Question

Noise must be less than _____ of the ADC.

(a) half of the LSB

(b) LSB

(c) half of the MSB

(d) MSB

I have been asked this question in an interview for internship.

My query is from ADC Tradeoffs topic in division Technology Tradeoffs in Software Defined Radio of Cognitive Radio

Answer 1

Right option is (a) half of the LSB

To explain: The effect of aliasing, spurious response in IF/RF processing and other noise must be less than half of the least significant bit of the ADC. If this condition is satisfied, then all the bits of ADC give only the useful signal power.