Analogue-digital converter using Josephson DAC and method thereof

摘要

The present invention relates to an analog-to-digital converter (ADC) and an analog-to-digital conversion method employing a Josephson digital-to-analog converter (DAC) into an extremely accurate ADC of a physical metrology grade. The ADC includes: a front end ADC for converting an analog input signal into digital data; the Josephson DAC for receiving the digital data from the front end ADC and converting the received digital data into reference analog voltage; a differential ADC for extracting a difference voltage between a reference analog voltage of the Josephson DAC and an unknown input signal; and a data processor for summing output data of the differential ADC and output data of the front end ADC and outputting the summed result. The present invention enables to realize a highly stable Josephson ADC with little time and low cost, which is more accurate in a long-term as compared to any existing semiconductor measurement unit and has a performance that is rarely changed during a lifespan, by combining a programmable array and an existing semiconductor ADC.