DC to DC converter

• US 6,853,569 B2
• Filed: 01/17/2003
• Issued: 02/08/2005
• Est. Priority Date: 01/17/2003
• Status: Expired due to Fees

• Current Assignee: Digipower Holdings Limited
• Original Assignee: Hong Kong Polytechnic University
• Inventors: Cheng, Ka Wai Eric, Yeung, Yiu Pun Benny
• Primary Examiner(s): Patel, Rajnikant B.
• Application Number:
  US10/346,167
• Publication Number:
  US 20040141345A1
• Time in Patent Office: 753 Days
• Field of Search: 363/16, 363/17, 363/19, 363/97, 363/98, 363/132, 363/127, 363/131
• US Class Current: 363/97
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A DC to DC converter includes a switch, a diode, and a capacitor connected in series with an inductor. The capacitor and inductor provide a resonant time period and are connected in series with the switch and the diode. A control circuit provides an on/off signal to the switch and has a switching time period longer than half the resonant time period.

Claims

1. A DC to DC converter including:

a switch,

a diode,

an inductor,

a capacitor connected in series with the inductor, the capacitor and the inductor connected in series having a resonant time period and being connected in series with the switch and the diode, and

a control circuit for providing on/off signals to the switch and having a switching time period shorter than the resonant time period and longer than one-half the resonant time period.

2. A DC to DC converter including:

a first positive node having a first voltage,

a second positive voltage node having a second voltage,

a common node,

a first switch and a second switch, the first switch being connected in series with the second switch, the first and second switches connected in series being connected between the first positive node and the common node,

a third switch and a fourth switch, the third switch being connected in series with the fourth switch, the third and fourth switches connected in series connecting the first positive node to the second positive node,

respective diodes connected across the first, second, third, and fourth switches,

an inductor,

a capacitor connected in series with the inductor, the capacitor and the inductor connected in series having a resonant time period and being connected across the first and third switches, and

a control circuit for providing on/off signals to the first, second, third, and fourth switches and having a switching time period longer than one-half the resonant time period.

3. The converter of claim 2 including a first filter capacitor connected between the first positive node and the common node, and a second filter capacitor connected between the second positive node and the common node.

4. The converter of claim 2 wherein the inductor is a coil with an air core.

5. The converter of claim 2 wherein the second voltage is substantially double the first voltage.

6. The converter of claim 2 wherein the control circuit provides the on/off signals only to the first switch and the second switch to produce current flow from the first positive node to the second positive node, and provides the on/off signals only to the third switch and the fourth switch to produce current flow from the second positive node to the first positive node.

7. The converter of claim 2 wherein the respective diodes are integral with the first, second, third, and fourth switches.

8. The converter of claim 2 wherein the first, second, third, and fourth switches are power semiconductor switches.

9. The converter of claim 2 wherein the first, second, third, and fourth switches are selected from the group consisting of metal oxide semiconductor field effect transistors and insulated gate bipolar transistors.

13. The converter of claim 2 wherein the control circuit provides on/off signals to the first, second, third, and fourth switches, the on/off signals having a switching time period shorter than the resonant time period.

10. A DC to DC converter including:

a first positive node,

a second positive node,

a common node,

a first filter capacitor connected between the first positive node and the common node,

a second filter capacitor connected between the second positive node and the common node,

first, second, third, and fourth switches including respective diodes connected across terminals of the corresponding first, second, third, and fourth switches, the first and second switches being connected in series between the first positive node and the common node, the third and fourth switches being connected in series between the first positive voltage node and the second positive node,

an inductor, and

a capacitor connected in series with the inductor, the capacitor and indicator connected in series being connected across the first and third switches.

11. A DC to DC converter including:

a first node,

a second node,

a first switch and a second switch, the first switch being connected in series with the second switch, the first and second switches connected in series being connected between the first node and the second node,

a third switch and a fourth switch, the third switch being connected in series with the fourth switch, the third and fourth switches connected in series connecting the first node to the second node,

respective diodes connected across the first, second, third, and fourth switches,

energy storage means connected across the first and third switches,

means for providing operating signals to the first and second switches for producing an output voltage across the first and second nodes at the third and fourth switches and having a first polarity, in response to an input voltage applied across the first and second nodes at the first and second switches and having a second polarity, opposite the first polarity, and providing operating signals to the third and fourth switches for in producing an output voltage across the first and second nodes at the first and second switches and having the second polarity, in response to an input voltage applied across the first and second nodes at the third and fourth switches and having the first polarity.

14. The converter of claim 11 wherein

the diodes connected across the first and second switches are connected in series, in the same direction, and with a first diode polarity, across the first and second nodes, and

the diodes connected across the third and fourth switches are connected in series, in the same direction, and with a second diode polarity, opposite the first diode polarity, across the first and second nodes.

12. A DC to DC converter including:

a first node,

a second node,

a first switch and a second switch, the first switch being connected in series with the second switch, the first and second switches connected in series being connected between the first and second nodes,

a third switch and a fourth switch, the third switch being connected in series with the fourth switch, the third and fourth switches connected in series being connected between the first and second nodes,

respective diodes connected across the first, second, third, and fourth switches,

an inductor,

a capacitor connected in series with the inductor, the capacitor and inductor connected in series having a resonant time period and being connected across the second and fourth switches, and

a controller for providing on and off signals to the first, second, third, and fourth switches and having a switching time period shorter than the resonant time period and longer than one-half the resonant time period.

15. The converter of claim 12 wherein

the diodes connected across the first and second switches are connected in series, in the same direction, and with a first diode polarity, across the first and second nodes, and

the diodes connected across the third and fourth switches are connected in series, in the same direction, and with a second diode polarity, opposite the first diode polarity, across the first and second nodes.