JP5283518B2 - Power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power converter capable of reducing consumption power, downsizing a circuit for decreasing a ripple and facilitating a design. <P>SOLUTION: A digital amplifier 1 includes a first driver 130 supplying a filter 150 with a voltage at the same potential as a ground potential, and a second driver 140 supplying the filter 150 with the voltage at the same potential as a specific potential higher than the ground potential. The digital amplifier 1 further includes a controller 10 for driving of the first driver 130 and second driver 140 on the basis of the potential of an input signal IN and the potential of a feedback signal FB. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to power conversion devices such as amplifiers, chargers, and dischargers.

  Conventionally, there is a digital amplifier as an amplifier circuit that amplifies an input signal (see, for example, Non-Patent Document 1).

  FIG. 4 is a circuit diagram of a digital amplifier 100 according to a conventional example. The digital amplifier 100 includes a control unit 110, an inverter 120, a first drive unit 130, a second drive unit 140, and a filter unit 150, and an output signal having a potential corresponding to the potential of the input signal IN input from the input terminal A. OUT is output from the output terminal B.

  The control unit 110 supplies the control signal CNT102, the duty ratio of which is controlled according to the potential of the input signal IN, to the second driving unit 140, and inverts the polarity of the control signal CNT102 by the inverter 120 to obtain the control signal CNT101. The first drive unit 130 is supplied.

  The operation of the control unit 110 will be described below with reference to FIGS. FIG. 5 is a flowchart of the control unit 110, and FIG. 6 is a timing chart of the control unit 110.

  In step S11, the potential of the control signal CNT101 is set to VGH, and the potential of the control signal CNT102 is set to VGL. In step S12, time measurement is started.

  In step S13, the control unit 110 controls the duty ratio of the control signal CNT101 and the duty ratio of the control signal CNT102 according to the potential of the input signal. Specifically, this will be described below with reference to FIG.

In FIG. 6, V _IN indicates the potential of the input signal IN, V _{CNT 101} indicates the potential of the control signal CNT 101, and V _{CNT 102} indicates the potential of the control signal CNT 102.

Control unit 110, when the potential _{V IN} of the input signal IN is 0, the duty ratio D101 control signal CNT101 well as 50%, also a 50% duty ratio D102 control signal CNT102.

On the other hand, when the potential _{V IN} of the input signal IN is higher than zero, in accordance with the potential _{V IN} of the input signal IN is high, the duty ratio D101 control signal CNT101 with greater than 50%, the duty ratio of the control signal CNT102 D102 is made smaller than 50%.

Further, when the potential _{V IN} of the input signal IN is lower than 0, in accordance with the potential _{V IN} of the input signal IN is low, the duty ratio D101 control signal CNT101 well as less than 50%, the duty ratio of the control signal CNT102 D102 is set larger than 50%.

  Returning to FIG. 5, in step S <b> 14, it is determined whether or not the measurement start time in step S <b> 12 is a time corresponding to the duty ratio of the control signals CNT <b> 101 and CNT <b> 102. When it is determined that the time according to the duty ratio of the control signals CNT101 and CNT102 has been reached, the process proceeds to step S15, and when it is determined that the time according to the duty ratio of the control signals CNT101 and CNT102 has not been reached. Step S14 is repeated.

  In step S15, the time measurement is finished, and in step S16, the potential of the control signal CNT101 and the potential of the control signal CNT102 are inverted. Specifically, in step S16, when the potential of the control signal CNT101 is VGH and the potential of the control signal CNT102 is VGL, the potential of the control signal CNT101 is set to VGL and the potential of the control signal CNT102 is set to VGH. . On the other hand, when the potential of the control signal CNT101 is VGL and the potential of the control signal CNT102 is VGH, the potential of the control signal CNT101 is set to VGH and the potential of the control signal CNT102 is set to VGL. When this process ends, the process proceeds to step S12.

Returning to FIG. 4, the first drive unit 130 intermittently _connects the reference potential source 160 and the filter unit 150 according to the potential V _CNT101 of the control signal CNT101. Specifically, when the potential V _CNT101 of the control signal CNT101 is VGH, the reference potential source 160 and the filter unit 150 are electrically connected to have the same potential as the ground potential that is the potential of the reference potential source 160. The voltage is supplied to the filter unit 150. On the other hand, when the potential _{V CNT101} control signal CNT101 is VGL has a reference potential source 160 and the filter unit 150 by insulating stops supplying the voltage of the ground potential and the same potential to the filter unit 150.

