JPH11275858A - Switching power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switching power unit which is improved in output stability, when the load current or input voltage of the unit changes abruptly, or the like, without making the control algorithm more complicated. SOLUTION: A switching power unit incorporates a switch circuit 40 which forms a switching output having a pulse-like waveform by switching input power, an output circuit 42 which outputs the switching output of the circuit 40 by converting the output into a direct current, and a digital control section 70. The control section 70 inputs the analog signal of at least one of the voltage and current outputted from the output circuit 42, converts the inputted analog signal into a digital signal, computes a command value which decides the switching frequency, turning-on time, or turning-off time of the switch circuit 40, based on the obtained digital output voltage signal or digital output current signal, generates a pulse based on the command value, and controls the switching operations of the switch circuit 40 by supplying the pulse to the circuit 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching power supply. In particular, the present invention includes a switch circuit for switching the input power to form a switching output having a pulse-like waveform that is intermittent, and converts the pulse-like output formed by the switch circuit into a direct current and outputs the converted output. The present invention relates to a switching power supply device that monitors this DC output by a control circuit and controls the switching operation so that the DC output becomes constant. More specifically, the present invention relates to a switching power supply using a digital circuit as a control circuit.

[0002]

2. Description of the Related Art In a conventional switching power supply device, a control circuit is usually constituted by an analog circuit. In this case, the signal representing the output voltage or output current is
This is a form of an analog signal, and the analog signal is processed as an analog quantity, and a control signal necessary for controlling the switching operation is obtained based on the processing result.
Generally, in a switching power supply, the operation mode of a power conversion circuit may be changed in accordance with a change in an input voltage or a load current in order to optimize control. In such a case, it is necessary to prepare a plurality of control algorithms corresponding to the respective operation modes in advance, and perform optimal control by appropriately switching and using these. However, in a conventional switching power supply device using an analog control circuit, the signal processing in the control circuit is entirely performed by a circuit configuration as hardware. To achieve optimal control by switching,
A control circuit, that is, hardware, corresponding to each control algorithm must be prepared in advance, and switched and used according to the operation mode. This means that a plurality of types of control circuits as hardware must be prepared. Therefore, this configuration
The circuit configuration becomes remarkably complicated and cannot be said to be realistic.

In a switching power supply device, when a control circuit is configured by a digital circuit, a signal processing time from detection of an output signal to output of a control signal tends to be longer than when the control circuit is configured by an analog circuit. This means that the followability when the load current or the input voltage changes suddenly or when an abnormal state occurs tends to be worse than when the analog circuit is used. JP-A-62-2
Japanese Patent No. 25163 discloses a technique of using a digital control device for a switch circuit in a switching power supply device. The switching power supply device disclosed in this publication includes a chopper circuit for switching input power and a detection circuit for detecting a load change, and a digital controller is provided for controlling the chopper circuit. The digital controller generates a control pulse having a predetermined duty ratio based on a signal detected by the detection circuit, and supplies the control signal to a switch circuit to control the operation of the switch circuit.

This publication teaches a technique for enabling a switching power supply having a digital control device of this type to perform appropriate switching control in response to a load change of the switching power supply. That is, the configuration recommended by this publication includes a storage circuit in which a control amount to be set in advance according to the load is stored for controlling the switch circuit, and the storage circuit stores the control amount in accordance with the load. The control amount is read to generate a control pulse having a predetermined duty ratio. In this case, it is necessary to store all control data within the operation range of the switching power supply in the storage circuit. Also,
Japanese Patent Application Laid-Open No. 2-74152 also discloses a technique of using a digital controller for a switch circuit in a switching power supply. The switching power supply disclosed in this publication includes a switch circuit for switching input power, and a smoothing circuit for smoothing and outputting the output of the switch circuit, and a digital controller for controlling the switch circuit. Is provided. The digital controller generates a control pulse signal having a predetermined duty ratio based on the output voltage value of the switching power supply,
This control pulse signal is applied to a switch circuit to control the operation of the switch circuit.

