RGPV Exams Papers IV Sem Digital Circuit & Systems June 2009
B.E. (Fourth semester) EXAMINATION,JUNE, 2009
(Common for EC/EE/EX Engg.)
(DIGITAL CIRCUIT AND SYSTEM – EE/EC/EX-4503)
Note: Attempt any five questions. Each Unit has internal choice question.
1 (a) Encode the following binary digits into -bit seven parity Hamming code :
(i) 0 1 1 1 (ii) 1 0 1 0
(b) Substract (595)10 from (378)10
© Convert the following decimal number into gray code:
(i) (87)10? (?) gray code (ii) (1100)10? (?) gray code
(d) What do you mean by Radix ? Also explain reflected code.
2 (a) Simplify the Boolean function using K-method :
F= A’B’C” + B’CD’ + A’B’CD’ + AB’C’+ ABCD
(b) Perform substraction using to 2’s complement method:
© prove the following using De Morgan’s theorem:
(A+B) (C+D) = (A+B) + (C+D)
And hence prove that an OR-AND configuration is equivalent to NOR-NOR configuration. Realize the
logic equation given above using only NOR gates.
3 (a) Explain the working of a 4-bit parallel binary adder .
(b) What do you understand but universal gate? Design all logic gates using universal gates.
4 (a) Compare truth table , excitation table and state table.
(b) Implement full substractor using any logic gate.
© Realize all logic gates using minimum number of NAND gates.
5 (a) Explain the working of Bistable multavibrator.
(b) Define the following:
(i)Propagation delay time of a logic gate
(ii) Figure of merit of digital IC
(iii) Fan-in and Fan-out
(iv) Noise margin
6 (a) Explain Schmitt trigger circuits.
(b) Write short notes on any two of the following:
(i) Asynchronous counter
(iii) Interfacing between TTL to MOS
7 (a) Design a Decade counter.
(b) What is a shift register? Explain.
8 (a) Implement a BCD To excess-3 code converter by using a PLA.
(b) Draw a 5-bit ring counter using J-K flip-flop and explain its working.
9 (a) Draw the block diagram of successive approximation A to D converter and explain its operation.
(b)Explain V-F Converter in brief.
10 (a) explain sample and hold circuit.
(b) What do you mean by A/D and D/A converter?
© What do you understand by Digital Circuit and Systems?