A microprocessor-based 6½-digit voltage divider

A microprocessor-based, self-checking voltage divider of 22-bit resolution has been implemented as a 7-digit instrument. After an automated calibration process that requires no trimming of components, the divider can provide voltage-compensated transfer ratios accurate to ±0.5 ppm, typically at 10-V input and 0–10-mA output.