JP2014166066A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact power supply device accompanying no increase in cost and SW loss, capable of normally operating even a SW element having a long ON time without influencing on voltage resistance of a drive circuit of an upper arm.SOLUTION: A power supply device 10 includes a first power supply system P1 driven in a long period includes an electric charge supply circuit F1 coupled to a second power supply E2, and is so configured that the electric charge supply circuit F1 inputs control signals IH2, IL2 of a second power supply system P2 driven in a short period and repeats charging and discharging of electric charges at a timing based on the control signals IH2, IL2 to supply electric charges to a BS circuit B1 of the first power supply system P1.

Description

  The present invention includes two switching elements (hereinafter abbreviated as SW elements) connected in series with an upper arm and a lower arm that are connected to a DC power supply, and power that outputs power to a load from the connection point of the two SW elements. It relates to a supply device. In particular, an object of the present invention is a power supply device configured to increase a voltage applied to a drive circuit of an upper arm by a bootstrap circuit (hereinafter abbreviated as a BS circuit).

  For example, Japanese Patent Application Laid-Open No. 11-69842 (Patent Document 1) discloses a power supply apparatus configured to increase the voltage applied to the upper arm drive circuit by the BS circuit.

  FIG. 16 is a diagram illustrating a basic configuration of a power supply apparatus having a BS circuit, and is a block diagram of a power supply apparatus 90 having two power supply systems. FIG. 17 is a specific example of the power supply apparatus 90 shown in the block diagram of FIG. 16, and is a circuit diagram of the power supply apparatus 90a.

  The power supply device 90 shown in FIG. 16 has two power supply systems, a first power supply system P1 and a second power supply system P2, surrounded by a broken line. The first power supply system P1 includes an upper arm SW element QH1 and a lower arm SW element QL1 connected in series to be connected to the first DC power source E1. And electric power is output to the load which is not illustrated from the connection point N1 of these two SW elements QH1 and QL1. The second power supply system P2 includes an upper arm SW element QH2 and a lower arm SW element QL2 connected in series to be connected to the same first DC power source E1. Then, power is supplied from a connection point N2 between the two SW elements QH2 and QL2 to a load (not shown).

  In the first power supply system P1, drive circuits KH1 and KL1 are connected to the SW elements QH1 and QL1 of the upper arm and the lower arm. The drive circuits KH1 and KL1 are connected to the same DC second power source E2, and receive the control signals IH1 and IL1, respectively, and output gate signals to the SW elements QH1 and QL1. The voltage of the second power supply E2 is applied to the lower arm drive circuit KL1 as it is, but the BS circuit B1 is added to the upper arm drive circuit KH1, and the voltage of the second power supply E2 is changed to BS. The voltage is increased by the circuit B1 and applied to the drive circuit KH1. Similarly, in the second power supply system P2, drive circuits KH2 and KL2 are connected to the SW elements QH2 and QL2 of the upper arm and the lower arm. The drive circuits KH2 and KL2 are connected to the same DC second power source E2, and receive the control signals IH2 and IL2, respectively, and output gate signals to the SW elements QH2 and QL2. The voltage of the second power supply E2 is applied as it is to the lower arm drive circuit KL2, but the BS circuit B2 is added to the upper arm drive circuit KH2, and the voltage of the second power supply E2 is changed to BS. The voltage is increased by the circuit B2 and applied to the drive circuit KH2.

  As shown in the circuit diagram of the power supply device 90a in FIG. 17, the SW elements QH1, QL1 of the first power supply system P1 and the SW elements QH2, QL2 of the second power supply system P2 may be MOS transistors. It may be an IGBT. When a load consisting of an inductance is connected to the power supply system P1, P2, normally, a free wheel diode (not shown) is connected in antiparallel to each SW element QH1, QL1, QH2, QL2. The

  In each of the power supply systems P1 and P2, the drive circuits KL1 and KL2 that drive the SW elements QL1 and QL2 of the lower arm are connected to the high potential side of the second power supply E2 on the high potential side of the power supply terminal. The potential side is connected to the low potential side of the SW elements QL1 and QL2, respectively. Further, the drive circuits KH1 and KH2 for driving the upper arm SW elements QH1 and QH2, respectively, are connected to the high potential side of the second power supply E2 via the BS circuits B1 and B2, respectively. Are connected to the low potential sides of the SW elements QH1 and QH2, respectively.

