Micro power converter

• US 8,031,041 B2
• Filed: 12/01/2008
• Issued: 10/04/2011
• Est. Priority Date: 12/05/2007
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Systems Company Limited
• Inventors: Sugahara, Satoshi
• Primary Examiner(s): Mai; Anh
• Application Number:
  US12/292,959
• Publication Number:
  US 20090146638A1
• Time in Patent Office: 1,037 Days
• Field of Search: 363/21.12, 336/200, 336/232, 336/223
• US Class Current: 336/200
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H02M 3/33569 having several active switching elements H02M3/3353 takes precedence

Abstract

An object of the invention is to provide a micro power converter of a step-up and step-down type without requiring more than two semiconductor switches, without increasing the size of a semiconductor chip, and without degrading efficiency. A micro power converter comprises a micro transformer composed of a planar transformer having a structure including a conductor wound on and through a planar magnetic core, and a semiconductor chip including semiconductor switches S1, S2, and a control circuit for controlling the switches. By constructing a flyback transformer using a micro transformer composed of a planar transformer, a micro power converter of a step-up and step-down type is provided having two semiconductor switches and an overall size comparable to a conventional micro power converter.

Claims

1. A micro power converter comprising:

a micro transformer having a conductor and a planar magnetic core, the conductor wound on and through the planar magnetic core to form primary and secondary coils; and

a semiconductor chip having first and second semiconductor switches mounted thereon, the first semiconductor switch connected to the primary coil, the second semiconductor switch connected to the secondary coil, and the first and second semiconductor switches each directly connected to a ground potential.

2. The micro power converter according to claim 1, wherein the two semiconductor switches each comprise one N-type semiconductor switch.

3. The micro power converter according to claim 2,

wherein sources of the N-type semiconductor switches are arranged side by side on the semiconductor chip.

4. The micro power converter according to claim 2,

wherein emitters of the N-type semiconductor switches are arranged side by side on the semiconductor chip.

5. The micro power converter according to claim 1, wherein the micro power converter is a step-up and step-down power converter.

6. The micro power converter according to claim 1, wherein the primary and secondary coils are arranged so that one turn of the primary coil corresponds to one turn of the secondary coil.

7. The micro power converter according to claim 1, wherein the primary and secondary coils are arranged so that plural turns of the primary coil correspond to plural turns of the secondary coil.

8. The micro power converter according to claim 1, wherein the primary and secondary coils are wound together.

9. The micro power converter according to claim 1, wherein the primary and secondary coils are separately wound.