Question

Fastest Logic family is ________.

• A. Emitter Coupled Logic family
• B. CMOS logic family
• C. Schottky TTL logic family
• D. Resistor Transistor Logic family

Hint:

Emitter Coupled Logic (ECL) is used where speed is critical. Remember: more speed means more power consumption.

Answer 1

The Correct Option is A

Why ECL is fastest:
It avoids transistor saturation ⇒ reduces switching time.
Operates in the active region of transistors.
Has low output voltage swing ⇒ less time to switch levels.
Comparison:
CMOS ⇒ low power but not the fastest.
TTL ⇒ faster than CMOS but slower than ECL.
ECL ⇒ fastest due to constant current mode operation.