JP2017085835A - Dc/dc converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a configuration capable of stabilizing an output at an earlier stage when rapid output variation occurs in a DC/DC converter in which feedback control to repeatedly update a duty ratio is performed on the basis of an output value.SOLUTION: A DC/DC converter 1 comprises: a voltage conversion part 3 for converting and outputting an input voltage; a detection part 20 for detecting a value on which at least either an output voltage or output currents from the voltage conversion part 3 is reflected; and a control part 2 for controlling the voltage conversion part 3 by a PWM signal, and for performing feedback control to update a duty ratio of the PWM signal on the basis of a target value of an output and a detection result of the detection part 20. The control part 2 stops and stabilizes the update of the duty ratio of the PWM signal when a degree of change of at least either the output currents or the output voltage is brought into a predetermined sudden variation state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a DCDC converter.

  In a DCDC converter that boosts or lowers a DC voltage by driving a switching element, a deviation between an output voltage or output current and a target value is obtained, and a desired output is obtained by performing feedback control based on the deviation. In this type of DCDC converter, at the start of output, soft start is performed to gradually increase the output voltage by gradually increasing the target value, thereby suppressing inrush current and stabilizing the output ( Patent Document 1).

Japanese Patent No. 4923846

  By the way, in the feedback control performed by this type of DCDC converter, overshoot occurring at the time of sudden current fluctuation becomes a problem. For example, when an inrush current occurs immediately after the start of output, there is a problem that a delay occurs until the current is suppressed because the delay in the feedback loop does not control the inrush current even after the output exceeds the target value. is there. In this delay period, the operation for increasing the current is continued, so that an additional current increase occurs.

  The present invention has been made based on the above-described circumstances, and in a DCDC converter that performs feedback control that repeatedly updates the duty ratio based on the output value, the output is stabilized earlier when a sudden output fluctuation occurs. It aims at realizing the structure which can be made into.

The DCDC converter of the present invention
A voltage converter that converts and outputs the input voltage; and
A detection unit for detecting a value reflecting at least one of an output voltage or an output current from the voltage conversion unit;
A control unit for controlling the voltage conversion unit by a PWM signal and performing feedback control for updating a duty ratio of the PWM signal based on a target value of an output and a detection result of the detection unit;
With
The control unit stops and fixes the update of the duty ratio of the PWM signal when the degree of change of at least one of the output current and the output voltage becomes a predetermined sudden fluctuation state.

  According to the DCDC converter of the present invention, when the output from the voltage conversion unit becomes a “predetermined sudden fluctuation state”, the duty ratio is quickly fixed, and an additional current increase or an additional current decrease occurs. Can be suppressed. For example, if the output suddenly fluctuates shortly before reaching the target value, it is possible to prevent excessive current increase or additional current decrease from continuing after the target value is reached. Shooting or excessive undershooting can be suppressed.

  As described above, according to the present invention, in a DCDC converter that performs feedback control that repeatedly updates the duty ratio based on the output value, the output can be stabilized earlier when a sudden output fluctuation occurs. .

  In the present invention, the predetermined sudden change state may be a state in which a physical quantity reflecting the output current or output voltage satisfies a predetermined condition (a condition indicating a predetermined sudden change). For example, the output current variation rate may be a condition that is equal to or greater than or equal to a predetermined threshold value, or the output voltage variation rate may be equal to or greater than a predetermined threshold value.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram schematically illustrating a DCDC converter according to a first embodiment and a related configuration. FIG. 2 is a block diagram illustrating details of a control unit and the like in the DCDC converter according to the first embodiment. 3 is a flowchart illustrating the flow of feedback control performed by the DCDC converter according to the first embodiment. 3 is a flowchart illustrating an example of calculation stop signal switching control in the DCDC converter according to the first embodiment. It is explanatory drawing which illustrates the correspondence of the waveform which shows a time-dependent change of a calculation result, and a calculation stop signal. It is a wave form diagram which illustrates a current waveform in case a sudden change state arises.

