For the TTL logic family, the approximate output levels for logic 0 and logic…
20072007
For the TTL logic family, the approximate output levels for logic 0 and logic 1 are:
- A.
0.1 and 5V
- B.
0.6 and 3.5 V
- C.
0.9 and 1.75 V
- D.
-1.75 and 0.9 V
Attempted by 221 students.
Show answer & explanation
Correct answer: B
Correct answer: 0.6 V and 3.5 V
Standard TTL circuits operate with a positive supply, commonly around 5 V. The important output-level idea is that LOW must remain below the TTL low threshold and HIGH must remain above the TTL high threshold.
Logic 0 (LOW): a voltage below about 0.8 V is treated as LOW, so 0.6 V is a valid approximate LOW level.
Logic 1 (HIGH): a voltage above about 2.2 V is treated as HIGH, and a typical TTL HIGH output is around 3.5 V.
Invalid ranges: negative voltages and values in the undefined region between LOW and HIGH thresholds are not suitable TTL output levels.
Final answer: 0.6 V and 3.5 V.
A video solution is available for this question — log in and enroll to watch it.