Deck 21: Discrete and Integrated Voltage Regulators

Question 1

What type of IC voltage regulator requires both positive and negative input voltages?

A) The fixed-negative regulator
B) The adjustable regulator
C) The variable polarity regulator
D) The dual-tracking regulator

Answer 1

The dual-tracking regulator

Question 2

A voltage regulator has an output that changes by 2 μV when its input changes by 10 V. The line regulation rating of the device is

A) 0.02 μV/V.
B) 50 μV/V.
C) 20 μV/V.
D) 9.998 V/V.

Answer 2

0.02 μV/V.

Question 3

The the load regulation rating of a voltage regulator, the higher the quality of the circuit.

A) lower
B) higher

Answer 3

lower

Question 4

A voltage regulator has the following ratings: Vin = 10 Vdc to 15 Vdc, IL = 20 mA maximum), and regulation = 0.01%. Which of the following statements is true?

A) The load current demand on the regulator cannot exceed 20 mA.
B) The rated output voltage must be some value that is less than 10 Vdc.
C) The rated output voltage falls somewhere between 10 Vdc and 15 Vdc.
D) As long as the input voltage remains within its rated range, Vout will equal 0.01% of Vin.

Question 5

Shunt voltage regulators require

A) shorted-load protection.
B) overvoltage protection.
C) high-frequency protection.
D) open-load protection.

Question 6

What is the purpose of RS?

A) It provides shorted load protection
B) It provides biasing current for Q1
C) It provides current for the zener diode
D) It reduces the power dissipated by the transistor

Question 7

The diode in the filter and clipping section of the switching power supply provides for the power switch.

A) rectification
B) current limiting
C) transient protection

Question 8

Q₁ in Figure is called a transistor.

A) pass
B) line
C) series
D) regulator

Question 9

Switching voltage regulator supplies

A) are not very efficient.
B) usually get very warm.
C) are very cool running and efficient.
D) have a simple circuit design.

Question 10

A disadvantages of switching regulator power supplies are their complex design and transmission of noise into the surrounding environment.

Question 11

The ideal voltage regulator maintains a constant dc output voltage despite anticipated changes in

A) its input voltage.
B) its output voltage demand.
C) its load current demand.
D) its load current demand and/or its input voltage.

Question 12

Which of the following best describes the circuit in Figure?

A) Series-pass regulator with voltage feedback
B) Shunt regulator with voltage feedback
C) Series-pass regulator without voltage feedback
D) Shunt regulator without voltage feedback

Question 13

Regulator A has a line regulation rating of 4 %/V. Regulator B has a line regulation rating of 15 ppm/V. Assuming that both are rated for a 10 Vdc output voltage, which is the better regulator?

A) Regulator A
B) Regulator B

Question 14

The regulated output voltage from the circuit in Figure is

A) 10.7 V.
B) 10 V.
C) 9.3 V.
D) equal to the difference between Vin and the zener voltage rating.

Question 15

The ideal line regulation rating is

A) extremely high.
B) in the range of 1 μV/V to 20 μV/V.
C) in the range of 0.1 μV/V to 1 μV/V.
D) zero.

Question 16

Switching regulators have power handling capability than linear regulators.

A) higher
B) lower
C) the same

Question 17

A voltage regulator is rated for an output range of IL = 0 to 40 mA. Under no-load conditions, the output voltage from the circuit is 4 Vdc. Under full-load conditions, the output voltage from the circuit is 3.984 Vdc. What is the load regulation rating of the circuit?

A) 400 μV/mA
B) 2.5 mV/mA
C) 0.4 Ω
D) Both 400 μV/mA and 0.4 Ω are correct.

Question 18

The ability of an IC voltage regulator to attenuate any input ripple voltage is called its rating.

A) ripple attenuation
B) ripple reduction
C) ripple rejection
D) ripple elimination

Question 19

Which of the following is not a type of IC voltage regulator?

A) Fixed negative
B) Adjustable
C) Variable polarity
D) Dual-tracking

Question 20

Both linear and switching regulators can function as step-up regulators.

Question 21

Using a signal to vary the pulse width of a rectangular wave without affecting its cycle time is called .

A) variable off-time modulation
B) pulse width modulation
C) power switch conduction
D) None of the above.

Question 22

A switching power supply has the following values: Vin = 18 Vdc, Ton = 4 ms, and Toff = 8 ms. What is the value of Vout for the circuit?

A) 27 Vdc
B) 9 Vdc
C) 6 Vdc
D) 12 Vdc

Question 23

Which type of voltage regulator would use a crowbar?

A) Series-pass regulator
B) Shunt regulator
C) Switching regulator
D) None of the above.

Question 24

A dual-polarity power supply would use a regulator.

A) Fixed-positive regulator
B) Fixed-negative regulator
C) Dual-tracking regulator
D) Both A and B

Question 25

is a rating that indicates the change in regulation output voltage that occurs per unit change in input voltage.

A) Regulation
B) Line regulation
C) Load regulation
D) Series regulation