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 70 μV in 1-V range of the ADC for all sampling rates.