JP2015061431A - Power supply device, method for controlling the same, and light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device capable of achieving high-speed responsiveness of output voltage control and the stability of an output voltage, with respect to the fluctuations of an input voltage caused by an external factor and to provide a method for controlling the power supply device and a light source device including the same.SOLUTION: The power supply device includes a digital power supply control part 10, a digital power supply power part 20, and a PWM adjustment part 30. The digital power supply control part 10 generates a PWM signal corresponding to an output current to a load 40 and outputs it to the digital power supply power part 20. The digital power supply power part 20 converts an input voltage Vin into an output voltage Vout having a predetermined voltage value, based on the PWM signal outputted from the digital power supply control part 10 and a Duty adjustment signal outputted from the PWM adjustment part 30, to supply the output voltage Vout to the load 40. The PWM adjustment part 30 generates the Duty adjustment signal for adjusting the Duty (ON time) of the PWM signal, based on the input voltage Vin and the output voltage Vout, to output the Duty adjustment signal to the digital power supply power part 20.

Description

  The present invention relates to a power supply device, a control method therefor, and a light source device, and more particularly to a power supply device applicable to driving a light source such as a video device, a printing device, and a copying machine, a control method therefor, and a light source device including the power supply device.

  In recent years, the price of high-performance DSPs (Digital Signal Processors) has been greatly reduced, and digital control systems have also been adopted in power supply units incorporated in relatively inexpensive products. Are beginning to be considered.

  The advantage obtained by digitalization of power supply control is that control of a plurality of complicated power supply configurations can be realized relatively easily. Also, in the field of light source drive technology such as video equipment, it is generally necessary to control the output current to be turned on and off at high speed for dimming, but the digital control method incorporates multiple feedback control characteristics. Therefore, there is an advantage that a high-speed response characteristic can be obtained as compared with the analog control method.

  In addition, since the control of state transition in the repetitive operation as described above can also correct the feedback transfer function by learning in the digital control method, a better control result can be obtained as compared with the power source of the analog control method. It has the merit of being able to.

  For such a digital control type power supply device, for example, Patent Document 1 discloses an input voltage detection circuit, an output circuit, a digital control unit including a digital control circuit and a digital PWM (Pulse Width Modulation) circuit, and , A digitally controlled switching power supply device is disclosed. And in this patent document 1, in addition to the output voltage from an output circuit to a load, the result which detected the input voltage is input into a digital control part, and operation | movement of an output circuit is described. In addition, about the power supply device which has a circuit structure substantially equivalent to patent document 1, it demonstrates as a comparative example in verification of the effect of this invention mentioned later.

JP2012-110201A

  In the above-mentioned Patent Document 1, the input voltage is accurately grasped, and the situation is reflected in the control, thereby realizing the optimum output voltage control and the problem of the stability of the output voltage due to the fluctuation of the input voltage. It is described that it is resolved. However, in an actual digital control system power supply device, since the DSP processing capability is still not sufficient, particularly when a plurality of channels (output voltages thereof) are controlled collectively, all channels are simultaneously feedback-controlled at the same time. There was a problem that could not be done.

  Therefore, it is necessary to perform intermittent control, but in that case, it has a demerit (response problem) that the response of digital control of output voltage is delayed with respect to fluctuation of input voltage due to external factors (disturbance). It was. In addition, when a plurality of output voltages are collectively controlled in a digitally controlled power supply device, the demerit (stability of stability) is likely to occur because of fluctuations in the input voltage that cause mutual interference between the output voltages. Problem).

  Therefore, in view of the above-described problems, the present invention provides a power supply apparatus capable of realizing high-speed response of output voltage control and stability of output voltage with respect to fluctuations in input voltage due to external factors, and a control method thereof. An object of the present invention is to provide a light source device including the same.

The power supply device according to the present invention is
An output signal control unit that converts an input signal into an output signal according to a PWM signal and outputs the output signal to a load;
A PWM signal generation unit that generates the PWM signal based on a feedback signal fed back according to the output signal to the load;
The on-time of the PWM signal according to the magnitude of the fluctuation amount of the input voltage with respect to the output signal and whether the fluctuation amount is a positive value or a negative value when the input signal fluctuates. A PWM adjustment unit for generating an adjustment signal for adjusting a parameter corresponding to at least one of a duty defining the frequency and the frequency of the PWM signal;
An operation control unit that adjusts the parameter of the PWM signal based on the adjustment signal and controls the conversion operation of the input signal into the output signal in the output signal control unit;
It is characterized by having.

The light source device according to the present invention includes:
Including the above power supply,
A plurality of light-emitting elements arranged one-dimensionally or two-dimensionally as the load;
The output signal control unit, the PWM adjustment unit, and the operation control unit are provided corresponding to each of the plurality of light emitting elements.

A method for controlling a power supply device according to the present invention includes:
The input signal is converted into an output signal according to the PWM signal and output to the load.
Generating the PWM signal based on a feedback signal fed back in response to an output signal to the load;
When the input signal fluctuates, during the adjustment period immediately after the input signal fluctuates, the magnitude of the fluctuation amount of the input signal with respect to the output signal when the input signal fluctuates, and An adjustment signal for adjusting a parameter corresponding to at least one of the duty defining the on-time of the PWM signal and the frequency of the PWM signal depending on whether the fluctuation amount is a positive value or a negative value. Continue generation,
During the adjustment period, the parameter of the PWM signal is adjusted based on the adjustment signal to control the conversion operation of the input signal to the output signal,
Stop generating the adjustment signal after the end of the adjustment period;
It is characterized by that.

  According to the power supply device, the control method thereof, and the light source device according to the present invention, it is possible to realize high-speed response of output voltage control and stability of output voltage against fluctuations in input voltage due to external factors.

1 is a schematic block diagram showing a first embodiment of a power supply device according to the present invention. It is a flowchart which shows the control method in the power supply device which concerns on 1st Embodiment. It is a figure which shows the concept of the control method applied to 1st Embodiment. It is a timing chart (the 1) which shows the specific example of the control method applied to 1st Embodiment. It is a timing chart (the 2) which shows the specific example of the control method applied to 1st Embodiment. It is a schematic block diagram which shows 2nd Embodiment of the power supply device which concerns on this invention. It is a flowchart which shows the signal control method of the power supply device which concerns on 2nd Embodiment. It is a figure which shows the concept of the control method applied to 2nd Embodiment. It is a timing chart (the 1) which shows the specific example of the control method applied to 2nd Embodiment. It is a timing chart (the 2) which shows the specific example of the control method applied to 2nd Embodiment. It is a schematic block diagram which shows 3rd Embodiment of the power supply device which concerns on this invention. It is a flowchart which shows the signal control method of the power supply device which concerns on 3rd Embodiment. It is a timing chart which shows the specific example of the control method applied to 3rd Embodiment. It is a schematic block diagram which shows 4th Embodiment of the power supply device which concerns on this invention. It is a flowchart which shows the signal control method of the power supply device which concerns on 4th Embodiment. It is a timing chart which shows the specific example of the control method applied to 4th Embodiment. It is a schematic block diagram which shows an example of the power supply device used as the comparison object of this invention. It is a timing chart (the 1) in the signal control method applied to a comparative example. It is a timing chart (the 1) in the signal control method applied to a comparative example. It is a schematic block diagram which shows one structural example at the time of applying the power supply device which concerns on this invention as a power supply device of a line light source. It is a schematic block diagram which shows the 1st example (projector) of a light source device provided with the power supply device which concerns on this invention. It is a schematic block diagram which shows the 2nd example (printer) of a light source device provided with the power supply device which concerns on this invention.

Hereinafter, a power supply device, a control method thereof, and a light source device according to the present invention will be described in detail with reference to embodiments. Here, as an embodiment, LED (Light Emitting
The case where the present invention is applied to a drive circuit having a load of a diode (light emitting diode) will be described. However, the present invention does not limit the circuit system or the type of load. For example, an LD (laser diode) is used as a load. It may be a thing.

<First Embodiment>
(Power supply)
FIG. 1 is a schematic block diagram showing a first embodiment of a power supply device according to the present invention.

The first embodiment of the power supply device according to the present invention has a circuit configuration and a control method for adjusting the duty (duty: ON time in PWM control) of a PWM signal in accordance with a change in input voltage due to disturbance. Yes.
Specifically, the power supply device according to the first embodiment is roughly divided into a digital power supply control unit (PWM signal generation unit) 10 and a digital power supply power unit (output voltage control unit) as shown in FIG. 20 and a PWM adjustment unit 30.

  The digital power supply control unit 10 includes an ADC (analog-digital converter) 11, a digital control unit 12 having an arithmetic circuit, and an oscillation circuit 13, and generates a PWM signal corresponding to the output current to the load 40. And output to the digital power supply power unit 20. Here, the ADC 11 generates a digital control feedback signal corresponding to the output current supplied to the load 40 such as an LED. Further, the digital control unit (arithmetic circuit) 12 generates a PWM signal for controlling the operation of the digital power source power unit 20 based on the digital control feedback signal, and supplies the PWM signal to the duty adjustment circuit 21 of the digital power source power unit 20. Output. The oscillation circuit 13 supplies an operation clock (reference clock) having a predetermined frequency that defines the operation of the digital control unit 12.

  The digital power source power unit 20 includes a duty adjustment circuit (operation control unit) 21, an output circuit including a switching element (SW) 22 and a diode (D) 23, and a smoothing including an inductor (L) 24 and a capacitor (C) 25. And an output current detection circuit having a current detection resistor (Rs) 26 and a current detection amplifier (AMP) 27. The digital power source power unit 20 outputs the input voltage Vin (input signal) to the PWM system based on the PWM signal output from the digital power source control unit 10 and the duty adjustment signal output from the PWM adjustment unit 30 described later. Is converted into an output voltage Vout (output signal) having a predetermined voltage value and supplied to the load 40.

