Electronics has a digital part and an analog part, in HardZone we usually deal with the digital part, but analog is just as important, because many functions in a PC are performed by analog circuits and not digital. . These functions are as essential as the digital ones, because without them our PCs could not function.
What are analog electronics?
Analog electronics are electronics which, unlike digital, do not work with discrete signals, but with variable continuous signals. It is said that digital electronics are discrete because each signal can only have two values. On the other hand, in analog electronics, each signal has a variable range.
Analog electronics are used in PC hardware for a series of specific utilities, but above all it must be taken into account that the world works in an analog way and that in many cases a transformation of the digital signal to analog and vice versa is necessary. .
The clearest case is therefore that of DACs, digital-to-analog converters and ADCs, analog-to-digital converters. And with this, we can also understand which one of the most popular basic utilities is speakers and microphones. In the first, a digital signal is transformed into an analog signal to generate sound through them. In the second, it is the opposite case and an analog signal is digitized.
Digital signals are much easier to manipulate by calculation, it is not in vain that memories store these signals in digital form and that processors of different types also process them digitally. The problem? Digital technology requires a large number of bits and therefore simultaneous signals to be able to achieve the precision of the analog signal.
As we add more bits of data, this is when we can make the square wave more and more similar to the sine wave of the analog signal. This is something that seems trivial to us today, but we must keep in mind that during the early years of computing, data processing was severely limited by cost.
The output devices of yesteryear, especially monitors, worked with very low precision analog signals, due to the process of converting very low precision digital signals to analog signals. This no longer happens today and we have great precision in the processing of image and sound.
Elements for analog circuit design
Analog circuits, like digital circuits, are also made of semiconductors, but they use completely different components. Apart from signal conversion, one of the applications of analog circuits is the processing of electricity and its distribution through the motherboard or the PCB of an expansion board.
Much of the stuff we’ll define next will sound familiar to you from the basics of electronics some of you did in high school. So we’re not talking about any sci-fi tech, but common components that you can find everywhere.
Resistors are one of the basic components for building analog circuits, because among their main functions is the fact that they can adequately distribute current and voltage between different parts of the electronic circuit.
Resistors are used to reduce the intensity of the current by reducing its voltage. That is why if you look at an electronic circuit with a processor in the middle, you will see how there is a series resistance circuit. Which serve to divide the tension successively.
Out of curiosity, older analog video systems used a resistance system, since the output of one color or another through the video signal depended on the voltage with which the signal was transmitted.
Capacitors, also called capacitors by their English name, are very common elements in circuit design. Its function is to temporarily store the electric charge and then to release it. To do this, it uses two conductive plates but separated by an insulating material.
To understand the functionality of a condenser, you have to imagine the flow of electric current as a river with a great force that suddenly meets a dam that stops this force and drains the water in a much smoother way. The difference is that a capacitor does this with the electric current reaching it.
Yes, your PC’s power supply has an analog circuit inside. What is your job ? Well, that of increasing and decreasing the voltage of an alternating current electric circuit. In this process, the electric power is lost, so the input power is not the same as the output. When we talk about the efficiency of a transformer, we are talking about the percentage of power lost in the process.
Diodes are two-terminal electronic components that only allow electrical flow in one of two directions. We call one of the terminals the anode, so current always flows to the other end, which is the cathode.
In the computer world and before the advent of ROMs, read-only data was stored by creating interconnected diode circuits. Today, diodes are no longer used in this sense, but a common type of diode is the LED diode, which is used to illuminate certain areas in order to transmit information about different states.
Transistors are the basis of digital electronics, as the memories and processors we use daily are made up of hundreds or even billions of very small transistors, but the beginnings of the transistor occurred in analog circuits, the one of the most famous applications was “transistor” radio, which replaced the use of vacuum tubes and made old furniture radios forget.
The most widely used in analog circuits are the so-called bipolar transistors, which can be found not only in PC hardware, but also in consumer electronics. Its name is a dimension of the English term “transfer resistance” which translates to transfer resistance. Its functionality? They perform the functions of amplifier, switch, oscillator or rectifier of the electrical signal, so they are very versatile and allow the construction of electronic circuits more complex than those seen
Your profits? Varied, they serve to amplify the signal, which is essential in radio, television and even in the use of musical instruments. They are also used to generate new signals, for example radio frequency signals such as Wi-Fi. Its switching capability not only allows you to control power supplies and act as switches, but with them you can create a Pulse width modulation or PWM circuit to control the fan of a graphics card.