DC to DC converter and DC to DC conversion system

A DC to DC conversion system, comprising:

• a DC to DC converter comprising:
• a transformer having a transformer core, a primary winding electrically coupled to a primary power circuit and a secondary winding, wherein the primary power circuit is configured to receive an input voltage, and deliver a power flow having a symmetrical voltage to a secondary side of the transformer during a positive switching cycle and a negative switching cycle generated on the primary winding, a magnetic flux in the transformer core is balanced through the power flow having the symmetrical voltage;
• an output inductor;
• a secondary bridge synchronous rectifying circuit electrically coupled to the secondary winding of the transformer, comprising:
• a first switch having a first end electrically coupled to one end of the output inductor, and a second end electrically coupled to a first end of the secondary winding;
• a second switch having a first end electrically coupled to the second end of the first switch;
• a third switch having a first end electrically coupled to the first end of the first switch, and a second end electrically coupled to a second end of the secondary winding;
• and
• a fourth switch having a first end electrically coupled to the second end of the third switch, and a second end electrically coupled to a second end of the second switch;
• and
• a control circuit configured to provide a primary driving signal for the primary power circuit and a secondary driving signal for the secondary bridge synchronous rectifying circuit, respectively, and when an output voltage of the primary power circuit is zero, the control circuit is configured to control the first switch, the second switch, the third switch and the fourth switch to be conductive;
• and
• a non-isolated switching regulator electrically coupled to an output terminal of the DC to DC converter, and configured to convert the input voltage of the DC to DC converter into one or more regulated voltages,
• wherein the control circuit comprises:
• a primary driving circuit configured to output the primary driving signal;
• a secondary driving circuit configured to output the secondary driving signal;
• an isolation circuit configured to electrically isolate the primary driving circuit from the secondary driving circuit;
• and
• a timing circuit configured to receive a fixed duty cycle signal or a variable duty cycle signal, and arrange a signal timing between the primary driving signal and the secondary driving signal based on the received fixed duty cycle signal or variable duty cycle signal.

A DC to DC conversion system, comprising:

• a DC to DC converter comprising:
• a transformer having a transformer core, a primary winding electrically coupled to an output terminal of a primary power circuit and a secondary winding, wherein the primary power circuit is configured to receive an input voltage, and deliver a power flow having a symmetrical voltage to a secondary side of the transformer during a positive switching cycle and a negative switching cycle generated on the primary winding, a magnetic flux in the transformer core is balanced through the power flow having the symmetrical voltage;
• an output inductor;
• a secondary bridge synchronous rectifying circuit electrically coupled to the secondary winding of the transformer, comprising:
• a first switch having a first end electrically coupled to one end of the output inductor, and a second end electrically coupled to a first end of the secondary winding;
• a second switch having a first end electrically coupled to the second end of the first switch;
• a third switch having a first end electrically coupled to the first end of the first switch, and a second end electrically coupled to a second end of the secondary winding;
• and
• a fourth switch having a first end electrically coupled to the second end of the third switch, and a second end electrically coupled to a second end of the second switch;
• and
• a control circuit configured to provide a primary driving signal for the primary power circuit and a secondary driving signal for the secondary bridge synchronous rectifying circuit, respectively, and when an output voltage of the primary power circuit is zero, the control circuit is configured to control the first switch, the second switch, the third switch and the fourth switch to be conductive;
• and
• a non-isolated switching regulator electrically coupled to an input terminal of the DC to DC converter,
• wherein the control circuit comprises:
• a primary driving circuit configured to output the primary driving signal;
• a secondary driving circuit configured to output the secondary driving signal;
• an isolation circuit configured to electrically isolate the primary driving circuit from the secondary driving circuit;
• and
• a timing circuit configured to receive a fixed duty cycle signal or a variable duty cycle signal, and arrange a signal timing between the primary driving signal and the secondary driving signal based on the received fixed duty cycle signal or variable duty cycle signal.