  Here, the duty adjustment circuit 21 has an exclusive OR circuit (XOR gate), and outputs a logical output having the PWM signal and the duty adjustment signal as inputs to the switching element (SW) 22 as an SW control signal. To do. The switching element (SW) 22 is controlled to be conductive (ON / OFF) based on the SW control signal output from the duty adjustment circuit 21, and the diode (D) 23 is switched to the conductive state of the switching element (SW) 22. Work on the basis. Further, the smoothing circuit (inductor (L) 24, capacitor (C) 25) smoothes the voltage component generated by the output circuit (switching element (SW) 22, diode (D) 23) to obtain the output voltage Vout. Output. The output current detection circuit detects the output current based on the voltage difference between both ends of the current detection resistor (Rs) 26 by the output current detection AMP 27, and causes the ADC 11 of the digital power supply control unit 10 to respond to the current value of the output current. A detection signal is output.

  The PWM adjustment unit 30 includes a comparison circuit 31, a DC component cut circuit 32, a voltage pulse width conversion circuit 33, a voltage frequency conversion circuit 34, and a gate and phase shift circuit (“gate & phase shift” in the drawing). 35). The PWM adjustment unit 30 generates a duty adjustment signal for adjusting the duty (ON time) of the PWM signal based on the input voltage Vin and the output voltage Vout, and outputs the duty adjustment signal to the digital power supply power unit 20. Here, the comparison circuit 31 compares the input voltage Vin and the output voltage Vout, and generates a comparison output having a level corresponding to the difference between the input voltage Vin and the output voltage Vout. The DC component cut circuit 32 cuts the direct current component of the comparison output, so that when the input voltage Vin fluctuates, the magnitude component of the fluctuation amount of the input voltage Vin with respect to the output voltage Vout, and the fluctuation thereof. It is extracted whether the quantity is a positive value or a negative value (that is, whether the input voltage Vin has increased or decreased with respect to the output voltage Vout). The voltage pulse width conversion circuit 33 outputs a signal having a pulse width determined based on the magnitude of the fluctuation amount. The voltage frequency conversion circuit 34 outputs a length signal corresponding to the number of pulse outputs determined based on the magnitude of the fluctuation amount. The gate and phase shift circuit 35 applies a pulse signal having the pulse width determined by the voltage pulse width conversion circuit 33 to the number of times determined by the voltage frequency conversion circuit 34, with the fluctuation amount being a positive value or a negative value. The phase is shifted according to whether or not there is a duty adjustment signal synchronized with the reference clock supplied from the oscillation circuit 13.

(Control method)
Next, a control method (PWM signal duty adjustment method) executed by the PWM adjustment unit 30 in the power supply apparatus having the above-described circuit configuration will be described.

  FIG. 2 is a flowchart illustrating a control method in the power supply device according to the present embodiment. FIG. 3 is a diagram illustrating a concept of a control method applied to the present embodiment. Here, FIGS. 3A and 3B are conceptual diagrams showing a configuration relating to the duty adjustment method of the PWM signal according to the present embodiment, and FIGS. 3C and 3D are illustrated according to the present embodiment. It is a timing chart which shows the concept of the duty adjustment method of the PWM signal implement | achieved. 4 and 5 are timing charts showing specific examples of the control method applied to the present embodiment. Here, FIG. 4 is a timing chart when the input voltage fluctuates in the power supply apparatus according to the present embodiment, and FIG. 5 is a timing chart when the input voltage fluctuates.

  In the control method (PWM signal duty adjustment method) in the power supply device according to the present embodiment, first, the comparison circuit 31 of the PWM adjustment unit 30 compares the input voltage Vin with the output voltage Vout, as shown in the flowchart of FIG. Then, a comparison output having a level proportional to the difference is generated (step S101). Next, based on the comparison output from the comparison circuit 31, the DC component cut circuit 32 determines whether or not the difference between the input voltage Vin and the output voltage Vout has changed (step S102). When it is determined that the difference has changed, the DC component cut circuit 32 causes the magnitude component of the fluctuation amount of the input voltage Vin to the output voltage Vout and the fluctuation amount to be a positive value or a negative value. Is extracted (step S103). On the other hand, when it is not determined that the difference has changed, the processes of steps S101 and S102 are repeatedly executed. That is, in this state, the duty adjustment signal is not output from the PWM adjustment unit 30, and the PWM generated by the digital power supply control unit 10 (digital control unit 12) is supplied to the switching element (SW) 22 of the digital power supply power unit 20. The signal is supplied as it is as a SW control signal.

  Next, the voltage frequency conversion circuit 34 calculates an adjustment period corresponding to the extracted amount of fluctuation (step S104). Specifically, the voltage frequency conversion circuit 34 determines the number of pulse outputs based on the extracted fluctuation amount, and generates a length signal (adjustment period signal) that defines an adjustment period according to the number of pulse outputs. Output. Also, before or after step S104, or in parallel with step S104, the voltage pulse width conversion circuit 33 calculates a duty adjustment width corresponding to the extracted amount of variation (step S105). Specifically, the pulse width is determined based on the extracted amount of variation, and a width signal (Duty adjustment signal) that defines the duty adjustment width according to the width is output. Next, the phase of the duty adjustment signal whose duty adjustment width is calculated by the gate and phase shift circuit 35 is shifted depending on whether the extracted fluctuation amount is a positive value or a negative value, This is output to the duty adjustment circuit 21 of the digital power source power unit 20 (step S106).

  At this time, it is constantly monitored whether or not the duty adjustment signal is output during the adjustment period calculated by the voltage frequency conversion circuit 34 (step S107). When it is determined that the duty adjustment signal is output during the adjustment period, it is determined that the adjustment period for outputting the duty adjustment signal to the duty adjustment circuit 21 of the digital power source power unit 20 has ended. Returning to step S101, the above-described series of processing of steps S101 to S107 is repeatedly executed. On the other hand, if it is not determined that the duty adjustment signal has been output during the adjustment period, the process returns to step S106 and the operation of outputting the duty adjustment signal to the duty adjustment circuit 21 of the digital power source power unit 20 is repeated. Run.

  The control method executed by the PWM adjustment unit 30 described above is, for example, whether or not the input voltage Vin is interrupted prior to the process of comparing the input voltage Vin and the output voltage Vout in step S101, and the control method (PWM signal). (Duty adjustment method) The presence / absence of the end instruction of itself is detected, and when the input voltage Vin is interrupted or the end of the process is instructed, a series of processes (steps S101 to S107) are stopped.

  As a result, in this embodiment, the duty adjustment signal having the pulse width determined by the voltage pulse width conversion circuit 33 is applied to the DC component cut circuit only during the adjustment period corresponding to the number of pulse outputs determined by the voltage frequency conversion circuit 34. The phase is shifted according to whether the fluctuation amount extracted by 32 is a positive value or a negative value, and is output to the duty adjustment circuit 21 of the digital power source power unit 20. The exclusive OR circuit of the duty adjustment circuit 21 receives the PWM signal output from the digital control unit 12 of the digital power supply control unit 10 and the duty adjustment signal output from the PWM adjustment unit 30. The conduction state of the switching element (SW) 22 is controlled by the SW control signal that is the logic output, and output voltage control is executed as described later (see FIGS. 4 and 5).

  Here, in the present embodiment, the voltage frequency conversion circuit 34 calculates (determines) an adjustment period for adjusting the duty of the PWM signal according to the amount of fluctuation of the input voltage Vin with respect to the output voltage Vout due to disturbance. The method was shown. The present invention is not limited to this method, and a preset fixed period may be applied as the adjustment period. According to this, the process for determining the adjustment period can be omitted, and the processing burden on the power supply device can be reduced. This fixed period is set to a time corresponding to a digital control reaction disabled time caused by a control delay of the digital control unit 12.

  In the present embodiment, the voltage pulse width conversion circuit 33 calculates (determines) the adjustment width of the duty of the PWM signal in accordance with the amount of fluctuation of the input voltage Vin with respect to the output voltage Vout due to disturbance. Indicated. The present invention is not limited to this method, and a preset fixed value may be applied as the duty adjustment width. According to this, the process for determining the duty adjustment width can be omitted, and the processing burden on the power supply device can be reduced.

In the present embodiment, the pulse widths of the plurality of SW control signals output from the duty adjustment circuit 21 to the switching element (SW) 22 are set to the same duty during the adjustment period calculated by the voltage frequency conversion circuit 34. The method of adjusting to become is shown. The present invention is not limited to this, and the pulse widths of the plurality of SW control signals output within the adjustment period may be adjusted so as to change for each SW control signal (pulse signal). Good.
Note that the PWM signal adjustment period and the duty adjustment width setting method in the control method according to this embodiment described above are similarly applied to other embodiments described later.

The PWM signal duty adjustment method applied to the above-described output voltage control can be described based on the following concept.
In the present embodiment, as shown in FIGS. 3A and 3B, the PWM signal Sa output from the digital control unit 12 of the digital power supply control unit 10 and the PWM adjustment unit 30 output the PWM signal. Based on the duty adjustment signal Sb that defines the adjustment range of the duty, the duty (ON time) of the PWM signal is adjusted and output to the switching element (SW) 22 as the SW control signal (PWM signal after adjustment) Sc. A duty adjustment circuit 21 is provided. Here, in the present embodiment, as shown in FIG. 3B, a configuration in which an exclusive OR circuit (XOR gate) is applied as an example of the duty adjustment circuit 21 is shown. Note that the duty adjustment circuit 21 is not limited to this configuration, and other configurations may be applied as long as an equivalent duty adjustment function can be realized. For example, in the output voltage control, an AND circuit (AND gate) can be applied when the input voltage Vin varies upward, and an OR circuit (OR gate) can be applied when the input voltage Vin varies downward.

