What is Analog Circuit | Wira Electrical

In order to understand “what is analog circuit?”, we must have understood that it is a circuit consisting of analog electronics to process and produce analog signals.

This circuit is able to produce variable signals continuously with the proportional relationship between voltage or current level and electrical signal. Meaning is, we can generate an analog signal with a variety of scaling.

Contents show

What is Analog Circuit Design

Analog circuit utilizes a lot of forms of signal to process and convert it to an electrical signal we can read and analyze. For example, some temperature sensors are able to show a continuous signal every time it captures the result.

Electrical signals can give us a lot of information related to voltage, current, frequency, phase, and many more. These signals are processed through an analog circuit with physical forms as an input (light, pressure position, sound, temperature, and more).

Unlike digital circuits where an output signal only has two level voltage (represents 0 and 1), the analog circuit produces a signal with any value from a given range and it is unique to deliver different information. Each signal represents different types of phenomenon.

A temperature sensor can be represented by an electrical signal with a proportional calculation, for example one volt can represent one degree Celsius. We can further modify it to our liking by changing the scaling, say ten degree Celsius is represented by one volt.

Not only the difference of the encoding information with digital circuits, their processing method is also different. Analog circuit is able to act as an amplifier, filter, limiter, and others.

Keep in mind that using an analog circuit means we need to be careful of the noise factor. The greater the noise, the greater disruption to our signal processing and output. On the other hand, a digital circuit is not affected by the presence of noise until a certain threshold level.

How to Design Analog Circuits

Analog circuits are typically more complex to design compared to digital circuits. More skills are required to build a proper analog circuit. It is built from active and passive components such as resistor, inductor, capacitor, transistor, diode, and many more.

Analog circuits can be either AC circuits or DC circuits based on their input.

An analog circuit operates purely with analog signals, a signal that has continuous variable values forming a specific wave depending on how we built it.

Analog signals resemble our real world phenomenon compared to digital circuits. Sound, light, vibration, and all the things that can be represented by a waveform are all electromagnetic spectrum. This electromagnetic spectrum is an analog thing.

Every physical phenomenon is felt and processed with continuous waves and thus the analog circuit is proportional to the world.

It is really easy to build an analog circuit with all the known electrical circuit elements. It is far easier than building a digital circuit with the same components. But it does not mean it has no weakness.

When talking about integrated circuits, a digital circuit is far easier to build since we have been introduced to digital components along with how we make it programmable. This is the drawback of an analog circuit, it is not as automated as a digital circuit.

Analog circuits are also prone to noise in its surrounding environment. Its error rate is significantly higher caused by higher complexity, variability, limited assessment of reliability, less automation, and needs extra analysis to mitigate the error and noise.

Observe the example circuit below.

This is the most basic example of an operational amplifier, an inverting amplifier. Before we design an analog circuit, we need to be ready with our analytical skills.

Fortunately, analyzing an analog circuit can be done efficiently with our known electrical circuit analysis such as Ohm’s Law, Kirchhoff’s Laws, Node Voltage, Mesh Current, and many more.

What is the Difference Between Analog and Digital Circuits

Even with the popularity of digital circuits, analog circuits are still used in many industry sectors such as power electronics, biomedical engineering, telecommunications, and instrumentation such as electrical measurement.

Analog circuit is an electrical circuit that utilizes and produces a signal that varies continuously from zero to maximum voltage supply input to the circuit. This is the basic difference with a digital circuit where it utilizes binary signals, 0 or 1.

If an analog circuit can produce zero voltage to maximum voltage supply input continuously, a digital circuit can only produce 0 or maximum voltage supply input. With a digital circuit we can generate True (1) and False (0) logic programs.

How to Learn Analog Circuit Design

If we really want to learn how to design an analog circuit, we have to familiarize ourselves with its important analog integrated circuit. It is an operational amplifier or op amp for short. This component is very versatile and can be used to build a lot of different analog circuits based on its configuration.

Observe the circuit below.

The triangle is the op amp, and based on its configuration, this is a non-inverting op amp. The input is not inverted since it is supplied to the positive terminal while the negative terminal is supplied by feedback from its output.

Opposed to this, an inverting op amp will invert the input waveform with a simple modification of the example above. Observe the circuit below.

The input is supplied to the negative terminal, thus it will be inverted based on our configuration of the remaining components.

Operational amplifier can be crafted further into:

With more advanced study and analysis, we can even make circuit filters easier with an operational amplifier, as an active filter.

The real question, is an analog circuit slower?

Frequently Asked Questions

What is the analog circuit?

Analog circuit is a circuit that is built from a few components and some simple ICs. Analog circuit is connected to sensor devices to receive input signals from the environment. This signal will be processed and presented.

Where are Analog circuits used?

The applications of analog circuits are quite wide such as active filters, oscillators, modulators. These applications are very helpful to process continuous signals in real time. Outside of those, we can utilize analog circuits to be a battery charger, power converter, and voltage regulator.

What is the difference between an analog and a digital circuit?

Why do we need analog circuits?

Even if analog circuits and digital circuits are very different, we can utilize analog circuits to process the analog signal to be further received and processed by the digital circuit. Some basic elements such as resistor, inductor, capacitor, transistor, and operational amplifier can help a digital circuit greatly.

Is analog AC or DC?

Looking from the inputs, the analog circuit is mostly used with DC voltage. The signal is mainly represented in DC voltage level. But analog circuits can be used in AC voltage for communication devices while analog circuits in DC voltage as signal transmission.