JNTU
JNTU B.Tech III LINEAR AND DIGITAL IC APPLICATIONS Previous Question Paper (August - 2022 - R13)
Answer any five questions. All questions carry equal marks.
Main
With a neat diagram, explain the equivalent circuit of an operational amplifier along with its features.
Answer
The equivalent circuit of an operational amplifier consists of an input stage with a differential input impedance Zi, an input voltage vd = v2 - v1, and an output voltage source Avvd in series with an output impedance Zo. The input terminals are connected to the differential amplifier, which provides high input resistance and voltage gain.
Key features include:
- High Input Impedance: Minimizes loading effects on the signal source.
- Low Output Impedance: Allows the op-amp to drive low-impedance loads without significant voltage drop.
- High Open-Loop Gain: Enables precise control through negative feedback.
- Differential Input: Rejects common-mode signals, providing high common-mode rejection ratio (CMRR).
Explain in detail all the DC and AC characteristics of an ideal OP-AMP with relevant expressions.
Answer
An ideal op-amp is characterized by the following DC and AC parameters:
- Infinite Open-Loop Gain (Av = ∞): Ensures that for any finite output voltage, the differential input voltage must be zero.
- Infinite Input Impedance (Zi = ∞): Ensures zero input current, preventing loading of the source.
- Zero Output Impedance (Zo = 0): Ensures the output voltage remains independent of the load current.
- Infinite Bandwidth (BW = ∞): The gain remains constant for all frequencies from DC to infinity.
- Infinite CMRR: The op-amp completely rejects common-mode signals, resulting in zero output for common-mode inputs.
- Zero Offset Voltage (Vos = 0): When both inputs are at the same potential, the output is exactly zero.
- Zero Slew Rate (SR = ∞): The output voltage can change instantaneously in response to an input step.
These parameters define the theoretical limit of op-amp performance, where the output voltage is expressed as vo = Av(v2 - v1).
What is an ideal active integrator? Explain its working with neat circuit diagram.
Answer
Sign in to view the complete answer paper.
Explain the working of op-amp as a comparator along with a neat diagram.
Answer
Sign in to view the complete answer paper.
Explain internal block diagram and operation of 555 timer.
Answer
Sign in to view the complete answer paper.
Design a band pass filter for cut off frequencies of 500 Hz and 1.5 kHz with a pass band gain of 4.
Answer
Sign in to view the complete answer paper.
Describe how PLL is used as FM demodulator? Also explain its operation with neat circuit diagram.
Answer
Sign in to view the complete answer paper.
Derive expression for the duty cycle of Astable multivibrator using IC 555 with a neat circuit and waveforms.
Answer
Sign in to view the complete answer paper.
Define important performance specifications of Digital to Analog converters and list their typical values.
Answer
Sign in to view the complete answer paper.
Draw the circuit of successive approximation A/D converter and explain its operation with an example.
Answer
Sign in to view the complete answer paper.
Explain the working of R-2R Ladder type D/A converter.
Answer
Sign in to view the complete answer paper.
With a neat diagram, explain the operation of Parallel comparator type ADC.
Answer
Sign in to view the complete answer paper.
Design a driving circuit for LED and which 74XX series IC is used for it.
Answer
Sign in to view the complete answer paper.
Draw the circuit and explain the operation of binary adder-subtractor.
Answer
Sign in to view the complete answer paper.
Explain the operation of synchronous RAM with the help of its internal architecture.
Answer
Sign in to view the complete answer paper.
Design a divide-by-6 ripple up counter using negative edge triggered T flip flop.
Answer
Sign in to view the complete answer paper.