Q.1

Which of the following characterizes an analog quantity?

  • Discrete levels represent changes in a quantity.
  • Its values follow a logarithmic curve.
  • It can be described with a finite number of steps.
  • It has a continuous set of values over a given range.
Q.2

Which of the following characterizes an analog quantity?

  • Discrete levels represent changes in a quantity.
  • Its values follow a logarithmic response curve.
  • It can be described with a finite number of steps.
  • It has a continuous set of values over a given range.
Q.3

If the range of output voltage of a 6-bit DAC is 0 to 15 volts, what is the step voltage of the output?

  • 0.117 volt/step
  • 0.234 volt/step
  • 2.13 volts/step
  • 4.26 volts/step
Q.4

Inaccurate A/D conversion may be due to:

  • constant analog input voltage
  • linear ramp usage
  • intermittent counter inputs
  • faulty sample-and-hold circuitry
Q.5

A certain digital-to-analog converter has a step size of 0.25 V and a full-scale output of 7.75 V. Determine the percent of resolution and the number of input binary bits.

  • 31%, 4 bits
  • 3.23%, 4 bits
  • 31%, 5 bits
  • 3.23%, 5 bits
Q.6

What is the resolution of a D/A converter?

  • the comparison between the actual output of the converter and its expected output
  • the reciprocal of the number of discrete steps in the D/A output
  • the deviation between the ideal straight-line output and the actual output of the converter
  • the ability to resolve between forward and reverse steps when sequenced over its entire range
Q.7

What is the purpose of a sample-and-hold circuit?

  • To keep temporary memory
  • To hold a voltage constant so an ADC has time to produce an output
  • To hold a voltage constant so a DAC has time to produce an output
  • To hold data after a multiplexer has selected an output
Q.8

What is the disadvantage to using a counter-ramp type ADC?

  • complex circuit
  • high cost
  • very slow
Q.9

Three characteristics of op amps make them almost ideal amplifiers: very high input impedance, very low impedance, and ________.

  • very high voltage gain
  • unlimited bandwidth
  • a low slew rate
  • very high current gain
Q.10

What is the resolution, in percent, of a 12-bit DAC?

  • 8.33
  • 0.049
  • 0.000488
  • 0.083
Q.11

Why is a binary-weighted DAC usually limited to 4-bit binary conversion?

  • too many pins on the IC
  • too many op amps needed
  • too many different values of capacitors
  • too many different values of resistors
Q.12

A 4-bit stairstep-ramp A/D converter has a clock frequency of 100 kHz and a maximum input of 10 V, and has 6 V applied to the input. The conversion time will be ________.

  • 10 microseconds
  • 160 microseconds
  • 90 microseconds
  • 6250 seconds
Q.13

A counter-ramp ADC uses a comparator to compare the input voltage with ________.

  • a binary number
  • the output of a counter
  • the output of a DAC
  • a voltage divider network
Q.14

A simultaneous A/D converter is also known as a(n) ________ A/D converter.

  • flash
  • synchronous
  • comparator
  • asynchronous
Q.15

Sample-and-hold circuits in A/D converters are designed to:

  • sample and hold the output of the binary counter during the conversion process
  • stabilize the comparator's threshold voltage during the conversion process
  • stabilize the input analog signal during the conversion process
  • sample and hold the D/A converter staircase waveform during the conversion process
Q.16

What circuitry is on an ADC0808 IC?

  • A multiplexer
  • An ADC
  • A 3-bit select input code
  • All of the above
Q.17

What is the resolution of a D/A converter?

  • It is the reciprocal of the number of discrete steps in the D/A output.
  • It is the comparison between the actual output of the converter and its expected output.
  • It is the deviation between the ideal straight-line output and the actual output of the converter.
  • It is the converter's ability to resolve between forward and reverse steps when sequenced over its entire range of inputs.
Q.18

A major application for DSP is in ________ and ________ of analog signals.

  • sending, receiving
  • digitizing, weighting
  • filtering, conditioning
  • leveling, translating
Q.19

A simultaneous A/D converter is also known as a(n) ________ A/D converter.

  • flash
  • synchronous
  • comparator
  • asynchronous
Q.20

A binary-weighter resistor DAC is practical only up to a resolution of ________.

  • 10 bits
  • 2 bits
  • 8 bits
  • 4 bits
Q.21

________ ADCs have a fixed value of conversion time that is not dependent on the value of the analog input.

  • Substandard
  • Dual
  • Recessive-approximation
  • Successive-approximation
Q.22

________ ADCs use no clock signal, because there is no timing or sequencing required.

  • Actuator
  • Dual
  • Flash
  • Bipolar
Q.23

________ ADCs use no clock signal, because there is no timing or sequencing required.

  • Actuator
  • Dual
  • Flash
  • Bipolar
Q.24

If the range of output voltage of a 6-bit DAC is 0 to 15 volts, what is the step voltage of the output?

  • 0.117 volt/step
  • 0.234 volt/step
  • 2.13 volts/step
  • 4.26 volts/step
Q.25

Sample-and-hold circuits in A/D converters are designed to:

  • sample and hold the output of the binary counter during the conversion process
  • stabilize the comparator's threshold voltage during the conversion process
  • stabilize the input analog signal during the conversion process
  • sample and hold the D/A converter staircase waveform during the conversion process
Q.26

What is the main disadvantage of the counter-ramp A/D converter?

  • It requires a counter.
  • The counter must count up from zero at the beginning of each conversion sequence, and the conversion time will vary depending on the input voltage.
  • It requires a precision clock in order for the conversion to be reliable.
  • The counter must count up from zero at the beginning of each conversion sequence, and the conversion time will vary depending on the input voltage. It requires a precision clock in order for the conversion to be reliable.
Q.27

What is the maximum conversion time for an 8-bit successive-approximation ADC with a clock frequency of 20 kHz?

  • 12.8 ms
  • 6.4 ms
  • 0.05 ms
  • 0.4 ms
Q.28

The fastest analog-to-digital converter is the ________.

  • counter ADC
  • successive-approximation ADC
  • dual slope ADC
  • parallel ADC
Q.29

The DSO ________, ________, and ________ analog waveforms.

  • filters, conditions, sends
  • levels, stores, weighs
  • sends, receives, translates
  • digitizes, stores, displays
Q.30

A simultaneous A/D converter is also known as a(n) ________ A/D converter.

  • flash
  • synchronous
  • comparator
  • asynchronous
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