JP2000014129A - Power device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the increase in the ripple current on an input side at a simultaneous-on time of a plurality of switching-type regulators, by providing a switching operation scattering means for scattering the switching timings of necessary regulators from among a plurality of switching-type regulators. SOLUTION: A saw-tooth wave from a chopped wave generating means 3 is delayed by a delaying means 6, so that the delay quantities of a switching operation scattering means differ, and these saw-tooth waves having different delay quantities are inputted to respective DC/DC converter blocks 1, 2. When only the DC/DC converter 1 is operating, a reference voltage generating means generates a standard voltage for comparing the difference from a target output voltage Vout1 and outputs it to a comparing means. Since a saw-tooth wave delayed against a saw-tooth wave inputted into the DC/DC converter 1 is inputted by the delaying means 6, peaks of a ripple current flowing in an input smoothing capacitor at this time are scattered, as compared with those generated in the DC/DC converter 1, and the peak of a resultant ripple current can be lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a power supply device,
The present invention mainly relates to a power supply device using a switching regulator.

[0002]

2. Description of the Related Art A conventional power supply device includes a DC / DC converter as a switching regulator which converts an input voltage to a target output voltage and outputs the converted output voltage.

Here, as a conventional power supply device, as shown in FIG. 8, a common input voltage Vin is input to two DC / DC converters 1 and 2, and a target output voltage Vout1 is output.
An example in which the output is converted to Vout2 will be described as an example.

This power supply device has a common input voltage Vin and a triangular wave generating means 3 which is an oscillator for generating a sawtooth signal.
DC / DC which is a circuit block for converting
And a switching operation of the DC / DC converters 1 and 2 based on a sawtooth signal from the triangular wave generating means 3, and a common input voltage for the DC / DC converters 1 and 2. Vin is converted and output to target output voltages Vout1 and Vout2, respectively.

[0005] For example, this DC / DC converter 1
As shown in FIG. 9, the reference voltage generation means 11, the comparison means 12, the PWM comparator 13, the switching means 14, the input smoothing capacitor 15, the diode 16, the coil 17, the resistors 18a and 18b, and the output smoothing capacitor 1.
9. Also, DC / DC converter 2
Is similarly configured.

Here, the common input voltage V
The operation of converting and outputting “in” to target output voltages Vout1 and Vout2 will be described. The sawtooth wave T shown in FIG. 10 generated by the triangular wave generating means 3 is input to each of the DC / DC converters 1 and 2 at the same timing as shown in FIG.

Here, a case where only the DC / DC converter 1 of the DC / DC converters 1 and 2 is operating will be described. As shown in FIG. 9, the reference voltage generating means 11 outputs the target output voltage Vout1.
A standard voltage for comparing the deviation from the standard voltage is generated and output to the comparing means 12. The comparing means 12 compares the standard voltage from the reference voltage generating means 11 with the voltage fed back from the output voltage to determine the error amount E as the PWM comparator 13.
Output to

In the PWM comparator 13, FIG.
As shown in (a), a switching drive signal obtained by calculating the sawtooth wave T from the triangular wave generating means 3 and the error amount E from the comparing means 12 is supplied to the switching means 14.
The switching means 14 performs a switching operation based on the switching drive signal so as to maintain and output the target output voltage Vout1 according to the open / close ratio of the switching means 14. At this time, the ripple current R1 flowing through the input smoothing capacitor 19 becomes a current as shown in FIG.

In the case where only the DC / DC converter 1 is operating but not the DC / DC converter 1, only the DC / DC converter 2 operates.
It operates in the same manner as the DC / DC converter 1 described above, and performs a switching operation so as to output a target output voltage Vout2. At this time, the ripple current R2 flowing through the input smoothing capacitor 19 of the DC / DC converter 2 is as shown in FIG.
The current is as shown in FIG.

[0010]

However, in the conventional power supply device, as shown in FIG. 10, the switching operation of the DC / DC converters 1 and 2 generates a ripple current on the input side of the power supply device. The input smoothing capacitors 19 of the DC / DC converters 1 and 2 provided on the input side of the power supply device are required to have a large allowable ripple current value.

