ATO Test 4 Exam |72 Accurate Q’s and
A’s
Diode - -a uni-directional device which allows current to flow in one direction
- Semiconductor Materials - -offers less resistance to electron flow than
insulators, but more than conductors
- Most used semiconductors - -Silicon and Germanium
- Doping - -Process of adding impurities to semiconductor material
- Doping Process - -Restructures the semi conductor to require less energy
to produce current flow by lowering resistance of the material. (Allowing
more current)
- N-Type Semiconductor - -High concentration of electrons , majority
carriers of current.
Low concentration of holes, minority carriers of current
- P-Type Semiconductor - -High concentration of holes , majority carriers of
current.
Low concentration of electrons, minority carriers of current
- Recombination - -When an electron breaks free from another atom, it
leaves a hole.
- Bias - -after voltage is applied to a semiconductor, it directs the flow of
holes in electrons.
- (T/F) Holes and Electrons are present in both type materials. - -True
- Depletion Region - -The region created when the charge carriers (i.e.
electrons/holes) diffuse away.
- Forward Bias - -Offers very little resistance to current flow. Must have a
potential high enough to overcome barrier potential
- Reverse Bias - -Opposes current flow, so no current will flow. Voltage is
insufficient or bias polarities are reversed.
- Breakdown - -Excessive biased voltage. Causes bonds in the depletion
region to break apart.
, - Zener effect - -Reverse-bias breakdown below 6V
- Avalanche Effect - -Reverse bias breakdown above 6V
- Diode Types - -Junction Diodes
Light-Emitting Diodes (LEDs)
Zener Diodes
- Junction Diode - -Allows current to flow in one direction only .When voltage
is on, forward bias, it acts as a closed switch.
- Zener Diode - -Used to set a voltage reference or to regulate voltage.
When placed in reverse bias in a circuit it acts as a voltage regulator. I
forward bias it acts as a junction diode.
- A rapid increase of reverse bias current might destroy the diode unless the
______________ is placed in series with a zener diode. - -Current Limiting
Resistor
- Load resistance is - -A fixed value
- Light Emitting Diode (LED) - -Special type of p-n junction diode that emits
light when positive voltage is applied.
- When does the LED light up? - -When given a forward voltage rating
- Rectifiers - -Conducts very heavily when forward bias. Offers very high
resistance when reversed biased. Converts AC to pulsing DC.
- Switches (Signal Diode) - -Opens or closes a circuit in proper conditions.
Limits the amplitude.
- Clampar - -used to add a DC voltage level to a AC input signal. Caused by
fast charging and slow discharging.
- Shockley Diode - -A four layer, two electrode semiconductor diodes used
for producing trigger pulses when turned on.
- Two outermost materials are ____________, two innermost materials are
_____________. - -Forward biased, Reverse Biased.
- Silicon Controlled Rectifier (SCR) - -Essentially a Shockley diode with an
electrode (gate) connected to the internal P material.
- Conditions for destruction of a Diode - -Exceeding the max peak reverse
voltage rating.
A’s
Diode - -a uni-directional device which allows current to flow in one direction
- Semiconductor Materials - -offers less resistance to electron flow than
insulators, but more than conductors
- Most used semiconductors - -Silicon and Germanium
- Doping - -Process of adding impurities to semiconductor material
- Doping Process - -Restructures the semi conductor to require less energy
to produce current flow by lowering resistance of the material. (Allowing
more current)
- N-Type Semiconductor - -High concentration of electrons , majority
carriers of current.
Low concentration of holes, minority carriers of current
- P-Type Semiconductor - -High concentration of holes , majority carriers of
current.
Low concentration of electrons, minority carriers of current
- Recombination - -When an electron breaks free from another atom, it
leaves a hole.
- Bias - -after voltage is applied to a semiconductor, it directs the flow of
holes in electrons.
- (T/F) Holes and Electrons are present in both type materials. - -True
- Depletion Region - -The region created when the charge carriers (i.e.
electrons/holes) diffuse away.
- Forward Bias - -Offers very little resistance to current flow. Must have a
potential high enough to overcome barrier potential
- Reverse Bias - -Opposes current flow, so no current will flow. Voltage is
insufficient or bias polarities are reversed.
- Breakdown - -Excessive biased voltage. Causes bonds in the depletion
region to break apart.
, - Zener effect - -Reverse-bias breakdown below 6V
- Avalanche Effect - -Reverse bias breakdown above 6V
- Diode Types - -Junction Diodes
Light-Emitting Diodes (LEDs)
Zener Diodes
- Junction Diode - -Allows current to flow in one direction only .When voltage
is on, forward bias, it acts as a closed switch.
- Zener Diode - -Used to set a voltage reference or to regulate voltage.
When placed in reverse bias in a circuit it acts as a voltage regulator. I
forward bias it acts as a junction diode.
- A rapid increase of reverse bias current might destroy the diode unless the
______________ is placed in series with a zener diode. - -Current Limiting
Resistor
- Load resistance is - -A fixed value
- Light Emitting Diode (LED) - -Special type of p-n junction diode that emits
light when positive voltage is applied.
- When does the LED light up? - -When given a forward voltage rating
- Rectifiers - -Conducts very heavily when forward bias. Offers very high
resistance when reversed biased. Converts AC to pulsing DC.
- Switches (Signal Diode) - -Opens or closes a circuit in proper conditions.
Limits the amplitude.
- Clampar - -used to add a DC voltage level to a AC input signal. Caused by
fast charging and slow discharging.
- Shockley Diode - -A four layer, two electrode semiconductor diodes used
for producing trigger pulses when turned on.
- Two outermost materials are ____________, two innermost materials are
_____________. - -Forward biased, Reverse Biased.
- Silicon Controlled Rectifier (SCR) - -Essentially a Shockley diode with an
electrode (gate) connected to the internal P material.
- Conditions for destruction of a Diode - -Exceeding the max peak reverse
voltage rating.
