Switching power source apparatus and control method thereof

• US 8,278,885 B2
• Filed: 08/30/2011
• Issued: 10/02/2012
• Est. Priority Date: 08/21/2007
• Status: Expired due to Fees

• Current Assignee: S-Printing Solution Co., Ltd. (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jo, Sung-jo, Choi, Jong-moon, Jung, Jee-hoon
• Primary Examiner(s): Tran, Nguyen
• Application Number:
  US13/137,628
• Publication Number:
  US 20110316496A1
• Time in Patent Office: 399 Days
• Field of Search: 323/222, 323/226, 323/235, 323/270, 323/271, 323/282
• US Class Current: 323/222
• CPC Class Codes: H03K 17/0406 in composite switches
• CPC Class Codes: H03K 17/08148 in composite switches
• CPC Class Codes: H03K 17/168 in composite switches
• CPC Class Codes: H03K 17/567 Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT

Abstract

A switching power source apparatus includes a converting unit to convert a voltage level of power, a first switch to switch power supplied to the converting unit, a second switch connected in series with the first switch and turned on after the first switch has been turned on, and a voltage clamp unit to clamp a level of a voltage applied across the series connection of the first switch and the second switch to a predetermined voltage or less.

Claims

1. A switching power source apparatus, comprising:

a converting unit to convert a voltage level of power;

a first switch to switch a power supplied to the converting unit;

a second switch connected in series with the first switch and turned on after the first switch has been turned on; and

a voltage clamp unit to clamp a level of a voltage applied across the series connection of the first switch and the second switch to a predetermined voltage or less, wherein the second switch has a withstanding voltage equal to or greater than a predetermined value that is high enough to withstand a maximum voltage applied across the series connection of the first switch and the second switch during operation of the switching power source apparatus.

2. The switching power source apparatus of claim 1, wherein the first switch comprises a metal-oxide-semiconductor field-effect transistor (MOSFET).

3. The switching power source apparatus of claim 2, wherein the second switch comprises a bipolar junction transistor (BJT).

4. The switching power source apparatus according to claim 3, wherein:

the MOSFET comprises a drain terminal;

the BJT comprises an emitter terminal; and

the drain terminal of the MOSFET is connected to the emitter terminal of the BJT.

7. The switching power source apparatus of claim 1, wherein turning off either the first switch or the second switch turns off the switching power source apparatus.

8. The switching power source apparatus of claim 1, wherein:

the first switch comprises a first capacitor;

the second switch comprises a second capacitor; and

the first capacitor and the second capacitor form a resonant circuit with the converting unit.

9. The switching power source apparatus of claim 8, wherein:

the converting unit comprises a transformer having an inductance; and

the inductance of the transformer is the inductance of the converting unit that forms the resonant circuit with the first capacitor and the second capacitor.

5. A switching power source apparatus, comprising:

a converting unit to convert a voltage level of power;

a first switch to switch power supplied to the converting unit;

a second switch connected in series with the first switch and turned on after the first switch has been turned on; and

a voltage clamp unit to clamp a level of a voltage applied across the series connection of the first switch and the second switch to a predetermined voltage or less,

wherein the voltage clamp unit comprises a diode connected to the series connection of the first switch and the second switch to conduct a current in a direction opposite to a direction of a current that flows from the series connection of the first switch and the second switch to the converting unit when the first switch and the second switch are turned on.

6. The switching power source apparatus of claim 5, wherein the diode is connected in parallel with the series connection of the first switch and the second switch.