CCE
M.B. Khalsa College
Bsc IInd Year (3rd Semester)
Electronics Paper II: Digital Electronics II (EL-2102)

Objective

Q1. The main advantage of Schottky TTL logic is its least:
(a) Power dissipation (b) Propagation delay (c) Fan-In (d) none of these.

Q2. A Flip-Flop may be built with:
(a) NAND gates (b) AND gates (c) AND plus OR gate (d) Any of the above.

Q3. Shifting the contents of a shift register, left by one place, equivalent to:
(a) Dividing the contents by 10 (b) Dividing the contents by 2 (c) Multiplying the
contents by 2 (d) none of these.

Q4. In Sequential circuits memory elements are: (a) Astable (b) monostable (c) bistable (d) Tri-state flip-flops.

Q5. An ADC, with 8-bit output, giving full deflection for 12V analog signal, its resolution is: (a) 8/12 V (b) (8*12) mV (c) 8/256 V (d) 12/256 V.

Subjective Questions

Q1. Explain TTL NAND & NOR Gate with suitable diagram.

Q2.What is meant by Racing Condition and Race Around condition in flip-flop?

Q3. Explain Master Slave JK flip-flop. Why Master Slave flip-flops is preferred Over JK Flip Flop.

Q4. Distinguish between Synchronous & Asynchronous Counter. What are important Applications of Counter?

Q5. What do you understand by term Accuracy and Resolution of an ADC?

Q6. What is Totem-Pole connection? Why it is so called? Explain it’s working & advantages when used in TTL circuits.

Q7 List the main characteristics of CMOS logic family & compare with TTL logic family.

Q8. What are different forms of triggering flip-flops? Explain each one with example.

Q9. Explain the operation of PIPO & PISO shift register with the help of a diagram.

Q10. Explain the operation of Bi-directional shift register with the help of a diagram.

Q11. Explain Asynchronous mod-6 up counter with the help of a timing diagram.

Q12. Describe the operation of BCD down counter with help of timing diagram.

Q13. Explain R-2R ladder digital to analog converter (DAC) with help of diagram.

Q14. Explain Continuous analog to digital converter (ADC) with help of diagram.

    Bsc III Semester

EL-2102

DIGITAL ELECTRONICS -II

Unit I: TTL Circuits

TTL Circuits,  Digital Integrated Circuits:  7400  Series, TTL  Characteristics,  TTL Overview, Open
Collector  & Totem  Pole Outputs,  Difference between TTL types including  Schottky, Low power
Schottky, Standard and Low Power TTLs. Introduction to MOS Logic Family, Comparison between TTL
and MOS Families.

Unit II: Latches & Flip Flops

RS  and  D-Latches,  RS Flip-Flop, Edge triggered D,  JK and T  Flip-Flop.  Concept of  Racing  and JK
Master Slave Flip Flops.

Unit III: Registers

Buffer Registers, Shift Registers, Controlled Shift Registers.

Unit IV: Counters

Ripple Counters, Synchronous Counters, Ring Counters, Synchronous and Asynchronous loading of the
Counters, Clear and Preset in the counters.

Unit V: Converters

Basic D/A Converters: R-2R, Binary Weighted Resistor type, A/D Converters: Counter, Ramp, Flash
and Successive Approximation. Sample and Hold Circuits: Basic Concept and Working.

BOOKS RECOMMENDED:
1.  Digital Principles and Applications   : Malvino and Leach
2.  Modern Digital Electronics           : R.P. Jain
3.  Digital Computer Electronics     : Malvino and Brown

Note: The question paper will have the usual Note saying “Attempt five questions choosing one from
each unit”. Thus the paper will clearly specify units and have a pattern of two questions per unit with an
option to attempt any one of these two within each unit. The balance of paper will be maintained by
including appropriate (Numerical / Objective / Conceptual / Analytical / Theoretical) combination of
subsections in each question.