4.1.3 Integrated Circuits Flashcards
What are integrated circuits?
Combination of several electronic components in a common housing.
What are some of the disadvantages of integrated circuits?
Cannot be repaired
Need additional cooling
What are the three components normally integrated into an IC?
Semiconductors
Resistors
Capacitors
What are logic circuits
created on ICs and are made up of individual logic gates, that when assembled, perform the desired function.
What is used to construct logic gates?
Transistors
What does the symbol x mean?
Physical switch (input)
A switch in logic state 0 is what?
Open and therefore the system is off
What is a NOT gate also known as?
Inverter
What does a NOT gate do?
Invert the logic so that if the input is 0 then the output is 1.
How does an AND gate work?
If all the inputs are 1.
How does an OR gate work?
Only one input is required for an output.
What is the boolean algebra for an OR gate?
X = A+B (+ signifies OR)
What is a NAND gate?
Combination of AND and NOT, meaning AND must be met and then inverted.
What is a NOR gate?
Inverted OR gate. Essentially always off unless there is zero input.
What is an XOR gate?
Modified OR gate, there can only be one input for it to be on, if they’re both off or On then it is off
What are analogue integrated circuits?
Integrated circuits that operate over an entire range of continuous values of the signal amplitude
What is a linear integrated circuit?
linear relationship between its voltage and current
What is an example of a linear IC?
IC 741, eight pin dual inline package
What is a radio frequency IC?
non-linear relation between its voltage and current.
What is a linear circuit?
One where the input is directly proportional to the output.
Where are linear circuits used?
These circuits are used in small signal amplifiers, differentiators, and integrators.
What is the most used linear IC?
Operational amplifier (Op-Amp)
What circuits are Op-Amps used in?
Signal processing circuits, control circuits, and instrumentation.
What differs an OP-Amp from a transformer?
Unlike a transformer that can only amplify voltage or current, the Op-Amp also amplifies power output.
How is pin 1 marked on a IC?
With a dot, starting on the left they are then numbered anti-clockwise.
The + and - on the OP-Amp don’t indicate polarity, what do they indicate?
The pin which has inverting input (-) and the pin with non-inverting input (+).
If an OP-Amp has voltage inputs of +/-30Vdc what can the input swing by?
+/-15Vdc either side of 0
When getting feedback from an Op-Amp, what happens when the loop is connected to the inverting side?
You get negative feedback.
What is negative feedback?
gain of the amplifier decreases, but the stability and bandwidth increase and there is a decrease in distortion.
What is the key idea of amplifiers?
They give us power gain
How are Op-Amps defined?
By their uses:
Inverters
Buffers
Differential
Summing
Comparator
What is an inverting Op-Amp?
constant or fixed-gain amplifier producing a negative output voltage as its gain is always negative.
What is a buffer (Voltage follower) Op-Amp?
voltage follower unity gain, a non-inverting buffer that requires only an operational amplifier.
What is a differential Op-Amp?
voltage subtractor circuit that produces an output voltage proportional to the voltage difference of two input signals.
What is a summing Op-Amp?
combine the voltages present on two or more inputs into a single output voltage.
What is a comparator Op-Amp?
compares one analogue voltage level with another analogue voltage level or some preset and produces an output signal based on this voltage comparison
What is an integrator Op-Amp?
Considers duration of the signal, main difference is the feedback loop is replaced with a capacitor.