The desirable form of invention is illustrated below.
In the present invention, the control unit reaches a set threshold in which at least one of a current fluctuation rate that is a fluctuation amount of the output current per predetermined time and a voltage fluctuation rate that is the fluctuation amount of the output voltage per predetermined time is set. In such a case, the update of the duty ratio of the PWM signal may be stopped and fixed.

  According to this configuration, it is possible to more accurately determine whether or not a sudden change in current or voltage has occurred, and when a sudden change occurs, it is possible to more reliably grasp the situation and fix the duty ratio.

  In the present invention, after stopping and fixing the update of the duty ratio of the PWM signal, the control unit cancels the update stop when the current fluctuation rate or voltage fluctuation rate reaches the release threshold, and detects the target value and The configuration may be such that the control for updating the duty ratio of the PWM signal is restarted based on the detection result of the unit.

  According to this configuration, it is possible to fix the duty ratio by focusing on a period in which a sudden change in current or voltage occurs. When sudden fluctuations are eliminated, normal feedback control can be resumed, so that the fixed duty continues after elimination of sudden fluctuations, and the output and target value are too far apart. Can be prevented.

<Example 1>
Embodiment 1 of the present invention will be described below.
The DCDC converter 1 shown in FIG. 1 is configured as, for example, a vehicle-mounted multiphase DCDC converter. The DCDC converter 1 includes a voltage conversion unit 3 that converts and outputs an input voltage applied to the input side conductive path 7A, and a control unit 2 that controls the voltage conversion unit 3 using a PWM signal. The DC voltage (input voltage) applied to 7A is voltage-converted by a step-down method, and an output voltage obtained by stepping down the input voltage is output to the output side conductive path 7B.

  The input side conductive path 7A is configured, for example, as a primary (high voltage side) power supply line to which a relatively high voltage is applied, and is connected to the high potential side terminal of the primary side power storage device 91, and the power storage device A predetermined DC voltage (for example, 48 V) is applied from 91. The power storage device 91 is configured by power storage means such as a lithium ion battery or an electric double layer capacitor, for example, and a voltage of 48 V, for example, is output from the high potential side terminal. Further, a power supply 93, a load 94, and the like are also connected to the input side conductive path 7A.

  The output side conductive path 7B is configured as a secondary (low voltage side) power supply line to which a relatively low voltage is applied. For example, the output-side conductive path 7B is electrically connected to the high-potential side terminal of the secondary-side power storage device 92, and a DC voltage (for example, 12V) smaller than the output voltage of the power storage device 91 is applied from the power storage device 92. The structure is made. The power storage device 92 is configured by power storage means such as a lead storage battery, and a voltage of, for example, 12 V is output from the high potential side terminal. A load 95 and the like are also connected to the output side conductive path 7B.

  Between the input-side conductive path 7A and the output-side conductive path 7B, a voltage converter 3 that functions as a synchronous rectification step-down converter is provided. The voltage conversion unit 3 includes a high-side switching element 4, a low-side switching element 6, and an inductor 12. The switching element 4 is configured as an N-channel MOSFET, and the input side conductive path 7 </ b> A is connected to the drain of the switching element 4. The drain of the switching element 6 on the low side and one end of the inductor 12 are connected to the source of the switching element 4. The switching element 6 has a drain connected to a connection point between the switching element 4 and the inductor 12 and a source grounded. The other end of the inductor 12 is connected to the output side conductive path 7B. Further, an input capacitor 8 is connected to the input side conductive path 7A, an output capacitor 10 is connected to the output side conductive path 7B, and the other end of each is grounded.

