
492
Digital Systems
4. An accuracy of ADC output is defined by the ADC quantization error. A quantized
level means a discrete level. Let us assume that we have a 10-bit ADC, which is re-
ceiving the analog inputs. The peak measurable voltage is say, 2.0 V. The resolution
is then equal to division of 2.0 V by 2
10
= 1.95 mV/bit. We can then say that there are
the 2
10
= 1024 quantized levels. The levels are from 0 to 2000 mV. These are 0 mV,
1.95 mV, 3.90 mV, 5.85 mV, ..., 2000 mV. If analog input is at a quantized level then
only it will be accurately measured. If analog input is 1.98 mV. It will be converted
to bits 1.95 mV, the nearest quantized level. ...