1

GATE ECE 2016 Set 2

MCQ (Single Correct Answer)

+2

-0.6

In an N bit flash ADC, the analog voltage is fed simultaneously to 2

^{N}− 1 comparators. The output of the comparators is then encoded to a binary format using digital circuits. Assume that the analog voltage source V_{in}(whose output is being converted to digital format) has a source resistance of 75 Ω as shown in the circuit diagram below and the input capacitance of each comparator is 8 pF. The input must settle to an accuracy of 1/2 LSB even for a full scale input change for properconversion. Assume that the time taken by the thermometer to binary encoder is negligible. If the flash ADC has 8 bit resolution, which one of the following alternatives is closest to the maximum sampling rate?2

GATE ECE 2008

MCQ (Single Correct Answer)

+2

-0.6

In the following circuit, the comparator output is logic “I” if V

_{1}> V_{2}and is logic “0” otherwise. The D/A conversion is done as per the relation $$${V_{DAC}} = \sum\limits_{n = 0}^3 {{2^{n - 1}}{b_n}\,\,} Volts,$$$ where b_{3}(MSB), b_{2}, b_{1}and b_{0}(LSB) are the counter outputs.The counter starts from the clear state.

The magnitude of the error between V_{DAC} and V_{in} at steady state in volts is

3

GATE ECE 2008

MCQ (Single Correct Answer)

+2

-0.6

In the following circuit, the comparator output is logic “I” if V

_{1}> V_{2}and is logic “0” otherwise. The D/A conversion is done as per the relation $$${V_{DAC}} = \sum\limits_{n = 0}^3 {{2^{n - 1}}{b_n}\,\,} Volts,$$$ where b_{3}(MSB), b_{2}, b_{1}and b_{0}(LSB) are the counter outputs.The counter starts from the clear state.

The stable reading of the LED display is

4

GATE ECE 2007

MCQ (Single Correct Answer)

+2

-0.6

In the digital-to-Analog converter circuit shown in the figure below,

$${V_{R\,}}\, = \,10V$$ and $$R\, = \,10k\Omega $$

$${V_{R\,}}\, = \,10V$$ and $$R\, = \,10k\Omega $$

The current i is

Questions Asked from Analog to Digital and Digital to Analog Converters (Marks 2)

Number in Brackets after Paper Indicates No. of Questions

GATE ECE Subjects

Signals and Systems

Representation of Continuous Time Signal Fourier Series Fourier Transform Continuous Time Signal Laplace Transform Discrete Time Signal Fourier Series Fourier Transform Discrete Fourier Transform and Fast Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Discrete Time Linear Time Invariant Systems Transmission of Signal Through Continuous Time LTI Systems Sampling Transmission of Signal Through Discrete Time Lti Systems Miscellaneous

Network Theory

Control Systems

Digital Circuits

General Aptitude

Electronic Devices and VLSI

Analog Circuits

Engineering Mathematics

Microprocessors

Communications

Electromagnetics