Digital Electronics - Interfacing to the Analog World

Exercise : Interfacing to the Analog World - General Questions
26.
When comparing the conversions from digital-to-analog and analog-to-digital, the A/D conversion is generally:
less complicated but more time consuming than the D/A conversion.
more complicated and more time consuming than the D/A conversion.
less complicated and less time consuming than the D/A conversion.
more complicated but less time consuming than the D/A conversion.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

27.
Which of the statements below best describes the basic operation of a dual-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.
Two ramps are generated: one by the input voltage and the other by a reference voltage. The input voltage ramp charges the integrating capacitor, while the reference voltage discharges the capacitor and enables the counter until the capacitor is discharged, at which time the counter value is loaded into the output latches.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

28.
The output of a basic 4-bit input digital-to-analog converter would be capable of outputting:
16 different values of voltage or current that are not proportional to the input binary number
16 different values of voltage or current that are proportional to the input binary number
32 different values of voltage or current that are not proportional to the input binary number
32 different values of voltage or current that are proportional to the input binary number
Answer: Option
Explanation:
No answer description is available. Let's discuss.

29.

Referring to the given figure, what appears to be wrong, if anything, with the D/A converter and what should be done to correct the problem?

There is nothing wrong with the converter.
There is an offset error; if no provision is made for adjusting the offset, the op-amp may need to be changed.
There is a nonlinearity error; the op-amp must be changed.
The power supply voltage appears to be too high; adjust the power supply to the correct value.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

30.
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.
Answer: Option
Explanation:
No answer description is available. Let's discuss.