Lovely Professional University 2009 B.Tech Computer Science and Engineering Digital Electronics - Question Paper
Digital Electronics
Time allowed: 3 hrs Max marks: 100
1. Wib paper contains eftfht questions on one page.
2. Answer all question* in serial order
J. I'he marks assigned to each question am shown ai the end of each question in square brackets.
1. a) Simplify A.B.C.
b) I low digital IC of two different logic families can be connected on a single chip.
c) Give some examples of combinational logic circuits.
d) If a flip flop is in its toggle mode of operation. what will the output look like on repeated clock pulses.
c) Give the advantages of PLD. [5x2*10]
2. a) Convert(0.5l3)iotooctal. [2]
b) Subtract using2s complement lOlOIOO-iOOOOl 1. [2]
c) In a new number system X &. Y arc successive digits such that (XY)r 71 & (YX)r ~ 79 Find X ,Y, r. [4]
d) IC 2732 is a 4096 x 8 EPROM . how many address lines does it have. [21
3. ft) Draw a circuit to implement Ihe express;vr. Y ~ AB i AC + BC + ABC. [5] b) Draw ihe symbol of exclusive QK gate and prepare truth table for a 2 inputs exclusive OR gates.
Draw a TTL circuit with totem pole output &. explain its working . why should it not be used for wired AND connection. fioj
5. a) Ube kamaugh map to Amplify and then draw logic circuit also.
f(A,D,C,U) - m 1,12,13,14.15) [10]
b) Design a logic circuit with 4 input variables such that rhc output Is 1 when any three and only
three input variables are high. [10]
6. (aj Realize using a 16; I multiplexer.
f(A,&C,D)-Vm (0,1,3,4,6,8.10,11,12,15) [10]
mi)) Design & draw the complete circuit of a 4 line to 16 line decoder. [10]
7. Draw the logic circuit of edge triggered JK flip flop & explain ib working. [5] b) Draw the circuit fcf a 4 bit ripple countcr. explain its working & draw its liming diagram. [5]
0
Show the connections in a_PAL to yield the following outputs Yo = A + B0 *-_CD Yl *= ABCD + ABCD Y2 ABC
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| Earning: Approval pending. |