  Further, the BS circuits B1 and B2 for increasing the voltage applied to the upper arm drive circuits KH1 and KH2 include diodes D1 and D2 and capacitive elements C1 and C2, respectively. The diodes D1, D2 are respectively inserted in the forward direction from the high potential side of the second power supply E2 toward the high potential side of the power supply terminals of the drive circuits KH1, KH2. Capacitance elements C1 and C2 have one end connected to the cathode side of diodes D1 and D2, and the other end connected to the low potential side of the power supply terminals of drive circuits KH1 and KH2.

JP 11-69842 A

  In the power supply apparatus configured to increase the voltage applied to the drive circuit of the upper arm by the BS circuit, as shown in FIGS. 16 and 17, only one second power source E2 for the drive circuit can be used for each power supply system. The upper and lower arm drive circuits KH1, KL1, KH2, and KL2 can be operated. For this reason, a power supply is simplified and it can be set as a small and cheap electric power supply apparatus.

  On the other hand, when a BS circuit is used as the power supply for the upper arm drive circuit, the maximum ON time during which the drive circuit can operate normally has the following restrictions. As shown in FIG. 17, the charging to the capacitive elements C1 and C2 constituting the BS circuits B1 and B2 is performed by the SW element QL1 of the lower arm in which the connection points N1 and N2 are at a low potential (GND potential), respectively. , QL2 is performed at the time when it is ON. On the other hand, during the time when the SW elements QH1 and QH2 of the upper arm are ON, the capacitors C1 and C2 are not charged, and the charges accumulated in the capacitors C1 and C2 are stored in the respective drive circuits KH1, It is consumed by KH2. Therefore, when the ON time of the control signal for the upper arm becomes longer, the charges stored in the capacitive elements C1 and C2 continue to decrease, and finally the drive circuit supplies the potential necessary for turning on the gate potentials of the SW elements QH1 and QH2. The SW elements QH1 and QH2 are turned off and cannot operate normally. As described above, in the power supply device 90a of FIG. 17, the maximum ON time during which the upper arm drive circuits KH1 and KH2 can operate normally can charge the capacitive elements C1 and C2 constituting the BS circuits B1 and B2. It depends on the amount of charge and the current consumption of the drive circuits KH1 and KH2.

  As a means for solving the above-described problem in the power supply device 90a of FIG. However, the capacitance elements C1 and C2 having large capacitance values are generally expensive, resulting in an increase in cost. In addition, if the switching period of the SW elements QH1, QL1 and SW elements QH2, QL2 of the upper arm and the lower arm is shortened while the capacitance values of the capacitive elements C1, C2 are left as they are, the cost does not increase. Switching loss (hereinafter abbreviated as SW loss) increases.

  For this reason, in Patent Document 1, in a drive circuit that generates a plurality of phases of alternating current, the BS circuit in each phase of the alternating current generation block includes a first capacitor having one end connected to the output point of the own phase, and the other phase. And a second capacitor having one end connected to the output point. Then, the second capacitor of the self phase having a long cycle is charged during the time when the SW element of the lower arm of the other phase with a short cycle is ON, and the second capacitor is charged when the SW element of the upper arm of the other phase is ON. The charge accumulated in the capacitor is replenished to the first capacitor of the own phase. As a result, the SW element of the upper arm of the own phase can be turned on with a long period.

  On the other hand, the circuit of Patent Document 1 described above has the following problems because one end of the second capacitor that replenishes the first capacitor of the own phase is connected to the output point of the other phase. That is, the SW element of the upper arm is connected to a first power supply different from the second power supply for the drive circuit. Therefore, when the SW element of the lower arm of the own phase is ON and the SW element of the upper arm of the other phase is turned ON, the SW element of the upper arm of the other phase, the second capacitor of the own phase, and the own phase The charging path to the SW element of the lower arm of the own phase is formed through the first capacitor. Therefore, when the first power supply is set to a high voltage, the high voltage is also applied to the self-phase drive circuit, which may cause a problem that the breakdown voltage of the drive circuit is exceeded. In addition, when a withstand voltage protection circuit is built in the drive circuit, a large protection circuit is required.

