Block 2 - lecture 5

Question 1

downside of analog to digital conversion?

Answer 1

accuracy is usually lost

Question 2

upside of analog to digital conversion?

Answer 2

• more immune to noise

- more immune to power supply drift

Question 3

how to decide on logic gates to use for an alarm?

Answer 3

• denote variables and write out the alarm conditions in logic equation
• simplify equation (ideally with to just nor and nand gates

Question 4

What’s the bus?

Answer 4

the connection of the digital lines

Question 5

information in the bus?

Answer 5

• data lines
• address lines
• control lines

Question 6

data lines?

Answer 6

carry data between processors

Question 7

Address lines

Answer 7

used to select external locations for input and output

Question 8

control lines?

Answer 8

instructions for operations, eg. reading, writing and interrupts

Question 9

output of a comparator?

Answer 9

±15V for an op-amp

0V to 5V possible

Question 10

TTL logic levels for inputs and outputs

Answer 10

Vin: 0< 0.8V, 1> 2V
Vout: 0< 0.4V, 1> 2.4V

Question 11

how can a comparator with an open-collector output be used?

Answer 11

using a pull-up resistor

output = 0.2V or Vcc

Question 12

hysteresis comparator?

Answer 12

comparator with a feedback resistor to Vin

Once triggered, the input is raised, thus needs to be lower for the output to drop

Question 13

equation for hysteresis comparator deadband?

Answer 13

(R/Rf)*Vout