This document discusses analog to digital conversion and digital to analog conversion. It describes four types of analog to digital conversion including successive approximation type conversion. For successive approximation conversion, a successive approximation register is used which counts bit values from most to least significant to determine if the analog input is greater or less than the count. Digital to analog conversion can be done with binary weighted resistor or R-2R ladder methods. Applications of conversion include electronic weighing systems, digital voltmeters, and digital motor control.

1. ANALOG TO DIGITAL
COVERSION
DIGITAL TO ANALOG
CONVERSION

2. ANALOG TO DIGITAL CONVERSION
• An ADC converts analog signal to
digital signal .
• There are four type of the conversion:
Flash type converter
Counter type converter
Tracking /servo converter
Successive approximation type
converter

3. SUCCESSIVE APPROXIMATION REGISISTOR
• A Successive Approximation Registor (SAR)
is added to the circuit .
• Instead of counting up in binary sequence
,this register counts by trying all the values
of bits starting with the MSB to LSB.
• the registor moniters the comparators
output to see if the binary count is greater
or less than the analog signal input and
adjust the bits accordingly.
• The SAR architecture mainly uses the binary
search algorithm.

4. APPLICATION OF ANALOG TO DIGITAL CONVERSION:-
Based on area of application divided
into 4 type
 Data transmission
 Data processing
 Data read out
 Data storage

5. APPLICATION OF ANALOG TO DIGITAL CONVERSION:-
• Most popular applications are-
Electronic weighing system
Digital voltmeter
Digital micrometer using LVDT

6. DIGITAL TO ANALOG COVERSION
• A digital to analog converter (DAC)
converts a digital signal to an analog
signal in form of voltage or current .
• There are two method of the
conversation:
Binary weighted resistor method
R-2R ladder

7. BINARY WEIGHTED RESISTOR METHOD
Depending upon the digital input bit logic
circuit performs switching of resistor
networks between Vref and ground.
 transistors are used to switch between Vref
and ground .
Weighted resistors are used to distinguish
each bit from the MSB to LSB.

8. • ADVANTAGE:
Simplest in terms of operational theory
Most efficient in terms of speed ,veryfast
Limited onlyin terms of comparator and gate propagation delay
• DISADVANTAGE:
Lower resolution
Expensive
For each additional output bit,the number of comparators is doubled
BINARY WEIGHTED RESISTOR

9. APPLICATION OF DIGITAL TO ANALOG CONVERSION :-
Digital Motor Control
Computer Printers
Sound Equipment(e.g. CD/MP3
Players,etc)
Function generators/oscilloscopes
Digital Audio

10. END
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