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Basics of Electronics - 2

Digital Technologies

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More Circuit Devices - Diode

A diode is a small electronic part that acts like a one-way door for electricity.

It lets electricity flow in one direction but blocks it from going the other way.

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Forward Bias vs. Reverse Bias

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Question:

Which light bulb will be turned on?

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Forward Bias vs. Reverse Bias

In this circuit, we use the diode as a switch:

    • If it is forward biased, the bulb is turned on;
    • If it is revise biased, the bulb is turned off.

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Questions: �

How can we make an LED blink on and off at regular intervals?

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Method:

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To control the on/off state of a switch

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Binary-state of the switch: state ‘1’ or state ‘0’

How can we make an LED blink on and off at regular intervals?

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Digital Signals

The digital signal takes one of two values. It can be generated by any devices that have two distinct states.

Example:

  • Switch: On vs. Off
  • Voltage: High voltage vs. Low Voltage
  • Spinning component:  clockwise vs. counter-clockwise

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A Simple Digital Control System

To control a light from two locations.

e.g. upstairs and downstairs.

https://techovedas.com/from-light-switches-to-laptops-how-logic-gates-define-the-world-of-digital-vlsi-design/

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Digital Technology

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Digital Technology

Digitized information is recorded in binary code of combinations of the digits 0 and 1, also called bits, which represent words, images and other multimedia representation.

0101000011…

Digital technology makes many things possible …

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IoT – Internet of Things

Physical objects with sensors, software, and other technologies that allow them to connect and exchange coded digital data over the internet. 

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Digital Communication

  • 1G delivered analog voice.
  • 2G introduced digital voice (e.g., CDMA). 
  • 3G brought mobile data (e.g., CDMA2000). 
  • 4G LTE ushered in the era of mobile Internet.
  • 5G expands mobile networks to support a vast diversity of devices and services and connect new industries with improved performance

Exchanging information, messages, and ideas via digital technologies and platforms. 

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Cloud Computing

Cloud computing is the delivery of computing services—including servers, storage, databases, networking, software, analytics, and intelligence—over the internet (“the cloud”).

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Autonomous Vehicle

An autonomous vehicle (also called a self-driving car) is a vehicle that can drive itself without a human control.

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It uses sensors, cameras, radar, GPS, and artificial intelligence (AI) to understand the road, detect obstacles, and make driving decisions.

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These systems represent, process, and compute all information in digital form.

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Binary Number Representation

  • Common numbering system is “base10” -decimal numbers

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  • Numbers in base 10
    • Ten different digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
    • Number is represented by a sequence of digits: an an-1 … a1 a0
    • Value of number: an×10n+an-1×10n-1+…+a1×101+a0×100

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  • Positional notation
    • General equation:
    • May contain a decimal point
    • Negative index for digits after decimal point

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  • Examples
    • 1234.56 – if ambiguous, write (1234.56)10
    • Leading zeros cause no problems: 00001234.56

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Positional Integer Number Values

Given a digit series of

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The full expression for the represented value is

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Binary Numbers

  • Binary numbers use only two digits: 0, 1

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Advantages:

Easy for implementation. Use devices or methods that have two distinct states.

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Binary numbers are made by combining multiple binary digits—0s and 1s—in a specific order to represent values

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Number Base Conversions

  • Convert a decimal number to a binary number�
  • Example: convert (41)10 to binary (r=2)
    • 41 = 20 × 2 + 1
    • 20 = 10 × 2 + 0
    • 10 = 5 × 2 + 0
    • 5 = 2 × 2 + 1
    • 2 = 1 × 2 + 0
    • 1 = 0 × 2 + 1

a0 = 1

a1 = 0

a2 = 0

a3 = 1

a4 = 0

a5 = 1

(101001)2

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Exercise

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Convert (36)10 to the binary representation

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Analog signals carry continuous waves of data. 

Digital signals carry a flow of discrete data.

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Real-world signals are inherently analog, including temperature, humidity, sound, light, and many others.

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By nature, temperature signals vary continuously over time.

Analog signals vs. Digital signals

A digitized temperature signal takes on discrete values.

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Digital Systems

  • For a digital systems to operate on a continuous data, it needs to quantize (digitize) that data first

Covert data into digital representation

    • Almost any measurable quantity, for example, weight, humidity, pressure, mass or air flow, temperature, light intensity, speed, and so on, is analog in nature.
    • Analog signals must be represented in digital format in order to be processed by the digital system.
    • A non-electrical quantity must be converted into electrical voltage before it can be converted into a digital value.
    • An analog to digital (A/D) converter can convert an electrical voltage to a digital value.

A digital thermometer

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Digital System –Hardware Circuit Structure

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Question:

For an analog temperature signal that varies continuously from 0°C to 100°C, we use a 4-bit digital representation. In this system, 0°C is represented as '0000' and 100°C as '1111’.

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How many discrete steps are there, and what is the step size (resolution)?

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Solution

A 4-bit binary number can represent:

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so, we have 16 steps total.

The total range is from 0°C to 100°C, divided into 15 equal intervals

Question:

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To achieve a finer resolution (smaller step size), what can we do?