Further, a common input voltage Vin is supplied to a plurality of DCs.
In a power supply device that converts and outputs a target output voltage with a DC / DC converter, a ripple current generated by a switching operation of each DC / DC converter is combined, and there is a problem that a larger ripple current is generated. Specifically, in a power supply device using two DC / DC converters 1 and 2 as shown in FIG.
The ripple current R1 shown in FIG. 10A and the ripple current R2 shown in FIG. 10B generated by the switching operation of the DC / DC converter 2 are combined, and as shown in FIG. There is a problem that R occurs.

In addition to the above-described power supply device, as shown in FIG. 11, an output voltage Vout1 is supplied to an MPU (microprocessor unit) 5 or the like as a load operated by a reference clock from a reference clock generating means 4. In the case of the power supply device provided with the DC / DC converter 1 as a switching regulator, the output voltage Vout is generated by the current consumption that changes with the transition of the operation clock of the MPU 5.
1 has a problem that a ripple occurs.

More specifically, since the MPU 5 operates with this reference clock, the current consumption of the MPU 5 has a waveform as shown in FIG. 6A, and the conventional output voltage Vout1 of the DC / DC converter 1 has a ripple. It has occurred.

The present invention suppresses an increase in the input-side ripple current that occurs when a plurality of switching regulators are simultaneously turned on, smoothes the input-side current consumption, and supplies the load to a load that operates on a reference clock. An object is to provide a power supply device in which an output voltage is smoothed.

[0015]

According to the power supply device of the present invention, the switching timing of a required switching regulator among a plurality of switching regulators is dispersed so as to reduce the peak of a combined ripple current generated on the input side. A switching operation dispersing means is provided.

According to the present invention, it is possible to suppress an increase in the ripple current on the input side which occurs when a plurality of switching regulators are simultaneously turned on, and to smooth the current consumption on the input side.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION
In a power supply device that inputs a common input voltage to a plurality of switching regulators and converts the output to a desired output voltage, a plurality of switching regulators are used to reduce the peak of a combined ripple current generated on the input side. This is a power supply device provided with switching operation dispersing means for dispersing the switching timing of a required switching regulator, and can suppress an increase in input-side ripple current that occurs when a plurality of switching regulators are simultaneously turned on. , The current consumption on the input side can be smoothed.

According to a second aspect of the present invention, the switching operation distributing means is configured to delay a reference signal for determining switching timing as compared with one switching type regulator and to input the reference signal to the other switching type regulator. A power supply device according to claim 1.

According to a third aspect of the present invention, in a power supply device provided with a switching regulator for supplying an output voltage to a load operated by a reference clock, a peak of a ripple generated in the output voltage is reduced. The power supply device includes a timing adjustment unit that adjusts a timing between a switching drive signal for performing a switching operation of the switching regulator and the reference clock. The power supply device includes a load-side operation clock and a switching operation timing of a DC / DC converter. By optimizing, it is possible to supply a good power supply voltage with almost no ripple in the output voltage. In addition, quick power supply can be performed to a load that consumes a large current.

Hereinafter, a power supply device of the present invention will be described based on specific embodiments. (Embodiment 1) A power supply according to Embodiment 1 of the present invention
As shown in FIG. 1, switching operation dispersing means for dispersing switching timing of DC / DC converters 1 and 2 as a plurality of switching regulators so as to reduce a peak of a combined ripple current generated on an input side is provided. It is. The switching operation dispersing means is configured to delay the reference signal output from the triangular wave generating means 3 for determining the switching timing as compared with the DC / DC converter 1 and to input the delayed reference signal to the DC / DC converter 2.

The switching operation distribution means includes, for example, a delay means 6. The DC / DC converters 1 and 2 have the same configuration as the conventional one, as shown in FIG. Here, a common input voltage Vin is set to 2
The operation of inputting the DC / DC converters 1 and 2 and converting the output to the desired output voltages Vout1 and Vout2 will be described.

As shown in FIG. 1, the sawtooth wave T from the triangular wave generating means 3 is delayed by the delay means 6 so as to have different delay amounts.
/ DC converter blocks 1 and 2. D
As shown in FIG. 3, the sawtooth wave T input to the C / DC converter 2 is input later than the DC / DC converter 1 by the time t1.

