Topic: Digital Circuits
The A/D converter used in a digital voltmeter, could be (1) successive approximation type (2) Flash converter type (3) Dual slope converter type. The correct sequence in the increasing order of their conversion times is
- A. 1, 2, 3
- B. 2, 1, 3
- C. 3, 2, 1
- D. 3, 1, 2
Answer: B. 2, 1, 3
Explanation: Flash converters are the fastest ADCs (shortest conversion time). Successive approximation ADCs are slower than flash but faster than dual-slope. Dual-slope integrating ADCs are the slowest but offer high resolution and noise rejection, hence widely used in digital voltmeters. Thus, increasing order of conversion time is Flash (2), SAR (1), Dual-slope (3).