The second driving unit 140 intermittently _connects the constant potential source 170 and the filter unit 150 according to the potential V _CNT102 of the control signal CNT102. Specifically, when the potential V _CNT102 of the control signal CNT102 is VGH, the constant potential source 170 and the filter unit 150 are electrically connected to have the same potential as the specific potential that is the potential of the constant potential source 170. The voltage is supplied to the filter unit 150. On the other hand, when the potential _{V CNT102} control signal CNT102 is VGL has a constant potential source 170 and the filter unit 150 by insulating stops supplying the voltage of a particular potential and the same potential to the filter unit 150. Note that the specific potential is higher than the ground potential.

  Here, as described above, since the control signal CNT101 is obtained by inverting the polarity of the control signal CNT102, the first drive unit 130 and the second drive unit 140 are alternately driven by the control unit 110. It will be. That is, when a voltage having the same potential as the ground potential is supplied to the filter unit 150, the control unit 110 drives the first driving unit 130 to electrically connect the reference potential source 160 and the filter unit 150. Then, the control unit 110 stops the driving of the second driving unit 140 to insulate the constant potential source 170 and the filter unit 150 from each other. On the other hand, when a voltage having the same potential as the specific potential is supplied to the filter unit 150, the control unit 110 stops driving the first drive unit 130 to insulate the reference potential source 160 from the filter unit 150, The control unit 110 drives the second drive unit 140 to electrically connect the constant potential source 170 and the filter unit 150.

  The filter unit 150 includes an inductor and a capacitor, reduces the ripple of voltage based on the voltage supplied from the first driving unit 130 and the second driving unit 140, and outputs the ripple from the output terminal B as the output signal OUT. That is, the filter unit 150 reduces the ripple of the output signal OUT.

  According to the digital amplifier 100 having the above configuration, the driving of the first driving unit 130 and the second driving unit 140 is controlled by the control unit 110 in accordance with the potential of the input signal IN, and in accordance with the potential of the input signal IN. The potential output signal OUT can be output.

http: // japan. maxim-ic. com / appnotes. cfm / an_pk / 3777

  However, in the digital amplifier 100 described above, the duty ratio of the control signal CNT101 and the duty ratio of the control signal CNT102 change according to the potential of the input signal IN, but never 0% and 100%. For this reason, the first driving unit 130 and the second driving unit 140 always operate at a cycle according to the potential of the input signal IN, although the driving timing changes, so that the power consumption may not be reduced. It was.

Further, the above-described digital amplifier 100, when the potential _{V IN} of the input signal IN is 0, the duty ratio D101 control signal CNT101, and the duty ratio D102 control signal CNT102, both become 50%. For this reason, the first driving unit 130 and the second driving unit 140 are alternately driven every predetermined period, and the filter unit 150 has the same potential as the specific potential and the ground potential every predetermined period. The potential voltage is supplied alternately. Therefore, the voltage supplied to the filter unit 150 pulsates at a predetermined cycle and includes a so-called ripple. Therefore, in order to reduce this ripple, it is necessary to increase the inductance of the inductor of the filter unit 150, which may increase the circuit scale of the filter unit 150.

In the digital amplifier 100 described above, since the control signal CNT101 is obtained by inverting the polarity of the control signal CNT102, the first drive unit 130 and the second drive unit 140 are driven alternately. . Here, the time from when the potential V _CNT101 of the control signal CNT101 is _changed from VGL to VGH until the first drive unit 130 electrically connects the reference potential source 160 and the filter unit 150, and the potential V of the control signal CNT102. _{The time from when the CNT 102} is _changed from VGH to VGL until the second drive unit 140 insulates the constant potential source 170 from the filter unit 150 may be different. In addition, the time from when the potential V CNT101 of the control signal CNT101 is _changed from VGH to VGL until the first drive unit 130 insulates the reference potential source 160 and the filter unit 150, and the potential V _CNT102 of the control signal CNT102 is _changed from VGL. There is a case where the time from when the VGH is set until the second drive unit 140 electrically connects the constant potential source 170 and the filter unit 150 may be different.

