Amplifier is a circuit that receives an inclusion signal on the input, and as an output signal it is not change and no bigger on the output.
In the amplifier circuit, external feedback resistance connected between the output terminal and the input terminal (-). This type of circuit is called a negative feedback circuit. By adding resistance feedback, we form a string of output to input (-). Then this circuit has a gain amplifier. Gain amplifier depends on external resistance alone.
Op-Amp generally have two inputs and one output. We already know that the Op-Amp output is divided into two according to the Inverting amplifier and Non-Inverting amplifier.
- Inverting amplifier
Gain inverting amplifier circuit-closed strands of Ei to Vo is determined by Rf and Ri, which can amplify signals ac or dc signals. In the picture, a positive voltage is applied through the input resistance Ri to the input (-) op-amp. Negative feedback made by prisoners Rf. Voltage between input (+) and (-) equal to zero. Hence the input terminal (-) and ground potential is also worth 0 vol.
- Non-inverting amplifier
In the non-inverting amplifier Vo has the same polarity as Ei. Resistance input of the non-inverting amplifier is very large exceed 100 Mega Ohm. The voltage between (+) and (-) of the op-amp is zero, the two inputs are located at the same potential Ei. Picture shows a non-inverting amplifier circuit.