How does a current mirror work?

How does a current mirror work?

A current mirror is a circuit designed to copy a current through one active device by controlling the current in another active device of a circuit, keeping the output current constant regardless of loading. The current being “copied” can be, and sometimes is, a varying signal current.

Why Wilson modified the current mirror circuit diagram?

The improved Wilson current mirror circuit is made using 4 transistor versions so it is useful for the operation at high currents. The Wilson current mirror circuit provides low impedance at the input. It doesn’t require additional bias voltage and minimum resources are needed to construct it.

How is the output of a mirror circuit improved?

There are several options to improve the output of Current Mirror Circuit. In one of the solution one or two transistors are added over the traditional two transistors design. Construction of those circuits uses emitter follower configuration to overcome the base current mismatch of the transistors.

How is a Wilson current mirror circuit simulated?

Here the Wilson current mirror is simulated using Proteus. The three active components (BJT) are used to make the circuitry. The BJTs are all 2N2222, with same specifications. The pot is selected to change the current across Q2 collector which will further reflect on the Q3 collector.

Where does the name current mirror circuit come from?

From the name of George R. Wilson, the improved current mirror circuit designed by him is called Wilson Current Mirror Circuit. Wilson current mirror circuit uses three active devices that accept the current across its input and provide the exact copy or mirrored copy of the current to its output. Wilson Current Mirror Circuit

How are transistors used in current mirror circuit?

So to get a stable output, additional techniques are used in current mirror circuits. There are several options to improve the output of Current Mirror Circuit. In one of the solution one or two transistors are added over the traditional two transistors design.