Integrated Circuits

Question 1

Draw the voltage ranges for transistors

Answer 1

Question 2

Draw a PNP transistor in
Phyiscal
Two-diode
Circuit Symbols

Answer 2

Question 3

Draw an NPN transistor in
Physical
Two-diode
Circuit Symbol

Answer 3

Question 4

What are the 3 regions of operation for BJT’s

Answer 4

Active - Amplifier
Saturation - ON
Cut Off - OFF

Question 5

What is an advantage of NMOS over PMOS

Answer 5

More dense, faster

Question 6

What is an advantage of CMOS over NMOS and PMOS?

Answer 6

Less dense, faster, lower power

Question 7

Is NMOS pull up or pull down?

Answer 7

Pull down

Question 8

Is PMOS pull up or Pull down?

Answer 8

Pull up

Question 9

What is a semi-conductor?

Answer 9

A device which has electrical conductivity between an insulator and a conductor. When a driving voltage is applied, it can flip open and closed to permit or deny the flow of current.

Question 10

What is Moores Law?

Answer 10

Transistor density doubles every 2 years

Question 11

List 3 types of chips

Answer 11

PLD
CPLD Complex Programmable Logic Devices
FPGA Field Programmable Gate Arrays

Question 12

Define Fan Out

Answer 12

The maximum number of standard logic inputs that can be fed from an output of the previous logic gate or transistor

Question 13

What can be used to increase fan out

Answer 13

buffer

Question 14

What is propagation delay?

Answer 14

Delay to switch a transistor from 0 to 1 or 1 to 0

Question 15

What is t_PLH?

Answer 15

Delay from 0 to 1

Question 16

What is T_PHL?

Answer 16

Delay from 1 to 0

Question 17

What is I_cc

Answer 17

Power supply current

Question 18

What is TTL

Answer 18

Transistor Transistor Logic

Uses BJT’s.

Question 19

What is the Fan Out of a BJT

Answer 19

Question 20

What is ECL?

Answer 20

Emitter Coupled Logic

Uses BJT’s kept below saturation to allow lower gate delays.

Question 21

What are some factors of ECL?

Answer 21

Transistors never saturate

-0.8V to -1.7V for 1 and 0

Large noise margin 250mV

Question 22

What are MOSFETs

Answer 22

Uses FET (Field Effect Transistors) with MOS (metal Oxide Semi Conductors)

Question 23

Draw a PMOS. If V_G = 0, is the gate On or Off?

Answer 23

Question 24

What happens if you apply a positive voltage to a PMOS? A negative voltage?

Answer 24

PMOS uses holes to conduct so applying a negative charge will attract holes, allowing it to conduct.

Ie its the opposite of the P.

Question 25

Draw an NMOS. When V_G = 0, is the gate open or closed?

Answer 25

Question 26

What is CMOS?

Answer 26

Uses both PMOS and NMOS to make combinational logic gates.

Question 27

What advantages and disadvantages of TTL?

Answer 27

PRO: Can be high speed or low power.

CON: Slow due to saturation

Question 28

What are advantages and disadvantages of ECL?

Answer 28

PRO: Fast because it does not saturate/
CON: High Power

Question 29

What are advantages and disadvantages of MOSFETs?

Answer 29

PRO: Cheap, dense, low power

CON: Slow