The detection unit 20 includes a current detection unit 22 that detects an output current and a voltage detection unit 24 that detects an output voltage. The detection unit 20 detects a value reflecting the output current and the output voltage in the output-side conductive path 7B, and outputs the detected values. To do. The current detection unit 22 may be configured to output a voltage value corresponding to a current (output current) flowing through the output-side conductive path 7B as a detection value. For example, the current detection unit 22 includes a resistor and a differential amplifier that are interposed in the output-side conductive path 7B, and the voltage across the resistor is input to the differential amplifier, and resistance is generated by the current flowing through the output-side conductive path 7B. The amount of voltage drop generated in the device is amplified by a differential amplifier and output as a detection value. The voltage detector 24 outputs, for example, a value reflecting the voltage (output voltage) of the output side conductive path 7B (for example, the voltage of the output side conductive path 7B itself, or a divided value). Hereinafter, the value output from the current detection unit 22 is referred to as “current value” that is a value indicating the output current, and the value output from the voltage detection unit 24 is referred to as “voltage value” that is a value indicating the output voltage. To do.
As shown in FIG. 2, the control unit 2 mainly includes a microcomputer 30, a current fluctuation measurement circuit 32 </ b> A, a voltage fluctuation measurement circuit 32 </ b> B, a sudden fluctuation determination circuit 33, and a PWM drive circuit 31.

  The microcomputer (microcomputer) 30 includes, for example, a CPU, a ROM, a RAM, a nonvolatile memory, and the like. The microcomputer 30 stores a setting threshold value ΔIt1 and a release threshold value ΔIt2 related to the current fluctuation rate, a setting threshold value ΔVt1 and a release threshold value ΔVt2 related to the voltage fluctuation rate.

  The current fluctuation amount measurement circuit 32A monitors the output value from the current detection unit 22 and measures the fluctuation rate ΔIr of the output current per predetermined time. ΔIr, which is the fluctuation amount of the output current per predetermined time, corresponds to the fluctuation rate of the output current.

  The voltage variation measuring circuit 32B monitors the output value from the voltage detector 24 and measures the variation rate ΔVr of the output voltage per predetermined time. ΔVr, which is the fluctuation amount of the output voltage per predetermined time, corresponds to the fluctuation rate of the output current.

  The sudden change determination circuit 33 is a circuit that performs the sudden change determination process shown in FIG. 4, and includes the output current change rate ΔIr output from the current change amount measurement circuit 32A and the output voltage output from the voltage change amount measurement circuit 32B. The fluctuation rate ΔVr is input. In addition, a setting threshold value ΔIt1 and a release threshold value ΔIt2 related to the current fluctuation rate, and a setting threshold value ΔVt1 and a release threshold value ΔVt2 related to the voltage fluctuation rate are input from the microcomputer 30.

  The PWM drive circuit 31 is a circuit that performs feedback control so that the output from the voltage conversion unit 3 becomes a set target value. Specifically, based on the current value Iout and voltage value Vout of the output-side conductive path 7B, the output current target value Ita (target current value), and the output voltage target value Vta (target voltage value), a known PID is known. A control amount (duty ratio) is determined by feedback calculation using a control method. Then, the PWM signal having the determined duty ratio is complementarily output to the voltage conversion unit 3.

  In the DCDC converter 1 configured as described above, the control unit 2 sets a dead time and then outputs a PWM signal to the voltage conversion unit 3 in a complementary manner, and outputs an ON signal to the gate of the switching element 4. During output, an OFF signal is output to the gate of the switching element 6, and an ON signal is output to the gate of the switching element 6 during output of the OFF signal to the gate of the switching element 4. In response to such a complementary PWM signal, the voltage conversion unit 3 performs switching between the ON operation and the OFF operation of the switching element 4 in synchronization with the switching between the OFF operation and the ON operation of the switching element 6. As a result, the DC voltage applied to the input side conductive path 7A is stepped down and output to the output side conductive path 7B. The output voltage of the output side conductive path 7B is determined according to the duty ratio of the PWM signal applied to each gate of the switching elements 4 and 6 (that is, the duty ratio set by the PWM drive circuit 31).

