An analog to digital converter (ADC) allows digital circuits to interface with the real world by converting analog signals, like sound from a microphone, into digital data. ADCs work by sampling the analog signal at discrete time intervals and then quantizing the signal amplitude into discrete levels represented by a binary code. The sampling rate must be at least twice the highest frequency component of the analog signal per the Nyquist criterion. The resolution of an ADC, defined as the smallest voltage increment it can detect, is determined by the number of bits in its output. Common applications of ADCs include data acquisition, control systems, sensors, audio/video devices, and more.

1. A/D Convertor
PRESENTEDBY:-

2. Introduction
Analogue to digital converter, or A/D converter
is data converter which allows digital circuits to
interface with the real world by encoding an
analogue signal to a binary code.
So to simply put it, it converts an analogue input
like sound from a microphone into digital
sound..

3. WHY ADC IS IMPORTANT ?
 All microcontrollers store information using digital logics.
 Compress information to digital form for efficient storage.
 Medium for storing digital data is more robust.
 Digital data transfer is more efficient .
 Digital data is easily reproducible.
 Provides a link between a real world signals and data storage.

4. WorkingPrinciple
Two main steps of process
1.Sampling .
2. Quantization :-
• Resolution.

5. Sampling
• Reduction of a continuous signal to discrete signal.
• The time during which the circuit generates the sample of the
input signal is called sampling time.
• Sampling time is usually in between 1us to 14us while holding
time cam assume any value as required in the application.

6. Nyquist criteria
 The Nyquist theorem specifies that a sinusoidal function in time or distance
can be regenerated with no loss of information as long as it is sampled at a
frequency greater than or equal to twice per cycle.
 Nyquist's theorem states that a periodic signal must be sampled at more than
twice the highest frequency component of the signal.
fs>=2B

7. Quantization…
Separating the input signal into a discrete states with N
increments.
• N= 2𝑛
. N is the number of bits of the ADC.
Assigning a unique Digital code to each state for input
into the microprocessor.
:- if n=2 :𝟐𝟐 = 4
so number of level to which the signal is quantized is 4 level.

8. RSOLUTIONOF ADC:-
 The ADC resolution is defined as the smallest incremental
voltage that can be recognized and thus causes a change in
the digital output. It is expressed as the number of bits
output by the ADC.
𝑽𝑭𝒔
𝟐𝒏
𝑹𝒆𝒔𝒐𝒍𝒖𝒕𝒊𝒐𝒏 =
𝑽𝒎𝒂𝒙 − 𝑽𝒎𝒊𝒏
𝟐𝒏
=

9. Typical ADC Architecture for Analog to Digital Signal Conversion

10. TypesofA/DConvertor
Flash A/D Converter.
Delta-Sigma A/D Converter
Dual Slope A/D Converter
Pipelined A/D Converter

11. Analog and Digital Signals: Systems and Applications
Measurements/ Data Acquisition
Control Systems
PLCs ( Programmable Logic
Controllers)
Sensor Integration
Cell Phones
Audio recording and reproduction.
Video Devices
Audio Devices

12. CONCLUSION
This article introduces some of the basic concepts of analog and digital
signals, and their uses in electronics. There are clear advantages and
disadvantages with each technology, and knowing your application’s needs
and performance requirements will help you determine which signal(s) to
choose.

13. acknowledgement
We would especially like to thank each and everyone present
over here who took out their precious time from their busy
schedule to listen to us. We would also like to thank our teacher
Ms. Ayesha Ali who gave us this opportunity to present on this
topic. We would also like to thank our classmates who helped us
during preparation of this topic.