A system is provided for calibrating a device. The system includes a reference component, a sampling component, a calibration component, a comparing component and a proportional integral component. The reference component provides a reference power signal based on a voltage instruction and a current instruction. The sampling component samples a voltage signal to obtain a sampled voltage value and samples a current signal to obtain a sampled current value. The calibration component generates a calibrated power signal based on the sampled voltage value and the sampled current. The comparing component generates an error signal based on the reference power signal and the calibrated power signal. The proportional integral component and the calibration component are a feedback system that is operable to calibrate the gain of the sampled voltage and the sample current based on the error signal.