The feedback control by the control unit 2 will be described with reference to FIG.
The feedback control in FIG. 3 is a control executed by the PWM drive circuit 31 and is a process repeated at a short time interval. The PWM drive circuit 31 performs control according to the flow of FIG. 3 when a predetermined operation start condition is established. The operation start condition is, for example, switching of the ignition signal from off to on, and other operation start conditions may be used.

  First, an output current value Iout and an output voltage value Vout output from the detection unit 20 are acquired (S1). For example, when the processing of FIG. 3 is realized by the hardware circuit shown in FIG. 2, the deviation calculation circuit 34 acquires the output current value Iout, and the deviation calculation circuit 35 acquires the output voltage value Vout. Further, the deviation calculating circuit 34 acquires the current target value Ita set by the microcomputer 30, and the deviation calculating circuit 35 acquires the voltage target value Vta (S2).

  For example, the microcomputer 30 sets the current target value Ita to a predetermined fixed current value in the steady output state, and sets the current target value Ita to 0 during soft start performed immediately after the start of the operation of the DCDC converter 1. Until the fixed current value is reached. Similarly, the current target value Vta is set to a predetermined fixed voltage value in the steady output state, and during the soft start, the current target value Vta is gradually increased from 0 to the fixed voltage value as time elapses. It is supposed to let you.

  Further, the duty ratio set in the previous processing of FIG. 3 (that is, the latest duty ratio set in the previous S9) is acquired (S3). For example, the latest duty ratio set in S9 is stored in a memory (not shown), and the latest duty ratio is acquired from this memory in the process of S3.

  Further, the arithmetic circuits 36 and 37 determine whether or not an arithmetic stop signal is output from the sudden fluctuation determination circuit 33 (S4). When the calculation output signal is not output from the sudden fluctuation determination circuit 33, the process proceeds to N in S4. When the calculation output signal is output from the sudden fluctuation determination circuit 33, the process proceeds to Y in S4.

  When the process proceeds to N in the determination process of S4, that is, when the calculation output signal is not output from the sudden fluctuation determination circuit 33, the calculation circuit 36 performs a current control calculation (S5), and the calculation circuit 37 performs a voltage control calculation. (S6). In the process of S5, the arithmetic circuit 36 obtains the deviation between the output current value Iout and the current target value Ita output from the deviation calculation circuit 34, and the deviation, preset proportional gain, differential gain, and integral gain. Based on the above, the operation amount (increase / decrease amount of the duty ratio) for making the output current close to the current target value Ita is determined by a known PID arithmetic expression. In the process of S6, the arithmetic circuit 37 obtains a deviation between the output voltage value Vout output from the deviation calculation circuit 35 and the voltage target value Vta, and the deviation, preset proportional gain, differential gain, and integral gain. Based on the above, the operation amount (increase / decrease amount of the duty ratio) for bringing the output voltage close to the voltage target value Vta is determined by a known PID arithmetic expression.

  In the processing of S7, the arbitration circuit 38 performs arbitration of current / voltage control. In this process, the arbitration circuit 38 determines whether to give priority to current control or voltage control. Specifically, it is determined which of the operation amount determined by the arithmetic circuit 36 and the operation amount determined by the arithmetic circuit 37 is prioritized. There are various methods for determining which to prioritize. For example, among the operation amounts of the arithmetic circuits 36 and 37, a method of giving priority to a small operation amount (a calculation result with a small duty ratio) can be considered. The arbitration method is not limited to this method, and other known methods may be used.

  The arbitration circuit 38 calculates a new duty ratio by adding a priority operation amount (duty ratio increase / decrease amount) among the operation amounts of the arithmetic circuits 36 and 37 to the current control amount (duty ratio). When a new duty ratio is determined in S7, the memory is updated to reflect the duty ratio as a new duty ratio (S9). As described above, when a new duty ratio is set in S9, the PWM signal of that duty ratio is continuously output to the voltage conversion unit 3 at least until the next processing of S9 is performed, and the voltage conversion is performed. Made.

