The GATE Grind

GATE 2025 EC – Question 44

Digital Circuits · Data Converters · 2 marks · Multiple choice

A 10-bit analog-to-digital converter (ADC) has a sampling frequency of 1 MHz and a full scale voltage of 3.3 V.

For an input sinusoidal signal with frequency 500 kHz, the maximum SNR (in dB, rounded off to two decimal places) and the data rate (in Mbps) at the output of the ADC are ________, respectively.

  1. 61.96 and 10
  2. 61.96 and 5
  3. 33.36 and 10
  4. 33.36 and 5

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Correct answer: (A) 61.96 and 10

Explanation

For a full-scale sinusoid the maximum SNR is $6.02N+1.76=6.02\times10+1.76=61.96$ dB. The output data rate is $N\times f_s=10\times1\text{ MHz}=10$ Mbps. (The input frequency 500 kHz is exactly the Nyquist frequency and does not change either number.)