1 |
0 |
1 |
1 |
1 |
0 |
1 |
1 |
1 |
从 NAND 门的真值表可以看出，NAND 门的操作与 AND 门后跟非门的操作相同。因此，NAND 的符号如图 2 所示。
From the truth table of NAND gate, it is clear that the operation of the NAND gate is same as that of the AND gate followed by a NOT gate. For this reason, the symbol of the NAND is like as shown in the Figure-2.
Implementation of NOT Gate using NAND Gate
正如我们在上面一节中所讨论的，NAND 门是一个通用门，因此我们可以用它来实现任何基本逻辑门。使用 NAND 门实现非门如图 3 所示。
As we discussed in the above section that the NAND gate is a universal gate, thus we can use it to realize any basic logic gate. The realization of NOT gate using NAND gate is shown in Figure-3.
从图 3 可以看出，为了使用 NAND 门实现非门，我们必须将 NAND 门的两个输入端连接起来，形成非门的单个输入端，并且非门的输出从 NAND 门的输出端获取。
From Figure-3, it is clear that to realize the NOT gate using the NAND gate, we have to join the two input terminals of the NAND gate to form a single input terminal of the NOT gate, and the output of the NOT gate is taken from the output terminal of the NAND gate.