  On the other hand, when the process proceeds to Y in the determination process of S4, the previous duty ratio acquired in S3 is set as a new duty ratio as it is (S8), and in S9, the duty ratio is left as it is. That is, in the process of FIG. 3, while the calculation stop signal is output, the duty ratio is not updated, and is fixed at the duty ratio immediately before the calculation stop signal is output.

Next, the calculation stop signal switching control will be described with reference to FIG.
The control shown in FIG. 4 is performed by the sudden change determination circuit 33 shown in FIG. The sudden change determination circuit 33 acquires a setting threshold value ΔIt1 and a release threshold value ΔIt2 relating to the current fluctuation rate, a setting threshold value ΔVt1 and a release threshold value ΔVt2 relating to the voltage fluctuation rate from the microcomputer 30 (S11). Further, the sudden fluctuation determination circuit 33 acquires the output current fluctuation rate ΔIr from the current fluctuation amount measurement circuit 32A, and acquires the output voltage fluctuation rate ΔVr from the voltage fluctuation amount measurement circuit 32B (S12).

  Then, the sudden change determination circuit 33 determines whether or not the calculation is currently stopped, that is, whether or not the calculation stop signal is being output (S13). When the sudden change determination circuit 33 determines that the calculation stop signal is not being output at the time when the process of S13 is performed, whether or not the output current change rate ΔIr exceeds the set threshold value ΔIt1 and the output voltage change It is determined whether rate ΔVr exceeds set threshold value ΔVt1 (N in S13, S14).

  The abrupt change determination circuit 33 determines that the output current change rate ΔIr exceeds the set threshold value ΔIt1 or the output voltage change rate ΔVr exceeds the set threshold value ΔVt1 in S14. Is output (Y in S14, S15). When it is determined that the variation rate ΔIr of the output current is equal to or less than the set threshold value ΔIt1 and the variation rate ΔVr of the output voltage is equal to or less than the set threshold value ΔVt1, the calculation stop signal is not output (N in S14, S16). .

  If it is determined in S13 that the calculation stop signal is being output, the sudden fluctuation determination circuit 33 determines whether or not the output current fluctuation rate ΔIr exceeds the release threshold ΔIt2 and the output voltage fluctuation rate ΔIr. It is determined whether or not release threshold value ΔVt2 is exceeded (Y in S13, S17).

  The abrupt fluctuation determination circuit 33 outputs an operation stop signal when it is determined in S17 that the output current fluctuation rate ΔIr is not less than the release threshold value ΔIt2 or the output voltage fluctuation rate ΔIr is not less than the release threshold value ΔVt2. The maintained state is maintained (N in S17, S15). When it is determined that the fluctuation rate ΔIr of the output current is less than the release threshold value ΔIt2 and the fluctuation rate ΔIr of the output voltage is less than the release threshold value ΔVt2, the calculation stop signal is not output (Y in S17, S16). .

  As described above, in this configuration, the control unit 2 controls the voltage conversion unit 3 with the PWM signal, and updates the duty ratio of the PWM signal based on the output target value and the detection result of the detection unit 20. When the change degree of at least one of the output current and the output voltage is in a predetermined sudden fluctuation state, updating of the duty ratio of the PWM signal is stopped and fixed.

  Specifically, the control unit 2 is set to at least one of a current fluctuation rate ΔIr that is a fluctuation amount of the output current per predetermined time and a voltage fluctuation rate ΔVr that is a fluctuation amount of the output voltage per predetermined time. When the set threshold value is reached, the updating of the duty ratio of the PWM signal is stopped and fixed. Further, after stopping and fixing the update of the duty ratio of the PWM signal, the control unit 2 stops the update when one or both of the current fluctuation rate ΔIr and the voltage fluctuation rate ΔVr reach the release threshold. The control for canceling and updating the duty ratio of the PWM signal based on the target value and the detection result of the detection unit 20 is resumed.

