Question 1:
a) Draw and explain the functional block diagram of IC 555.
b) Explain the functioning of 555 in Monostable configuration.
Question 2:
a) Explain how astable mode of 555 can be modified to get a square wave generator.
b) Design a 555 based square wave generator to produce a symmetrical square wave of 1 KHz. If VCC = 12V. Draw the voltage across timing capacitor and the output.
Question 3:
a) Describe the 555 timer
i) Monostable multivibrator application in Pulse Width Modulation.
ii) Astable multivibrator application in FSK generator.
b) A 555 timer is configured to run in astable mode with R1 = 20K and R2 = 8K and C = 0.1uf. Determine the output frequency and duty cycle.
Question 4:
a) Design an astable multivibrator using 555 timer to produce a square wave of 2 KHz frequency and 70% duty cycle. Draw the circuit with all component values.
b) Explain how a PLL is used as a frequency multiplier.
Question 5:
a) Explain the role of the basic building blocks of PLL.
b) Determine the DC control voltage vc at lock if signal frequency fs = 10 KHz, VCO free running frequency is 10.66 KHz and the voltage to frequency transfer coefficient of VCO is 6600 Hz/V.
Question 6:
a) Draw the schematic circuit diagram of the following and explain their working.
i) Analog phase detector.
ii) VCO.
Derive necessary expressions.
b) What is their role in PLL? Explain.
Question 7:
a) Describe how frequency division and multiplication can be achieved using a Phase Locked Loop.
b) Draw the circuit of a PLL AM detector and explain its operation.