Hardware interview practice
Classify CMOS power components
A powered CMOS block is measured both while idle and while switching at frequency f. Which classification and scaling statement is correct?
Choose one
Answer choices
- A. An idle powered block consumes exactly zero power because no clock edges occur.
- B. Leakage contributes static power; capacitive switching and short-circuit current contribute dynamic power, with switching power approximately alpha*C*V^2*f.
- C. All CMOS power is proportional only to frequency, so lowering voltage has no first-order effect.
- D. Subthreshold leakage is dynamic power because it flows through a transistor, while capacitive charging is static power.