  In addition, the duty adjustment signal Sb output from the PWM adjustment unit 30 defines the duty adjustment width of the PWM signal Sa and is given a polarity code according to the increase / decrease in the fluctuation of the input voltage Vin. As a result, when the polarity sign is positive, the duty of the SW control signal (PWM signal after adjustment) Sc is increased (extended) by the adjustment width, and when the polarity sign is negative, the duty of the SW control signal Sc is increased. It can be reduced (limited) by the adjustment width. Thus, by giving polarity to the duty adjustment signal Sb, it is possible to cope with both fluctuations in the rise and fall of the input voltage Vin.

  That is, as shown in FIG. 3C, when a specific rising timing of the PWM signal is used as a reference, the phase advance with respect to the reference is defined as positive, and the duty adjustment signal Sb output from the PWM adjustment unit 30. Is set to positive, the duty (ON time) of the SW control signal Sc that is a logical output (adjustment result) in the duty adjustment circuit (exclusive OR circuit) 21 can be increased. On the other hand, as shown in FIG. 3 (d), by setting the phase delay to be negative with respect to the reference and setting the polarity sign of the duty adjustment signal Sb to be negative, the duty adjustment circuit (exclusive OR) The duty (ON time) of the SW control signal Sc that is a logic output (adjustment result) in the circuit 21 can be reduced.

Specifically, the following output voltage control is executed based on the concept of the PWM signal duty adjustment method described above.
First, as shown in the timing chart of FIG. 4, when the input voltage Vin suddenly changes (rising fluctuation), the voltage pulse width conversion is performed only during the adjustment period according to the number of times determined by the voltage number conversion circuit 34 of the PWM adjustment unit 30. The circuit 33 outputs a duty adjustment signal set to lower the duty of the PWM signal. As a result, as shown in FIG. 3D, the pulse width of the SW control signal output to the switching element (SW) 22 is reduced. As a result, the duty of the switching element (SW) 22 is reduced (ON). Therefore, the transmission energy is optimized and the output voltage Vout is stabilized. Then, after the adjustment period ends, the output of the duty adjustment signal is stopped. At this time, since digital control functions normally, the duty of the SW control signal is continuously adjusted as described above, and a stable output voltage Vout is output.

On the other hand, as shown in the timing chart of FIG. 5, when the input voltage Vin suddenly changes (falls down), the PWM signal is converted by the voltage pulse width conversion circuit 33 during the adjustment period corresponding to the number of times determined by the voltage number conversion circuit 34. A duty adjustment signal set so as to increase the duty is output. As a result, as shown in FIG. 3C, the pulse width of the SW control signal is extended. As a result, the duty of the switching element (SW) 22 is increased (the ON time is increased), so that the transmitted energy is reduced. As a result, the output voltage Vout is stabilized. Then, after the adjustment period ends, the output of the duty adjustment signal is stopped. At this time, since digital control functions normally, the duty of the SW control signal is continuously adjusted as described above, and a stable output voltage Vout is output.
In the timing charts shown in FIGS. 4 and 5, the output voltage Vout (when the duty is not adjusted) in a comparative example of the present invention to be described later is indicated by a bold dotted line.

  Further, in the above-described embodiment, when a new change in the input voltage Vin occurs during the adjustment period in which the duty adjustment signal is output to the duty adjustment circuit 21, it is shown in FIGS. 3 (a) and 3 (b). The following control is executed by the duty adjustment unit of the PWM signal including the digital control unit 12, the duty adjustment circuit 21, and the PWM adjustment unit 30. That is, by adding a polarity to the duty adjustment signal that defines the duty adjustment width of the PWM signal, if a new change in the input voltage Vin having the same polarity occurs, the duty depends on the degree of the change. The control for adding the adjustment width is performed. On the other hand, if a change in the input voltage Vin having a different polarity occurs, control is performed to subtract the adjustment width of the duty according to the degree of the change. Then, by reflecting the result as a new duty adjustment width in the SW control signal, even if a new input voltage change occurs during the adjustment period, an output voltage at which a stable output voltage Vout is output. Control can be realized.

<Second Embodiment>
Next, a second embodiment of the power supply device according to the present invention will be described.
In the first embodiment described above, the configuration including the circuit (Duty adjustment unit) that adjusts the duty of the PWM signal according to the change of the input voltage due to the disturbance is shown. The second embodiment has a configuration including a circuit (frequency adjustment unit) that adjusts the frequency of the PWM signal in accordance with a change in the input voltage due to disturbance.

(Power supply)
FIG. 6 is a schematic block diagram showing a second embodiment of the power supply device according to the present invention. Here, about the structure equivalent to 1st Embodiment mentioned above, the same or equivalent code | symbol is attached | subjected and the description is simplified.

  As shown in FIG. 6, for example, the power supply device according to the second embodiment is roughly divided into a digital power supply control unit 10, a digital power supply power unit 20, and a PWM adjustment unit, as in the first embodiment described above. 30.

  The digital power supply control unit 10 includes a variable oscillation circuit (operation control unit) 14 instead of the oscillation circuit 13 in addition to the ADC 11 and the digital control unit 12 similar to those in the first embodiment, and an output current to the load 40. The frequency of the PWM signal is adjusted based on a frequency adjustment signal output from a PWM adjustment unit 30 to be described later and output to the digital power supply power unit 20. That is, the variable oscillation circuit 14 sets the frequency of the operation clock (reference clock) that defines the operation in the digital control unit 12 during a predetermined adjustment period based on a frequency adjustment signal output from the PWM adjustment unit 30 described later. Only adjust and supply.

  The digital power source power unit 20 has a configuration in which the duty adjustment circuit 21 is omitted from the configuration in the first embodiment, and based on a PWM signal (SW control signal) output from the digital power source control unit 10, The conduction state (on-off) of the switching element (SW) 22 is directly controlled.

  The PWM adjustment unit 30 includes a level conversion circuit 36 in addition to the comparison circuit 31, the DC component cut circuit 32, and the voltage frequency conversion circuit 34 similar to those in the first embodiment, and is based on the input voltage Vin and the output voltage Vout. Thus, a frequency adjustment signal for adjusting the frequency of the PWM signal is generated and output to the digital power supply control unit 10. Here, the level conversion circuit 36 generates a frequency adjustment signal proportional to the magnitude of the fluctuation amount of the input voltage Vin with respect to the output voltage Vout extracted by the DC component cut circuit 32. The frequency adjustment signal is a positive value or a negative value for the fluctuation amount only during the adjustment period defined by the length signal corresponding to the number of pulse outputs, which is output from the voltage frequency conversion circuit 34. In accordance with this, the signal level is set to be raised or lowered with the specified standard voltage value as the center and output. Thus, during the adjustment period, the control voltage value of the frequency adjustment signal is changed so as to be higher (increased) or lower (lower) than the standard voltage value. The value of the frequency of the operation clock (reference clock) generated by the variable oscillation circuit 14 of the power supply control unit 10 is controlled in proportion to the control voltage value of the frequency adjustment signal.

(Control method)
Next, a control method (PWM signal frequency adjustment method) executed by the PWM adjustment unit 30 in the power supply apparatus having the above-described circuit configuration will be described.

  FIG. 7 is a flowchart showing a signal control method of the power supply device according to the present embodiment. FIG. 8 is a diagram illustrating a concept of a control method applied to the present embodiment. Here, FIGS. 8A and 8B are conceptual diagrams showing a configuration relating to the frequency adjustment method of the PWM signal according to the present embodiment, and FIG. 8C is a PWM realized by the present embodiment. It is a timing chart which shows the concept of the frequency adjustment method of a signal. 9 and 10 are timing charts showing specific examples of the control method applied to the present embodiment. Here, FIG. 9 is a timing chart when the input voltage fluctuates in the power supply device according to the present embodiment, and FIG. 10 is a timing chart when the input voltage fluctuates. In addition, about the control method equivalent to 1st Embodiment mentioned above, the description is simplified.

  As shown in the flowchart of FIG. 7, the control method (PWM signal frequency adjustment method) in the power supply device according to the present embodiment first compares the input voltage Vin and the output voltage Vout by the comparison circuit 31 of the PWM adjustment unit 30. (Step S201). Next, based on the comparison output from the comparison circuit 31, the DC component cut circuit 32 determines whether or not the difference between the input voltage Vin and the output voltage Vout has changed (step S202). When it is determined that the difference has changed, the DC component cut circuit 32 determines the magnitude component of the fluctuation amount of the input voltage Vin with respect to the output voltage Vout, and the fluctuation amount is a positive value or a negative value. It is extracted (step S303). On the other hand, when it is not determined that the difference has changed, the processes of steps S201 and S202 are repeatedly executed. In other words, in this state, the frequency adjustment signal set to the standard voltage value is output from the PWM adjustment unit 30 to the digital power supply control unit 10 and is generated by the variable oscillation circuit 14. ) A PWM signal generated based on the frequency operation clock is supplied as it is to the switching element (SW) 22 of the digital power source power unit 20 as a SW control signal.