  In these cases, the first driving unit 130 and the second driving unit 140 are driven simultaneously, and an excessive current flows from the constant potential source 170 toward the reference potential source 160 to the first driving unit 130 and the second driving unit 140. May flow, and the first driving unit 130 and the second driving unit 140 may be damaged. Therefore, when the first driving unit 130 and the second driving unit 140 are driven alternately, the dead time is between the period for driving the first driving unit 130 and the period for driving the second driving unit 140. It is necessary to provide a period, and the design of the digital amplifier 100 may be complicated.

  In view of the above-described problems, an object of the present invention is to provide a power conversion device that can realize reduction in power consumption, reduction in circuit scale of a circuit for reducing ripple, and simplification of design. .

The present invention proposes the following items in order to solve the above-described problems.
(1) The present invention includes a potential control unit that controls a potential at a specific point, and a drive control unit that controls driving of the potential control unit based on the potential of an input signal and the potential at the specific point. The potential control unit includes a first driving unit that supplies a voltage of a first potential to the specific point, and a second driving unit that supplies a voltage of a second potential higher than the first potential to the specific point; The drive control unit drives the second drive unit and stops driving the first drive unit when the potential of the input signal is higher than the potential of the specific point, and the input When the potential of the signal is equal to the potential of the specific point, the driving of the first driving unit and the second driving unit is stopped, and when the potential of the input signal is lower than the potential of the specific point, Driving the first driving unit and stopping the driving of the second driving unit. It proposes a power converter according to symptoms.

  According to the present invention, the potential control unit that controls the potential of the specific point and the drive control unit that controls the driving of the potential control unit based on the potential of the input signal and the potential of the specific point are provided. The potential control unit is provided with a first drive unit that supplies a voltage of a first potential to a specific point, and a second drive unit that supplies a voltage of a second potential higher than the first potential to the specific point. Then, the drive control unit stops driving the first drive unit and the second drive unit when the potential of the input signal is equal to the potential of the specific point.

  For this reason, when the potential of the input signal is equal to the potential of the specific point, the driving of the first drive unit and the second drive unit is stopped, so that the first drive unit and the second drive unit are cycled according to the potential of the input signal. The power consumption can be reduced as compared with the case where the two driving units always operate.

  Further, when the potential of the input signal is equal to the potential at the specific point, the driving of the first drive unit and the second drive unit is stopped, so that no voltage is supplied to the specific point and no ripple occurs at the specific point. . For this reason, when an inductor is provided in a circuit for reducing the ripple at a specific point, the inductance of the inductor can be reduced, and the circuit scale of the circuit for reducing the ripple at the specific point can be reduced.

  Further, according to the present invention, when the potential of the input signal is higher than the potential at the specific point, the drive control unit drives the second drive unit, stops driving the first drive unit, and When the potential is equal to the potential at the specific point, the driving of the first driving unit and the second driving unit is stopped, and when the potential of the input signal is lower than the potential at the specific point, the first driving unit is driven. The driving of the second driving unit is stopped.

  For this reason, since a period in which the first drive unit and the second drive unit are driven simultaneously cannot occur, a dead time period is provided between the period in which the first drive unit is driven and the period in which the second drive unit is driven. There is no need to provide. Therefore, simplification of the design of the power conversion device can be realized.

  (2) The present invention proposes a power conversion device according to (1), which includes an inductor and a capacitor, and includes a ripple reduction unit that reduces a ripple at the specific point. Yes.

  According to the present invention, since the ripple reduction unit including the inductor and the capacitor is provided, the ripple at the specific point can be reduced by the ripple reduction unit.

  (3) In the power conversion device according to (1) or (2), the drive control unit compares the potential of the input signal with the potential at the specific point, and the comparison by the comparison unit. A first unit drive control unit that controls the drive of the first drive unit based on a result; a second unit drive control unit that controls the drive of the second drive unit based on a comparison result by the comparison unit; The power converter characterized by providing these is proposed.

