Multi-phase power circuit

• US 9,369,044 B2
• Filed: 08/29/2013
• Issued: 06/14/2016
• Est. Priority Date: 03/05/2013
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Teh, Chen Kong
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Torres-Rivera, Alex
• Application Number:
  US14/013,779
• Publication Number:
  US 20140253066A1
• Time in Patent Office: 1,020 Days
• Field of Search: 323/225, 323/268, 323/271, 323/272, 323/350, 363/65, 307/82
• US Class Current: 1/1
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: H02M 3/1586 switched with a phase shift, i.e. interleaved

Abstract

According to one embodiment, a power circuit includes an input terminal 1 to which a DC input voltage is applied, an output terminal 2, a first DC/DC converter which receives the DC input voltage and supplies a first phase output current to the output terminal 2, a second DC/DC converter which supplies an output current lower than the first phase output current to the output terminal in a second phase which is different from the first phase, and a controller which controls operations of the first and second DC/DC converters.

Claims

1. A power circuit, comprising:

an input terminal which receives a DC input voltage;

an output terminal which outputs an output voltage;

an error calculating circuit which outputs an error signal based on a comparison of the output voltage with a reference voltage;

a compensating circuit which outputs a control signal based on the error signal;

a first DC/DC converter which receives the DC input voltage and supplies a first output current of a first phase to the output terminal, wherein the first output current is controlled with a first control signal which is obtained by a calculation using the control signal of the compensating circuit;

a second DC/DC converter which receives the DC input voltage and supplies a second output current lower than the first output current to the output terminal in a second phase which is different from the first phase, wherein the second output current is controlled with a second control signal which is obtained by the calculation using the control signal of the compensating circuit;

a first current sensor which senses the first output current and outputs a first output current information corresponding to the first output current; and

a second current sensor which senses the second output current and outputs a second output current information corresponding to the second output current, wherein

a load current value is obtained by summing the first output current information and the second output current information,

a control circuit which compares a predetermined mode threshold value associated with a driving mode of the first and second DC/DC converters with the load current value obtained by summing the first and second output current information and stops one of the first and second DC/DC converters in accordance with a comparison result, and

wherein when the driving mode is switched into a mode which stops one of the first and second DC/DC converters, the control circuit performs to forcibly rewrite a value of the control signal of the compensating circuit to change values of the first and the second control signals such that a value of the output current of the first or second DC/DC converter after the driving mode is switched is equal to a value obtained by summing the output currents of the first and second DC/DC converters before the driving mode is switched, and

wherein a ratio between average values of the first output current and the second output current is set to a predetermined value.

2. The power circuit according to claim 1, wherein the first DC/DC converter includes a first switching element in which a first electrode is connected to the input terminal and which outputs the first output current from a second electrode, and a first inductance element which is connected between the second electrode of the first switching element and the output terminal, and

the second DC/DC converter includes a second switching element in which a third electrode is connected to the input terminal and which outputs the second output current from a fourth electrode, and a second inductance element which is connected between the fourth electrode of the second switching element and the output terminal.

3. The power circuit according to claim 2, wherein a switching frequency of the first DC/DC converter is higher than a switching frequency of the second DC/DC converter and an inductance of the first inductance element is lower than an inductance of the second inductance element.

4. The power circuit according to claim 3, wherein a size of the first switching element is larger than a size of the second switching element, wherein the size of the first switching element and the second switching element are adjusted according to the ratio between the average values of the first output current and the second output current.

5. The power circuit according to claim 3, further comprising:

a third DC/DC converter which operates at the same phase as the second DC/DC converter,

wherein a third output current of the third DC/DC converter is supplied to the output terminal through the second inductance element.

6. The power circuit according to claim 2, further comprising:

a third DC/DC converter which receives the DC input voltage supplied to the input terminal and supplies a third output current lower than the second output current to the output terminal in a third phase which is different from the first phase and the second phase, and

wherein a ratio between average values of the first output current, the second output current and the third output current is set using a multiplier of two.

7. The power circuit according to claim 2, wherein a size of the first switching element is larger than a size of the second switching element, wherein the size of the first switching element and the second switching element are adjusted according to the ratio between the average values of the first output current and the second output current.

8. The power circuit according to claim 7, further comprising:

a third DC/DC converter which operates at the same phase as the second DC/DC converter,

wherein a third output current of the third DC/DC converter is supplied to the output terminal through the second inductance element.