Switching power converter and controller for a switching power converter

A switching power supply comprising:

• a power converter having a transformer, a low side switch configured to draw current from a supply voltage through a primary winding of the transformer and a high side switch configured to couple the primary winding of the transformer to a snubber capacitor;
• and
• a controller configured to synchronously control the opening and closing of the low side switch and the high side switch, wherein the low side switch and the high side switch are each repeatedly opened and closed in a series of switching cycles so as to form a regulated output voltage, wherein a first voltage is generated at a node between the low side switch and the high side switch, and wherein the controller is further configured to open the high side switch during each switching cycle when the first voltage falls to a determined level and wherein the determined level is higher than the supply voltage by an amount that is adjusted dependent on a monitored level of the supply voltage.

A controller configured to control a power converter, the power converter having a transformer, a low side switch for drawing current from a supply voltage through a primary winding of the transformer and a high side switch for coupling the primary winding of the transformer to a snubber capacitor, wherein the controller is configured to generate drive signals to control the opening and closing of the low side switch and the high side switch to form a regulated output voltage, and wherein the controller is configured to operate in a first mode in which the high side switch is opened during each switching cycle when a first voltage generated at a node between the low side switch and the high side switch falls to a level of the supply voltage and wherein the controller is configured to operate in a second mode in which the high side switch is opened during each switching cycle when the first voltage falls to a determined level, the determined level being higher than the supply voltage by an amount that is adjusted dependent on a monitored level of the supply voltage.

A switching power supply comprising:

• a power converter having a transformer, a low side switch configured to draw current from a supply voltage through a primary winding of the transformer and a high side switch configured to couple the primary winding of the transformer to a snubber capacitor;
• and
• a controller configured to synchronously control the opening and closing of the low side switch and the high side switch, wherein the low side switch and the high side switch are each repeatedly opened and closed in a series of switching cycles so as to form a regulated output voltage, wherein a first voltage is generated at a node between the low side switch and the high side switch, and wherein the controller is further configured to operate in a first mode in which the high side switch is opened during each switching cycle when the first voltage falls to a level of the supply voltage and wherein the controller is configured to operate in a second mode in which the high side switch is opened during each switching cycle when the first voltage falls to a determined level and wherein the determined level is higher than the supply voltage by an amount that is adjusted dependent on a monitored level of the supply voltage.