Digital Systems (CY-304) - Important Questions

Convert the following: i) (516)7 = (?)10 = (?)16 ii) (250.5)10 = (?)8 = (?)4 iii) (2ED)16 = (?)8 = (?)2 iv) Obtain the 9's and 10's complement of (864)10.

Simplify the following function using K-map: F(A,B,C) = sum m(1,2,3,5,7). Also draw the simplified logic diagram.

Implement the Boolean function F(A,B,C) = AB + A'C using only NAND gates.

Represent the decimal number 6 in i) Excess-3 code ii) BCD code iii) Gray code iv) 84-2-1 code v) 2421 code.

What is a multiplexer? Explain its role and how it selects one input among several inputs. Explain an 8:1 multiplexer with truth table and expression.

Write a short note on decoder.

Explain the working of a full adder with truth table and logic diagram. Why is it required in arithmetic circuits?

Explain the working of the master-slave J-K flip-flop with timing diagram.

Explain asynchronous (ripple) counters and synchronous counters and compare them with respect to speed and hardware complexity.

Write a short note on PLA.

With a neat diagram explain the operation of R-2R ladder DAC.

Explain the principle and working of a sample and hold circuit with diagram and its need in ADC systems.

Explain the need for interfacing between TTL and MOS logic and how TTL-to-MOS/CMOS interfacing is achieved.

Explain the Pulse Code Modulation (PCM) system with a neat block diagram.

Write short notes on any two (7 marks each): a) Internal block diagram, working and two applications of IC 555 timer b) Quantization process and quantization error/noise in PCM and how it can be reduced c) Schmitt trigger circuit and its working d) Time Division Multiplexing (TDM) with block diagram.