Electronics Flashcards
What is boolean algebra?
boolean algebra defines logic applied to anything that has only two states
How can logic and computers also be accomplished?
organically (DNA, neurons), or optically or chemically
What are the 7 Boolean laws?
- Idempotent Rule (Redundancy rule)
- Law of complemention
- Demorgans Law
- Commutative Law
- Distributive Law
- Associative Law
- Laws of absorption
What does Idempotent mean?
Same power
What is demorgans law also referred to as?
Alternate logic
How do you demorganize or determine the alternate logic for a gate?
- Invert the Inputs
- Change the gate (or sign)
- Invert the Output
What are the 2 levels of logic demorgans law can be applied to?
- Product of sums
- a sum of products
What is another way to demorganize?
“break the line and change the sign”
What is the rule for “break the line and change the sign” ?
you cannot break more than one line at a time but you can break one line more than once in a single step
What are the properties of human and machine in encoding and decoding?
Human :
- # ’s, letters, symbols (punctuation)
- video, audio
Machine :
- Binary, Octal, Hex, BCD, ASC11
How does encoding and decoding work?
Encoding = Human to Machine Decoding = Machine to Human
What are flip flops used as?
Memory devices
What is the most common gate used to make all other gates?
NAND (also the least power consumption)
If all flip flops have J and K tied high, what does this mean?
In toggle mode
What is another way of saying 16 combinations?
“modulus” 16 counter (MOD16)
What would a MOD16 counter count from?
0-15
For counting up, which output would you connect to?
Use Q and clear
For counting down, which output would you connect to?
use NOT Q and Preset
What is a Shift Register? What is an example?
a chain of Flip Flops used to move binary data from one location to another
Ex: calculator display is a “shift left” register
What is serial loading?
data is entered one bit at a time
what is data loading?
data is moved simultaneously with one pulse
what is serial out?
data is shifted out one bit at a time
what is parallel out?
data is shifted out all at once
What are the 4 types of Flip Flops? Which are synchronous and asynchronous?
- SR NOR & SR NAND - synchronous
- Clocked RS - asynchronous
- D-Type (Data FF) - asynchronous
- JK Flip Flop - asynchronous
What is an Astable Multivibrator?
Oscillator
What is a Monostable Multivibrator?
One-Shot
What is a Bistable Multivibrator?
Flip-Flop
What is another term for Flip Flop?
Latch
What is a 555 used for?
- Used for multivibrators (clocks, timers, etc..)
Which Flip Flop is most widely used?
J-K
If a J-K flip flop is in toggle position, what is the relationship between the clock pulses and output pulses?
Q is half the frequency of the clock
To allow normal operation of a J-K flip flop, Present and Clear must be ______?
High
What makes a Flip Flop synchronous?
If it has a clock signal
The clocked J-K flip flop is normally in which mode?
synchronous
Preset and Clear are called _________ inputs?
asynchronous
Flip Flops are wired together to form what kind of devices?
Counters, Registers
Name one application of the simple RS Flip Flop
Switch Debouncers
What is the essential difference in connections between an up counter and a down counter?
Up uses clear function
Down uses Preset function
How do you release the clear?
tie high
What do shift registers do in a simple calculator?
Store temporary data
What are the two common classifications of shift registers and state their advantages and disadvantages?
Serial - Slower but simple and less wiring
Parallel - Faster but more wiring and more complex
What are the 2 main types of logic gate families?
- CMOS
2. TTL
What does CMOS stand for?
Complementary Metal Oxide Semi-Conductor
What type of transistor does a CMOS use?
FET type transistors
What are some characteristics of CMOS?
- High efficiency with lower power consumption than TTL
How is the higher efficiency in CMOS achieved?
achieved using insulated gates however, the high impedance of the gates makes them susceptible to damage (destruction) from static electricity discharge
What precautions need to be taken when using CMOS?
- Grounding wrist bands with bonding leads to ground
- Grounded mats on work benches
- Static rated packing
What is the voltage supply of CMOS?
3 - 18V
What does TTL stand for?
Transistor-Transistor Logic
What type of transistors do TTLs use?
Bipolar junction transistors
What are some characteristics of TTLs? What is their supply voltage?
- More robust but not as efficient as CMOS
- 5V plus/minus .25V
What can subfamilies provide within both families?
- Faster speed
- Lower power consumption
- Wider operating temperature ranges
- Military specification (5400 TTL series)
What is the standard series for the TTL family?
7400
What do the last 2 digits refer to in the series number?
type of gates on the integrated circuit (IC)
What series are including in the CMOS family?
4000A and 4000B series
what is integrated circuit Pin Out?
how the gates are connected to the pins of the IC
what is integrated circuit Fan Out?
the number of gates that an output of a gate can drive
What is the typically number of Fan Outs for each family?
CMOS = 50 TTL = 10
What must the NAND gate fan out be?
greater than or equal to 5
What are some common packages for CPU’s?
- Pin Grid Array (Pins are 0.1” apart)
- LAND Grid Array (Pins are .05” apart)
Both of these are zero insertion force sockets (clamped down)
What are some Operational Amplifier characteristics?
- Relatively low power amplifier (about .5 watts)
- Used as building blocks for industrial purposes
- Comparators, integrators, differentiators
- Pre packaged opposed to discrete devices
What is the gain, input impedance, output impedance and bandwidth dependant on in an OP Amp?
the external components we connect
What are the two different inputs in an Op Amp?
Inverting ( - )
Non-Inverting ( + )
the output is _______ times the difference between the inputs
200,000 times
What does the comparator Output do?
Swings from fully on to fully off if no feedback is provided and the input voltages differ by very little (0.001V)
Explain a specialized integrator?
Vout varies with how long the input has been applied
Explain a specialized differentiator?
Vout varies with how quickly the input is changing
What is meant by the term noise margin as applied to logic gates?
difference between valid input and output for highs and for lows
What should be done with an unused input to an OR gate?
Tied low or to another input
What should be done with an unused input to an AND gate?
Tied high or to another input