Hereinafter, the effect of this configuration will be exemplified.
According to the DCDC converter 1 of this configuration, when the output from the voltage conversion unit 3 is in a “predetermined sudden fluctuation state”, the duty ratio is quickly fixed, and an additional current increase or an additional current decrease occurs. It is possible to suppress the occurrence. For example, if the output suddenly fluctuates shortly before reaching the target value, it is possible to prevent excessive current increase or additional current decrease from continuing after the target value is reached. Shooting or excessive undershooting can be suppressed.

  Specifically, the control unit 2 is set to at least one of a current fluctuation rate ΔIr that is a fluctuation amount of the output current per predetermined time and a voltage fluctuation rate ΔVr that is a fluctuation amount of the output voltage per predetermined time. When the set threshold value is reached, the updating of the duty ratio of the PWM signal is stopped and fixed. According to this configuration, it is possible to more accurately determine whether or not a sudden change in current or voltage has occurred, and when a sudden change occurs, it is possible to more reliably grasp the situation and fix the duty ratio.

  For example, as shown in the waveform of the duty ratio (calculation result) shown in FIG. 5 and the output current waveform shown in FIG. 6, in the soft start accompanying the start of driving of the DCDC converter 1, the duty ratio is gradually increased. When the output current gradually increases, if ΔIr> ΔIt1 or ΔVr> ΔVt1 at time t1, output of the calculation stop signal is started at that time t1, and the duty ratio becomes the value at that time t1. Fixed. For this reason, when the current or voltage suddenly increases, it is possible to suppress the increase in the duty ratio as indicated by the broken line in FIG. 5 and to suppress the occurrence of excessive overshoot as indicated by the broken line in FIG. Can do.

  In addition, after stopping and fixing the update of the duty ratio of the PWM signal, the control unit 2 stops the update when one or both of the current fluctuation rate ΔIr and the voltage fluctuation rate ΔVr reach the release threshold. The control for canceling and updating the duty ratio of the PWM signal based on the target value and the detection result of the detection unit 20 is resumed. For example, as shown in FIG. 5, after the duty ratio is fixed at time t1, when ΔIr <ΔIt2 and ΔVr <ΔVt2 at time t2, the output of the calculation stop signal is stopped and the duty ratio is fixed at time t2. Is released. The current release threshold value ΔIt2 is smaller than the current setting threshold value ΔIt1, and is, for example, a negative value. The voltage release threshold ΔVt2 is smaller than the voltage setting threshold ΔVt1, and is, for example, a negative value.

  According to this configuration, it is possible to fix the duty ratio by focusing on a period in which a sudden change in current or voltage occurs. When sudden fluctuations are eliminated, normal feedback control can be resumed, so that the fixed duty continues after elimination of sudden fluctuations, and the output and target value are too far apart. Can be prevented.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

