Multiphase DC-DC converter
Disclosed is a multiphase DC-DC converter including a plurality of DC-DC converter circuits connected in parallel to one another; an output section to add up outputs of the plurality of DC-DC converter circuits to obtain one output; a timing generating circuit to generate timing signals for respectively operating the plurality of DC-DC converter circuits; a control circuit to selectively and sequentially operate the plurality of DC-DC converter circuits in synchronization with the timing signals outputted from the timing generating circuit so that output phases of the plurality of DC-DC converter circuits are different from one another; and a current detection circuit to detect an output current of each of the plurality of DC-DC converter circuits, wherein the control circuit selects one of the plurality of DC-DC converter circuit to be operated next based on an output of the current detection circuit.
1. A multiphase DC-DC converter, comprising:
a plurality of DC-DC converter circuits connected in parallel to one another;
an output section to add up outputs of the plurality of DC-DC converter circuits to obtain one output;
a timing generating circuit to generate timing signals for respectively operating the plurality of DC-DC converter circuits;
a control circuit to selectively and sequentially operate the plurality of DC-DC converter circuits in synchronization with the timing signals outputted from the timing generating circuit so that output phases of the plurality of DC-DC converter circuits are different from one another; and
a current detection circuit to detect an output current of each of the plurality of DC-DC converter circuits, wherein
the control circuit selects one of the plurality of DC-DC converter circuit to be operated next based on an output of the current detection circuit.
2. The multiphase DC-DC converter according to claim 1 , wherein the control circuit operates one of the plurality of DC-DC converter circuits in connection with one of the timing signals.
3. The multiphase DC-DC converter according to claim 1 , wherein the control circuit selects one of the plurality of DC-DC converter circuits to be operated next so that differences in output currents among the plurality of DC-DC converter circuits are reduced.
4. The multiphase DC-DC converter according to claim 1 , wherein the control circuit selects one DC-DC converter circuit having a smallest output current of the plurality of DC-DC converter circuits as a DC-DC converter circuit to be operated next.
5. The multiphase DC-DC converter according to claim 1 , wherein the control circuit selects one DC-DC converter circuit having a smallest output current, as a DC-DC converter circuit to be operated next, of the plurality of DC-DC converter circuits except for one or more DC-DC converter circuits which have been operated during the past n timing signals (n is a natural number smaller than the number of the plurality of DC-DC converter circuits).
6. The multiphase DC-DC converter according to claim 4 , wherein if there is a DC-DC converter circuit which has not been operated during the past m timing signals (m is an integer which is the number of the plurality of DC-DC converter circuits or more), the control circuit selects the DC-DC converter circuit concerned as a DC-DC converter circuit to be operated next.
7. The multiphase DC-DC converter according to claim 6 , wherein the current detection circuit detects an output current of a DC-DC converter circuit operated by the control circuit at a predetermined timing after starting the operation.
8. The multiphase DC-DC converter according to claim 1 , wherein the plurality of DC-DC converter circuits are switching converters which are operated under pulse frequency modulation control.
9. The multiphase DC-DC converter according to claim 8 , wherein the plurality of DC-DC converter circuits are voltage resonance type or current resonance type switching converters using resonant switches.
10. The multiphase DC-DC converter according to claim 1 , wherein the timing generating circuit changes frequency of the timing signal based on an output voltage of the multiphase DC-DC converter.