4.1.2-4.2 transistors integrated circuits and PCB Flashcards
What are the 5 types of transistors?
BJT Bipolar Junction transistor
UJT unijunction transistor
Phototransistor
JFET junction field affect transistor
MOSFET metal oxide semiconductor field effect transistor
What is a transistor used for?
Switching and controlling a current in a circuit
How many junctions does a BJT have?
Three
If the arrow is pointing inwards (emitter) on a BGT is this PNP or NPN?
PNP
What are the two junction transistors?
UJT and BJT
How many depletion areas are there on a BGT?
Two with three parts of P+N type semiconductor material
How is current controlled in an FET?
By the action of an electron field
What are BJT’s predominantly used for?
Amplification and switching
What is an integrated circuit
Combination of several electronic components in common housing
What are the three advantages of ICS?
Very high density of components
Very compact
Quite resistant mechanical stress
What are the two disadvantages of ICS?
Small housing or requires heat sink for cooling
Cannot be repaired faulty IC must be replaced
What three components can be integrated into an IC?
Semiconductor (transistor and diode)
Resistors
Capacitors
ICS can be found in what type of appliances?
All modern appliances, both analog and digital
What are the three basic logic gates?
NOT
AND
OR
What is an NOT logic gate commonly known as?
An inverter
Is radio frequency integrated circuit linear or non-linear?
Non-linear
What is the main purpose of an operational amplifier?
Integrated circuit that can amplify weak electrical signals
How many voltage supplies does an amp have?
2 DC voltage supplies
What is at the input and output stages of an operational amplifier?
Input stage differential amplifier
Output stage push pull power amplifier
How would you receive positive feedback?
Connecting output to the positive terminal input
(connecting to negative terminal gives negative feedback)
What are the most common uses of an operational amplifier? (5)
Inverters
Buffers
Differential
Summing
Comparative
What does an inverter do to the input?
Invert the input
What is the main purpose of a differential op amp?
It is a voltage subtracter
What is the main purpose of a printed circuit board (PCB)?
It is a mounting surface which physically supports electrical circuit components
What are the two main materials used for PCB?
Copper laminated paper treated with epoxy resin
Copper laminated glass silk weave reinforced with fibreglass
Why is epoxy resin used with copper laminated paper?
For its flame resistant properties
What two main steps are there in producing a PCB?
Patterning- circuit diagram into pattern using CAD
Printing - pattern to PCB
What are the two methods of printing the pattern to the PCB?
Etching method
Addition method
What’s printing method works by dipping the PCB into an acidic solution?
Etching method
What is the main difference between single sided board and double sided board?
Single sided board has wiring on one side components on reverse
Double sided board has wiring on both and may have components on both sides
What is the disadvantage of multi layer board?
Internal plane act as a heat sink
When would automatic or mass soldering be required?
For mass batch production of PCB
What are these and advantage for?
Smaller parts
Denser layout
Cheaper PCB
Improve shock and vibration
Shielding from EMI
SMT surface mount
What is SMT also known as?
Planar mounting