  As described above, the present invention is a power supply device that includes two SW elements connected in series of an upper arm and a lower arm, and outputs power to a load from a connection point of the two SW elements. The present invention is intended for a power supply apparatus configured to increase the voltage applied to the arm drive circuit. An object of the present invention is a compact power supply device that does not increase cost and SW loss, and allows a long ON time SW element to operate normally without affecting the withstand voltage of the upper arm drive circuit. An object of the present invention is to provide a power supply device capable of performing the above.

  A power supply apparatus according to the present invention includes two SW elements (for example, a MOS transistor and an IGBT) connected in series with an upper arm and a lower arm connected to a first DC power source, and a connection point between the two SW elements. It is the electric power supply apparatus which outputs electric power to a load from. The power supply system is connected to a second DC power source, inputs two control signals of the two SW elements and outputs a gate signal, two upper arm and lower arm drive circuits, and an upper arm drive circuit It is composed of a BS circuit for increasing the voltage to be applied and the two SW elements. The power supply apparatus has a plurality of the power supply systems, and at least two power supply systems are driven at different periods. And the 1st electric power supply system driven with a long period has composition which has an electric charge replenishment circuit connected to the 2nd power supply. The charge replenishment circuit inputs a control signal for the second power supply system driven in a short cycle, repeats charge charging and discharging at a timing based on the control signal, and charges the BS circuit of the first power supply system. It is configured to replenish.

  The power supply device is a power supply device configured to increase the voltage applied to the drive circuit of the upper arm by the BS circuit, and has a plurality of power supply systems, and at least two power supply systems are driven at different periods. The In the power supply apparatus configured to increase the voltage applied to the drive circuit of the upper arm by the BS circuit, the drive circuits of the upper arm and the lower arm of each of the plurality of power supply systems are provided with only one second power source for the drive circuit. Can be operated. For this reason, a power supply is simplified and it can be set as a small and cheap electric power supply apparatus.

  On the other hand, in the case of a power supply device using a BS circuit, only the basic configuration limits the maximum ON time during which the upper arm drive circuit can operate normally, as described above. The BS circuit is charged when the lower arm SW element is ON, and the accumulated charge is consumed by the drive circuit when the upper arm SW element is ON. Therefore, if the ON time of the upper arm becomes longer, the electric charge stored in the BS circuit continues to decrease, and finally the SW element is turned OFF without maintaining a sufficient gate potential.

  As means for solving the above problems, for example, it is conceivable to increase the amount of charge that can be accumulated in the BS circuit, but in this case, the cost increases. Further, if the switching period of the SW elements of the upper arm and the lower arm is shortened while keeping the amount of charge that can be accumulated in the BS circuit, the cost is not increased, but in this case, the SW loss increases.

  For this reason, in the said electric power supply apparatus, the 1st electric power supply system driven with a long period becomes a structure which has an electric charge replenishment circuit connected to a 2nd power supply. Then, the charge replenishment circuit inputs a control signal for the second power supply system that is driven with a short cycle, repeats charge charging and discharging at a timing based on the control signal, and supplies it to the BS circuit of the first power supply system. It is comprised so that an electric charge may be replenished. Thus, since the charge replenishment circuit continues to replenish charges to the BS circuit of the first power supply system by the control signal of the second power supply system that is driven with a short period, the first power that is driven with a long period is used. It becomes possible to keep the SW element of the upper arm of the supply system ON. As described above, the power supply apparatus is released from the restriction on the maximum ON time during which the upper arm drive circuit can operate normally.

