DC/DC CONVERTER AND GAME MACHINE USING IT

• US 20140111172A1
• Filed: 10/08/2013
• Published: 04/24/2014
• Est. Priority Date: 10/24/2012
• Status: Active Grant

• Current Assignee: Sony Interactive Entertainment Inc. (Sony Group Corp.)
• Original Assignee: Sony Computer Entertainment Incorporated (Sony Group Corp.)
• Inventors: Mitsui, Kazuaki, Sasao, Kazuki
• Granted Patent: US 8,963,525 B2
• Time in Patent Office: Days
• US Class Current: 323/271
• 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
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take 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

The present disclosure is to provide a DC/DC converter capable of suppressing increase in the ripple amount of the output voltage in association with switching of the number of drive phases. N (N is an integer equal to or larger than 2) switching circuits each generate a switching voltage at the switching node according to an input pulse signal. A phase controller dynamically switches the number K (K is an integer equal to or smaller than N) of drive phases according to the state of a DC/DC converter at the time. A pulse modulator generates a pulse signal whose frequency changes according to the number K of drive phases. A distributor selects K switching circuits among the N switching circuits and distributes the pulse signal to each of the selected K switching circuits with a phase difference of (360/K) degrees.

Claims

1. A DC/DC converter comprising:

an input line to which a DC input voltage is supplied;

a smoothing circuit that includes an output line and at least one output capacitor connected to the output line;

N switching circuits that each include a switching transistor and a synchronous rectifier transistor provided in series between the input line and a ground line, and each generate a switching voltage at a switching node that is a connecting node of the switching transistor and the synchronous rectifier transistor according to an input pulse signal, wherein N is an integer at least 2;

N inductors that are each provided for a respective one of the switching circuits and are each provided between the switching node of the switching circuit that corresponds and the output line;

a phase controller that dynamically switches the number K of drive phases according to a state of the DC/DC converter at the time, wherein K is an integer up to N;

a pulse modulator that generates the pulse signal whose duty ratio is so adjusted that a feedback voltage depending on an output voltage of the output line corresponds with a predetermined reference voltage and whose frequency changes according to the number K of drive phases; and

a distributor that selects K switching circuits among the N switching circuits and distributes the pulse signal to each of the selected K switching circuits with a phase difference of 360/K degrees.

2. The DC/DC converter according to claim 1, wherein

if the smoothing circuit has a certain resonant frequency fr, for at least one number k1 of drive phases, frequency f1 of the pulse signal is so set as to be equal to fr/k1.

3. The DC/DC converter according to claim 2, wherein

if the smoothing circuit has the certain resonant frequency fr, for at least two numbers k1 and k2 of drive phases, frequencies fx1 and fx2 of the pulse signal are so set as to be equal to fr/k1 and fr/k2, respectively.

4. The DC/DC converter according to claim 2, wherein

if the smoothing circuit has resonant frequencies fr1 and fr2, for at least two numbers k1 and k2 of drive phases, frequencies fx1 and fx2 of the pulse signal are so set as to be equal to fr1/k1 and fr2/k2, respectively.

5. The DC/DC converter according to claim 1, wherein

the frequency of the pulse signal is set based on a resonant frequency of impedance of the smoothing circuit for all of the numbers of drive phases.

6. The DC/DC converter according to claim 1, wherein

the state of the DC/DC converter is a load current.

7. The DC/DC converter according to claim 1, wherein

the phase controller selects the number of drive phases giving highest efficiency in the state of the DC/DC converter at the time.

8. A DC/DC converter comprising:

an input line to which a DC input voltage is supplied;

a smoothing circuit that includes an output line and at least one output capacitor connected to the output line;

N switching circuits that each include a switching transistor and a synchronous rectifier transistor provided in series between the input line and a ground line, and each generate a switching voltage at a switching node that is a connecting node of the switching transistor and the synchronous rectifier transistor according to an input pulse signal, wherein N is an integer at least 2;

N inductors that are each provided for a respective one of the switching circuits and are each provided between the switching node of the switching circuit that corresponds and the output line;

a pulse modulator that generates the pulse signal whose duty ratio is so adjusted that a feedback voltage depending on an output voltage of the output line corresponds with a predetermined reference voltage;

a phase controller that decides the number K of drive phases; and

a distributor that selects K switching circuits among the N switching circuits and distributes the pulse signal to each of the selected K switching circuits with a phase difference of 360/K degrees,

wherein

frequency of the pulse signal for each of the numbers of drive phases is so set that a ripple of the output voltage becomes smaller compared with a case in which the frequency of the pulse signal is set constant irrespective of the number of drive phases.

9. The DC/DC converter according to claim 8, wherein:

the pulse modulator controls frequency of the pulse signal in such a manner that a product of the number K of drive phases and the frequency of the pulse signal becomes a predetermined value set according to a resonant frequency of the smoothing circuit.

10. A game machine comprising

a DC/DC converter including:

an input line to which a DC input voltage is supplied;

a smoothing circuit that includes an output line and at least one output capacitor connected to the output line;

N switching circuits that each include a switching transistor and a synchronous rectifier transistor provided in series between the input line and a ground line, and each generate a switching voltage at a switching node that is a connecting node of the switching transistor and the synchronous rectifier transistor according to an input pulse signal, wherein N is an integer at least 2;

N inductors that are each provided for a respective one of the switching circuits and are each provided between the switching node of the switching circuit that corresponds and the output line;

a phase controller that dynamically switches the number K of drive phases according to a state of the DC/DC converter at the time, wherein K is an integer up to N;

a pulse modulator that generates the pulse signal whose duty ratio is so adjusted that a feedback voltage depending on an output voltage of the output line corresponds with a predetermined reference voltage and whose frequency changes according to the number K of drive phases; and

a distributor that selects K switching circuits among the N switching circuits and distributes the pulse signal to each of the selected K switching circuits with a phase difference of 360/K degrees.