US-20260128677-A1 - POWER CONVERTER WITH COUPLED INDUCTORS

US20260128677A1US 20260128677 A1US20260128677 A1US 20260128677A1US-20260128677-A1

Abstract

A power converter has an inductor assembly and two power dies. The inductor assembly has two windings that share a magnetic core to form coupled inductors. Each winding has a main body, a first portion and a second portion. The main body extends towards a top surface of the inductor assembly. The first portion extends to form a first end at a bottom surface of the inductor assembly. The second portion extends to form a second end at the bottom surface of the inductor assembly. Each power die comprises a pair of switches that form a switch node electrically connected to a corresponding winding. A partially overlapped region between the two windings determines a coupling coefficient between the coupled inductors.

Inventors

TING GE

Assignees

MONOLITHIC POWER SYSTEMS, INC.

Dates

Publication Date: 20260507
Application Date: 20250929

Claims (20)

1 . A power converter, comprising: an inductor assembly having two windings that share a magnetic core to form coupled inductors, wherein each winding has a main body extending towards a top surface of the inductor assembly, a first portion extending to form a first end at a bottom surface of the inductor assembly, and a second portion extending to form a second end at the bottom surface of the inductor assembly; and two power dies, wherein each of the power dies comprises a pair of switches that form a switch node electrically connected to the first end of a corresponding winding, and the second end of the corresponding winding is electrically connected to provide an output voltage; wherein a partially overlapped region between the two windings determines a coupling coefficient between the coupled inductors.
2 . The power converter of claim 1 , wherein the first ends of the two windings are located at opposite edges of the bottom surface of the inductor assembly, the second ends of the two windings are located at a middle region of the bottom surface of the inductor assembly, and the two power dies are placed on opposite sides of the inductor assembly.
3 . The power converter of claim 2 , further comprising: an interconnect connecting the second ends of the two windings together to provide the output voltage.
4 . The power converter of claim 1 , wherein the main bodies of the two windings are arranged perpendicular to the top and bottom surface of the inductor assembly and partially overlap with each other to create an inverse coupling between the two windings.
5 . The power converter of claim 1 , wherein the first portion of a first winding and the second portion of a second winding extend towards a first side surface of the magnetic core, the second portion of the first winding and the first portion of the second winding extend towards a second side surface of the magnetic core, the first side surface is opposite to the second side surface.
6 . The power converter of claim 1 , wherein a gap between the two windings is less than 0.4 mm.
7 . A power converter, comprising: an inductor assembly having four windings that share a magnetic core to form coupled inductors, wherein each winding has a main body extending towards a top surface of the inductor assembly, a first portion extending to form a first end at a bottom surface of the inductor assembly, and a second portion extending to form a second end at the bottom surface of the inductor assembly; and two power dies placed on opposite sides of the inductor assembly, wherein each of the power dies comprises two pairs of switches, each pair of switches forms a switch node that is electrically connected to the first end of a corresponding winding, and the second end of the corresponding winding is electrically connected to provide an output voltage.
8 . The power converter of claim 7 , wherein: a first partially overlapped region between a first winding and a second winding determines a first coupling coefficient between the first winding and the second winding; and a second partially overlapped region between a third winding and a fourth winding determines a second coupling coefficient between the third winding and the fourth winding.
9 . The power converter of claim 8 , wherein: a first end of the first winding is electrically connected to the switch node formed by a first pair of switches from a first power die; a first end of the second winding is electrically connected to the switch node formed by a first pair of switches from a second power die; a first end of the third winding is electrically connected to the switch node formed by a second pair of switches from the first power die; and a first end of the fourth winding is electrically connected to the switch node formed by a second pair of switches from the second power die.
10 . The power converter of claim 7 , wherein the first ends of the four windings are located at edges of the bottom surface of the inductor assembly, and the second ends of the four windings are located at a middle region of the bottom surface of the inductor assembly.
11 . The power converter of claim 10 , further comprising an interconnect connecting the second ends of the four windings together to provide the output voltage.
12 . The power converter of claim 7 , wherein: the main body of a first winding and the main body of a second winding are arranged perpendicular to the top and bottom surface of the inductor assembly and partially overlap each other, creating inverse coupling between them; and the main body of a third winding and the main body of a fourth winding are arranged perpendicular to the top and bottom surface of the inductor assembly and partially overlap each other, creating inverse coupling between them.
13 . The power converter of claim 7 , wherein: the first and second windings are placed adjacent to each other to form a first group of inversely coupled windings, there is a first gap between the first and second windings; and the third and fourth windings are placed adjacent to each other to form a second group of inversely coupled windings, there is a second gap between the third and fourth windings.
14 . The power converter of claim 13 , wherein the first gap and the second gap are smaller than a third gap between the first and second groups of the inverse coupled windings.
15 . The power converter of claim 13 , wherein each of the first and second gaps is less than 0.4 mm.
16 . An inductor assembly for a power converter, comprising: a magnetic core; and a first winding and a second winding that share the magnetic core; wherein each of the first and second windings has a main body extending towards a top surface of the inductor assembly, a first portion extending to form a first end at a bottom surface of the inductor assembly, and a second portion extending to form a second end at the bottom surface of the inductor assembly; and a first partially overlapped region between the first and second windings determines a coupling coefficient between the first and second windings.
