| 摘要 |
PROBLEM TO BE SOLVED: To solve such problems that, although a phase to turn on/off the switching element is changed so that a plurality of switching elements are prevented from being simultaneously turned on/off or a frequency of a signal to drive the switching element is modulated so that noise is prevented from being biased to a specific frequency in a power supply device using a plurality of switching power supply parts, such a method can cope only with a specific situation, or since the noise generating situation is changed after assembly in a semiconductor testing device in which numerous module substrates are selected and used, it is difficult to cope with such a case.SOLUTION: A signal representing a state of the switching element in a switching power supply part is inputted, and based on this signal, the frequency and phase of a modulation signal to control the switching element so that the noise is minimized are changed, then a configuration to generate this modulation signal is changed. Since the power supply device thus configured can cope with various situations, it is suitable for use in the semiconductor testing device in which the numerous module substrates are selected and used. |