Here, a case where only the DC / DC converter 1 of the respective DC / DC converters 1 and 2 is operating will be described. As shown in FIG. 2, the reference voltage generating means 11 outputs the target output voltage Vout1.
A standard voltage for comparing the deviation from the standard voltage is generated and output to the comparing means 12. The comparing means 12 compares the standard voltage from the reference voltage generating means 11 with the voltage fed back from the output voltage to determine the error amount E as the PWM comparator 13.
Output to

In this PWM comparator 13, FIG.
As shown in (a), the sawtooth wave T from the triangular wave generation means 13
And the error amount E from the comparison means 12
The value output is supplied to the switching means 14 as a switching drive signal. The switching means 14 performs a switching operation based on the switching drive signal so as to maintain and output the target output voltage Vout1 according to the open / close ratio of the switching means 14.

The input smoothing capacitor 15 supplies a current flowing at the moment when the switching means 14 is turned on, and smoothes the inflow of the current from the input side. At this time, the ripple current R1 flowing through the input smoothing capacitor 15 is as shown in FIG.
The current is as shown in FIG. The coil 17 and the output smoothing capacitor 19 smooth the output voltage. The diode 16 becomes a current path of the coil 17 which is a current supply source while the switching means 14 is off.

If only the DC / DC converter 2 is operating instead of the DC / DC converter 1, the DC / DC converter 2 has a DC / DC converter as shown in FIG. Sawtooth T input to DC converter 1
Since the sawtooth wave T, which is delayed as compared with the above, is input by the delay means 6, the ripple current R2 flowing through the input smoothing capacitor 15 at this time is, as shown in FIG. 1 is a ripple current R2 whose peak is dispersed as compared with the ripple current R1 generated by R1.

Here, two DC / DC converters 1,
2 is operating, the combined ripple current R is as shown in FIG.
As shown in (c), the ripple current R1 generated by the switching operation of the DC / DC converter 1 and the DC / D
The ripple current R2 generated by the switching operation of the C converter 2 is combined, and is canceled out by the dispersed peaks, resulting in a combined ripple current R having a small peak.

With this configuration, the peak of the combined ripple current R generated on the input side can be reduced.
The current on the input side can be smoothed, and it is not necessary to use an input smoothing capacitor having a large allowable ripple current value as in the related art, and an input smoothing capacitor having a small allowable ripple current value can be used.

In the first embodiment, the switching operation dispersing means is constituted by the delay means 4 and the required switching timings of the switching regulators are shifted to disperse them. However, as shown in FIG. Reference clock generator 7 and PLL (Phase Locke
d Loop The same effect can be obtained even when the circuit is configured with the circuit 8 and the timing is adjusted by the PLL circuit 8 to disperse the necessary switching timing of the switching regulator.

In the first embodiment, the switching timing of the two switching regulators is shifted and dispersed by the switching operation dispersing means.
The same effect can be obtained even when the switching operation dispersing means is configured to shift and disperse the switching timing of the required switching regulator among the plurality of switching regulators.

(Embodiment 2) A power supply apparatus according to Embodiment 2 of the present invention is a DC / DC as a switching regulator so as to reduce a peak of a ripple generated in an output voltage Vout1 as shown in FIG. It is provided with timing adjusting means 9 for adjusting the timing between a switching drive signal for switching operation of the converter 1 and a reference clock. The timing adjusting means 9 adjusts the phase of the sawtooth wave T with respect to the reference clock from the reference clock generating means 4, and causes the triangular wave generating means 3 to generate the sawtooth wave T phase-locked to the reference clock. It is configured.

The power supply according to the second embodiment includes, for example,
It is used in mobile phones and electronic organizers, and controls the mobile phone and electronic organizer to supply power to an MPU (microprocessor unit) that operates on a reference clock.

Since the DC / DC converter 1 is the same as that of the first embodiment, a detailed description thereof will be omitted here. Here, in the power supply device provided with the DC / DC converter 1, the MP as the load operated by the reference clock is used.
An operation of supplying an output voltage to U5 and the like will be described.

The reference clock from the reference clock generator 4 is input to the MPU 5 and the timing adjuster 9 as shown in FIG. The MPU 5 operates with this reference clock.

As shown in FIG. 6, the timing adjusting means 9 controls the power consumption in the MPU 5 and the DC / DC converter 1
The phase of the sawtooth wave T is adjusted with respect to the reference clock so that the timing with the supply of power in the step S11 is close to that of the reference clock. .

