Split inductor with fractional turn of each winding and PCB including same

• US 6,307,458 B1
• Filed: 09/22/1999
• Issued: 10/23/2001
• Est. Priority Date: 09/22/1999
• Status: Expired due to Term

• Current Assignee: Optis Cellular Technology LLC (Brevet Capital)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Zhang, Jun, Hart, William, Farrington, Richard
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US09/401,573
• Time in Patent Office: 762 Days
• Field of Search: 336/200, 336/232, 336/223
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 2017/0093 Common mode choke coil
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/34 Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H05K 1/0233 Filters, inductors or a magnetic substance
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/09063 Holes or slots in insulating substrate not used for electrical connections

Abstract

An inductor configuration (50) comprising a three-legged inductor core (20) with a first leg (22), second leg (24), and third leg (26) integrally extending from a base (28). The first leg (22) and second leg (24) are predisposed and spaced about a first surface (30) of the base (28) to form a first channel area (32). The second leg (24) also forms, along with the third leg (26), a second channel area (34) separated from the first channel area (32) by the second leg (24). The inductor also comprises an inductor winding (36) arranged about the inductor core (20) to provide relatively equal magnetic flux through the first leg (22), second leg (24), and third leg (26) when current flows through the inductor winding (36). The inductor configuration may be used as an input or output inductor for a synchronous rectifier circuit (100).

Claims

1. A printed circuit board (PCB) assembly with an onboard inductor comprising:

a plurality of PCB layers, each of said layers including a conductive core sub-layer predisposed between two base material sub-layers, each conductive core sub-layer formed into circuit pathways, said circuit pathways adapted to connect circuit components to said PCB assembly;

a plurality of insulation layers predisposed between each PCB layer;

an inductor core having a base with first, second and third legs extending therefrom;

first, second and third openings extending through said plurality of PCB layers, said openings adapted to accept said inductor core; and

split inductor windings integrated into said plurality of PCB layers and arranged about said inductor core in order to balance the magnetic flux in each of said first, second and third legs;

wherein said split inductor windings adapted to provide an equal number of signal paths through a first area defined by said first and second openings and through a second area defined by said second and third openings.

2. The PCB assembly according to claim 1 wherein said split inductor winding configuration is integrated within a quarter brick power module to combine the inductor windings and magnetics onto a scale platform, said power module having input pins (Vin+ and Vin−

) and output pins (Vout+ and Vout−

) located at opposite ends of said module.

3. The PCB assembly according to claim 2 wherein said power module is divided into sections including a primary switch section, a transformer section, a rectifier section, an output inductor section and an output capacitor section.

4. The PCB assembly according to claim 1 wherein said split inductor windings have the characteristic of filtering out common mode noise and reducing output noise.