Interfacing to the Analog World MCQs

Question 1

The process by which a computer acquires digitized analog data is referred to as ________.

Accepted Answer

data acquisition

Answer

monotonicity

Answer

analog resolution

Answer

systematic digital conversion

Question 2

Two principal advantages of the dual-slope ADC are its:

Accepted Answer

low sensitivity to noise and low cost.

Answer

high speed and low cost.

Answer

high sensitivity to noise and low cost.

Answer

low sensitivity to noise and high speed.

Question 3

________ are the most linear of all the temperature transducers.

Accepted Answer

IC temperature sensors

Answer

Thermistors

Answer

Thermocouples

Answer

Resistance temperature detectors

Question 4

The basic approach to testing D/A converters is to:

Accepted Answer

apply a sequence of binary codes covering the full range of input values to the circuit input while observing the output on an oscilloscope. The output should consist of a linear stairstep ramp.

Answer

single-step the device through its full input range while checking the output with a DMM.

Answer

check the output with zero input and then full input. The output of the converter should extend from zero to its maximum value. If so, then everything in between can be assumed to be operating properly.

Answer

apply the correct input to the analog terminal and then check to see if the proper binary code exists on the digital inputs.

Question 5

One major difference between a counter-ramp A/D converter and a successive-approximation converter is:

Accepted Answer

with the successive-approximation converter the final binary result is always slightly less than the equivalent analog input, whereas with the counter-ramp A/D converter it is slightly more

Answer

the counter-ramp A/D converter is much faster than the successive-approximation converter

Answer

with the successive-approximation converter the final binary result is always slightly more than the equivalent analog input, whereas with the counter-ramp A/D converter it is slightly less

Answer

none of the above

Question 6

What is the resolution of a D/A converter?

Accepted Answer

the reciprocal of the number of discrete steps in the D/A output

Answer

the comparison between the actual output of the converter and its expected output

Answer

the deviation between the ideal straight-line output and the actual output of the converter

Answer

the ability to resolve between forward and reverse steps when sequenced over its entire range

Question 7

What is the conversion time of a flash converter?

Accepted Answer

The conversion takes place continuously.

Answer

20 s

Answer

10 s

Answer

1 s

Question 8

What is the speed of the up/down digital-ramp ADC (tracking ADC)?

Accepted Answer

Relatively slow

Answer

20 s

Answer

10 s

Answer

1 s

Question 9

What is the major advantage of the R/2R ladder DAC as compared to a binary-weighted-input DAC?

Accepted Answer

It uses only two different resistor values.

Answer

It has fewer parts for the same number of inputs.

Answer

It is much easier to analyze its operation.

Answer

The virtual ground is eliminated and the circuit is therefore easier to understand and troubleshoot.