DC/DC converter and communication power supply with common mode noise suppression

A communication power supply, comprising a DC/DC converter and a rectifier circuit,

• the DC/DC converter comprising:
• a primary-side winding, a secondary-side winding, a resonant inductor, a resonant capacitor, and a noise suppression network, wherein:
• the primary-side winding and the secondary-side winding form a transformer;
• the noise suppression network is connected between a primary-side quiescent point and a secondary-side quiescent point of the transformer, the primary-side quiescent point is a direct current stable potential at an input terminal of the DC/DC converter, and the secondary-side quiescent point is a direct current stable potential at an output terminal of the DC/DC converter;
• a first parasitic capacitance between a first terminal of the primary-side winding and the secondary-side quiescent point is equal to a second parasitic capacitance between a second terminal of the primary-side winding and the secondary-side quiescent point;
• and the noise suppression network is configured to generate a suppression current, a direction of the suppression current is opposite to a direction of a total noise current generated by the resonant inductor and the resonant capacitor;
• the noise suppression network comprises a signal source and an impedance network;
• and
• the signal source and the impedance network are connected between the primary-side quiescent point and the secondary-side quiescent point after being connected in series, a first terminal of the rectifier circuit is configured to connect to an alternating current power supply;
• the rectifier circuit is configured to convert an alternating current of the alternating current power supply into a direct current;
• a second terminal of the rectifier circuit is configured to connect to a first terminal of the DC/DC converter;
• a second terminal of the DC/DC converter is configured to supply power to a load;
• and
• the DC/DC converter is configured to receive the direct current output by the rectifier circuit, and perform voltage conversion on the direct current.