[0005] This publication discloses a switching power supply provided with a digital control device of this kind, which is generated when the output of a power supply for supplying an input to the switching power supply fluctuates. Techniques for enabling appropriate switching operations in response to voltage changes are taught. That is, in the configuration recommended by this patent publication, a plurality of arithmetic expressions are prepared for controlling the switch circuit, and a desired arithmetic expression is selected from the plurality of arithmetic expressions according to the detected value of the input voltage to the switching power supply. Is used. In this case, the input voltage is detected by the input voltage detecting means.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a switching power supply having a high output stability without a complicated control algorithm when a load current or an input voltage changes suddenly or when an abnormal state occurs. It is to provide. Another object of the present invention is to provide a switching power supply device capable of storing and correcting command value information to be stored during operation of the device.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a switching power supply according to the present invention comprises a switch circuit for switching input power to form a switching output having an intermittent pulse waveform, and An output circuit that converts a switching output into a direct current and outputs the converted output, and a digital control unit. The digital control unit receives an analog signal of at least one of a voltage and a current output from the output circuit, converts the analog signal into a digital signal, and converts the analog signal into a digital output signal or a digital output current signal or both. A command value that determines at least one of the switching frequency, the on-time, and the off-time of the switch circuit is calculated based on the command value, a pulse is generated based on the command value, and the pulse is supplied to the switch circuit to perform the switch operation. Control.

In particular, the switching power supply of the present invention
Command value compensation information corresponding to at least one of the output voltage digital signal and the output current digital signal is stored in the storage means in advance, and when the output voltage digital signal or the output current digital signal suddenly changes, the command value compensation information is stored. A command value given to the switch circuit is calculated based on the output voltage digital signal and the rapidly changing one of the output current digital signals. In one embodiment of the present invention,
The output voltage analog signal and / or the output current analog signal are captured in the same phase of the switching cycle in synchronization with the switching cycle of the switch circuit, and based on the analog signal, the output voltage digital signal and / or the output current digital signal are converted. can get. The output current analog signal may be a current flowing through any part of the output circuit.
For example, if an output circuit is provided with a smoothing circuit for rectifying and smoothing the output, and this circuit is provided with an inductor, it is possible to detect an inductor current flowing through the inductor and obtain an output current analog signal. it can.

The cycle of the command value calculation is an integral multiple of the switching cycle, and the capture of the analog signal is performed at least once every cycle of the command value calculation. In a switching power supply, the output smoothed by the output circuit also has some periodic fluctuation corresponding to the switching cycle of the switch circuit, but the digital signal is based on the analog signal acquired in the same phase of the switching cycle. Is generated and used for calculating the command value, it is possible to suppress the influence of the periodic fluctuation. Thus, in this aspect of the invention, data pre-processing such as data averaging can be omitted. In one embodiment of the present invention in which the information stored in the storage means is used in the command value calculation, the necessary information is to compare the output voltage digital signal and / or the output current digital signal with the stored information. Obtained by: By using the information obtained in this way, the command value can be easily obtained without the need for complicated command value calculation based on the control algorithm, so that the signal processing (calculation) time can be reduced. It becomes possible. Further, in this embodiment, in addition to storing the information in the storage means in advance, it is also possible to store necessary information in the storage means or to modify the stored information. Since the information to be stored can be stored and corrected as needed, the control algorithm (computation result) can be corrected in advance as needed, so that optimal control can be easily realized.

[0010]

FIG. 1 is an electric circuit diagram of an embodiment of a switching power supply according to the present invention. The switching power supply device according to this embodiment of the present invention includes a switch circuit 40 for switching the power input to the device to form a switching output of an intermittent pulse waveform, and a DC power supply for switching the output of the switched pulse waveform. And an output circuit 50 for converting the data into an output and a digital control unit 70. In this embodiment, the switching power supply has input terminals IN1 and IN2 for inputting AC power.
1, the AC power supplied to IN2 is applied to the rectifying and smoothing circuit 20 through the input filter 10. Rectifier smoothing circuit 20
Includes a full-wave rectifier diode 21 and a smoothing capacitor 22. The output of the rectifying / smoothing circuit 20 is supplied to the switch circuit 40.