  In addition, the power supply apparatus and the conventional drive circuit in which the BS circuit described above includes the first capacitor and the second capacitor are long by using a power supply system (AC generation block) that is driven in a short cycle. This is common in that charge is continuously supplied to the periodic BS circuit. However, the power supply device has a configuration different from the conventional drive circuit described above in the following points. That is, in the conventional drive circuit, one end of the second capacitor that replenishes the first phase capacitor is connected to the output point of the SW element of the other phase connected to the first power source. For this reason, as described above, in the conventional drive circuit, when the SW element of the lower arm of the own phase is ON and the SW element of the upper arm of the other phase is turned ON, There is a problem that a charging path exceeding the withstand voltage of the driving circuit is formed.

  On the other hand, the charge replenishment circuit in the power supply device is connected to the second power source for the drive circuit, and is charged based on the control signal of the drive circuit of the second power supply system that is driven with a short cycle. Repeat charging and discharging. For this reason, unlike the conventional drive circuit, in the power supply apparatus, even when the first power supply is set to a high voltage, a charging path in which withstand voltage is a problem is not formed.

  As described above, the above-described power supply apparatus is a small-sized power supply apparatus that does not increase cost and SW loss, and has a long ON time without affecting the withstand voltage of the upper arm drive circuit. The device is a power supply device that can also operate normally.

  In the power supply device, for example, the drive circuit has a configuration in which the high potential side of the power supply terminal is connected to the high potential side of the second power supply, and the low potential side of the power supply terminal is connected to the low potential side of the SW element. In this case, the BS circuit has a diode inserted in the forward direction from the high potential side of the second power supply toward the high potential side of the power supply terminal of the drive circuit, one end connected to the cathode side of the diode, and the other end And a capacitor connected to the low potential side of the power supply terminal of the drive circuit.

  In the above configuration, the charge replenishment circuit can be configured by two switch elements (hereinafter abbreviated as “S element”), a third capacitor element, a third diode, and a fourth diode connected in series as shown below. . Two S elements connected in series are inserted into a path connecting a connection point of two SW elements of the first power supply system and a connection point of two SW elements of the second power supply system. The third capacitor element has one end connected to the connection point of the two S elements and the other end connected to the high potential side of the second power supply. The third diode is inserted in the forward direction from the high potential side of the second power supply toward the other end of the third capacitive element. The fourth diode is inserted in the forward direction from the other end of the third capacitive element toward the high potential side of the power supply terminal of the drive circuit of the first power supply system. Of the two S elements connected in series, the first S element on the output side of the first power supply system is turned on in the same manner in synchronization with the control signal of the SW element of the upper arm of the second power supply system. Turn off. Further, the second S element on the output side of the second power supply system is configured to be turned on and off in the same manner in synchronization with the control signal of the SW element of the lower arm of the second power supply system.

  The S element is preferably a transistor element (hereinafter abbreviated as T element) in order to switch at the same speed as the SW element. Further, when the T element is composed of a MOS transistor element (hereinafter abbreviated as M element), the fifth diode serves as a connection point between the two M elements in order to cut off the current path of the parasitic diode associated with the M element. Is preferably inserted in the forward direction toward the connection point of the two SW elements of the second power supply system.

  In the above configuration, the first S element that is turned on and off in the same manner in synchronization with the control signal of the SW element of the upper arm and the second S that is turned on and off in the same manner in synchronization with the control signal of the SW element of the lower arm. The element can adopt the following connection configuration. For example, the first S element is configured to input a control signal for the SW element of the upper arm of the second power supply system, and the second S element is configured to input a control signal for the SW element of the lower arm of the second power supply system. To do. The first S element inputs a control signal for the SW element of the upper arm of the second power supply system, and the second S element inputs an inverted signal of the control signal for the SW element of the upper arm of the second power supply system. It may be configured as follows. Conversely, the first S element inputs the inverted signal of the control signal of the lower arm SW element of the second power supply system, and the second S element receives the control signal of the lower arm SW element of the second power supply system. It may be configured to.

  As described above, the above-described power supply apparatus is a small-sized power supply apparatus that does not increase cost and SW loss, and has a long ON time without affecting the withstand voltage of the upper arm drive circuit. The device is a power supply device that can also operate normally.

  Therefore, the power supply apparatus is suitable as a vehicle-mounted power supply apparatus that is required to be small and low-cost and that integrates a plurality of power supply systems that are driven at various cycles.

