4.1.3 Integrated Circuits

Question 1

What are integrated circuits?

Answer 1

Combination of several electronic components in a common housing.

Question 2

What are some of the disadvantages of integrated circuits?

Answer 2

Cannot be repaired
Need additional cooling

Question 3

What are the three components normally integrated into an IC?

Answer 3

Semiconductors
Resistors
Capacitors

Question 4

What are logic circuits

Answer 4

created on ICs and are made up of individual logic gates, that when assembled, perform the desired function.

Question 5

What is used to construct logic gates?

Answer 5

Transistors

Question 6

What does the symbol x mean?

Answer 6

Physical switch (input)

Question 7

A switch in logic state 0 is what?

Answer 7

Open and therefore the system is off

Question 8

What is a NOT gate also known as?

Answer 8

Inverter

Question 9

What does a NOT gate do?

Answer 9

Invert the logic so that if the input is 0 then the output is 1.

Question 10

How does an AND gate work?

Answer 10

If all the inputs are 1.

Question 11

How does an OR gate work?

Answer 11

Only one input is required for an output.

Question 12

What is the boolean algebra for an OR gate?

Answer 12

X = A+B (+ signifies OR)

Question 13

What is a NAND gate?

Answer 13

Combination of AND and NOT, meaning AND must be met and then inverted.

Question 14

What is a NOR gate?

Answer 14

Inverted OR gate. Essentially always off unless there is zero input.

Question 15

What is an XOR gate?

Answer 15

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

Question 16

What are analogue integrated circuits?

Answer 16

Integrated circuits that operate over an entire range of continuous values of the signal amplitude

Question 17

What is a linear integrated circuit?

Answer 17

linear relationship between its voltage and current

Question 18

What is an example of a linear IC?

Answer 18

IC 741, eight pin dual inline package

Question 19

What is a radio frequency IC?

Answer 19

non-linear relation between its voltage and current.

Question 20

What is a linear circuit?

Answer 20

One where the input is directly proportional to the output.

Question 21

Where are linear circuits used?

Answer 21

These circuits are used in small signal amplifiers, differentiators, and integrators.

Question 22

What is the most used linear IC?

Answer 22

Operational amplifier (Op-Amp)

Question 23

What circuits are Op-Amps used in?

Answer 23

Signal processing circuits, control circuits, and instrumentation.

Question 24

What differs an OP-Amp from a transformer?

Answer 24

Unlike a transformer that can only amplify voltage or current, the Op-Amp also amplifies power output.

Question 25

How is pin 1 marked on a IC?

Answer 25

With a dot, starting on the left they are then numbered anti-clockwise.

Question 26

The + and - on the OP-Amp don't indicate polarity, what do they indicate?

Answer 26

The pin which has inverting input (-) and the pin with non-inverting input (+).

Question 27

If an OP-Amp has voltage inputs of +/-30Vdc what can the input swing by?

Answer 27

+/-15Vdc either side of 0

Question 28

When getting feedback from an Op-Amp, what happens when the loop is connected to the inverting side?

Answer 28

You get negative feedback.

Question 29

What is negative feedback?

Answer 29

gain of the amplifier decreases, but the stability and bandwidth increase and there is a decrease in distortion.

Question 30

What is the key idea of amplifiers?

Answer 30

They give us power gain

Question 31

How are Op-Amps defined?

Answer 31

By their uses: Inverters Buffers Differential Summing Comparator

Question 32

What is an inverting Op-Amp?

Answer 32

constant or fixed-gain amplifier producing a negative output voltage as its gain is always negative.

Question 33

What is a buffer (Voltage follower) Op-Amp?

Answer 33

voltage follower unity gain, a non-inverting buffer that requires only an operational amplifier.

Question 34

What is a differential Op-Amp?

Answer 34

voltage subtractor circuit that produces an output voltage proportional to the voltage difference of two input signals.

Question 35

What is a summing Op-Amp?

Answer 35

combine the voltages present on two or more inputs into a single output voltage.

Question 36

What is a comparator Op-Amp?

Answer 36

compares one analogue voltage level with another analogue voltage level or some preset and produces an output signal based on this voltage comparison

Question 37

What is an integrator Op-Amp?

Answer 37

Considers duration of the signal, main difference is the feedback loop is replaced with a capacitor.