  Next, the voltage frequency conversion circuit 34 calculates an adjustment period corresponding to the extracted amount of fluctuation (step S204). Also, before or after step S204, or in parallel with step S204, the level conversion circuit 36 calculates a frequency adjustment amount that defines a frequency proportional to the extracted amount of variation (step S205). ). Then, the level conversion circuit 36 assigns a polarity indicating whether the extracted fluctuation amount is a positive value or a negative value to the frequency adjustment signal that defines the frequency adjustment amount, thereby controlling the digital power supply. This is output to the variable oscillation circuit 14 of the unit 10 (step S206).

  At this time, it is constantly monitored whether or not the frequency adjustment signal is output during the adjustment period calculated by the voltage frequency conversion circuit 34 (step S207). If it is determined that the frequency adjustment signal has been output during the adjustment period, it is determined that the adjustment period for outputting the frequency adjustment signal to the variable oscillation circuit 14 of the digital power supply control unit 10 has ended. Returning to step S201, the series of processes of steps S201 to S207 described above are repeatedly executed. On the other hand, if it is not determined that the frequency adjustment signal has been output during the adjustment period, the process returns to step S206 and the operation of outputting the frequency adjustment signal to the variable oscillation circuit 14 of the digital power supply control unit 10 is repeated. Run.

  The control method executed by the PWM adjustment unit 30 described above is, for example, whether or not the input voltage Vin is blocked prior to the comparison process between the input voltage Vin and the output voltage Vout in step S201, and the control method (the frequency of the PWM signal). Adjustment method) The presence or absence of an end instruction of itself is detected, and when the input voltage Vin is interrupted or the end of the process is instructed, a series of processes (steps S201 to S207) are stopped.

  As a result, in the present embodiment, the frequency adjustment signal whose frequency adjustment amount is defined by the level conversion circuit 36 is supplied to the DC component cut circuit only during the adjustment period corresponding to the number of pulse outputs determined by the voltage number conversion circuit 34. In accordance with whether the fluctuation amount extracted by 32 is a positive value or a negative value, it is set to a predetermined signal level and output to the variable oscillation circuit 14 of the digital power supply control unit 10. Then, the operation clock (reference clock) whose frequency is adjusted based on the frequency adjustment signal in the variable oscillation circuit 14 is supplied to the arithmetic circuit of the digital control unit 12, and the digital control unit 12 has a period corresponding to the frequency. Is generated. The conduction state of the switching element (SW) 22 is controlled based on the PWM signal (SW control signal), and output voltage control is executed as described later (see FIGS. 9 and 10).

  Here, in the present embodiment, the voltage frequency conversion circuit 34 calculates (determines) an adjustment period for adjusting the frequency of the PWM signal in accordance with the amount of fluctuation of the input voltage Vin with respect to the output voltage Vout due to disturbance. The method was shown. The present invention is not limited to this method, and a preset fixed period may be applied as the adjustment period. According to this, the process for determining the adjustment period can be omitted, and the processing burden on the power supply device can be reduced.

  Further, in the present embodiment, a method is shown in which the level conversion circuit 36 calculates (determines) the adjustment amount of the frequency of the PWM signal in accordance with the amount of fluctuation of the input voltage Vin with respect to the output voltage Vout due to disturbance. . The present invention is not limited to this method, and a fixed value set in advance may be applied as the frequency adjustment amount. According to this, the process for determining the frequency adjustment amount can be omitted, and the processing burden on the power supply device can be reduced.

In the present embodiment, a plurality of SW control signals output from the digital control unit 12 to the switching element (SW) 22 within the adjustment period calculated by the voltage frequency conversion circuit 34 are set to the same frequency (period). The method of adjusting to become is shown. The present invention is not limited to this, and adjusts the frequency (cycle) of a plurality of SW control signals output within the adjustment period so as to change for each SW control signal (pulse signal). May be.
Note that the PWM signal adjustment period and frequency adjustment amount setting method in the control method according to the present embodiment described above are similarly applied to other embodiments described later.

The PWM signal frequency adjustment method applied to the above-described output voltage control can be described based on the following concept.
In this embodiment, as shown in FIGS. 8A and 8B, the oscillation frequency is increased based on the frequency adjustment signal Se that is output from the PWM adjustment unit 30 and defines the adjustment amount of the frequency of the PWM signal. Alternatively, it has a variable oscillation circuit 14 that generates a reduced operation clock (reference clock) Sd and outputs it to the digital control unit 12. Here, in this embodiment, as shown in FIG. 8B, a crystal oscillator whose oscillation frequency changes with the control voltage value is applied as an example of the variable oscillation circuit 14. Note that the variable oscillation circuit 14 is not limited to this configuration, and other configurations may be applied as long as an equivalent frequency adjustment function can be realized. Thus, in the digital control unit 12, the frequency of the SW control signal (adjusted PWM signal) Sf output to the switching element (SW) 22 is similarly changed by changing the frequency of the operation clock Sd that generates the PWM signal. Will change.

  The frequency adjustment signal Se output from the PWM adjustment unit 30 defines a frequency adjustment amount of the PWM signal, and is given a polarity code according to increase / decrease in fluctuation of the input voltage Vin. As a result, when the polarity code is set to be positive (set higher than the standard voltage), the frequency of the operation clock Sd generated by the variable oscillation circuit 14 is adjusted to be higher, and the SW control signal (adjustment) is adjusted. The frequency of the subsequent PWM signal) Sf can be increased according to the adjustment amount. On the other hand, when the polarity sign is set to be negative (set lower than the standard voltage), the frequency of the operation clock Sd is adjusted to be lower, and the frequency of the SW control signal Sf is decreased according to the adjustment amount. Can be made. In this way, by giving polarity to the frequency adjustment signal Se, it is possible to cope with both fluctuations in the rise and fall of the input voltage Vin.

  That is, as shown in the center part of the timing chart of FIG. 8C, the operation clock Sd generated by the variable oscillation circuit 14 becomes faster by setting the frequency adjustment signal Se higher than the standard voltage, so that the SW control The period of the signal Sf is shortened, and as a result, both the pulse width when the switching element (SW) 22 is ON and the pulse width when it is OFF can be shortened. On the other hand, as shown on the right side of the timing chart of FIG. 8C, the operation clock Sd generated by the variable oscillation circuit 14 is delayed by setting the frequency adjustment signal Se lower than the standard voltage, so that the SW control The period of the signal Sf becomes longer. As a result, both the pulse width when the switching element (SW) 22 is ON and the pulse width when it is OFF can be increased.

Specifically, the following output voltage control is executed based on the concept of the above-described PWM signal frequency adjustment method.
First, as shown in the timing chart of FIG. 9, when the input voltage Vin suddenly changes (rises up), the level conversion circuit 36 only during the adjustment period corresponding to the number of times determined by the voltage number conversion circuit 34 of the PWM adjustment unit 30. As a result, the frequency adjustment signal set so that the frequency of the PWM signal is increased is output. As a result, as shown in the center of FIG. 8C, the cycle of the SW control signal output to the switching element (SW) 22 is reduced. As a result, the ON time of the switching element (SW) 22 is reduced. Both off-time is shortened. As a result, the transmission energy is optimized and the output voltage Vout is stabilized. Then, after the adjustment period ends, the output of the frequency adjustment signal is stopped. At this time, since digital control functions normally, the cycle of the SW control signal is continuously adjusted, and a stable output voltage Vout is output.

On the other hand, as shown in the timing chart of FIG. 10, when the input voltage Vin suddenly changes (falls down), the level conversion circuit 36 performs the frequency of the PWM signal only during the adjustment period according to the number of times determined by the voltage number conversion circuit 34. A frequency adjustment signal set so as to be low is output. As a result, as shown on the right side of FIG. 8C, the cycle of the SW control signal increases, and as a result, both the on time and the off time of the switching element (SW) 22 become longer. As a result, the transmission energy is optimized and the output voltage Vout is stabilized. Then, after the adjustment period ends, the output of the frequency adjustment signal is stopped. At this time, since digital control functions normally, the cycle of the SW control signal is continuously adjusted, and a stable output voltage Vout is output.
In the timing charts shown in FIGS. 9 and 10, the output voltage Vout (when the frequency is not adjusted) in a comparative example of the present invention described later is indicated by a thick dotted line.

  Further, in the above-described embodiment, when a new change in the input voltage Vin occurs during the adjustment period in which the frequency adjustment signal is output to the variable oscillation circuit 14, it is shown in FIGS. 8 (a) and 8 (b). The following control is executed by the PWM signal frequency adjusting unit including the digital control unit 12, the variable oscillation circuit 14, and the PWM adjusting unit 30. In other words, if a change occurs in the input voltage Vin having the same polarity by giving a polarity to the frequency adjustment signal that defines the frequency adjustment amount of the PWM signal, the frequency depends on the degree of the change. The control for adding the adjustment amount is performed. On the other hand, if a change in the input voltage Vin having a different polarity occurs, control is performed to subtract the frequency adjustment amount according to the degree of the change. Then, by reflecting the result as a new frequency adjustment amount in the SW control signal, a stable output voltage Vout is output even when a new change in the input voltage Vin occurs during the adjustment period. Output voltage control can be realized.

<Third Embodiment>
Next, a third embodiment of the power supply device according to the present invention will be described.
In the first or second embodiment described above, means for adjusting only one of the duty or frequency (period) of the PWM signal in accordance with the change in the input voltage due to disturbance (Duty adjustment circuit, frequency adjustment circuit) A configuration provided with The third embodiment has a configuration including a circuit that adjusts both the duty and the frequency of the PWM signal in accordance with a change in the input voltage due to a disturbance.

(Power supply)
FIG. 11 is a schematic block diagram showing a third embodiment of the power supply device according to the present invention. Here, about the structure equivalent to 1st or 2nd embodiment mentioned above, the same or equivalent code | symbol is attached | subjected and the description is simplified.

