Intellectual Capital: Patents

The innovative designs used in our products may include one or more of the following patents:

US Patent 8,350,659 issued Jan. 8, 2013

Transformer with concentric windings and method of manufacture

This patent describes a new extension of helical wound inductor technology by describing a method to take the inductor to the transformer function and optimize magnetic structures for compactness. The result is lower copper losses resulting in higher efficiency converters. This discovery provides more compact transformers with less variability, particularly in higher frequency and higher voltage power converters.

US Patent 5,521,807

DC-To-DC converter with secondary flyback core reset

This patent is for a secondary flyback core reset (SFCR) for single-ended forward DC-to-DC converters. The secondary magnetizing inductor and a parasitic reset capacitance form a secondary flyback reset circuit. The magnetic flux built up through the primary winding when the main switch is turned on is reset through this secondary flyback reset circuit when the main switch is turned off. The secondary flyback reset circuit initiates a half resonant cycle and resets the transformer. With proper design of the reset time, the maximum duty cycle of the main switch can go beyond 50% while fixing reset voltage independent of input voltage. The advantage is elimination of reset windings and a constant flyback voltage.

US Patent 5,694,303

Semi-regulated power supply using forward converter leakage energy

A forward converter circuit transfers a reset current to a capacitor each switching cycle that is independent of the value of input voltage. The reset current stored in a capacitor is transferred to an inductor and, in turn, transferred to a filter capacitor each cycle, thereby providing a semi-regulated voltage to a constant resistive load. The recovered energy improves efficiency while providing some transient snubbing.

US Patent 5,631,822

Integrated planar magnetics and connector

This patent covers an integrated planar magnetics and connector technique that provides a single integrated transformer and inductor set. Interlayer high current connections are achieved by pads and pins that also allow for a stress relieved mounting of the assembly and provide connections to the circuit where required. The assembly is self aligning. The magnetics assembly is very robust for a large mass, capable of surviving MIL-STD-883 screening including temperature extremes of -65° to 150° C and many thousands of Gs of acceleration. The unique design minimizes the number of connections required, allows for high current densities and very low internal hotspot temperatures, and is capable of continuous operation at pad temperatures of 125° C.

The present invention provides a magnetics substrate for implementing a coupled transformer and inductor. In one version, the transformer and inductor are used in a DC to DC converter. The transformer includes primary and secondary windings, each comprising a set of planar windings coupled to one another in series and lying on planar surfaces of layers of the magnetics substrate. The primary and secondary windings are magnetically coupled to one another. The planar windings are magnetically coupled to one another through an inductor core positioned along the inductor core axis. The magnetics substrate includes an interconnect coupling the secondary transformer winding to the inductor. It also includes terminal padscoupled to the inductor and the primary and secondary transformer windings. Each terminal pad is constructed to receive and couple to a conductive offset pin. The conductive offset pins position the magnetics substrate and the first substrate in a spaced apart parallel relationship and also couple the transformer and inductor to the circuit of the first substrate.