主要区别-反相与非反相放大器

反相和同相放大器是两种配置，运算放大器可以在其中设置。反相放大器和同相放大器的主要区别在于，反相放大器产生的输出与输入相差180度，而同相放大器产生的输出与输入同相。

什么是反相放大器(an inverting amplifier)？

逆变放大器是一种差分放大器，它将输入端之间的微小电压差放大为输出端上的大电压。输出电压与输入电压相差180度。反向放大器的设置如下所示。

An operational amplifier.

For amplifiers, the output voltage  is given in terms of the two input voltages  and  as:

where  is the gain of the operational amplifier. Since is connected to Earth, . The point marked is virtual Earth so the potential at this point is almost 0 V. No current passes through this point. Therefore the current that flows through the resistor  is the same as the current  that flows through the resistor  .

If the potential difference across   is  , then,

Similarly for  , 

Then the gain can be expressed as:

这里的负号表示输出与输入的相位差为180度。

什么是同相放大器(a noninverting amplifier)？

同相放大器是产生与输入同相的输出的放大器。非反相放大器的设置如下所示：

A noninverting amplifier.

In the noninverting amplifier,  . The gain in a noninverting amplifier is quite large, so the difference between and is negligible. So we can say that . Using the idea of a potential divider, we can write

. Equating the two expressi*** for  , we have:

. Then, we can write the gain as:

. Dividing both the numerator and the denominator by  , we get:

反转(inverting)和同相放大器(noninverting amplifier)的区别

相位差：

在反相放大器中，输出电压与输入电压相差180度。

在同相放大器中，输出电压与输入电压同相。

放大器增益：

对于反相放大器，增益只是两个电阻之间的比值。

对于同相放大器，增益是1+电阻之间的比值。