Power Management
What is the role of a level shifter inserted when passing signals between two blocks running at different supply voltages?
- ATo double the signal frequency
- BTo encrypt the signal
- CTo convert the signal's voltage to 0 and 1 levels matching the receiving side's supply
Show answer and explanation
Answer: C. To convert the signal's voltage to 0 and 1 levels matching the receiving side's supply
If a block running at 0.6 V sends a 1 (0.6 V) to a block running at 1.0 V, the receiver sees an intermediate voltage it cannot reliably read as 1, causing malfunction or shoot-through current. A level shifter converts the signal to voltages suited to the receiving side's supply. Designs that save power by running blocks at different voltages need them on every signal crossing a voltage boundary.
- A. It does not change frequency.
- B. It does not encrypt.
- C. Correct. It is especially needed going from low to high voltage.