17 . The inductor assembly of claim 16 , wherein: the first end of the first winding is electrically connected to a first switch node formed by a first pair of switches; the second end of the first winding is electrically connected to a first output pad; the first end of the second winding is electrically connected to a second switch node formed by a second pair of switches; and the second end of the second winding is electrically connected to a second output pad.
18 . The inductor assembly of claim 17 , wherein the first ends of the first and second windings are located at opposite edges of the bottom surface of the inductor assembly, and the second ends of the first and second windings are located at a middle region of the bottom surface of the inductor assembly.
19 . The inductor assembly of claim 16 , further comprising: a third winding and a fourth winding that share the magnetic core; wherein each of the third and fourth windings has a main body extending towards a top surface of the inductor assembly, a first portion extending to form the first end at the bottom surface of the inductor assembly, and a second portion extending to form the second end at the bottom surface of the inductor assembly; and a second partially overlapped region between the third and fourth windings determines a coupling coefficient between the third and fourth windings.
20 . The inductor assembly of claim 19 , wherein: the first and second windings are placed adjacent to each other to form a first group of inversely coupled windings, and there is a first gap between the main body of the first winding and the main body of the second windings; the third and fourth windings are placed adjacent to each other to form a second group of inversely coupled windings, and there is a second gap between the main body of the third winding and the main body of the fourth windings; and the first gap and the second gap are smaller than a third gap between the first and second groups of the inversely coupled windings.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims the benefit of U.S. Provisional Application No. 63/716,564, filed on Nov. 5, 2024, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to electrical components, and more particularly but not exclusively relates to power converter. 2. Description of Related Art Inductors are widely used in various electrical circuits, such as filters and power converters. As a particular example, in a power converter, a single output inductor may be used to couple a switch node to an output node of the power converter. Additionally, coupled inductors may be used to couple together the output phases of a multiphase power converter. A power converter, as known in the art, converts an input power to an output power, providing a load with required voltage and current. Multiphase power converters which comprise a plurality of paralleled power stages operating out of phase, offer several advantages, including lower output ripple voltage, better transient performance, and reduced ripple-current-rating requirements for input capacitors. Coupled inductors have been widely used in power converters. These inductors are designed with symmetric windings and opposite current directions to realize an inverse coupling coefficient. SUMMARY OF THE INVENTION In one embodiment, a power converter comprises an inductor assembly and two power dies. The inductor assembly has two windings that share a magnetic core to form coupled inductors. Each winding has a main body extending towards a top surface of the inductor assembly, a first portion extending to form a first end at a bottom surface of the inductor assembly, and a second portion extending to form a second end at the bottom surface of the inductor assembly. Each of the power dies comprises a pair of switches that form a switch node electrically connected to the first end of a corresponding winding. The second end of the corresponding winding is electrically connected to provide an output voltage. A partially overlapped region between the two windings determines a coupling coefficient between the coupled inductors. In another embodiment, a power converter comprises an inductor assembly and two power dies. The inductor assembly has four windings that share a magnetic core to form coupled inductors. Each winding has a main body extending towards a top surface of the inductor assembly, a first portion extending to form a first end at a bottom surface of the inductor assembly, and a second portion extending to form a second end at the bottom surface of the inductor assembly. The power dies are placed on opposite sides of the inductor assembly. Each of the power dies comprises two pairs of switches. Each pair of switches forms a switch node that is electrically connected to the first end of a corresponding winding. The second end of the corresponding winding is electrically connected to provide an output voltage. In yet another embodiment, an inductor assembly for a power converter comprises a magnetic core, and a first and second windings that share the magnetic core. Each of the first and second windings has a main body extending towards a top surface of the inductor assembly, a first portion extending to form a first end at a bottom surface of the inductor assembly, and a second portion extending to form a second end at the bottom surface of the inductor assembly. A first partially overlapped region between the first and second windings determines a coupling coefficient between the first and second windings. These and other features of the present disclosure will be readily apparent to persons of ordinary skill in the art upon reading the entirety of this disclosure, which includes the accompanying drawings and claims. BRIEF DESCRIPTION OF DRAWINGS The present invention can be further understood with reference to the following detailed description and the appended drawings, wherein like elements are provided with like reference numerals. These drawings are only for illustration purpose, thus may only show part of the devices and are not necessarily drawn to scale. FIG. 1 illustrates a schematic diagram of a power converter 100 in accordance with an embodiment of the present invention. FIG. 2 illustrates a perspective view of an inductor assembly 20. FIG. 3A illustrates a perspective view of an inductor assembly 30 of FIG. 1 in accordance with an embodiment of the present invention. FIG. 3B illustrates a perspective view of a winding 302 in accordance with an embodiment of the present invention. FIG. 3C illustrates a perspective view of a winding 303 in accordance with an embodiment of the present invention. FIG. 4 illustrates a front perspective view of the inductor assembly 30 of FIG. 3A in accordance with an embodiment of the present invention. FIG. 5 illustrates a top view of the inductor assembly 30 of FIG. 3A in accordan