公开(公告)号：US09601992B2

公开(公告)日：2017-03-21

申请号：US14531726

申请日：2014-11-03

Applicant: Infineon Technologies AG

Inventor： Kok Kee Lim ,  Yong Siang Teo ,  Siew Teng Winson Wong

IPC: H02M1/44 ,  H02M3/335 ,  H02M7/48

CPC classification number: H02M1/44 ,  H02M3/33507 ,  H02M3/33515 ,  H02M2007/4815 ,  Y02B70/1433

Abstract: This disclosure relates to a switching power supply with regulated voltage suppression to reduce transformer audio noise. The switching power supply is operable to be fed a zero crossing voltage and to generate an output voltage. The output voltage may have a voltage level set using a modulated gate signal. A circuit is provided to reduce audio noise in a switching power supply by setting a ringing suppression time of the modulated gate signal to a first time period when the zero crossing voltage is below a predetermined voltage threshold and to a second time when the zero crossing voltage is above the predetermined threshold voltage.