The difference between AC coupling and DC recovery

1. The difference between AC coupling and DC recovery:

When DC coupled, the real signal is displayed on the screen. When AC coupling is coupled, the input signal is coupled through a capacitor, then the amplification circuit of the oscilloscope is entered. The DC component in the measured signal will be filtered out because of the capacitor's isolation, and the oscilloscope shows only the AC component.

The difference between the AC coupling and the DC coupling on the matching circuit: the DC coupling is the direct connection of the wire, including the connection of the linear elements such as the resistance. It is applicable to amplifying circuits for signals including DC components. In DC coupled circuits, the static working points of all circuits are interacted. The working level of the first level changes the adjacent two level will also be affected. Therefore, the current and voltage of the working point can not be adjusted separately. In AC coupled DC uncoupled circuits, all circuits at different levels are separated by capacitors or inductors. Therefore, the static work point is independent, and it is easier to adjust the static working point. In DC coupling, because the input and output impedances at all levels are certain, it is difficult to make impedance transformation. In the AC coupled circuit, impedance conversion is carried out well through the line transformer to achieve high efficiency matching. In particular, the LC resonant circuit, which is widely used in the frequency selective amplifying circuit, has greatly improved the efficiency of the circuit.

2. The AC coupling (AC COUPLED) is the coupling of the capacitance in series in series, the type of capacitance is not limited, and the AC coupling function is to remove the DC component in the signal. It has no special effect on the pure AC signal (without any DC component), and the DC component is removed for the DC signal, which is the characteristic of the capacitor charging stability.