The switch circuit 40 functions to control on / off of the power supplied from the rectifying / smoothing circuit 20. The switch circuit 40 includes a switching element 42 constituted by a field effect transistor (FET), and a main transformer 41 for coupling the on / off output to an output circuit 50. The drain of the switching element 42 is connected in series to one terminal of the primary coil 411 of the main transformer 41. The other of the primary coils 411 of the main transformer 41 is connected to the rectifying and smoothing circuit 20. The output circuit 50 is a rectifying / smoothing circuit, and converts the switching output supplied from the switch circuit 40 into DC and outputs the DC. The DC output Vo is supplied from the output terminals OUT1 and OUT2 to the load Z. In the power supply line of the output circuit 50,
An output current detection circuit 60 for detecting the output current I is coupled. The output circuit 50 includes a choke input type smoothing circuit to obtain a stabilized output. The illustrated smoothing circuit includes diodes 51 and 52, an inductor 53, and a capacitor 54. One diode 51 has an anode connected in series to one terminal of a secondary coil 412 of the main transformer 41. The other diode 52 is connected in parallel to the secondary coil 412 of the main transformer 41, and has a cathode connected to the cathode of the diode 51. Inductor 53
Is connected to the connection point between the diode 51 and the diode 52. The capacitor 54 is connected to the output terminal of the inductor 53.

The output from the output circuit 50 is a voltage analog signal.
The signal is taken out as AS1, the output from the output current detection circuit 60 is taken out as a current analog signal AS2, and these analog signals are supplied to the digital control unit 70. Then, the control output from the digital control unit 70 is supplied to the switching element 42 constituting the switch circuit 40. The switching element 42 operates so as to determine a ratio between the on-time and the off-time, ie, a duty ratio, in a switching cycle that can be defined as a sum of the on-time and the off-time. The digital control unit 70 receives as input the voltage analog signal AS1 output from the output circuit 50 and the current analog signal AS2 output from the output current detection circuit 60, and converts these analog signals AS1 and AS2 to digital signals, respectively. The digital control unit 70 calculates a command value for determining the ON time and the OFF time of the switch circuit 40 based on the obtained output voltage digital signal and output current digital signal. Instead of or in addition to determining the ON time and OFF time of the switch circuit 40, the switching cycle may be determined. The cycle time of the command value calculation (hereinafter, sometimes referred to as “control cycle”) is an integral multiple of the switching cycle, and one command value calculation may be performed for each of a plurality of switching cycles.

When the information stored in the storage means is used in the command value calculation, the necessary information is the output voltage digital signal and / or the output current digital signal and the information stored in the storage means. Obtained by matching. Further, in addition to storing the information in the storage means in advance, it is also possible to appropriately store necessary information in the storage means or to modify the stored information. Next, the digital control unit 70 generates a pulse based on the command value obtained by the calculation, and supplies the pulse to the switch circuit 40 to control the switch operation.
As a result, the DC output voltage appearing at the output terminals OUT1 and OUT2
Vo and DC output current I are controlled. As described above, the switching power supply according to the present invention employs the digital control method having the digital control unit 70,
The control algorithm for each operation mode can be easily switched and executed by software. Also, since the increase in the number of control algorithms can be handled by software, the circuit does not become complicated. Further, since the necessary control algorithm can be executed by software, the hardware of the digital control unit 70 can be standardized.

FIG. 2 is a more specific electric circuit diagram of the switching power supply according to the present invention. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, a starting circuit 30 is connected to the rectifying / smoothing circuit 20. Start-up circuit 30
Is the digital control unit when starting up after the AC power is turned on.
Generate power to operate 70. The drive circuit 90 is connected to the output side of the start circuit 30. An auxiliary power supply circuit 80 is connected to the main transformer 41. The auxiliary power supply circuit 80 constitutes a power supply of the digital control unit 70, and a circuit 82 including a rectifying and smoothing circuit is connected to an auxiliary winding 81 provided in the main transformer 41. Auxiliary power supply circuit 80
Generates a power supply voltage to be supplied to the digital control unit 70, and this power supply voltage is supplied to power supply terminals T5 and T6 provided in the digital control unit 70.

The output current detection circuit 60 detects the inductor current I
A current sensor 61 for detecting L and a resistor 62 for converting a current value to a voltage value are provided. The current sensor 61 may be connected in series with the inductor 53 in some cases. In this embodiment, since the output circuit 50 is a choke input type rectifying / smoothing circuit, the output current detection circuit 60 is
Will be detected as a voltage value of the inductor current of the inductor 53 included in. Hereinafter, the output current detection circuit 60 is referred to as an inductor current detection circuit 60. Next, the digital control unit 70 includes an AD conversion unit 72, a digital signal processing unit 71, and a pulse generation unit 73. Digital control unit 70
Includes a digital signal processor called a DSP as a main element. Some DSPs include the AD conversion unit 72 in their configuration. When a DSP is used as the digital control unit 70, the pulse generation unit 73 may be provided as an internal element of the DSP, or a part or all of the pulse generation unit 73 may be externally attached to the DSP as an external element.