  For example, as shown in FIG. 11, the power supply device according to the third embodiment is roughly divided into the digital power supply control unit 10, the digital power supply power unit 20, and the first or second embodiment described above. And a PWM adjustment unit 30.

  Similar to the second embodiment, the digital power supply control unit 10 includes an ADC 11, a digital control unit 12, and a variable oscillation circuit 14. From the output current to the load 40 and a PWM adjustment unit 30 described later. Based on the output frequency adjustment signal, the frequency of the PWM signal is adjusted and output to the digital power source power unit 20.

  The digital power source power unit 20 has the same configuration as that of the first embodiment. The frequency adjusted PWM signal output from the digital power source control unit 10 and the duty adjustment output from the PWM adjustment unit 30 described later. Based on the signal, the duty of the PWM signal is adjusted and output from the duty adjustment circuit 21 to the switching element (SW) 22 as a SW control signal. As a result, the digital power source power unit 20 converts the input voltage Vin into an output voltage Vout having a predetermined voltage value and supplies the output voltage Vout to the load 40.

  In addition to the comparison circuit 31, the DC component cut circuit 32, the voltage pulse width conversion circuit 33, the voltage frequency conversion circuit 34, and the gate and phase shift circuit 35, the PWM adjustment unit 30 is similar to the first embodiment. A level conversion circuit 36 similar to that of the second embodiment is provided. The PWM adjustment unit 30 outputs a duty adjustment signal synchronized with the reference clock supplied from the variable oscillation circuit 14 for adjusting the duty (ON time) of the PWM signal based on the input voltage Vin and the output voltage Vout. A frequency adjustment signal for adjusting the frequency (period) of the PWM signal is generated and output to the digital power supply control unit 10 while being generated and output to the digital power supply power unit 20.

(Control method)
Next, a control method (a PWM signal duty adjustment method and a frequency adjustment method) executed by the PWM adjustment unit 30 in the power supply device having the above-described circuit configuration will be described.

  FIG. 12 is a flowchart showing a signal control method of the power supply device according to the present embodiment. FIG. 13 is a timing chart showing a specific example of the control method applied to the present embodiment. Here, FIG. 13 is a timing chart when the input voltage fluctuates in the power supply apparatus according to the present embodiment. In addition, about the control method equivalent to 1st or 2nd embodiment mentioned above, the description is simplified.

  As shown in the flowchart of FIG. 12, the control method (the PWM signal duty and frequency adjustment method) in the power supply device according to the present embodiment is first performed by the comparison circuit 31 of the PWM adjustment unit 30 by the input voltage Vin and the output voltage. Vout is compared (step S301). Next, based on the comparison output from the comparison circuit 31, it is determined whether or not the difference between the input voltage Vin and the output voltage Vout has changed (step S302). When it is determined that the difference has changed, the DC component cut circuit 32 determines the magnitude component of the fluctuation amount of the input voltage Vin with respect to the output voltage Vout, and the fluctuation amount is a positive value or a negative value. The polarity indicating whether or not there is is extracted (step S303). On the other hand, when it is not determined that the difference has changed, the processes of steps S301 and S302 are repeatedly executed. In other words, in this state, the frequency adjustment signal set to the standard voltage value is output from the PWM adjustment unit 30 to the digital power supply control unit 10 and is generated by the variable oscillation circuit 14. ) A PWM signal is generated based on the frequency operation clock and is output to the duty adjustment circuit 21 of the digital power source power unit 20. In this state, since the duty adjustment signal is not output from the PWM adjustment unit 30, the digital power supply control unit 10 (digital control unit 12) is supplied from the duty adjustment circuit 21 to the switching element (SW) 22 of the digital power supply power unit 20. The PWM signal generated in is supplied as an SW control signal as it is.

  Next, the voltage frequency conversion circuit 34 calculates an adjustment period corresponding to the extracted amount of fluctuation (step S304). Further, before or after step S304, or in parallel with step S304, the level conversion circuit 36 calculates a frequency adjustment amount that defines a frequency proportional to the extracted amount of variation (step S305). ). Then, the level conversion circuit 36 assigns a polarity indicating whether the extracted fluctuation amount is a positive value or a negative value to the frequency adjustment signal that defines the frequency adjustment amount, thereby controlling the digital power supply. This is output to the variable oscillation circuit 14 of the unit 10 (step S306).

  Also, before or after step S304, or in parallel with step S304, the voltage pulse width conversion circuit 33 calculates a duty adjustment width corresponding to the extracted amount of variation (step S307). The gate and phase shift circuit 35 shifts the phase of the duty adjustment signal that defines the duty adjustment width according to the polarity indicating whether the extracted fluctuation amount is a positive value or a negative value. And output to the duty adjustment circuit 21 of the digital power supply unit 20 (step S308).

  In steps S306 and S308, whether the frequency adjustment signal and the duty adjustment signal are output during the adjustment period calculated by the voltage number conversion circuit 34 in a state where the frequency adjustment signal and the duty adjustment signal are output. Is constantly monitored (step S309). When it is determined that the frequency adjustment signal and the duty adjustment signal are output over the adjustment period, the frequency adjustment signal is output to the variable oscillation circuit 14 of the digital power supply control unit 10 and the duty adjustment signal is output to the digital power supply. It is determined that the adjustment period to be output to the duty adjustment circuit 21 of the power unit 20 has ended, the process returns to step S301, and the series of processes of steps S301 to S309 described above are repeatedly executed. On the other hand, if it is not determined that the frequency adjustment signal and the duty adjustment signal have been output over the adjustment period, the process returns to steps S306 and S308, and the frequency adjustment signal is output to the variable oscillation circuit 14 of the digital power supply control unit 10. And the operation of outputting the duty adjustment signal to the duty adjustment circuit 21 of the digital power source power unit 20 are repeatedly executed.

  The control method executed in the PWM adjustment unit 30 described above is, for example, whether or not the input voltage Vin is blocked prior to the comparison process between the input voltage Vin and the output voltage Vout in step S301, and the control method (the frequency of the PWM signal). And the adjustment method of the duty) The presence / absence of the end instruction of itself is detected, and when the input voltage Vin is interrupted or the end of the process is instructed, a series of processes (steps S301 to S309) are stopped. .

  As a result, in the present embodiment, the frequency adjustment signal whose frequency adjustment amount is defined by the level conversion circuit 36 is supplied to the DC component cut circuit only during the adjustment period corresponding to the number of pulse outputs determined by the voltage number conversion circuit 34. In accordance with whether the fluctuation amount extracted by 32 is a positive value or a negative value, it is set to a predetermined signal level and output to the variable oscillation circuit 14 of the digital power supply control unit 10. The phase of the duty adjustment signal having the pulse width determined by the voltage pulse width conversion circuit 33 is shifted depending on whether the fluctuation amount extracted by the DC component cut circuit 32 is a positive value or a negative value. And output to the duty adjustment circuit 21 of the digital power supply power unit 20. Then, the operation clock (reference clock) whose frequency is adjusted based on the frequency adjustment signal in the variable oscillation circuit 14 is supplied to the arithmetic circuit of the digital control unit 12, and the digital control unit 12 has a period corresponding to the frequency. Is generated. The exclusive OR circuit of the duty adjustment circuit 21 includes a PWM signal whose period is adjusted, which is output from the digital control unit 12 of the digital power supply control unit 10, and a duty adjustment signal which is output from the PWM adjustment unit 30. Is input, the conduction state of the switching element (SW) 22 is controlled by the SW control signal which is the logic output, and output voltage control is executed as described later (see FIG. 13).

  Here, also in the present embodiment, the PWM adjustment unit 30 calculates (determines) an adjustment period for adjusting the frequency and duty of the PWM signal according to the amount of fluctuation of the input voltage Vin with respect to the output voltage Vout due to disturbance. The method to do was shown. The present invention is not limited to this method, and a preset fixed period may be applied as the adjustment period. According to this, the process for determining the adjustment period can be omitted, and the processing burden on the power supply device can be reduced.

  That is, the output voltage control according to the present embodiment is specifically performed by the voltage frequency conversion circuit 34 of the PWM adjustment unit 30 when the input voltage Vin suddenly changes (rises) as shown in the timing chart of FIG. The frequency adjustment signal set so that the frequency of the PWM signal is increased by the level conversion circuit 36 is output for the adjustment period corresponding to the determined number of times. Also, during the adjustment period, the duty adjustment signal set so as to lower the duty of the PWM signal by the voltage pulse width conversion circuit 33 is output by the number of times determined by the voltage number conversion circuit 34. As a result, the pulse width of the SW control signal output to the switching element (SW) 22 is reduced. As a result, the duty of the switching element (SW) 22 is reduced (ON time is shortened), so that the transfer energy is appropriate. And the output voltage Vout is stabilized. After the adjustment period, the output of the duty adjustment signal and the output of the frequency adjustment signal are stopped, and the digital control functions normally. Therefore, the duty and cycle of the SW control signal are continuously adjusted. Thus, a stable output voltage Vout is output.

  Although FIG. 13 does not show the change of the output voltage Vout, it is similar to the timing charts shown in the first and second embodiments (see FIGS. 4, 5, 9, and 10). The output voltage Vout is controlled based on the cycle and pulse width of the SW control signal that controls the conduction state of the switching element (SW) 22.