In the power supply apparatus 90a of FIG. 17, it is the figure which showed an example of the timing chart about the case where the 1st power supply system P1 is made into a long cycle drive, and the 2nd power supply system P2 is made into a short cycle drive. It is the figure which showed the operation mode of the electric power supply apparatus 90a in the timing (LH) and (LL) shown in the chart of FIG. It is the figure which showed the operation mode of the electric power supply apparatus 90a in the timing (LD) shown in the chart of FIG. It is the figure which showed the operation mode of the electric power supply apparatus 90a in the timing (HH) and (HL) shown in the chart of FIG. It is the figure which showed the operation mode of the electric power supply apparatus 90a in the timing (HD) shown in the chart of FIG. It is a figure which shows the basic composition of the electric power supply apparatus which concerns on this invention, and is a block diagram of the electric power supply apparatus 10 which has the electric power supply system P1, P2 driven by at least two different periods among several electric power supply systems. . FIG. 7 is a specific example of the power supply device 10 shown in the block diagram of FIG. 6 and is a circuit diagram of the power supply device 10a. It is the figure which showed an example of the timing chart of the electric power supply apparatus 10a of FIG. It is the figure which showed the operation mode of the electric power supply apparatus 10a in the timing (LH) and (LL) which are shown to the chart of FIG. It is the figure which showed the operation mode of the electric power supply apparatus 10a in the timing (LD) shown in the chart of FIG. It is the figure which showed the operation mode of the electric power supply apparatus 10a in the timing (HH) and (HL) shown in the chart of FIG. It is the figure which showed the operation mode of the electric power supply apparatus 10a in the timing (HD) shown in the chart of FIG. FIG. 8 is a circuit diagram of the power supply device 10b, and is a diagram illustrating a circuit configuration example when the S elements S1 and S2 of the charge supply circuit F1a in the power supply device 10a of FIG. 7 are M elements M1 and M2. It is a circuit diagram of the power supply apparatus 10c, and is a figure which shows the modification of the power supply apparatus 10a shown in FIG. It is a circuit diagram of the power supply apparatus 10d, and is a diagram showing a modification of the power supply apparatus 10a shown in FIG. It is a figure which shows the basic composition of the power supply apparatus which has a BS circuit, and is a block diagram of the power supply apparatus 90 which has two power supply systems. FIG. 17 is a specific example of the power supply apparatus 90 shown in the block diagram of FIG. 16 and is a circuit diagram of the power supply apparatus 90a.

  The present invention includes two SW elements (for example, a MOS transistor and an IGBT) connected in series with an upper arm and a lower arm connected to a first DC power source, and power is supplied to a load from a connection point of the two SW elements. The present invention relates to an output power supply device. Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  First, the problems of the conventional power supply apparatus 90a shown in FIG. 17 described in the problem column will be described in more detail.

  FIG. 1 is a diagram showing an example of a timing chart in the case where the first power supply system P1 is set to the long cycle drive and the second power supply system P2 is set to the short period drive in the power supply apparatus 90a of FIG. . FIG. 1 shows waveforms of the control signals IL1, IH1, IL2, and IH2, the output voltages V1 and V2, and the voltage VC1 of the capacitive element C1 in the BS circuit B1 of the first power supply system P1 shown in FIG. .

  2 to 5 show the operation modes of the power supply device 90a at the timings (LH), (LL), (LD), (HH), (HL), and (HD) shown in the chart of FIG. FIG.

  1 to 5, the left symbol in parentheses indicating the operation mode of the power supply apparatus 90a indicates the operation mode of the first power supply system, and the right symbol in parentheses indicates the second power supply. It shows the operation mode of the system. Reference numeral H denotes a mode in which the upper arm control signal is ON and the lower arm control signal is OFF. Symbol L indicates a mode in which the upper arm control signal is OFF and the lower arm control signal is ON. Reference D indicates a dead time mode in which both the upper arm control signal and the lower arm control signal are OFF.