The A / D converter 72 outputs the output voltage analog signal AS1.
And convert the inductor current analog signal AS2 into digital signals DS1 and DS2, respectively. The AD converter 72 can also include an AD converter 721 and an AD converter 722. Here, the output voltage analog signal AS1 is supplied to the AD converter 721 through the terminal T1, and the inductor current analog signal AS2 is supplied to the AD converter 722 through the terminal T2. The digital signal processing unit 71 of the digital control unit 70 includes a program memory 713, data memories 714, 715, 716,
A main processing unit (hereinafter referred to as CPU) 711. The data memories 714 and 715 temporarily store data of the digital signals DS1 and DS2 supplied from the AD converter 72. The supply of the digital signal from the AD converter 72 may be performed in each switching cycle, but the cycle time of the command value calculation,
That is, it may be performed for each control cycle. In any case, it is preferable to supply data in the same phase in synchronization with the switching cycle or the control cycle. By performing the calculation of the command value based on the in-phase data, data pre-processing such as data averaging can be omitted. CPU 711 is connected to data memory via bus 712
It takes in data from 714 and 715 and performs necessary operations such as four arithmetic operations and logical operations.

The pulse generator 73 includes counters 731, 732, 73
3, a latch circuit 734, and an output circuit 735. The counter 731 determines the off timing of the main switch 42 based on the command value given from the digital signal processing unit 71. The counter 732 determines the ON timing of the main switch 42 based on the command value given from the digital signal processing unit 71. The counter 733 determines the cycle time of the command value calculation, that is, the control cycle. Latch circuit 734
Is set (logical value 1) at the ON timing set by the counter 732 and reset (logical value 0) at the OFF timing of the counter 731. With this operation, a pulse for driving the main switch 42 is output from the latch circuit 734.

The drive circuit 90 transmits a drive signal to the switch circuit 40.
A pulse transformer 91 and a resistor 92 for transmitting the pulse signal to the power supply are provided. The drive signal from the digital control unit 70 is transmitted to the main switch 42 through the resistor 92. Next, the operation of the circuit of the illustrated embodiment will be described. The analog signal AS1 of the output voltage Vo of the output circuit 50 is taken into the digital control unit 70, and is converted into the digital signal DS1 by the AD conversion unit 721. The converted digital signal DS1 is stored in the data memory 714
Is stored temporarily. Analog signal AS2 of inductor current IL obtained by inductor current detection circuit 60
Is taken into the digital control unit 70 and converted into a digital signal DS2 by the AD conversion unit 722. The inductor current digital signal DS2 is temporarily stored in the data memory 715.

The CPU 711 reads the contents of the data memories 714 and 715 based on the control program. Then, using the read data, a command value for determining the ON time and the OFF time of the main switch 42 included in the switch circuit 40 is calculated. The command value calculated by the CPU 711 is taken into the pulse generator 73. At time t1, the pulse generator
When the counter 732 of the 73 overflows or underflows, a signal corresponding thereto is supplied to the latch circuit 734. The latch circuit 734 outputs a logical value by this signal.
Set to 1. Next, when the ON time instructed by the CPU 711 has elapsed, the counter 731 overflows or underflows, and sets the OFF timing of the main switch 42. The ripple carry signal or the borrow signal of the counter 731 is supplied to the latch circuit 734. The output of the latch circuit 734 is reset to the logical value 0 by this signal. As a result, the main switch is
An on-time pulse for driving 42 is output.

The control cycle of the command value calculation is set by the counter 733. The control cycle is an integral multiple m of the switching cycle. By doing so, the data memory 71
4, 715 stores each detected signal value detected in each control cycle. The CPU 711 reads the data from the data memories 714 and 715, and calculates the ON time of the main switch 42 according to a control algorithm, for example, a control algorithm during a constant voltage operation. Then, the command value updated for each control cycle is supplied to the pulse generator 73. Output circuit 735
Supplies the pulse supplied from the latch circuit 734 to the gate of the main switch 42 via the pulse transformer 91. As a result, the output voltage Vo of the output circuit 50 and the inductor current IL are controlled to values based on the control algorithm of the CPU 711.

