Calibration of AC Voltage for a High Speed Sampling ADC Board Using Thermal Voltage Converters

This paper describes a calibration technique for a commercial Analog-to-Digital Converter (ADC) board using Thermal Voltage Converters (TVCs) up to 1 MHz with various sampling rates. The DC voltage was calibrated first. Then, AC-DC transfer difference of the ADC board was measured by comparing it with a standard TVC. The AC voltage error was calculated by using both calibration results. The estimated expanded uncertainty of the AC voltage error for 0.5 Vrms was less than $\pmb{70\ \mu} \mathbf{V}$ in 1-V range of the ADC for all sampling rates.