| 摘要 |
<p>A single-ended DC-to-DC converter includes a power transformer having a primary winding and a secondary winding, with a primary switch and an input voltage source coupled in series with the primary winding of the transformer. The primary switch is periodically made active upon application of a control input to permit current flow through the primary winding. The primary switch further has a parasitic capacitance. In a first embodiment of the invention, a reset circuit is provided including an auxiliary switch, an auxiliary voltage source coupled to the auxiliary switch, and a diode coupled between the auxiliary switch and the secondary winding of the transformer. The auxiliary switch is made active when the primary switch is inactive. During off periods of the primary switch, the transformer is reset in part by resonating magnetizing energy from the transformer to the parasitic capacitance and in part by clamping the secondary winding of the transformer to the auxilliary voltage source through the auxilliary switch and the diode. The single-ended converter further comprises at least one synchronous rectification device having a control terminal responsive to a voltage present on the secondary winding to thereby conduct a load current.</p> |
