In integrated circuits not everything is digital, but there are analog parts and even analog circuits in their entirety. They are so called due to the fact that they do not deal with digital but analog signals, although they are not usually promoted as part of the hardware of our PCs if they are an integral part of it in different parts of the hardware that we use daily, where we find their use different areas of hardware.
Electronics has a digital and an analog part, in HardZone we usually treat the digital part of it, however the analog is just as important, since there are many functions in a PC that are carried out by analog and non-digital circuits . These functions are as essential as digital ones, since without them our PCs would not be able to function.
What is analog electronics?
Analog electronics is one that, unlike digital, does not work with discrete signals, but with variable continuous signals. We say that digital electronics are discrete due to the fact that 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 it must especially be taken into account that the world works in an analog way and that in many cases a transformation of the digital signal to the analog and vice versa is necessary. .
So the clearest case of this are DACs, digital to analog converters, and ADCs, analog to digital converters. And with this we can also understand which is one of the most popular basic utilities, that of speakers and microphones. In the first one, a digital signal is transformed into an analog one to generate sound through them. In the second it is the opposite case and an analog signal is digitized.
Signal conversion
Digital signals are much easier to manipulate via computation, it is not for nothing that memories store these signals in digital form and processors of different types also process them digitally. The problem? Digital requires a large number of bits and therefore simultaneous signals to be able to reach the precision of the analog signal.
As we add more bits of data, it is when we can make the square wave more and more similar to the sine wave of the analog signal. This is something that today seems trivial to us, but we must bear in mind that during the first years of computing, the processing of data was greatly limited due to cost issues.
The output peripherals of yesteryear, especially monitors, worked with very low precision analog signals, due to the process of converting very low precision digital signals to analog. This no longer occurs today and we have great precision when dealing with image and sound.
Elements for the design of analog circuits
Analog circuits, like digital ones, are also made up of semiconductors, but they use completely different components. Apart from signal conversion, one of the applications of analog circuitry is the treatment of electricity and distribution through the motherboard or the PCB of an expansion card.
A good part of the elements that we are going to define next will sound familiar to you from the basic electronics that some of you will have done in the secondary schools. So we are not talking about any kind of science fiction technology but about common components that you can find everywhere.
Resistors
Resistors are one of the basic components for the construction of analog circuits, since among their main functions is the fact that they can adequately distribute current and voltage between the 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 take a look at an electronic circuit with a processor in the middle you will see how there is a series resistor circuit. Which are used to divide the voltage successively.
As a curiosity, the old analog video systems made use of a resistor system, since the output of one color or another through the video signal depended on the voltage with which the signal was transmitted.
Capacitors
Capacitors, also called capacitors by their English name, are very common elements in circuit design. Its function is to temporarily store the electrical charge and then release it. It does this by making use of 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 great force that suddenly meets a dam that what it does is to slow down that force and that discharges the water in a much smoother way. The difference is that a capacitor does it with the electric current that reaches it.
Transformers
Yes, your PC’s power supply has an analog circuit inside. What is your function? Well, that of increasing and decreasing the voltage of an alternating current electrical circuit. In this process, electrical 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 that is lost in the process.
Diodes
Diodes are two-terminal electronic components that only allow electrical circulation in one of the two directions. We call one of the terminals the anode, and this makes the current always flow in the direction of the other end, which is the cathode.
In the world of computing and before the advent of ROM memories, read-only data was stored by creating interconnected diode circuits. Today diodes are no longer used in that sense, but a common type of diode is the LED diode, which is used to illuminate certain areas to transmit information of different states.
Bipolar transistors
Transistors are the basis of digital electronics, since the memories and processors that we use daily are made up of hundreds and even billions of transistors at very small size, but the beginnings of the transistor occurred in analog circuits, being a of the most famous applications the “transistor” radio that replaced the use of vacuum tubes and sent old furniture radios into oblivion.
The most used in analog circuits are the so-called bipolar transistors, which we can find not only in PC hardware, but also in consumer electronics. Its name is a dimension of the English term “transfer resistor” which translates as transfer resistance. Its functionality? They perform the functions of amplifier, switch, oscillator or rectifier of the electrical signal, so they are highly versatile and allow the construction of more complex electronic circuits than those seen
Your profits? Varied, they are used 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 capacity not only allows you to control power supplies and act as switches, but with them you can build a pulse width modulation or PWM circuit to control the fan of a graphics card.