The triangular wave generating means 3 generates a sawtooth wave T phase-locked to the reference clock from the reference clock generating means 4 by the timing adjusting means 9 to obtain a DC / D signal.
Input to the C converter 1.

As described above, when the timing between the power consumption of the MPU 5 and the supply of the power of the DC / DC converter 1 is brought close to each other by adjusting the timing between the switching drive signal and the reference clock, FIG. The current flowing into the output smoothing capacitor 19 of the DC / DC converter 1 has a waveform as shown in FIG. 6B, and the final output voltage Vout1 is an output voltage with small ripple.

With this configuration, by optimizing the operation clock on the load side and the timing of the switching operation of the DC / DC converter 1, power consumption in the MPU 5 and power supply in the DC / DC converter 1 can be reduced. And the occurrence of ripples in the output voltage Vout1 is suppressed, and a good power supply voltage with almost no ripples can be supplied to the output voltage Vout1. In addition, quick power supply can be performed to a load that consumes a large current.

In the second embodiment, the timing adjusting means for adjusting the timing between the switching drive signal for switching the switching regulator and the reference clock is provided. However, as shown in FIG. The same effect can be obtained even when the timing adjusting means is provided inside.

In each of the above embodiments, a DC / DC converter is used as the switching regulator. However, the configuration of the DC / DC converter block is not particularly limited. The same effect can be obtained if the power supply device uses the switching type regulator.

[0041]

As described above, according to the power supply device of the present invention, the switching timing of the switching regulator required among the plurality of switching regulators is reduced so as to reduce the peak of the combined ripple current generated on the input side. By providing the switching operation dispersing means for dispersing, the peak of the ripple current generated by the switching operation of the switching regulator can be dispersed, and the peak of the combined ripple current generated on the input side can be reduced. The current on the input side can be smoothed, and it is not necessary to use an input smoothing capacitor having a large allowable ripple current value as in the related art, and an input smoothing capacitor having a small allowable ripple current value can be used. In addition, since the peak value of the supply current on the input side (power supply side) can be suppressed, the battery drive time can be extended when applied to a battery drive device.

Further, in a power supply device provided with a switching regulator for supplying an output voltage to a load operated by a reference clock, a switching operation for switching the switching regulator so as to reduce a peak of a ripple generated in the output voltage. When the timing adjusting means for adjusting the timing between the drive signal and the reference clock is provided, the output voltage has almost no ripple by optimizing the operation clock on the load side and the switching operation timing of the DC / DC converter. Power supply voltage can be supplied.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a power supply device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a DC / DC converter according to the first embodiment;

FIG. 3 is a diagram showing signal waveforms of main parts of the power supply device according to the first embodiment;

FIG. 4 is a block diagram showing a power supply device different from the first embodiment of the present invention;

FIG. 5 is a block diagram showing a power supply device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing signal waveforms of main parts of the power supply device according to the second embodiment.

FIG. 7 is a block diagram showing another power supply device according to the second embodiment;

FIG. 8 is a block diagram showing a conventional power supply device.

FIG. 9 is a block diagram showing a conventional DC / DC converter.

FIG. 10 is a diagram showing signal waveforms of main parts of a conventional power supply device.

FIG. 11 is a block diagram showing a power supply device for supplying an output voltage to a conventional MPU.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 DC / DC converter 2 DC / DC converter 3 Triangular wave generation means 6 Delay means 7 Reference clock generation means 8 PLL circuit 9 Timing adjustment means 15 Input smoothing capacitor 19 Output smoothing capacitor

Claims (3)

[Claims] In a power supply device for inputting a common input voltage to a plurality of switching regulators and converting and outputting them to target output voltages, a plurality of switching devices are provided so as to reduce a peak of a combined ripple current generated on an input side. A power supply device provided with switching operation distribution means for dispersing the switching timing of a required switching type regulator among the type regulators. 2. The power supply device according to claim 1, wherein the switching operation dispersing means is configured to delay a reference signal for determining a switching timing as compared with one switching regulator and to input the reference signal to the other switching regulator. 3. A power supply device provided with a switching regulator for supplying an output voltage to a load operated by a reference clock, wherein a switching operation of the switching regulator is performed so as to reduce a peak of a ripple generated in the output voltage. A power supply device provided with timing adjustment means for adjusting the timing between a drive signal and the reference clock.