Digital electronics is a part of the electronics sector. This field includes the study of digital signals that deal in zero and one. Now-a-days it has made its place in every domain.
Signal
In simple words, the signal is a variation in parameters (like pressure, temperature, speed, audio, and video). In the electrical and electronics world, the signal is a variation in voltage and current with time.
Transducer
It is a device that converts non-electrical quantities or physical quantities into electrical quantities and vice-versa. If the input is an electrical signal then the output signal of the transducer is light, sound, movement, etc.
Examples: loudspeakers, microphones, thermometers, pressure sensors, and antennae.
Figure: Transducer Pictures
Continuous-Time Signal
It is a signal which is a continuous function of time. Indirectly we can calculate its value at any given time instant. Example: Speech, sine wave, temperature etc.
Figure: Sine Continuous Time Signal
Discrete-Time Signal
A signal is known as a discrete signal when it is defined at given instants of time.
Figure: Discrete Signal
Digital Signal
Data represented as a sequence of discrete values is known as a digital signal. it has a voltage level to represent each and every level of discrete value. So we fixed the level of voltage for the digital system, which is called a digital signal.
Figure: Analog to digital signal conversion
Why From Analog To Digital Technology:
- More accuracy.
- Reduce extra/hard work.
- Storage Flexible.
- Easy to simulate and design.
- Required for high performance.
- For fast work and time-saving.
- The storing of digital signals is easy.
- Easily manipulation with less error.
- Transmission and reproduction are simple.
Note:
- Accuracy depends upon the no of level the digital signal.
- Digital technology is more reliable for generating or reproducing signals.
Building Block Of Signal Processing
Most of the systems in real life have analog input. Because of the various benefits of digital signal processing, we convert the analog signal into a digital signal and then process them into digital form. After that, digital signal is converted back to an analog signal.
Figure: Building Block Of Signal Processing
- Analog Signal: Those signals which are continuous in nature are known as analog signals. Almost every signal is available in the analog form.
Example: Audio Signal, temperature, pressure etc. - Pre-Processing: This step is not compulsory in the process. But if the signal has low power or not enough energy to reach the next process then this process comes into picture.
Example: Amplification Of Signal - Conversion Into Digital Signal: In this step, an analog signal is converted to a digital signal with the help of ADCs(Analog to digital converters).
Example: Counter ADC, Flash ADC, Dual Slope ADC and SAR ADC - Digital Signal Processing: This process is very important in all these steps because the digital signal process, analyzes, improves, and optimizes only in this block. To generate a high-quality signal, various mathematical calculations, computations, and operations are done.
- Digital To Analog: After all the operations on the digital signal, it will converted back into an analog signal using DACs(Digital to Analog Converter). Example: Weighted Resistor DAC, R-2R Ladder Type DAC.
Building Block Of Digital Circuit And Systems:
There are mainly two types of Digital logic circuits already mention below. Those circuits helps us to design big systems of digital electronics:
- Combinational Circuit
- Sequential Circuit
01. Combinational Circuit:
The combinational circuit is a digital circuit in which we combine the different gates(And, Or, Not, etc) in the specific manner to get desired output circuit.
Examples: Half Adder, Full Adder, Comparator, Encoder, Decoder, Multiplexer, and Demultiplexer.
02. Sequential Circuits:
There are no memory element in the combinational circuit. Hence the previous state input does not have any effect on the present state of the circuit. But sequential circuit has memory so output can change based on input and previous state as well.
Sequential Circuits = Combinational Circuit + Memory Element
