Question

An input signal with a certain characteristic is digitized using an N-bit ADC with a fixed input range. The SQNR is 32 dB when N is 7. What should the minimum value of N be if you want an SQNR of at least 46 dB

Answer 1

10

Step-by-step explanation:

From the information given:

The input for a fixed voltage range for SQNR when N = 7 is 32 dB

Required: To find the minimum value of N such that SQNR ≥ 46 dB

For an ADC:

SQNR = 6.02(N) + 1.76 dB

Comparing both SQNR such that SQNR₁ = 32 dB and SQNR₂ = 46 dB

Taking the ratio:

`(32 - 1.76)/(46-1.76)= (7)/(N_(minimum))`

`(30.24)/(44.24)= (7)/(N_(minimum))`

`N_(minimum) * 30.24 = 44.24 * 7`

`N_(minimum) = (44.24 * 7)/(30.24)`

`N_(minimum) = 10.24`

`N_(minimum) \simeq 10`