  According to the present invention, the drive control unit includes the comparison unit that compares the potential of the input signal with the potential at the specific point, and the first unit drive that controls the drive of the first drive unit based on the comparison result by the comparison unit. A control unit and a second unit drive control unit that controls driving of the second drive unit based on a comparison result by the comparison unit are provided. Therefore, the comparison unit compares the potential of the input signal with the potential at the specific point, and based on the comparison result, the first unit drive control unit controls the drive of the first drive unit, and the second unit By controlling the driving of the second driving unit by the unit driving control unit, the potential at the specific point can be controlled.

  (4) In the power conversion device according to (3), the first unit drive control unit may be configured such that the potential of the input signal is lower than the potential of the specific point based on a comparison result by the comparison unit. In addition, the first drive unit is driven only during a period according to the difference between the potential of the input signal and the potential of the specific point, and the second unit drive control unit is based on the comparison result by the comparison unit, When the potential of the input signal is higher than the potential of the specific point, the second drive unit is driven for a period corresponding to a difference between the potential of the input signal and the potential of the specific point. A device is proposed.

  According to the present invention, when the potential of the input signal is lower than the potential at the specific point, the first unit drive control unit performs the first drive for a period corresponding to the difference between the potential of the input signal and the potential at the specific point. When the input signal potential is higher than the specific point potential, the second unit drive control unit controls the second drive unit for a period corresponding to the difference between the input signal potential and the specific point potential. It was decided to drive. Therefore, the first unit drive control unit controls the driving of the first drive unit according to the difference between the potential of the input signal and the potential at the specific point, and the second unit drive control unit controls the second drive unit. The potential at a specific point can be controlled by controlling the driving of.

  According to the present invention, it is possible to reduce power consumption as compared with the case where the first drive unit and the second drive unit always operate in a cycle according to the potential of the input signal. In addition, the circuit scale of the circuit for reducing the ripple at the specific point can be reduced. Further, the design of the power conversion device can be facilitated.

1 is a circuit diagram of a digital amplifier according to an embodiment of the present invention. It is a circuit diagram of the control part with which the digital amplifier is provided. It is a timing chart of the digital amplifier. It is a circuit diagram of a digital amplifier according to a conventional example. It is a flowchart of the control part with which the digital amplifier which concerns on a prior art example is provided. It is a timing chart of the control part with which the digital amplifier concerning the above-mentioned conventional example is provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the constituent elements in the following embodiments can be appropriately replaced with existing constituent elements and the like, and various variations including combinations with other existing constituent elements are possible. Accordingly, the description of the following embodiments does not limit the contents of the invention described in the claims.

  FIG. 1 is a circuit diagram of a digital amplifier 1 according to an embodiment of the present invention. The digital amplifier 1 is different from the digital amplifier 100 according to the conventional example shown in FIG. In the digital amplifier 1, the same components as those of the digital amplifier 100 are denoted by the same reference numerals, and the description thereof is omitted.

Control unit 10, the potential _{V IN} of the input signal IN, and the potential _{V FB} of the feedback signal FB output from the filter unit 150, in response to supply of the control signal CNT1 which controls the duty ratio to the first drive unit 130 At the same time, the control signal CNT2 in which the duty ratio is controlled is supplied to the second drive unit 140.

  FIG. 2 is a circuit diagram of the control unit 10. The control unit 10 includes a comparison unit 11, a first unit control unit 12, and a second unit control unit 13.

Comparing section 11, the potential V _IN of the input signal IN, compares, and potential V _FB of the feedback signal FB, a signal corresponding to the comparison result to the first unit control section 12 and the second unit the control unit 13 Supply.

Specifically, the comparing unit 11, when the potential _{V IN} of the input signal IN is higher than the potential _{V FB} of the feedback signal FB supplies the Low level signal to the first unit controller 12, the second A high level signal is supplied to the unit controller 13. Here, the period during which a low level signal is supplied to the first unit control section 12 and the period during which a high level signal is supplied to the second unit control section 13 are the same, and these periods are defined as the input signal IN Is increased as the error between the potential V _IN and the potential V _FB of the feedback signal FB increases.

On the other hand, when the potential _{V IN} of the input signal IN is lower than the potential _{V FB} of the feedback signal FB supplies the Hi-level signal to the first unit controller 12, Low level to the second unit control section 13 Supply the signal. Here, the period during which the Hi level signal is supplied to the first unit controller 12 and the period during which the Low level signal is supplied to the second unit controller 13 are made the same, and these periods are defined as the input signal IN. Is increased as the error between the potential V _IN and the potential V _FB of the feedback signal FB increases.