  As shown in the chart of FIG. 1, three timings (LH), (LL), and (LD) in which the left sign in the parenthesis is L are the control of the upper arm in the first power supply system P1 of long-period driving. This is an operation mode in which the signal IH1 is OFF and the lower arm control signal IL1 is ON. In any of these operation modes, as shown in FIGS. 2 (LH), (LL) and FIG. 3 (LD), the upper arm SW element QH1 is in the OFF state in the first power supply system of long cycle driving. Yes, the lower arm SW element QL1 is in the ON state. Therefore, the connection point N1 (lower potential of the capacitive element C1) between the two SW elements QH1 and QL1 becomes a low potential (ground potential, output voltage V1 is 0) via the lower arm SW element QL1. Therefore, the capacitive element C1 of the BS circuit B1 is charged through the path indicated by the broken line arrow. In this way, during the period in which the lower arm SW element QL1 is in the ON state in the first power supply system of the long cycle drive, the charging of the capacitive element C1 of the BS circuit B1 is continued in the first power supply system. Since charging is completed in an extremely short time, when the charge is accumulated in the capacitive element C1 until the saturated state, the charged state by the saturated charge is only continued thereafter. For this reason, the voltage VC1 of the capacitive element C1 during this period is maintained at a high voltage state due to the charges accumulated up to the saturation state, as shown in the lowermost stage of FIG.

  On the other hand, in the second power supply system, charging and discharging of the capacitive element C2 are repeated as follows. In the operation mode of FIG. 2 (LH), the upper arm SW element QH2 is in the ON state, and the lower arm SW element QL2 is in the OFF state. Accordingly, the connection point N2 between the two SW elements QH2 and QL2 becomes a high potential (the potential of the first power supply E1 via the upper arm SW element QH2), and the high potential output voltage V2 is output to the output terminal OUT2 with respect to the load. Supplied from At this time, the electric charge accumulated in the capacitive element C2 of the BS circuit B2 is discharged through the path indicated by the broken-line arrow and is consumed by the drive circuit KH2. In the operation mode of FIG. 2 (LL), the upper arm SW element QH2 is in the OFF state, and the lower arm SW element QL2 is in the ON state. Therefore, the connection point N2 between the two SW elements QH2 and QL2 becomes a low potential (ground potential, output voltage V2 is 0), and the capacitive element C2 of the BS circuit B2 is charged through the path indicated by the broken-line arrow. As described above, the second power supply system with short cycle driving operates independently of the first power supply system with long cycle driving.

  As shown in the chart of FIG. 1, three timings (HH), (HL), and (HD) in which the left symbol in the parenthesis is H are control signals for the upper arm in the first power supply system of long-period driving. This is an operation mode in which IH1 is ON and the lower arm control signal IL1 is OFF. In each of these operation modes, as shown in FIGS. 4 (HH), (HL) and FIG. 5 (HD), the upper arm SW element QH1 is turned on in the first power supply system of long cycle driving. Yes, the SW element QL1 of the lower arm is in the OFF state. Accordingly, the connection point N1 between the two SW elements QH1 and QL1 becomes a high potential (the potential of the first power supply E1 via the upper arm SW element QH1), and the high potential output voltage V1 is output from the output terminal OUT1 to the load. Supplied. At this time, the electric charge accumulated in the capacitive element C1 of the BS circuit B1 is discharged through the path indicated by the broken line arrow, and current is consumed in the drive circuit KH1. Thus, during the period in which the upper arm SW element QH1 is in the ON state in the first power supply system driven for a long period, the discharge of the capacitive element C1 of the BS circuit B1 is continued in the first power supply system. For this reason, the voltage VC1 of the capacitive element C1 during this period continues to decrease as shown in the lowermost stage of FIG. When the voltage drops below the threshold voltage Vth necessary for the operation of the drive circuit KH1 indicated by the alternate long and short dash line in the figure, the drive circuit KH1 cannot finally supply the potential necessary for turning on the gate potential of the SW element QH1, and the SW element QH1 is turned OFF and the output voltage V1 becomes zero. As described above, when the ON time of the control signal IH1 becomes long, the SW element QH1 does not operate normally even though the control signal IH1 is ON.

  Even when the upper arm control signal IH1 is ON and the lower arm control signal is OFF, in the second power supply system, the previous upper arm control signal IH1 is OFF and the lower arm control signal is ON. In the same manner, charging and discharging of the capacitive element C2 are repeated.

