Analog Electronics 2 - May 2014

Electronics & Telecomm. (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

Answer any four:-

1(a) Compare ideal and practical Op Amp.(5 marks) 1(b) Consider a BJT has parameter f_T=500MHz at Ic=1mA,β=100 and Cμ=0.3pF.
Calculate bandwidth f_β and capacitance Cπ of a BJT.(5 marks) 1(c) What is cross -over distortion in power Amplifier,How it is overcome?(5 marks) 1(d) Which type of biasing techniques is used to bias Integrated Circuit and why?(5 marks) 1(e) Find output voltage Ac=0.1 and input voltage are V₁=2+0.55 sinωt and V₂=0.5-0.005 sinωt.(5 marks) 1(f) Explain line regulation and load regulation of voltage regulator.draw load and line regulation characteristic of ideal and practical voltage regulator.(5 marks) 2(a) For the circuit shown in Fig 2a,the parameter are R₃=0.1k&Omega,R₁=20k&Omega,R_2.2kΩ,R_E=0.1kΩCc=47μf, and Vcc=10V.The transistor parameter are:V_BE(ON)=0.7V,β=200, and VA=&infty.
Derive expression for lower cut-off frequency (or time constant )due to coupling capacitor Cc,
Determine lower cut off frequency and mid-band voltage gain.

(10 marks) 2(b) For the circuit shown Fig 2b,the transistor parameter are:Kn=1mA/V²,V_TN=0.8V,λ=0,Cgs=2pF and cgd=0.2pF.Determine
(i)Miller capacitance
The upper 3dB(high cut off)frequency
The mid band voltage gain (10 marks) 3(a) For the circuit shown in fig.3a, find overall mid-band voltage gain and capacitor Cc¹, and Cc²such that the 3dB frequencies associated with each stage are equal. Assume BJT have parameters:V_BE(ON)=0.7 V,β=200, and VA=∞ (10 marks) 3(b) For the differential amplifier shown in fig 3b,derive expression for differential voltage gain,common -mode voltage gain and CMRR.
(10 marks) 4(a) The transistor parameter for the circuit shown in Fig 4a are β=100,V_BE(ON)=0.7,and VA=∞.
(i)determine R_Esuch that I_E=150μA.
Find Ad,Acm and CMRR for one sided output at V₀₂
Determine the differential and common-mod input resistances
(10 marks) 4(b) Explain the working of two transistor (BJT)current source with the help of necessary current relationship.also explain the effect of finite output resistance on current source performance and the techniques to improve the same.(10 marks) 5(a) Draw a circuit diagram of a transformer couple class.A power amplifier.Also draw as and dc load lines for the same.derive expression for the power conversion efficiency.(10 marks) 5(b) Explain working of basic differentiator with the help of input and output waveforms Also derive expression for output voltage of the same.What are the limitation of basic differentiator and how to overcome these limitations.(10 marks)

Write short notes on any Four:

6(a) Transistorized series regulator(5 marks) 6(b) High pass and low pass filters(5 marks) 6(c) power MOSFET(5 marks) 6(d) Wilson current source(5 marks) 6(e) Darlington pair.(5 marks)