**THIRD SEMESTER B.TECH DEGREE EXAMINATION JANUARY 2017**

**EC 205 Electronics Circuit**

**Time:**

**3 Hrs Marks: 100**

__PART A__
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**Answer any Three**)- Elaborate on integrator circuit. Discuss its response for step, pulse and square wave inputs.
- Derive the condition for the circuit to work as an integrator?
- An emitter follower circuit is having beta = 100 and R1 = 30K, R2 = 5K, Vcc = 20V. Calculate Ri and Av?
- Draw the small signal equivalent circuit of a CC amplifier and derive the expression for input resistance, output resistance, voltage gain and current gain.

__PART B__
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**Answer any Three**)- Draw the small signal equivalent circuit of a series feedback amplifier and derive the expression for input resistance, output resistance and voltage gain with feedback?
- An amplifier with open loop voltage gain 2000±150 is available. It is necessary to have an amplifier whose voltage gain varies no more than ±0.2%. Find the reverse transmission factor beta and the gain with feedback.
- Draw the circuit of a Wien bridge oscillator and explain its working.
- Explain

i)Broad banding techniques

ii)Feedback topologies

__PART C__
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**Answer any Four)**- For a common source MOSFET amplifier, the following parameters and circuit components are given: VGS(Q) = 2.12 V, VDD = 5 V, RD = 2.5 K, VTH = 1 V, Kn = 0.8

mA/V2 and Z = .02/V. Assume the transistor is in saturation, determine its voltage gain.

- Analyze a MOS differential amplifier and obtain the expression for the CMRR.
- What is body effect? Deduce the small signal equivalent circuit of an n-channel MOSFET including body effect?
- With relevant sketches explain the working of bootstrap sweep Circuit?
- Derive the expression for conversion efficiency, total load power, collector dissipation and figure of merit of a transformer coupled power amplifier?
- Draw the circuit of a series voltage regulator and explain its working? Also derive the expression for input regulation factor and output resistance?

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