In the switching power supply according to the illustrated embodiment of the present invention, the control algorithm is changed so as to keep the output voltage constant following changes in the input voltage and the inductor current IL. That is, each time the counter 733 overflows or underflows, each detected digital data is fetched into the CPU 711 as shown in FIG. 3 and each detected digital data or each detected digital data before one control cycle is used. Then, the operation state of the apparatus is determined, and a command value calculation program is appropriately selected according to the operation state. As an example, a control algorithm for controlling the output voltage Vo at a constant voltage will be described with reference to the flowchart in FIG. In this case, as the command value calculation means, paying attention to the fact that the inductor current changes according to the load, the calculation program when the inductor current is continuous, the calculation program when the inductor current is discontinuous, the calculation program when the overload is over, and the load The operation program at the time of sudden change is stored in the program memory 713 of the CPU 711 in advance. Each time the counter 733 overflows or underflows, each detected digital data is taken into the CPU 711, and the CPU 711 determines the operation state of the apparatus based on the read data. That is, whether or not the inductor current IL is discontinuous is determined by, for example, storing the continuous / discontinuous critical current value is of the inductor current in the program memory 713 and reading the stored critical current value is. It can be determined by comparing the obtained data. Also,
Whether an overload, for example, stores the maximum current value I _max in the program memory 713, can be determined by comparing the data read with the maximum current value I _max being the storage.

Further, whether the load has changed suddenly is determined by
For example, the allowable output voltage fluctuation value ΔV ₀ T1) is stored in the program memory 713, and the difference between the read data and the data one control cycle before, and the stored allowable output voltage fluctuation value ΔV ₀ (LT1 ) Can be determined by comparing Then, based on the determination, a calculation program corresponding to each operation state is selected, and a command value is calculated. When it is determined that the inductor current is continuous, a control algorithm for the continuous inductor current, for example, an output voltage average value V ₀ and an inductor current average value IL for each control cycle is calculated, and the calculated output voltage average value is calculated. Using V ₀ and the inductor current average value IL, state averaging means for describing the circuit state, that is, calculating the on-time Ton (n) of the main switching element 42 according to the equations (a) to (e) in FIG. I do.

If it is determined that the inductor current is discontinuous, a control algorithm for the discontinuity of the inductor current, for example, the read output voltage value V ₀ and the inductor current value IL previously stored in the storage stage , A means based on the control amount ΔV (iT), that is, the ON time To of the main switching element 42 according to the equation (f) shown in FIG.
Calculate n (n). When it is determined that an overload condition is present, a control algorithm at the time of overload, for example, means based on the read output voltage value Vo, the inductor current IL, and the maximum current value Imax, that is, the equation (a) shown in FIG. ), The ON time Ton (n) of the main switch 42 is calculated according to the equations (e) and (g). When it is determined that the load is suddenly changing, the on-time of the main switching element 42 is calculated according to the control algorithm at the time of sudden change shown in FIG.
That is, the difference ΔVo = Vo (n) − between the read output voltage value Vo (n−1) in the (n−1) th control cycle and the output voltage value Vo (n) in the (n) th control cycle. Based on Vo (n-1)
The correction amount ΔTo corresponding to the difference amount ΔVo having the relationship shown in FIG.
n is obtained from the data table stored in the storage means 716. Using the correction amount ΔTon thus obtained, the on-time Ton (n) of the main switching element 42 is calculated by the following equation.
(h) Ton (n) = Ton (n-1) + ΔTon ··· (h) In this equation, Ton (n-1) is (n
-1) Indicates the on-time in the control cycle.

