Consider the following statements regarding Logic Families:1.CMOS logic family exhibits high noise immunity due to large voltage margins and high input impedance characteristics.2.TTL logic consumes less static power compared to CMOS due to bipolar transistor operation.3.CMOS circuits allow higher fan-out due to negligible input current.Which of the above statements is/are correct?

Correct Answer: A - 1 and 3 only

Quick Concept Explanation

CMOS inputs draw extremely small steady-state current and offer large noise margins, giving high input impedance and high fan-out in many logic applications. Traditional TTL uses bipolar transistors and has higher static power than CMOS under comparable conditions. Key relation: Fan-out is limited by input loading and output drive; CMOS input current is very small.

Exam focus: CMOS usually wins on static power. Common trap: Do not assume bipolar TTL has lower static power than CMOS.

Statement-wise Verification

• Statement 1 - Correct.
  CMOS logic family exhibits high noise immunity due to large voltage margins and high input impedance characteristics.
  CMOS inputs draw extremely small steady-state current and offer large noise margins, giving high input impedance and high fan-out in many logic applications.
• Statement 2 - Incorrect.
  TTL logic consumes less static power compared to CMOS due to bipolar transistor operation.
  Traditional TTL generally consumes more static power than CMOS
• Statement 3 - Correct.
  CMOS circuits allow higher fan-out due to negligible input current.
  Fan-out is limited by input loading and output drive; CMOS input current is very small.

Core Concept

CMOS inputs draw extremely small steady-state current and offer large noise margins, giving high input impedance and high fan-out in many logic applications. Traditional TTL uses bipolar transistors and has higher static power than CMOS under comparable conditions.

Formula / Key Relationship

Fan-out is limited by input loading and output drive; CMOS input current is very small.

Why the Other Options Are Wrong

Option B is incorrect because it includes incorrect statement(s) 2 and omits correct statement(s) 1. Option C is incorrect because it includes incorrect statement(s) 2 and omits correct statement(s) 3. Option D is incorrect because it includes incorrect statement(s) 2.

Exam Shortcut / Approach

CMOS usually wins on static power.

Common Mistake

Do not assume bipolar TTL has lower static power than CMOS.

Quick Revision

Noise Immunity Power and Fan-Out is linked with CMOS and TTL, Logic Families and Digital Electronics. CMOS usually wins on static power.