  In FIG. 13, the output voltage control in the case where the input voltage Vin fluctuates upward has been described. This is because the change in the input voltage Vin generally has a high possibility that the output voltage Vout increases due to the rising fluctuation and causes the load 40 to be damaged. Corresponds to the importance of. Note that, even when the input voltage Vin fluctuates, similar output voltage control is executed based on the control methods shown in the first and second embodiments described above.

<Fourth Embodiment>
Next, a fourth embodiment of the power supply device according to the present invention will be described.
In the above-described first to third embodiments, the method of determining the fixed period set in advance as the PWM signal adjustment period according to the magnitude of the change in the input voltage due to the disturbance is shown. In the fourth embodiment, according to the state of the actual PWM signal adjusted by the PWM adjustment unit, the function of the PWM adjustment unit is disabled and the adjustment period of the PWM signal is ended, and the output voltage control by digital control is performed. Have a way to migrate.

(Power supply)
FIG. 14 is a schematic block diagram showing a fourth embodiment of the power supply device according to the present invention. Here, about the structure equivalent to the 1st thru | or 3rd embodiment mentioned above, the same or equivalent code | symbol is attached | subjected and the description is simplified.

  As shown in FIG. 14, for example, the power supply device according to the fourth embodiment is roughly divided into the digital power supply control unit 10, the digital power supply power unit 20, and the PWM adjustment unit, similarly to the third embodiment described above. 30.

  Similar to the second or third embodiment, the digital power supply control unit 10 includes an ADC 11, a digital control unit 12, and a variable oscillation circuit 14, and outputs current to the load 40 and PWM adjustment described later. Based on the frequency adjustment signal output from the unit 30, the frequency of the PWM signal is adjusted and output to the digital power source power unit 20. In addition, the digital control unit 12 of the digital power supply control unit 10 enables or disables the function of the PWM adjustment unit 30 based on the state of the SW control signal that controls the conduction state of the switching element (SW) 22 of the digital power supply power unit 20. Outputs the PWM adjustment function invalid signal to be set to invalid. Specifically, the digital control unit 12 calculates a calculation result (estimated by calculation) related to output voltage control based on a digital control feedback signal generated according to an output current supplied from the digital power source power unit 20 to the load 40. PWM signal) and the state of the SW control signal (actual PWM signal) adjusted by the PWM adjustment circuit 21 and supplied to the switching element (SW) 22 are monitored. When the digital control unit 12 is in an approximate state, the digital control unit 12 outputs a PWM adjustment function invalid signal for setting the PWM signal frequency and duty adjustment function by the PWM adjustment unit 30 to an invalid state. .

  In the first or third embodiment, the digital power source power unit 20 detects the state of the SW control signal output from the duty adjustment circuit 21 to the switching element (SW) 22 (denoted as “PWM output detection” in the figure). ). Then, the digital power source power unit 20 outputs the PWM signal duty based on the PWM signal whose frequency is adjusted, which is output from the digital power source control unit 10, and the duty adjustment signal which is output from the PWM adjusting unit 30, which will be described later. Is output from the duty adjustment circuit 21 to the switching element (SW) 22 as a SW control signal. As a result, the digital power source power unit 20 converts the input voltage Vin into an output voltage Vout having a predetermined voltage value and supplies the output voltage Vout to the load 40.

  The PWM adjustment unit 30 is supplied from the variable oscillation circuit 14 for adjusting the duty (ON time) of the PWM signal based on the input voltage Vin and the output voltage Vout in the same configuration as that of the third embodiment. A duty adjustment signal synchronized with the reference clock is generated and output to the digital power supply power unit 20, and a frequency adjustment signal for adjusting the frequency (period) of the PWM signal is generated and output to the digital power supply control unit 10. To do. Further, the PWM adjustment unit 30 disables the function of generating the duty adjustment signal and the frequency adjustment signal of the PWM signal based on the PWM adjustment function invalid signal output from the digital control unit 12 of the digital power supply control unit 10. Set to. Here, the level conversion circuit 36 generates a frequency adjustment signal proportional to the magnitude of the fluctuation amount of the input voltage Vin with respect to the output voltage Vout extracted by the DC component cut circuit 32. Whether the frequency adjustment signal is a positive value or a negative value during the period up to the end timing of the adjustment period defined based on the PWM adjustment function invalid signal output from the digital control unit 12 The signal level is set higher (increased) or lower (lowered) with respect to the standard voltage value and output. Thereby, the value of the frequency of the operation clock (reference clock) generated by the variable oscillation circuit 14 of the digital power supply control unit 10 is controlled in proportion to the control voltage value of the frequency adjustment signal.

(Control method)
Next, a control method (a PWM signal duty adjustment method and a frequency adjustment method) executed in the power supply apparatus having the above-described circuit configuration will be described.

  FIG. 15 is a flowchart illustrating a signal control method of the power supply device according to the present embodiment. FIG. 16 is a timing chart showing a specific example of the control method applied to the present embodiment. Here, FIG. 16 is a timing chart when the input voltage fluctuates in the power supply apparatus according to the present embodiment. In addition, about the control method equivalent to 3rd Embodiment mentioned above, the description is simplified.

  As shown in the flowchart of FIG. 15, the control method (the PWM signal duty and frequency adjustment method) in the power supply device according to the present embodiment is first performed by the comparison circuit 31 of the PWM adjustment unit 30 with the input voltage Vin and the output voltage. Vout is compared (step S401). Next, based on the comparison output from the comparison circuit 31, it is determined whether or not the difference between the input voltage Vin and the output voltage Vout has changed (step S402). When it is determined that the difference has changed, the DC component cut circuit 32 determines the magnitude component of the fluctuation amount of the input voltage Vin with respect to the output voltage Vout, and the fluctuation amount is a positive value or a negative value. The polarity indicating whether or not there is is extracted (step S403). On the other hand, when it is not determined that the difference has changed, the processes in steps S401 and S402 are repeatedly executed. That is, in this state, as in the third embodiment described above, the original (frequency) is set by the variable oscillation circuit 14 based on the frequency adjustment signal output from the PWM adjustment unit 30 and set to the standard voltage value. An operation clock having a frequency that is not adjusted is generated, and a PWM signal is generated by the digital control unit 12 based on this operation clock, and is output to the duty adjustment circuit 21 of the digital power source power unit 20. In this state, since the duty adjustment signal is not output from the PWM adjustment unit 30, the PWM signal generated in the digital control unit 12 is supplied as it is as the SW control signal from the duty adjustment circuit 21 to the switching element (SW) 22. Is done.

  Next, the level conversion circuit 36 calculates a frequency adjustment amount that defines a frequency proportional to the extracted variation amount (step S404). Then, the level conversion circuit 36 assigns a polarity indicating whether the extracted fluctuation amount is a positive value or a negative value to the frequency adjustment signal that defines the frequency adjustment amount, thereby controlling the digital power supply. This is output to the variable oscillation circuit 14 of the unit 10 (step S405).

  Also, before or after step S404, or in parallel with step S304, the voltage pulse width conversion circuit 33 calculates the duty adjustment width corresponding to the extracted change amount of the fluctuation amount (step S406). ). Then, the gate and phase shift circuit 35 shifts the phase of the duty adjustment signal that defines the duty adjustment width according to the polarity indicating whether the extracted fluctuation amount is a positive value or a negative value. Then, the data is output to the duty adjustment circuit 21 of the digital power source power unit 20 (step S407).

  In steps S405 and S407, the PWM adjustment function invalid signal for setting the frequency signal and duty adjustment function of the PWM adjustment unit 30 to the invalid state in the state in which the frequency adjustment signal and the duty adjustment signal are output is digital. Whether or not the power is output from the power supply control unit 10 is constantly monitored (step S408). When the PWM adjustment function invalid signal is output to the PWM adjustment unit 30, the frequency adjustment signal is output to the variable oscillation circuit 14 of the digital power supply control unit 10 and the duty adjustment signal is output to the duty adjustment of the digital power supply power unit 20. The adjustment period output to the circuit 21 is ended (adjustment operation is stopped), the process returns to step S401, and the series of processes of steps S401 to S408 described above are repeatedly executed. On the other hand, when the PWM adjustment function invalid signal is not output to the PWM adjustment unit 30, the operation returns to steps S405 and S407 to output the frequency adjustment signal to the variable oscillation circuit 14 of the digital power supply control unit 10, and The operation of outputting the duty adjustment signal to the duty adjustment circuit 21 of the digital power source power unit 20 is repeatedly executed.

  Here, the PWM adjustment function invalid signal is generated in the digital control unit 12 of the digital power supply control unit 10. The digital control unit 12 includes a calculation result related to output voltage control based on a digital control feedback signal generated according to an output current supplied from the digital power supply power unit 20 to the load 40, and a switching element ( The current SW control signal (PWM signal) actually output to (SW) 22 is monitored. When the digital control unit 12 determines that the two are in a specific approximate relationship, the PWM adjustment function for setting the PWM signal adjustment function in the PWM adjustment unit 30 to an invalid state (stopping the adjustment operation). Output invalid signal.

  The control method executed in the PWM adjustment unit 30 described above is, for example, whether or not the input voltage Vin is interrupted prior to the comparison process between the input voltage Vin and the output voltage Vout in step S401, and the control method (the frequency of the PWM signal). And the adjustment method of the duty) The presence / absence of the end instruction of itself is detected, and when the input voltage Vin is interrupted or the end of the process is instructed, a series of processes (steps S401 to S408) are stopped. .

