# US 9,520,765 B2 · DC/DC converter, switching power supply device, and electronic apparatus,configured to include a phase detector and a phase holder

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- Number: US 9,520,765 B2
- Document ID: US9520765B2
- Status: Granted
- Kind: B2
- Application number: 14/574,579
- Filed: 2014-12-18
- Published: 2015-07-02
- Granted: 2016-12-13
- Earliest claimed: 2013-12-27
- Assignees: Ricoh Company, Ltd.
- Applicants: Ryohsuke Nishi; Yasuaki Yorozu
- Inventors: Ryohsuke Nishi; Yasuaki Yorozu
- Web page: https://patentgrep.com/patent/US9520765B2

## CPC

- H02M 1/084: using a control circuit common to several phases of a multi-phase system
- H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators
- H02M 3/1584: {with a plurality of power processing stages connected in parallel}
- H02M 1/0012: {Control circuits using digital or numerical techniques (in DC/DC converters H02M3/157, H02M3/33515; in DC-AC converters H02M7/53873)}
- H02M 3/1586: {switched with a phase shift, i.e. interleaved}
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)

## Abstract

Provided is a DC/DC converter for a multi-phase switching power supply device which include a plurality of DC/DC converters including a master DC/DC converter and a plurality of slave DC/DC converters that are connected in parallel to each other and operate in different phases. The DC/DC converter includes: first and second terminals to cascade the plurality of DC/DC converters in a line; a phase detector that detects the number of operating converters in the switching power supply device and the phases of the plurality of DC/DC converters, on the basis of a current input to the first terminal and a current output from the second terminal; a phase holder that holds the detected phases and outputs a phase holding signal; and a clock generator that selects a clock corresponding to the phase of a host converter from multi-phase clocks, on the basis of the phase holding signal, and outputs the selected clock. The DC/DC converter performs a switching operation on the basis of the selected clock.

## Claims

### Claim 1

A DC/DC converter for a multi-phase switching power supply device which includes a plurality of DC/DC converters including a master DC/DC converter and a plurality of slave DC/DC converters that are connected in parallel to each other and operate in different phases, the DC/DC converter comprising:
first and second terminals that cascade the plurality of DC/DC converters in a line;
a phase detector that detects the number of operating converters amongst the converters connected in parallel and the phases of the DC/DC converters, on the basis of a current which flows to the first terminal and a current which flows from the second terminal;
a phase holder that holds the detected phases and outputs a phase holding signal indicating the detected phases; and
a clock generator that selects a clock corresponding to the phase of a host converter from multi-phase clocks which are generated from a reference clock, on the basis of the phase holding signal, and outputs the selected clock to the DC/DC converter,
wherein the DC/DC converter performs a switching operation on the basis of the selected clock output from the clock generator.

### Claim 2 (depends on 1)

The DC/DC converter according to claim 1, wherein, when the phase holder holds the detected phases, all of the DC/DC converters which are connected in parallel to each other perform the switching operation.

### Claim 3 (depends on 1)

The DC/DC converter according to claim 1, wherein, after the phase holder completes the operation of holding the detected phases, each of the DC/DC converters is set to an operating state or a stop state according to a load current to change the number of operating converters.

### Claim 4 (depends on 1)

A switching power supply device comprising:
a plurality of the DC/DC converters according to claim 1 that are connected in parallel to each other.

### Claim 5 (depends on 4)

An electronic apparatus comprising:
the switching power supply device according to claim 4.