Further, when the potential _{V IN} of the input signal IN is equal to the potential _{V FB} of the feedback signal FB supplies the Low level signal to the first unit controller 12 and the second unit control section 13.

When the high level signal is supplied from the comparison unit 11, the first unit control unit 12 sets the potential V _CNT1 of the control signal _{CNT 1} to VGH, and when the low level signal is supplied from the comparison unit 11. Sets the potential V _CNT1 of the control signal CNT1 to VGL.

The second unit control unit 13 sets the potential V _CNT2 of the control signal _CNT2 to VGH when a Hi level signal is supplied from the comparison unit 11, and when the Low level signal is supplied from the comparison unit 11 Sets the potential V _CNT2 of the control signal CNT2 to VGL.

  Below, operation | movement of the control part 10 is demonstrated, referring the flowchart of FIG.

In step S1, the potential V _CNT1 of the control signal CNT1 is set to VGL, and the potential V _CNT2 of the control signal CNT2 is set to VGL. Specifically, the comparison unit 11 supplies a low level signal to the first unit control unit 12 and supplies a low level signal to the second unit control unit 13. Accordingly, the first unit control unit 12 sets the potential V _CNT1 of the control signal CNT1 to VGL, and the second unit control unit 13 sets the potential V _CNT2 of the control signal _CNT2 to VGL. Accordingly, the driving of the first driving unit 130 and the second driving unit 140 is stopped.

In step S2, the comparison unit 11 compares the potential _{V IN} of the input signal IN, and the potential _{V FB} of the feedback signal FB, the. Then, when the potential _{V IN} of the input signal IN is the equal to the potential _{V FB} of the feedback signal FB shifts to the step S3, the potential _{V IN} of the input signal IN is not equal to the potential _{V FB} of the feedback signal FB is Move on to step S4.

In step S3, the potential V _CNT1 of the control signal CNT1 is set to VGL, and the potential V _CNT2 of the control signal CNT2 is set to VGL. Specifically, the comparison unit 11 supplies a low level signal to the first unit control unit 12 and supplies a low level signal to the second unit control unit 13. Accordingly, the first unit control unit 12 sets the potential V _CNT1 of the control signal CNT1 to VGL, and the second unit control unit 13 sets the potential V _CNT2 of the control signal _CNT2 to VGL. Accordingly, the driving of the first driving unit 130 and the second driving unit 140 is stopped. Then, when this process ends, the process proceeds to step S2.

In step S4, the comparison unit 11 compares the potential _{V IN} of the input signal IN, and the potential _{V FB} of the feedback signal FB, the. Then, when the potential _{V IN} of the input signal IN is lower than the potential _{V FB} of the feedback signal FB shifts to the step S5, the potential _{V IN} of the input signal IN is not lower than the potential _{V FB} of the feedback signal FB is Control goes to step S6.

In step S5, the potential V _CNT1 of the control signal CNT1 is set to VGH, and the potential V _CNT2 of the control signal CNT2 is set to VGL. Specifically, the comparison unit 11 supplies a Hi level signal to the first unit control unit 12 and supplies a Low level signal to the second unit control unit 13. Accordingly, the first unit control unit 12 sets the potential V _CNT1 of the control signal CNT1 to VGH, and the second unit control unit 13 sets the potential V _CNT2 of the control signal _CNT2 to VGL. Accordingly, the first driving unit 130 is driven, and the second driving unit 140 is stopped from driving. Then, when this process ends, the process proceeds to step S2.

In step S6, the potential V _CNT1 of the control signal CNT1 is set to VGL, and the potential V _CNT2 of the control signal CNT2 is set to VGH. Specifically, the comparison unit 11 supplies a low level signal to the first unit control unit 12 and supplies a high level signal to the second unit control unit 13. Accordingly, the first unit control unit 12 sets the potential V _CNT1 of the control signal CNT1 to VGL, and the second unit control unit 13 sets the potential V _CNT2 of the control signal _CNT2 to VGH. According to this, the first driving unit 130 is stopped from driving, and the second driving unit 140 is driven. Then, when this process ends, the process proceeds to step S2.

