Digital Circuits Questions and Answers Part-17

1. Semiconductors are made of ____________
a) Ge and Si
b) Si and Pb
c) Ge and Pb
d) Pb and Au

Answer: a
Explanation: Semiconductors are made of Silicon (Si) and Germanium (Ge). Semiconductors are devices having conductivity between conductors and insulators.

2. Which chip were the first RTC and CMOS RAM chip to be used in early IBM computers, capable of storing a total of 64 bytes?
a) The Samsung 146818
b) The Samsung 146819
c) The Motorola 146818
d) The Motorola 146819

Answer: c
Explanation: The Motorola 146818 was the first RTC and CMOS RAM chip to be used in early IBM computers; capable of storing a total of 64 bytes.

3. BiCMOS is an evolved semiconductor technology that integrates two formerly separate semiconductor technologies those of the _____________
a) CMOS and FET
b) MOSFET and CMOS
c) BJT and CMOS
d) BJT and MOSFET

Answer: c
Explanation: BiCMOS is an evolved semiconductor technology that integrates two formerly separate semiconductor technologies those of the BJT and CMOS. CMOS ensures low power dissipation, smaller noise margin and higher packaging density, while BJT offers high switching speed and improved noise performance.

4.We use BJT in BiCMOS because of its _____________
a) High speed
b) High gain
c) Low output resistance
d) All of the Mentioned

Answer: d
Explanation: Bipolar junction transistors offer high speed, high gain and low output resistance, which are excellent properties for high-frequency analog amplifiers. It also offers high switching speed and improved noise performance.

5. We use CMOS transistor in BiCMOS because of its _____________
a) High input resistance
b) Simple construction
c) Low power logic gates
d) All of the Mentioned

Answer: d
Explanation: CMOS ensures low power dissipation, smaller noise margin and higher packaging density. It also offers high input resistance and is excellent for constructing simple, low-power logic gates.

6. When was BiCMOS technology introduced?
a) 1990
b) 1991
c) 1992
d) 1989

Answer: a
Explanation: BiCMOS technology was introduced in 1990s. BiCMOS is an evolved semiconductor technology that integrates two formerly separate semiconductor technologies those of the BJT and CMOS. CMOS ensures low power dissipation, smaller noise margin and higher packaging density, while BJT offers high switching speed and improved noise performance.

7. On which technology the Pentium is based?
a) MOSFET
b) CMOS
c) BiCMOS
d) BJT

Answer: c
Explanation: The Pentium technology is based on BiCMOS technology because BiCMOS circuits use the characteristics of each type of transistor most appropriately. CMOS ensures low power dissipation, smaller noise margin and higher packaging density, while BJT offers high switching speed and improved noise performance

8. The advantage of BiCMOS circuit is that it gives _____________
a) Large fan-out
b) Large fan-in
c) Small fan-in
d) Small fan-out

Answer: a
Explanation:Fan-out is the measure of the maximum number of inputs that a single gate output can feed. BiCMOS circuits are particularly useful for logic with large fan-out (large capacitive load).

9. How many members a BiCMOS family have?
a) 5
b) 6
c) 7
d) 8

Answer: a
Explanation: BICMOS is a combination of both CMOS and BJT technology. The BiCMOS family has mainly 5 members and those are ABT logic, ALB logic, ALVT logic, BCT logic and LVT logic.

10. What is LVT logic?
a) Lower threshold voltage
b) Lower supply threshold voltage
c) Lower supply voltage while retaining TTL logic levels
d) All of the Mentioned

Answer: c
Explanation: LVT stands for Low Voltage BiCMOS Technology which is an integration of less power dissipation and less noise of CMOS along with the high switching speed and output drive of BJT. LVT logic is nothing but the lower supply voltage while retaining TTL logic levels.