Digital Circuits And Logic Design Question Paper of 3rd Semester CSE74 Download Previous Years Question Paper 13

Roll No.

Total No. of Questions : 09

B.Tech.  (Sem.–3)

DIGITAL CIRCUITS & LOGIC DESIGN

Subject Code : CS-205

Paper ID : [A0453]

Time : 3 Hrs.

Instruction to candidates :

1. SECTION-A is COMPULSORY consisting of TEN questions carrying

TWO marks each.

2. SECTION-B contains FIVE questions carrying FIVE marks each and

students has to attempt any FOUR questions.

3. SECTION-C contains THREE questions carrying TEN marks each and

students has to attempt any TWO questions.

SECTION-A

l. Answer briefly :

(a) Why one need to know variety of codes, whereas digital machine/

circuit understands, only binary code ?

(b) How negative numbers are represented?

(c) What should be best option for the unused inputs in a 4 input NAND

gate when only two inputs are to be used ?

(d) What do you mean by line termination ?

(e) What are the important parameters which need to be considered

while converting Analog to Digital ?

(f) What are the important features of any memory system ?

(g) How many select lines are required for 14 to 1 MUX ?

(h) List the advantages of MOS over TTL logic family.

(i) How many transistors can be integrated in a typical VLSI chip ?

Mention the chip size also.

(j) List the applications of ASCII code.

SECTION-B

2. Mention the varieties of ROM’s. Compare their relative advantages and

disadvantages.

3. Simplify the Boolean function :

f(A, B, C, D) =  (0, 2, 3, 5, 6, 7, 8, 9) with 10, 11, 12, 13, 14, 15 as

don’t cares.

4. Draw the circuit of a 4-bit shift register and explain its operation.

5. Draw the circuit of a CMOS–NOR gate and explain its truth table.

6. Calculate the conversion time of a ten-bit digital ramp A/D convertor and

a ten bit successive approximation A/D convertor, when the clock frequency

used by them is 1000 KHz.

SECTION-C

7.       (a) Draw the circuit of a successive approximation A/D convertor and

explain its operation.

(b) Discuss R–2R Ladder D/A convertor.

8.       (a) Explain the difference between combinational and sequential circuits.

(b) Draw the circuit of a MOS-Static RAM cell and explain its working.

(c) Draw the circuit of a Bitable Multivibraor and explain its working.

9.       (a) Draw the circuit of a tractate NOT gate and explain its working.

(b) Draw the circuit of a 3 input TTL NAND gate with totem pole output

and explain its truth table.