| 摘要 |
PROBLEM TO BE SOLVED: To enable reduction in peak value of switching noise and superposition of spectra of power conversion circuits without increasing cost in a digital control power supply device having plural power conversion circuits arranged in parallel.SOLUTION: A digital control power supply device has a frequency changing device 3 for repetitively outputting a frequency variation pattern comprising a combination of plural frequency values, and a controller 4 for performing ON/OFF control of switching elements 2a, 2b at a switching frequency based on the frequency variation pattern. Repetitive frequencies fm[a], fm[b] of the frequency variation pattern and differences Δf[a], Δf[b] between the maximum and minimum values of the switching frequencies are set for every power conversion circuit 20a, 20b so as to achieve a favorable peak value reduction effect of switching noise. When a diffused switching noise spectrum is superposed between the power conversion circuits 20a and 20b, fm[a] and Δf[a] are changed.SELECTED DRAWING: Figure 1 |
