Chapter 5 : Semiconductor Components Flashcards
Name the 3 different types of diodes
Silicon diode
Zener diode
LED
Draw the symbol for a silicon diode?
Triangle with a line at the top
Draw the symbol for a zener diode
Silicon diode but the line is longer
Draw the symbol for a LED
Silicon diode, with two arrows coming from it
How much is the voltage drop across a silicon diode during forward bias?
0.7V
For a silicon diode, what is the reverse bias current?
0A
What are the applications for a silicon diode?
1.Protection against back emf
2. Protection against reverse polarity
3. Rectification of AC
What is ‘back emf’?
When the current flowing through an inductor is switched off, it generates a high voltage in the opposite direction.
How can back emf be stopped on a MOSFET or transistor circuit?
Diode in parallel with the load
When does a zener diode begin to conduct?
When the reverse voltage across it rises too far
What is the forward bias voltage of a zener diode?
0.7V
Reverse bias zener diode voltages are specific values. List 3.
3.3V 5.1V 5.6V
The transistor has 3 terminals, what are they?
Collector (top)
Base (middle)
Emitter (bottom)
What is the voltage drop across a transistor?
0.7V
State the equation associated with transistor gain?
Ic=hfe x Ib
What are the units for transistor gain?
no units
What voltage does a transistor saturate?
0V
Whenever a load is connected to a voltage divider circuit, does the output voltage increase or decrease?
The output voltage will drop
What are the 3 things that need to be calculated in order to create Thevenin’s equivalent circuit
The open circuit voltage
The short circuit current
Resistance equivalent
How do you calculate open circuit voltage?
Potential divider equation
How do you calculate short circuit current
Vs/R1
How do you calculate equivalent resistance for thevenin
Voc/Isc
What is the rule of thumb for current regarding voltage divider circuit?
The current drawn by the load should be at least ten times smaller than the current flowing through the voltage divider?
What is the input current of a MOSFET?
0A
The MOSFET will be off, when the gate voltage is…?
Zero
What are the three terminals in a MOSFET?
Drain (top)
Gate (middle)
Source (bottom)
What is the equation used to calculate drain current?
Id=gm(Vgs-3)
gm=transconductance
What are the units for transconductance (gm)
Siemens (S)
What input voltage is required to turn a MOSFEt on?
3V
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