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ELCN100 : Electronic Lab 1 Cairo University
ELCN100 Electronic Lab.
Instruments and MeasurementsSpring 2018
Lecture 08:Digital Instruments Basics (cont.)
Dr. Hassan Mostafa
حسن مصطفى. د
ELCN100 : Electronic Lab 2 Cairo University
Objective of this chapter
In order to study the operation, applications, and performance of Digital Multi-Meters (DMM), we need to understand the following blocks:
Basic logic gates
Flip-flops
Digital displays
Digital counters
Frequency dividers
Analog-to-digital converters
Digital-to-analog converters
ELCN100 : Electronic Lab 3 Cairo University
Digital Counters
Mod-10 counter
RRRR
ClkClkClkClk
R = Reset
When R = ‘0’, the flip-flop
output = ‘0’
ELCN100 : Electronic Lab 4 Cairo University
Digital Counters
Mod-2000 counter
BCD-to seven segment display drivers
3.5 digits display
3 complete digits and one flip-flop ON/OFF
ELCN100 : Electronic Lab 7 Cairo University
Example
The ramp-type ADC system uses a 1MHz clock generator and a ramp voltage that increases from 0V to 1.25V in a time of 125msec. Determine the number of clock pulses counted into the register when Vi = 0.9V, and when Vi =0.75V.
ELCN100 : Electronic Lab 8 Cairo University
Solution
The ramp-type ADC system uses a 1MHz clock generator and a ramp voltage that increases from 0V to 1.25V in a time of 125msec. Determine the number of clock pulses counted into the register when Vi = 0.9V, and when Vi =0.75V.
For Vi = 0.9V
Vi/Vr = t1/(t1+t2) -->
0.9/1.25 = t1/125msec --> t1 = 90msec
For a clock frequency of 1MHz,
the clock pulse period = 1/1MHz = 1usec
The number of clock pulses counted =
90msec/1usec = 90000 pulses
ELCN100 : Electronic Lab 9 Cairo University
Solution
The ramp-type ADC system uses a 1MHz clock generator and a ramp voltage that increases from 0V to 1.25V in a time of 125msec. Determine the number of clock pulses counted into the register when Vi = 0.9V, and when Vi =0.75V.
For Vi = 0.75V
Vi/Vr = t1/(t1+t2) -->
0.75/1.25 = t1/125msec --> t1 = 75msec
For a clock frequency of 1MHz,
the clock pulse period = 1/1MHz = 1usec
The number of clock pulses counted =
75msec/1usec = 75000 pulses
ELCN100 : Electronic Lab 11 Cairo University
Quantization Noise
Quantization error = ± 0.5* VFS /(2n) = ± VFS /(2n+1)
VFS = Full scale voltage
n = number of ADC bits
2-bit ADC
quantization error of ± VFS /8 = ±12.5% of the full scale voltage
5-bit ADC
quantization error = ± VFS /64 = ±1.6% of the full scale voltage
ELCN100 : Electronic Lab 12 Cairo University
Course Project (15 marks)
Each group of students ( consists of 3-5 students) should select oneelectronic instrument from the following list and perform the following:
Send an email to ([email protected]) indicating the group members and their choice by Wednesday April 18, mid-night
Use Labview to build the instrument.
Deliver a hard copy report explaining all the steps of the design and several examples as well as user manual for their product.
Prepare and deliver a Youtube video showing their product similar to the below videos ( English or Arabic)
- https://www.youtube.com/watch?v=MrAH8fCWXXE
- https://www.youtube.com/watch?v=ZMPkOrXzaoU
- https://www.youtube.com/watch?v=hKiOQXfzdzI
List of Electronic Instruments:
Function Generator and Digital Scope
Digital Logic Analyzer
Function Generator and Digital Frequency Meter
ELCN100 : Electronic Lab 13 Cairo University
Course Project
Deadline of submitting the report and performing the presentations:
Wednesday (Last week) at lecture/lab time
Report (Hard Copy)
Video over email with subject “ELCN100 YouTube Video Link”
The group must appear in the video and their names should be clear on the end of the video for grading
Restrictions:
The report is maximum of 10-pages including the cover page
- <Each extra page receives -1 mark>
The video time is 5 minutes (Maximum)
- <Each extra minute receives -2 mark>
Delayed delivery of the group members names, reports, or video email receives a penalty of -3 mark/day.