Analog Circuits

State the advantage and disadvantage of FET over BJT.

Define slew rate and CMRR.

Why negative feedback is used mostly in operational amplifier circuits?

Draw the transfer characteristic of Op-Amp.

State Barkhausen Criterion for oscillation.

What are self bias circuits? Explain briefly.

Why BJT is preferred over FET for high frequency amplification purpose?

How many comparators are required in 4 bit flash type ADC?

What is the influence of voltage series feedback on input impedance?

What is cascode amplifier? Explain briefly.

Find the output voltage of the circuit as shown in figure 1. `` +--- 5k ---+ | | +---[-]-+ | | |Op-Amp | 5k |---- V_o | +[+]-+ | | GND +--- 5k --- V_1 | [R] | GND ``

Compare various configurations of BJT (i.e. CC, CB, and CE) with respect to voltage gain ($A_v$), current gain ($A_i$), input impedance ($Z_i$), output impedence ($Z_o$) and applications.

What is Schmitt trigger? How it is different from inverter? State its application also.

Find the transistor currents in the circuit as shown in Figure 2. A silicon transistor withh $\beta =100$ and $I_{co}=2\times 10^{-5}\text{ mA}$ is under consideration. `` +10V (Vcc) | [3k] Rc | +-----+ | c | 5V (Vbb) --[200k]--b BJT Rb | e | GND ``

What is switched capacitor circuits? Explain briefly.

Explain Hybrid - $\pi$ common emitter? Transistor model.

An 8 bit digital ramp ADC with have $40\text{ mV}$ resolution and a clock of $2.5\text{ MHz}$. Find the output of ADC when $5\text{ V}$ is applied to ADC input.

a. What is precision rectifier? Explain briefly. b. Find the output voltage of circuit as shown in figure 3. `` +--- 10k ---+ | | 1V -- 1k -+ | 2V -- 1k -+-[ - ]-----+ 3V -- 1k -+ |---- V_o | [ + ]---+ | | GND [5k] | GND ``

a. Draw the diagram of colpitt oscillator and explain its working in brief. [4] b. Design a low pass butter worth active filter for cutt off frequency of 10KHz. [6]

The circuit of figure. 4 has following parameters: $R_{c1}=3\text{k},R_{c2}=500\Omega$; $R_e=50\Omega ,R^{\prime }=R_f=1.2\text{k},h_{fe}=50,h_{ie}=1.1\text{ K}$ and $h_{re}=h_{oe}=0$. Find: a. Voltage gain with feedback ($A_{vf}$). b. Input resistance with feedback ($R_{if}$). c. The resistance seen by voltage source and d. The output resistance.

a. Explain FET small signal model. b. What is pinch off region in FET? Explain briefly.

Write short note on following : i. Gain and phase margin. ii. Transconductance amplifier.