(1) Although the step-down single-phase converter is illustrated in the first embodiment, it may be a step-up single-phase converter or a step-up / step-down single-phase converter. Further, regarding the direction of current flow, not only the direction from the power source 93 to the power storage device 92 but also the power source device 92 may flow from the power storage device 92 to the power source 93, or both bidirectional converters may be used.
(2) In the first embodiment, a single-phase DCDC converter is illustrated, but a multiphase DCDC converter in which a plurality of voltage converters having the same configuration as the voltage converter 3 are connected in parallel may be used. In this case, the number of phases should just be two or more. Further, it may be a step-down type multi-phase converter, a step-up type multi-phase converter, or a step-up / step-down type multi-phase converter. Further, regarding the direction of current flow, not only the direction from the power source 93 to the power storage device 92 but also the power source device 92 may flow from the power storage device 92 to the power source 93, or both bidirectional converters may be used.
(3) In the first embodiment, an example in which any variation rate of the output current and the output voltage is detected and the duty ratio is fixed when any variation rate reaches the set threshold is shown. Not limited. For example, only the output current fluctuation rate ΔIr may be detected, and the duty ratio may be fixed when the fluctuation rate ΔIr reaches the set threshold value ΔIt1. Alternatively, only the output voltage fluctuation rate ΔVr may be detected, and the duty ratio may be fixed when the fluctuation rate ΔVr reaches the set threshold value ΔVt1. Alternatively, the duty ratio may be fixed when the output current fluctuation rate ΔIr reaches the set threshold value ΔIt1 and the output voltage fluctuation rate ΔVr reaches the set threshold value ΔVt1.
(4) In the first embodiment, an example in which both the fluctuation rate of the output current and the output voltage is detected and the fixation of the duty ratio is released when both the fluctuation rates are less than the release threshold is shown. Not limited. For example, the duty ratio may be released when the output current fluctuation rate ΔIr is less than the release threshold value ΔIt2 or when the output voltage fluctuation rate ΔVr is less than the release threshold value ΔVt2. Alternatively, the configuration may be such that only the fluctuation rate ΔIr of the output current is detected and the duty ratio is released when the fluctuation rate ΔIr becomes less than the release threshold value ΔIt2. Alternatively, the configuration may be such that only the output voltage fluctuation rate ΔVr is detected and the duty ratio is released when the fluctuation rate ΔVr becomes less than the release threshold value ΔVt2.
(5) Although the switching element 6 is provided on the low side in the first embodiment, it can be replaced with a diode having an anode connected to the ground potential. The switching elements 4 and 6 may be P-channel MOSFETs or other switching elements such as bipolar transistors.
(6) Specific examples of the power storage device 91 and the power storage device 92 in the first embodiment are merely examples, and the type and generated voltage of the power storage means are not limited to the above-described examples, and can be variously changed. Further, for example, a configuration in which the secondary power supply unit does not exist can be employed.
(7) In the example of FIG. 1, an example of a generator or a load connected to the input-side conductive path or the output-side conductive path is shown, but various devices and electronic components can be connected to the input-side conductive path and the output-side conductive path. Can be connected to.
(8) The example of FIG. 2 shows an example in which a current variation measuring circuit 32A, a voltage variation measuring circuit 32B, a sudden variation determining circuit 33, and a PWM driving circuit 31 are provided separately from the microcomputer. However, the microcomputer 30 may perform some or all of these functions.

DESCRIPTION OF SYMBOLS 1 ... DCDC converter 2 ... Control part 3 ... Voltage conversion part 20 ... Detection part

Claims (3)

A voltage converter that converts and outputs the input voltage; and
A detection unit for detecting a value reflecting at least one of an output voltage or an output current from the voltage conversion unit;
A control unit for controlling the voltage conversion unit by a PWM signal and performing feedback control for updating a duty ratio of the PWM signal based on a target value of an output and a detection result of the detection unit;
With
The control unit is a DCDC converter that stops and fixes the update of the duty ratio of the PWM signal when a change degree of at least one of the output current or the output voltage is in a predetermined sudden change state.   The control unit has reached a set threshold in which at least one of a current fluctuation rate that is a fluctuation amount of the output current per predetermined time and a voltage fluctuation rate that is a fluctuation amount of the output voltage per predetermined time is set. The DCDC converter according to claim 1, wherein updating of the duty ratio of the PWM signal is stopped and fixed in a case.   The control unit, after stopping and fixing the update of the duty ratio of the PWM signal, cancels the update stop when the current fluctuation rate or the voltage fluctuation rate reaches a release threshold, and sets the target value and The DCDC converter according to claim 2, wherein the control for updating the duty ratio of the PWM signal is resumed based on the detection result of the detection unit.

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