  According to the digital amplifier 1 described above, the following effects can be obtained.

Digital amplifier 1, the potential _{V IN} of the input signal IN is the equal to the potential _{V FB} of the feedback signal FB stops driving of the first driving unit 130 and the second driving unit 140.

Therefore, when the potential _{V IN} of the input signal IN is equal to the potential _{V FB} of the feedback signal FB is, the driving of the first driving unit 130 and the second driving unit 140 is stopped, the electric potential _{V IN} of the input signal IN The power consumption can be reduced as compared with the case where the first drive unit 130 and the second drive unit 140 always operate at a corresponding cycle.

Further, when the potential _{V IN} of the input signal IN is equal to the potential _{V FB} of the feedback signal FB is, the driving of the first driving unit 130 and the second driving unit 140 is stopped, the voltage is supplied to the filter unit 150 As a result, no voltage is output from the filter unit 150. For this reason, no ripple occurs in the output signal OUT output from the filter unit 150. Therefore, in the filter unit 150 which is a circuit for reducing the ripple of the output signal OUT, the inductance of the inductor provided in the filter unit 150 can be reduced, and the circuit scale can be reduced.

The digital amplifier 1, the potential _{V IN} of the input signal IN is higher than the potential _{V FB} of the feedback signal FB is to stop the driving of the first driving unit 130 to drive the second driving unit 140. On the other hand, the potential _{V IN} of the input signal IN is lower than the potential _{V FB} of the feedback signal FB is configured to drive the first driving unit 130 stops driving the second driving unit 140.

  For this reason, a period in which the first driving unit 130 and the second driving unit 140 are simultaneously driven cannot occur, and therefore, a period between the period in which the first driving unit 130 is driven and the period in which the second driving unit 140 is driven. It is not necessary to provide a dead time period. Therefore, the design of the digital amplifier 1 can be facilitated.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made without departing from the gist of the present invention.

  For example, in the above-described embodiment, the digital amplifier is configured by using the control unit 10, the first drive unit 130, and the second drive unit 140. However, the present invention is not limited thereto, and for example, a charger or a discharger is configured. May be.

  The present invention can be applied to power conversion devices such as amplifiers, chargers, and dischargers.

1, 100; digital amplifier 10, 110; control unit 11; comparison unit 12; first unit control unit 13; second unit control unit 130; first driving unit 140; second driving unit 150;

Claims (3)

A potential control unit for controlling the potential at a specific point;
A drive control unit that controls driving of the potential control unit based on the potential of the input signal and the potential of the specific point;
A ripple reducing unit configured to include an inductor and a capacitor, and to reduce voltage ripple based on the voltage supplied from the potential control unit;
With
The signal output from the ripple reduction unit is fed back to the drive control unit, and the potential of the feedback is set to the potential of the specific point,
The potential controller is
A first driving unit for supplying a voltage of a first potential to the specific point;
A second driving unit that supplies a voltage of a second potential higher than the first potential to the specific point;
With
The drive control unit
When the potential of the input signal is higher than the potential at the specific point, the second driving unit is driven and the driving of the first driving unit is stopped,
When the potential of the input signal is equal to the potential at the specific point, the driving of the first driving unit and the second driving unit is stopped,
When the potential of the input signal is lower than the potential at the specific point, the power converter is configured to drive the first drive unit and stop driving the second drive unit. The drive control unit
A comparison unit that compares the potential of the input signal with the potential of the specific point;
A first unit drive control unit that controls driving of the first drive unit based on a comparison result by the comparison unit;
A second unit drive control unit that controls driving of the second drive unit based on a comparison result by the comparison unit;
The power converter according to claim 1 , further comprising: The first unit drive control unit determines a difference between the potential of the input signal and the potential of the specific point when the potential of the input signal is lower than the potential of the specific point based on a comparison result by the comparison unit. Driving the first driving unit only for a period according to
The second unit drive control unit determines a difference between the potential of the input signal and the potential of the specific point when the potential of the input signal is higher than the potential of the specific point based on the comparison result by the comparison unit. The power conversion device according to claim 2 , wherein the second drive unit is driven for a period according to.

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