Abstract: 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.

Abstract: The present invention relates to a finely programmable Josephson voltage standard device employing microwave driving of multiple frequencies. To this end, the programmable Josephson voltage standard device includes a first element group 10a having the plurality of Josephson junctions 2 connected in series and applied with a first frequency f1; a second element group 20a having a plurality of Josephson junctions 2 connected in series and applied with a second frequency f2 different from the first frequency f1; and current bias meant for selectively applying positive (+) current or negative (?) current to the Josephson junctions 2 of the element groups 10a, 20a or stopping the supply of the current, in response to an input command. The first element group 10a and the second element group 20a are connected in series.

Abstract: 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.