Q.1

A transducer is a device that:

  • converts a physical variable to an electrical variable
  • converts analog data to meaningful data
  • controls a physical variable
  • stores digital data and then processes that data according to a set of specified instructions
Q.2

When analog inputs from several sources are to be converted, a(n) ________ technique can be used.

  • demultiplexing
  • multiplexing
  • R/2R
  • comparator
Q.3

The delay between a change on the digital input of a DAC and the appearance of the change on the output is called settling time.

  • True
  • False
Q.4

The main advantage of the SAR ADC method is its high speed.

  • True
  • False
Q.5

The circuit shown below is a(n) ________.

  • R/2R ladder D/A converter
  • four-bit decoder
  • binary-weighted-input DAC
  • four-bit A/D converter
Q.6

An analog quantity varies from 0–7 V and is input to a 6-bit A/D converter. What analog value is represented by each step on the digital output?

  • 0.111 V
  • 1.17 V
  • 0.109 V
  • 0.857 V
Q.7

How many different voltages can be output from a DAC with a 6-bit resolution?

  • 6
  • 16
  • 32
  • 64
Q.8

A 4-bit R/2R D/A converter has a reference of 5 V. What is the analog output for the input code 0101?

  • 3.125 V
  • 0.3125 V
  • 0.78125 V
  • –3.125 V
Q.9

One way to determine the resolution of a DAC is to calculate the ratio of one step voltage to the maximum output voltage.

  • True
  • False
Q.10

Which of the following describes the basic operation of a single-slope A/D converter.

  • The input voltage is used to set the frequency of a voltage-controlled oscillator (VCO). The VCO quits changing frequency when the input voltage stabilizes. The frequency of the VCO, which is proportional to the analog input voltage, is measured and is displayed on the digital display as a voltage reading.
  • A ramp generator is used to enable a counter through a comparator. When the ramp voltage equals the input voltage the counter is latched and then reset. The counter reading is proportional to the input voltage since the ramp is changing at a constant V/second rate.
  • A ramp voltage and analog input voltage are applied to a comparator. As the input voltage causes the integrating capacitor to charge, it will at some point equal the ramp voltage. The ramp voltage is measured and displayed on the digital panel meter.
  • Any of the above could be correct, depending on the specific type of A/D converter involved.
Q.11

The stability of the ADC process can be improved by using a(n) ________ to hold the analog voltage constant while the A/D conversion is taking place.

  • sample-and-hold circuit
  • op-amp comparator
  • NPN amp
  • current loop
Q.12

The stability of the ADC process can be improved by using a(n) ________ to hold the analog voltage constant while the A/D conversion is taking place.

  • sample-and-hold circuit
  • op-amp comparator
  • NPN amp
  • current loop
Q.13

The output voltage or current of a digital-to-analog converter is truly an analog signal.

  • True
  • False
Q.14

The characteristic that a change of one binary step on the input of a DAC should cause exactly one step change on the output is called ________.

  • resolution
  • linearity
  • monotonicity
  • accuracy
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