  Thereby, in this embodiment, the calculation result based on the digital control feedback signal by the digital control unit 12 of the digital power supply control unit 10 and the state of the SW control signal actually output to the switching element (SW) 22 are: The period until it is determined that the specific approximate relationship has been reached is set as the PWM signal adjustment period. That is, in the present embodiment, the PWM signal adjustment period is determined by determining the output voltage control state in real time by the digital control loop unit having the digital power supply control unit 10 and the digital power supply power unit 20. Similarly to the above-described third embodiment, the frequency adjustment signal to which the polarity is given is output to the variable oscillation circuit 14 of the digital power supply control unit 10 during this adjustment period, and the phase is shifted according to the polarity. The duty adjustment signal is output to the duty adjustment circuit 21 of the digital power source power unit 20. Then, the logical output of the PWM signal whose period is adjusted based on the frequency adjustment signal and the duty adjustment signal in the duty adjustment circuit 21 is output to the switching element (SW) 22 as an SW control signal, which will be described later. Then, the output voltage control is executed (see FIG. 16).

  That is, the output voltage control according to the present embodiment is specifically a PWM adjustment function that is output from the digital control unit 12 when the input voltage Vin suddenly changes (rises up) as shown in the timing chart of FIG. In the period up to the end timing of the adjustment period defined based on the invalid signal, the level adjustment circuit 36 outputs a frequency adjustment signal set to increase the frequency of the PWM signal, and the voltage pulse width conversion circuit 33. As a result, the duty adjustment signal set to lower the duty of the PWM signal is output. This adjustment period is equal to or longer than the digital control non-response time region caused by the control delay. As a result, the pulse width of the SW control signal output to the switching element (SW) 22 is limited. As a result, the duty of the switching element (SW) 22 becomes small (ON time is short), so that the transfer energy is appropriate. And the output voltage Vout is stabilized. The state of such output voltage control is determined in real time, and when the digital control functions normally, the PWM adjustment function invalid signal is output, and the PWM signal adjustment function in the PWM adjustment unit 30 is stopped. At the same time, the output of the frequency adjustment signal is stopped and the frequency adjustment function is stopped (that is, the adjustment period ends). Then, after the adjustment period ends, the digital control functions normally, so the duty and cycle of the SW control signal are continuously adjusted, and a stable output voltage Vout is output.

  In FIG. 16, the change in the output voltage Vout is not shown, but it is the same as the timing charts shown in the first and second embodiments (see FIGS. 4, 5, 9, and 10). The output voltage Vout is controlled based on the cycle and pulse width of the SW control signal that controls the conduction state of the switching element (SW) 22.

  Further, in the present embodiment, the case where both the frequency and duty of the PWM signal are adjusted has been described as a method for adjusting the PWM signal. However, the present invention is not limited to this, and the first or second method is not limited thereto. As shown in the embodiment, the present invention may be applied to a method of adjusting only one of frequency and duty.

  In the present embodiment, the LED is used as a load, the input voltage is converted into an output voltage according to the PWM signal, and the current value, the input voltage, and the output of the current that flows through the load when the output voltage is applied to the load. The configuration for adjusting the PWM signal based on the difference from the voltage has been described. The present invention is not limited to this. For example, the input current is converted into an output current according to the PWM signal, and the voltage value of the voltage applied to the load and the input current when the output current is applied to the load The PWM signal may be adjusted based on the difference from the output current.

<Verification of effects>
Next, the effect of the power supply device according to each embodiment described above will be specifically described. Here, a circuit configuration equivalent to the power supply device described in Patent Document 1 described above is shown as a comparison object, and the superiority of the operational effect of the present invention is verified.

  FIG. 17 is a schematic block diagram illustrating an example of a power supply device to be compared with the present invention. Here, a digital control constant current step-down DC-DC converter circuit for supplying a constant control current to a load (LED, LD, etc.) is used as a power supply device to be compared (hereinafter referred to as “comparative example”). Show. 18 and 19 are timing charts in the signal control method applied to the comparative example. Here, FIG. 18 is a timing chart of the signal control method when the input voltage fluctuates up, and FIG. 19 is a timing chart of the signal control method when the input voltage fluctuates down.

  A power supply device as a comparative example of the present embodiment has a circuit configuration including only a digital control loop unit having a digital power supply control unit 10 and a digital power supply power unit 20, as shown in FIG. Here, the digital power source power unit 20 converts the input voltage Vin into an output voltage Vout having a predetermined voltage value and supplies the input voltage Vin to the load 40 as in the above-described embodiment. In addition, the digital power supply control unit 10 is based on a digital control feedback signal generated according to an output current supplied from the digital power supply power unit 20 to the load 40 as in the above-described embodiment. A PWM signal for controlling the operation of the digital power source is generated and output to the switching element (SW) 22 of the digital power source power unit 20. That is, in the comparative example, as shown in the above-described embodiment, the input / output voltages are compared to generate an adjustment signal for adjusting the duty and frequency of the PWM signal, and the digital power supply control unit 10 and the digital power supply power unit 20 does not include an analog control loop unit having a PWM adjustment unit 30 that outputs to 20, a duty adjustment circuit 21 that adjusts the duty of the PWM signal based on the adjustment signal, and a variable oscillation circuit 14 that adjusts the frequency of the PWM signal. .

  In such a comparative example, as shown in the timing chart of FIG. 18, when the input voltage Vin suddenly changes (increase fluctuation), the above-described embodiment is shown in the non-response time region of the digital control caused by the control delay. Such control is not performed to lower the duty of the PWM signal output from the digital control unit 12 (arithmetic circuit) (or the SW control signal output to the switching element (SW) 22). Therefore, the output voltage Vout supplied from the digital power source power unit 20 to the load 40 rises during the non-reactionable time region. And after the reaction impossible time region ends, the digital control functions, so the control works in the direction of lowering the duty of the PWM signal and lowering the output voltage Vout, but it is immediately reflected in the output voltage Vout. Therefore, a state where the original voltage value is not restored (unstable state) continues.

  On the other hand, as shown in the timing chart of FIG. 19, even when the input voltage suddenly changes (falls down), the PWM signal as shown in the above-described embodiment in the non-response time region of the digital control caused by the control delay. Control for increasing the duty of the (or SW control signal) is not performed. For this reason, the output voltage Vout falls in the non-reaction time region. Then, after the reaction impossible time region ends, the digital control functions, so the control works in the direction of increasing the duty of the PWM signal and increasing the output voltage Vout, but it is immediately reflected in the output voltage Vout. Therefore, a state where the original voltage value is not restored (unstable state) continues.

  As described above, in the comparative example, since the response of the digital control of the output voltage Vout is slow with respect to the fluctuation of the input voltage Vin due to an external factor (disturbance), the voltage fluctuation of the output voltage Vout is largely unstable. Has the problem of continuing.

  On the other hand, in the power supply device shown in each of the above-described embodiments, in addition to a known digital control loop unit, an analog control loop unit (PWM) having an input / output voltage comparison unit and a PWM signal adjustment signal generation unit. The circuit configuration includes an adjustment unit 30) and at least one of a PWM signal duty adjustment unit (Duty adjustment circuit 21) and a frequency adjustment unit (variable oscillation circuit 14). In the present invention, as shown in the timing chart of each embodiment, the input voltage Vin and the output voltage Vout are monitored, and an adjustment signal proportional to the magnitude of the change is immediately generated based on the fluctuation result. Thus, the duty and frequency of the PWM signal are adjusted.

  That is, in the present invention, when the input / output voltage suddenly fluctuates, in the digital control unresponsive time region caused by the control delay, the output voltage control correction operation is temporarily performed by the analog control loop, and the digital control When the control catches up and the feedback control after the voltage change becomes a steady state (when the control delay is eliminated), the control for stopping the correction operation by the analog control loop is executed.

  As a result, according to the power supply device of the present invention, it is possible to make up for inadequate control due to disturbance (non-response state due to control delay), and immediately with optimum feedback loop characteristics according to the state of change in input / output voltage. Can be controlled. Therefore, according to the present invention, it is possible to realize a power supply device having high-speed response of output voltage control and quick stability of output voltage.

<Light source device>
Next, an example of a light source device including the power supply device according to each embodiment described above will be described.
As described below, the power supply device according to each embodiment described above can be favorably applied as a light source device for various electronic devices such as a projector and a printer.

  FIG. 20 is a schematic configuration diagram illustrating a configuration example of a light source device including the power supply device according to the present invention. FIG. 21 is a schematic configuration diagram illustrating a first example (projector) of a light source device including a power supply device according to the present invention, and FIG. 22 illustrates a second example of a light source device including a power supply device according to the present invention (projector). 1 is a schematic configuration diagram illustrating a printer. Here, about the structure equivalent to each embodiment mentioned above, the same or equivalent code | symbol is attached | subjected and shown, and the description is simplified.

  As shown in FIG. 20, a light source device 100 including a power supply device according to the present invention includes a plurality of light sources 41 arranged one-dimensionally or two-dimensionally, and a digital power supply provided individually for each of the light sources 41. The power unit 20 and the PWM adjustment unit 30 and the single digital power supply control unit 10 provided in common for the plurality of light sources 41 are provided. Here, the digital power supply control unit 10, the digital power supply power unit 20, and the PWM adjustment unit 30 have the same configurations and functions as those of the above-described embodiments. Further, a light emitting element such as an LED or an LD is applied to the light source 41 serving as a load.

  In the light source device 100 having such a configuration, the PWM adjustment unit 30 monitors the input voltage Vin and the output voltage Vout, and an adjustment signal proportional to the magnitude of the change is generated based on the fluctuation result, thereby generating a digital power supply. It is output to the power unit 20. Based on this adjustment signal, the duty and frequency of the PWM signal output from the digital power supply control unit 10 are adjusted, and the output voltage control in the digital power supply power unit 20 is continuously and stably executed. Thereby, even if the input voltage Vin fluctuates, the plurality of light sources 41 are stably driven to emit light with a predetermined light emission luminance (or light emission amount).

