The GATE Grind

GATE 2023 EE – Question 40

Analog and Digital Electronics · Schmitt triggers, Sample and hold circuits, A/D and D/A converters · 2 marks · Multiple choice

An 8 bit ADC converts analog voltage in the range of 0 to +5 V to the corresponding digital code as per the conversion characteristics shown in figure. For $V_{in}=1.9922$ V, which of the following digital output, given in hex, is true?

Diagram for GATE 2023 EE question 40
  1. 64H
  2. 65H
  3. 66H
  4. 67H

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (C) 66H

Explanation

The step (LSB) is $5/256=19.53$ mV, and the transitions occur at half-LSB offsets, so code $n$ is centred at $n\times19.53$ mV. $\dfrac{1992.2}{19.53}=102.0$, so the code is 102, which is 66H.