PTU B.Tech EEE 3rd Semester May 2019 72164 DIGITAL ELECTRONICS Question Papers

PTU Punjab Technical University B-Tech May 2019 Question Papers 3rd Semester Electrical and Electronics Engineering (EEE)-EE-Electrical Engineering

Roll No.
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(EE) PT (Sem.?3)
DIGITAL ELECTRONICS
Subject Code : BTEE-404
M.Code : 72164
Time : 3 Hrs. Max. Marks : 60
INSTRUCTION TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
has to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
has to attempt any T WO questions.

SECTION-A
1.
Answer briefly :

a) What is the difference between a latch and a flip-flop?

b) How do you specify the delay in VHDL?

c) What is meant by a bit?

d) Which gates are called as universal gates and what are their advantages?

e) What are the fundamental properties of Boolean algebra?

f) What are minterm and maxterm?

g) What are the limitations of the Karnaugh map?

h) What do we need to generate hardware from VHDL model?

i) Write down the duality theorem.

j) What is meant by Checksum?

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SECTION-B
2.
Explain interface between TTL to CMOS circuit.

3.
Design a 4-bit BCD adder using full adder and explain its structure and compute the
circuit to add 1001 and 0101. Write the sum and carry outputs of the given binary
number.
4.
Select a 4096 ? 8 bit ROM memory to store a program. The memory chip has two chip
select inputs and operates from a 5V d.c. power supply. How many pins are needed for
the integrated circuit package? Draw a neat block diagram and label all the input and the
output terminals in the ROM.
5.
Design a 5 ? 32 decoder using 3 ? 8 decoder and summarize how many decoders are
required for designing the circuit.
6.
Explain the organization of ROM with suitable diagrams.

SECTION-C
7.
A 5-bit D/A converter produces VOUT = 0.2V for, a digital input of 0001. Find the value of
Vout for an input of 11111.
8.
Write a program to implement a BCD to Excess?3 code conversion using a PLA.
9.
Explain in detail about the working of bipolar SRAM cell and single transistor DRAM
cell with neat sketches.






NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.

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