CHAPTER 3 SPECIAL- PURPOSE DIODES

CHAPTER 3
SPECIAL- PURPOSE DIODES

1. Diodes that were designed to operate in reverse breakdown
Zener diode

2. A device that operates in reverse bias
photodiode

3. A zener diode operating in breakdown acts as a
Voltage regulator
4. A positive temperature means that the zener voltage
Increases with an increase in temperature on decreases with decrease in temperature.

5. A diode that always operates in reverse-bias and is doped to maximize the inherent capacitance of the depletion region is
Laser

6. When the light-emitting diode (LED) is forward-biased, __________pass the pn junction and recombine with____________ in the _________material.
Electrons, holes, p-type

7. The first visible red LEDs were produced using
GaAsp

8. The normalized output of the visible red, yellow, green and blue LED peaks at __________________ (nm) respectively.
660,590,540, and 460

9. Organic LEDs and LEDs produce light through the process of __________ and ___________ respectively.
Electrophophorescence and electroluminescence

10. An increase in the amount of light intensity produces an increase in
Reverse current

11. A diode that can be used as a variable-resistance device controlled by light intensity.
Photodiode

12. A diode that operates only with majority carriers
Schottky diode

13. A diode that takes advantage of the variable forward resistance characteristic.
PIN diode

14. No reverse leakage current
Schottky diode

15. Diode used in VHF and fast switching applications
Step- Recovery diode

16. When a PIN diode is forward-biased, it acts like a
Current-controlled variable resistance

17. If a tunnel diode is placed in series with the tank circuit and biased at the center of the negative-resistance portion of its characteristic curve, a _________ will result in the output.
Constant sinusoidal voltage

18. The tunnel diode is only used at
VHF

19. In a varactor diode, what happens to the capacitance if the reverse-bias voltage decreases
a. Increases

20. The varactor capacitance ratio is also known as
a. Tuning ratio

CHAPTER 2 DIODE APPLICATIONS

CHAPTER 2
DIODE APPLICATIONS

1. An open primary or secondary winding of a power supply transformer results in
0 V

2. The output frequency of a half-wave rectifier is _________to/of the input frequency
Equal

3. What is the average value of the half-wave rectified voltage given 25 V as its peak amplitude?
7.95 V

4. The PIV rating of the bridge diodes is __________to/than that required for the center-tapped configuration.
Less
5. Diode circuits used to clip off portions of signal voltages above or below certain levels,
Clippers

6. The output frequency of a full-wave rectifier is ________ the input frequency
Twice

7. A transformer is generally specified based on _____________rather than the turns ratio,
Secondary voltage
8. The period of a full-wave rectified voltage is ____________ that of a half-wave rectified voltage
Half

9. The indication of the effectiveness of the filter is called
Ripple factor

10. Eliminates the fluctuations in the rectified voltage and produces a relatively smooth dc voltage
Filter

11. Circuit that maintains a constant dc voltage for variations in the input line voltage or in the load
Regulator

12. A type of full-wave rectifier that uses two diodes connected to the secondary of a center-tapped transformer
Center-tapped rectifier

13. Use clamping action to increase peak rectified voltages without the necessity of increasing the transformer’s voltage rating
Voltage multipliers

14. Maximum voltage appearing across the diode in reverse bias
PIV

15. Caused by the charging and discharging of the filter capacitor
Ripple voltage

16. A systematic process of isolating, identifying, and correcting a fault in a circuit or system
Troubleshooting

17. Allows unidirectional current through the load during the entire 360° of the input cycle
Full-wave rectifier

18. Allows current through the load only during one-half of the cycle.
Half-wave rectifier

19. Generally used because of the surge current that initially occur s when power is first turned on
Slow-blow type fuse

20. A figure of merit used to specify the performance of a voltage regulator
regulation