The relationship between the difference amount of the output voltage value Vo shown in FIG. 5 and the correction amount ΔTon of the ON time of the main switching element 42 is expressed by the equations (i-1), (i-2), (i-3) in FIG. ), (i-4), (i-5). In this embodiment, the equations (i-1), (i-2),
The correction amount ΔTon obtained from (i-3), (i-4), and (i-5) is stored as a data table in the data memory 716 as storage means. Also, when the input voltage changes suddenly, the output voltage and output current also change suddenly.
By using a control algorithm corresponding to the sudden change in load described above, it is possible to cope with this. In this embodiment, the output voltage and the output current are constantly monitored. Therefore, even if an abnormal condition occurs at the output terminal, appropriate control can be performed by using the above-described control algorithm for a sudden load change. Can be. For example, when the output voltage Vo rises abnormally, the difference value ΔVo of the output voltage becomes a positive value, and control is performed so that the on-time of the main switching element 42 is shortened.

With such control, the calculation for control when the load current or the input voltage changes suddenly can be simplified, and the calculation time can be shortened. As a result, a power supply device with improved followability and high output stability can be obtained. In the present invention, for example, when the switching power supply is started and the initial settings of the registers and the pulse generator 73 in the CPU 711 are performed, the equation (i-
1), (i-2), (i-3), (i-4), and (i-5) are performed to obtain a correction amount ΔTon, which is stored in a data memory 716 as storage means.
Can be stored as a data table.
Thus, for example, in order to change the response characteristics, the constants in the above-described equations (i-1), (i-2), (i-3), (i-4), and (i-5) in FIG. Even when α, β, etc. are changed, the correction amount ΔTon
By revising only the changed parts of these equations instead of rewriting all the data in the data table, a desired data table can be obtained, so that the control program can be standardized.

Further, in the present invention, for example, the above-mentioned equation (i-2) in which only the constants α and β are changed during the operation is calculated again. Can be modified. This makes it possible to freely change the response characteristics of the power supply device even during operation.

[0027]

As described above, according to the present invention, the following effects can be obtained. (a) A switching power supply with high output stability can be provided without complicating the control algorithm when the load current or input voltage changes suddenly or when an abnormal condition occurs. (b) The command value information to be stored is stored when the device is started and / or
Alternatively, a switching power supply device that can be stored and modified during operation can be provided.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a detailed configuration of an embodiment of the switching power supply device according to the present invention.

FIG. 3 is a flowchart showing an example of a control procedure of the switching power supply according to the present invention.

FIG. 4 is a flowchart showing an example of a control procedure of the switching power supply according to the present invention.

FIG. 5 is a chart showing a control amount at the time of a sudden change in load in a control procedure of the switching power supply according to the present invention.

FIG. 6 is a chart showing mathematical expressions for explaining control of the switching power supply device according to the present invention.

[Description of Signs] 20 Primary side rectifying / smoothing circuit 40 Switch circuit 41 Main transformer 42 Main switch 50 Output circuit 60 Output current detection circuit (Inductor current detection circuit) 70 Digital control section 71 Digital signal processing section 72 AD conversion section 73 Pulse generator 90 Drive circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigetaka Maeyama TDK Corporation, 1-13-1 Nihonbashi, Chuo-ku, Tokyo

Claims (3)

[Claims] 1. A switching circuit for switching input power to form a switching output having a pulse-like waveform that is intermittent, an output circuit for converting the switching output to a direct current and outputting the direct current, and an output for the output circuit. A digital control unit for controlling a switching operation of the switch circuit in response to the output voltage. The digital control unit includes an output voltage analog signal of a voltage output from the output circuit and an output current of a current output from the output circuit. Receiving the analog signal, converting the output voltage analog signal and the output current analog signal into an output voltage digital signal and an output current digital signal, respectively, based on at least one of the output voltage digital signal and the output current digital signal; A switching cycle of the switch circuit;
Calculating a command value that determines at least one of an on-time and an off-time; generating a control pulse based on the command value;
A switching power supply device for supplying the control pulse to the switch circuit to control the switch operation thereof, wherein a command value corresponding to at least one of the output voltage digital signal and the output current digital signal in advance. Compensation information is stored in a storage means, and when the output voltage digital signal or the output current digital signal changes suddenly, the command value compensation information and the sudden change of the output voltage digital signal and the output current digital signal change. A switching power supply device configured to calculate the command value given to the switch circuit based on the signal of the switching power supply. 2. The switching power supply according to claim 1, wherein at least one of the command value information corresponding to the output voltage digital signal and the output current digital signal is stored in storage means during operation of the power supply. A switching power supply device. 3. The switching power supply according to claim 1, wherein the command value information stored in the storage means can be modified as needed during operation of the power supply. Switching power supply.