PARD Test

Under other parameters in constant conditions, PARD is the periodic and random deviation of DC output voltage from the average within a specified bandwidth. PARD can be measured by RMS (root-mean-square) value or peak to peak value. Generally the bandwidth is from 20Hz to 20MHz. As to adopt RMS value or peak to peak value, it depends on the use situation. Peak to peak value can provide amplitude and peak information in short duration. While the RMS value is useful in determining the expected signal to noise ratio.

JT63 series electronic load provides real-time display of Vpp and Ipp, which is the PARD measured by peak to peak value. Since this PARD bandwidth is also restricted by the sampling frequency (500KHz), this PARD is a little different from PARD in general. If you need to detect the PARD with higher frequency of the measured power supply, you need to use an oscilloscope with higher bandwidth for help. If you need to detect PARD RMS value, you must use a true RMS voltmeter with high bandwidth.