  The projector 210 shown in FIG. 21 is roughly divided into an excitation light source 211 in which a plurality of LDs are two-dimensionally arranged, a condensing optical system 212, a first light source 213 having a first light emitting color LED, A split light generation device 214, a second light source 215 having an LED of the second emission color, a light source side optical system 216, a display element 217, and a projection optical system 218 are provided. Here, the light source device 100 having the configuration shown in FIG. 20 is applied to the excitation light source 211, the first light source 213, and the second light source 215. According to this, even when the input voltage fluctuates, each light source (LD) arranged in the excitation light source 211, the first light source 213, and the second light source 215 is compensated for the reaction impossible state due to the control delay. And LED) can be driven to emit light stably at a predetermined light emission luminance (or light emission amount).

  22 is roughly divided into a photosensitive drum 221, a charging roller 222, an exposure head 223, a developing device 224, a conveyor belt 225, a transfer roller 226, a fixing roller 227, and a cleaning. A member 228 and an eraser light source 229 are provided. Here, the light source device 100 having the configuration shown in FIG. 20 is applied to the exposure head 223 in which a plurality of LEDs are arranged one-dimensionally. Then, the light emitted from each LED of the exposure head 223 is applied to the photosensitive drum 221, whereby an electrostatic latent image corresponding to the printing information and image data is formed on the outer peripheral surface of the photosensitive drum 221. The According to this, even when the input voltage fluctuates, each light source (LED) arranged in the exposure head 223 is compensated for the predetermined light emission luminance (or light emission amount) by compensating for the non-responsive state due to the control delay. ) Can be driven to emit light stably.

As mentioned above, although some embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It includes the invention described in the claim, and its equivalent range.
Hereinafter, the invention described in the scope of claims of the present application will be appended.

(Appendix)
[1]
An output signal control unit that converts an input signal into an output signal according to a PWM signal and outputs the output signal to a load;
A PWM signal generation unit that generates the PWM signal based on a feedback signal fed back according to the output signal to the load;
The on-time of the PWM signal according to the magnitude of the fluctuation amount of the input voltage with respect to the output signal and whether the fluctuation amount is a positive value or a negative value when the input signal fluctuates. A PWM adjustment unit for generating an adjustment signal for adjusting a parameter corresponding to at least one of a duty defining the frequency and the frequency of the PWM signal;
An operation control unit that adjusts the parameter of the PWM signal based on the adjustment signal and controls the conversion operation of the input signal into the output signal in the output signal control unit;
A power supply device comprising:

[2]
The parameter corresponds to the duty,
The power supply apparatus according to [1], wherein the operation control unit adjusts the duty of the PWM signal based on the adjustment signal to control the conversion operation in the output signal control unit.

[3]
The parameter corresponds to the frequency;
The power supply apparatus according to [1], wherein the operation control unit adjusts the frequency of the PWM signal based on the adjustment signal and controls the conversion operation in the output signal control unit.

[4]
The parameters correspond to the duty and the frequency,
The power control unit according to [1], wherein the operation control unit adjusts the duty and the frequency of the PWM signal based on the adjustment signal to control the conversion operation in the output signal control unit. apparatus.

[5]
The PWM adjustment unit continues the generation of the adjustment signal for the adjustment period immediately after the fluctuation of the input signal occurs, and stops the generation of the adjustment signal after the adjustment period ends,
The power supply apparatus according to any one of [1] to [4], wherein the operation control unit adjusts the parameter based on the adjustment signal of the PWM signal during the adjustment period.

[6]
The power supply apparatus according to [5], wherein the PWM adjustment unit calculates the adjustment period according to a magnitude of the fluctuation amount generated when the input signal fluctuates.

[7]
The power supply device according to [5], wherein the adjustment period is set to a preset fixed period.

[8]
The PWM adjustment unit calculates the adjustment period based on a comparison between the PWM signal whose parameter is adjusted by the operation control unit and a PWM signal estimated based on the feedback signal. The power supply device according to [5].

[9]
The power supply device according to any one of [1] to [8] is provided,
A plurality of light-emitting elements arranged one-dimensionally or two-dimensionally as the load;
The light source device, wherein the output signal control unit, the PWM adjustment unit, and the operation control unit are provided corresponding to each of the plurality of light emitting elements.

[10]
The input signal is converted into an output signal according to the PWM signal and output to the load.
Generating the PWM signal based on a feedback signal fed back in response to an output signal to the load;
When the input signal fluctuates, during the adjustment period immediately after the input signal fluctuates, the magnitude of the fluctuation amount of the input signal with respect to the output signal when the input signal fluctuates, and An adjustment signal for adjusting a parameter corresponding to at least one of the duty defining the on-time of the PWM signal and the frequency of the PWM signal depending on whether the fluctuation amount is a positive value or a negative value. Continue generation,
During the adjustment period, the parameter of the PWM signal is adjusted based on the adjustment signal to control the conversion operation of the input signal to the output signal,
Stop generating the adjustment signal after the end of the adjustment period;
A control method for a power supply device.

[11]
The method of controlling a power supply apparatus according to [10], wherein the adjustment period is calculated according to a magnitude of the fluctuation amount generated when the input signal fluctuates.

[12]
The method for controlling a power supply device according to [10], wherein the adjustment period is set to a preset fixed period.

[13]
The adjustment period is calculated based on a comparison between the PWM signal whose parameter is adjusted by the operation control unit and a PWM signal estimated based on the feedback signal. Control method of power supply.

10 Digital power supply controller 11 ADC
DESCRIPTION OF SYMBOLS 12 Digital control part 13 Oscillation circuit 14 Variable oscillation circuit 20 Digital power supply power part 21 Duty adjustment circuit 22 Switching element 27 Current detection amplifier 30 PWM adjustment part 31 Comparison circuit 32 DC component cut circuit 33 Voltage pulse width conversion circuit 34 Voltage frequency conversion circuit 35 Gate and phase shift circuit 36 Level conversion circuit 40 Load

Claims (13)

An output signal control unit that converts an input signal into an output signal according to a PWM signal and outputs the output signal to a load;
A PWM signal generation unit that generates the PWM signal based on a feedback signal fed back according to the output signal to the load;
The on-time of the PWM signal according to the magnitude of the fluctuation amount of the input voltage with respect to the output signal and whether the fluctuation amount is a positive value or a negative value when the input signal fluctuates. A PWM adjustment unit for generating an adjustment signal for adjusting a parameter corresponding to at least one of a duty defining the frequency and the frequency of the PWM signal;
An operation control unit that adjusts the parameter of the PWM signal based on the adjustment signal and controls the conversion operation of the input signal into the output signal in the output signal control unit;
A power supply device comprising: The parameter corresponds to the duty,
The power supply device according to claim 1, wherein the operation control unit adjusts the duty of the PWM signal based on the adjustment signal to control the conversion operation in the output signal control unit. The parameter corresponds to the frequency;
The power supply device according to claim 1, wherein the operation control unit adjusts the frequency of the PWM signal based on the adjustment signal to control the conversion operation in the output signal control unit. The parameters correspond to the duty and the frequency,
The power supply according to claim 1, wherein the operation control unit adjusts the duty and the frequency of the PWM signal based on the adjustment signal to control the conversion operation in the output signal control unit. apparatus. The PWM adjustment unit continues the generation of the adjustment signal for the adjustment period immediately after the fluctuation of the input signal occurs, and stops the generation of the adjustment signal after the adjustment period ends,
5. The power supply device according to claim 1, wherein the operation control unit adjusts the parameter based on the adjustment signal of the PWM signal during the adjustment period.   The power supply apparatus according to claim 5, wherein the PWM adjustment unit calculates the adjustment period according to a magnitude of the fluctuation amount generated when the input signal fluctuates.   The power supply apparatus according to claim 5, wherein the adjustment period is set to a preset fixed period.   The PWM adjustment unit calculates the adjustment period based on a comparison between the PWM signal whose parameter is adjusted by the operation control unit and a PWM signal estimated based on the feedback signal. The power supply device according to claim 5. A power supply device according to any one of claims 1 to 8,
A plurality of light-emitting elements arranged one-dimensionally or two-dimensionally as the load;
The light source device, wherein the output signal control unit, the PWM adjustment unit, and the operation control unit are provided corresponding to each of the plurality of light emitting elements. The input signal is converted into an output signal according to the PWM signal and output to the load.
Generating the PWM signal based on a feedback signal fed back in response to an output signal to the load;
When the input signal fluctuates, during the adjustment period immediately after the input signal fluctuates, the magnitude of the fluctuation amount of the input signal with respect to the output signal when the input signal fluctuates, and An adjustment signal for adjusting a parameter corresponding to at least one of the duty defining the on-time of the PWM signal and the frequency of the PWM signal depending on whether the fluctuation amount is a positive value or a negative value. Continue generation,
During the adjustment period, the parameter of the PWM signal is adjusted based on the adjustment signal to control the conversion operation of the input signal to the output signal,
Stop generating the adjustment signal after the end of the adjustment period;
A control method for a power supply device.   The method for controlling the power supply apparatus according to claim 10, wherein the adjustment period is calculated according to a magnitude of the fluctuation amount generated when the input signal fluctuates.   The method for controlling the power supply device according to claim 10, wherein the adjustment period is set to a preset fixed period.   11. The adjustment period according to claim 10, wherein the adjustment period is calculated based on a comparison between the PWM signal whose parameter is adjusted by the operation control unit and a PWM signal estimated based on the feedback signal. Control method of power supply.

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