PDC assignments unit 1, 2 & 3

Subject:  Pulse and Digital Circuits

Unit-I

1.a) What is linear wave shaping?

b) Explain how an RC low pass circuit works as an integrator?
c) Derive the expression for percentage tilt P of a square wave output of a RC high pass circuit.

2. Design C1 for the attenuator shown in fig. below to get i) Perfect compensation ii) Over compensation & iii) Under compensation. The input to the attenuator is a step of 20V. Calculate & plot the output for the same.

 3.  A 1KHz symmetrical square wave of ±10V is applied to a RC circuit having  1ms time constant calculate and plot the output for

i) High Pass RC circuit

ii) Low pass RC circuit                                                          

4.Derive expression for rise time in a RC low pass circuit.      

5 a)Derive the output equations and draw the output waveforms of a RC high pass circuit for the square wave input for different time constants.         

b) Explain about RLC ringing circuit.          

6 a) Explain how a high pass RC circuit works as a differentiator. Also, explain double differentiation.                                          

b) What is the amplitude and gain of a sinusoidal input in a RC high pass circuit?                                                                  

  7. A) Derive the output equations and draw the output wave forms of a RL low pass circuit for the step input.    

      B) A step of 10V is applied to Low pass RC circuit which produces output with rise time 200µs, calculate 3-dB frequency of the circuit , if the circuit uses a capacitor of 0.47µF and determine the value of R.  

8. a) Obtain the response of RL high pass series circuit for Step input voltage.    

    b) A 10KHz square wave is applied to high pass RC circuit with %P=3.8%, find 3-dB frequency if it uses c=0.47µF  and find the value of R.   

9  a)  Derive the output equations and draw the output waveforms of a RC high pass circuit for step input.      

    b) An ideal 1µs pulse is fed to low pass RC Circuit. Calculate & plot the output waveform under the following conditions the upper 3-dB frequency i)10MHz   ii)0.1MHz     

Unit-II

1.What is non-linear wave shaping? What is clipping? Explain the operation of below mentioned circuits with circuit diagrams, transfer characteristics and waveforms

a) Series positive clipper with and without VR.
b) Shunt negative clipper with and without VR.     

2. a) What is clamping operation? Explain the operation of biased positive peak clamper with output waveforms.

b)  For the circuit shown in below Vin –sinusoidal with 100V peak and assume ideal diodes , sketch the output voltage and transfer characteristics.

3.a) State and prove clamping circuit theorem.

 b) What is the effect of source resistance and the diode resistance in clamping circuits?

c) Explain the operation of diode comparator. Briefly mention various applications of comparators.                                                                                                                                                   

4.    a) Design a clipper circuit which produce the output shown in below figure and explain its operation with transfer characteristics.

b) Draw the output waveform of a practical clamping circuit when a square wave is given as input. Derive the relation between   and   in this case.     

5.a) What is synchronized clamping? Draw the circuit and explain its operation.  

b) Explain the operation of transistor clippers (common emitter type and emitter follower type) with neat sketches.                                                                             

Unit-III

1.a) Design a switch using diode and explain it with its switching characteristics.                 

b) Explain the breakdown voltage consideration of transistor. Derive expression for   BVCEO in terms of BVCBO. 

2. a) Draw piece wise linear model diode characteristics and explain.           

  b) Explain the operation of a transistor as switch with its switching characteristics.

3. a) How the minority carriers are distributed in a p­n junction diode during forward biased condition and the reverse biased condition?

b)  For a transistor switch, define the following a) rise time b ) storage time c) reverse recovery time d) transition time