Power converter load line control

A snubber circuit for improving the efficiency of a switching converter, comprising:

• a power source having a first rail and a second rail;
• a half-bridge power converter comprising a first switch and a second switch, a first terminal of each of the first and second switches being connected together to form a switch common point, a second terminal of the first switch being connected to the first rail and a second terminal of the second switch being connected to the second rail;
• a snubber transformer having a primary winding and a secondary winding, a first end of each of the primary and secondary windings being coupled together to form a transformer common point and a second end of the primary winding being connected to the switch common point;
• a first capacitor connected between the first rail and the transformer common point;
• a second capacitor connected between the second rail and the transformer common point;
• a first diode having a first anode and a first cathode, the first anode being connected to a second end of the secondary winding and the first cathode being connected to the first rail;
• a second diode having a second anode and a second cathode, the second cathode being connected to the second end of the secondary winding and the second anode being connected to the second rail;
• a third diode having a third anode and a third cathode, the third cathode being connected to the first rail and the third anode being connected to the switch common point;
• a fourth diode having a fourth anode and a fourth cathode, the fourth cathode being connected to the switch common point and the fourth anode being connected to the second rail;
• a filter inductor having a first inductor terminal and a second inductor terminal, the first inductor terminal being connected to the switch common point;
• and
• a load connected between the second inductor terminal and the power source,
• the snubber circuit being effective to suppress voltage transients in the converter circuitry and recover energy from said voltage transients, thereby improving the efficiency of the converter.

A half-bridge switching converter, comprising:

• a first voltage source and a second voltage source, a first terminal of each of the first and second voltage source being connected together to form a voltage source common point, a second terminal of the first voltage source forming a the first rail and a second terminal of the second voltage source forming a second rail;
• a first switch and a second switch, a first terminal of each of the first and second switches being connected together to form a switch common point, a second terminal of the first switch being connected to the first rail and a second terminal of the second switch being connected to the second rail;
• a first diode having a first anode and a first cathode, the first anode being connected to the switch common point and the first cathode being connected to the first rail;
• a second diode having a second anode and a second cathode, the second cathode being connected to the switch common point and the second anode being connected to the second rail;
• a first inductor having a first and a second end, the first end being connected to the switch common point;
• a second inductor having a third end and a fourth end, the third end being connected to the second end of the first inductor;
• a third, auxiliary switch and a fourth, auxiliary switch, a first terminal of each of the third and fourth switches being connected together to form an auxiliary switch common point, a second terminal of the first auxiliary switch being connected to the fourth end of the second inductor and a second terminal of the fourth switch being connected to the voltage source common point;
• a third diode having a third anode and a third cathode, the third anode being connected to the auxiliary switch common point and the third cathode being connected to the fourth end of the second inductor;
• and
• a fourth diode having a fourth anode and a fourth cathode, the fourth anode being connected to the auxiliary switch common point and the fourth cathode being connected to the voltage source common point.