81.1.5. Basic Characteristics of the Circuit

So, this application and this application circuit all together they are different. But as long as we ensure that M2, M3, and M1 they are similar in nature, then we can say that this current I3 is also satisfying all these conditions and so, this I3 can be obtained from the same reference current. In fact, you can generate n number of such kind of current reference.

This chunk introduces the concept of current mirrors, highlighting their importance in circuit applications. It explains that as long as the transistors (M1, M2, M3) used in the circuit are similar, you can derive certain currents (like I3) from a reference current. This means that a single reference can allow the generation of multiple current outputs, enhancing the flexibility and efficiency of the circuit.

Imagine you have a single fountain (the reference current), and from that fountain, you can create many small streams (the various currents generated). As long as the streams come from the same source and share the same properties, they will flow uniformly, just like how similar transistors allow for consistent output in electrical currents.

So, that is why; that is why we are using current mirror. So, we do have one current mirror here we do have these two together making another current mirror and so and so. So, this is MOSFET version current mirror. And we can have a BJT counterpart.

This part of the text emphasizes the use of current mirrors in circuit design. It mentions creating different configurations by combining current mirrors, allowing for various circuit functionalities. It also distinguishes between different types of current mirrors, such as those built with MOSFETs and those constructed using BJTs (Bipolar Junction Transistors), tapping into their unique characteristics and uses in circuits.

Think of current mirrors like different styles of cakes. You can have chocolate cake (MOSFET) and vanilla cake (BJT), both representing the same base idea of cake, but with different ingredients and flavors. Depending on what you want to achieve, you choose the right type of cake (current mirror) to serve your guests (the specific application needs in your circuit).

So, in the next slide we are having the current reference here. So, you can see here it is very similar; this circuit is very similar only thing is that we do have Q1 and Q2 instead of M1 and M2. Here also the collector and base they are connected to make transistor-1 diode connected. And rest of the thing it is very similar and this circuit. Of course, it offers this basic characteristic.

In this section, there's a description of a circuit diagram featuring transistors Q1 and Q2, drawing a comparison to the previous mentions of MOSFETs. It notes a key change: the connection of the collector and base of a transistor to create a diode connection, which is an important method in circuit design. Such configurations are common as they help achieve desired circuit characteristics and functionalities.

You can think of the transistor diode connection like using a door (the diode) that can open in only one direction. Just as you can’t enter a room if the door swings the other way, similarly, a current can only flow through the transistor in one specific direction when set up in this manner. This is crucial in managing the flow of electricity in circuits.

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