  Next, the basic configuration and operation of the power supply apparatus according to the present invention that solves the above-described problems of the power supply apparatus 90a will be described with reference to FIGS.

  FIG. 6 is a diagram showing a basic configuration of a power supply apparatus according to the present invention. Of the plurality of power supply systems, FIG. 6 shows a power supply apparatus 10 having power supply systems P1 and P2 driven at least two different periods. It is a block diagram. FIG. 7 is a specific example of the power supply apparatus 10 shown in the block diagram of FIG. 6, and is a circuit diagram of the power supply apparatus 10a. In the power supply apparatuses 10 and 10a shown in FIGS. 6 and 7, the same parts as those of the power supply apparatuses 90 and 90a shown in FIGS.

  The power supply device 10 shown in FIG. 6 has two power supply systems, a first power supply system P1 and a second power supply system P2, surrounded by a broken line. In the power supply apparatus 10, at least two power supply systems P1 and P2 among a plurality of power supply systems are driven with different periods, and the one driven with a long period is the first power supply system P1, and is driven with a short period. This is the second power supply system P2.

  In the power supply apparatus 10 of FIG. 6, the following components are the same as those of the power supply apparatus 90 shown in FIG.

  That is, the first power supply system P1 includes an upper arm SW element QH1 and a lower arm SW element QL1 that are connected in series to the first DC power source E1. Then, power is supplied to a load (not shown) from the connection point N1 between the two SW elements QH1 and QL1. The second power supply system P2 includes an upper arm SW element QH2 and a lower arm SW element QL2 connected in series to be connected to the same first DC power source E1. Then, power is supplied from a connection point N2 between the two SW elements QH2 and QL2 to a load (not shown).

  Further, in the first power supply system P1, drive circuits KH1 and KL1 are connected to the SW elements QH1 and QL1 of the upper arm and the lower arm. The drive circuits KH1 and KL1 are connected to the same DC second power source E2, and receive the control signals IH1 and IL1, respectively, and output gate signals to the SW elements QH1 and QL1. The voltage of the second power supply E2 is applied to the lower arm drive circuit KL1 as it is, but the BS circuit B1 is added to the upper arm drive circuit KH1, and the voltage of the second power supply E2 is changed to BS. The voltage is increased by the circuit B1 and applied to the drive circuit KH1. Similarly, in the second power supply system P2, drive circuits KH2 and KL2 are connected to the SW elements QH2 and QL2 of the upper arm and the lower arm. The drive circuits KH2 and KL2 are connected to the same DC second power source E2, and receive the control signals IH2 and IL2, respectively, and output gate signals to the SW elements QH2 and QL2. The voltage of the second power supply E2 is applied as it is to the lower arm drive circuit KL2, but the BS circuit B2 is added to the upper arm drive circuit KH2, and the voltage of the second power supply E2 is changed to BS. The voltage is increased by the circuit B2 and applied to the drive circuit KH2.

  On the other hand, unlike the power supply device 90 shown in FIG. 16, the power supply device 10 of FIG. 6 has a first power supply system P1 driven with a long cycle provided with a charge replenishment circuit F1 connected to the second power supply E2. It is the composition which has. The charge replenishment circuit F1 receives the control signals IH2 and IL2 of the second power supply system P2 that is driven with a short cycle, and repeats charge charging and discharging at timings based on the control signals IH2 and IL2. The BS circuit B1 of the supply system P1 is configured to replenish electric charges.

  In the power supply apparatus 10 of FIG. 6, the same block components as those of the power supply apparatus 90 shown in FIG. 16 can be embodied as follows, similarly to the power supply apparatus 90 a of FIG. 17.

  As shown in the circuit diagram of the power supply device 10a in FIG. 7, the SW elements QH1, QL1 of the first power supply system P1 and the SW elements QH2, QL2 of the second power supply system P2 may be MOS transistors. It may be an IGBT. When a load consisting of an inductance is connected to the power supply system P1, P2, normally, a free wheel diode (not shown) is connected in antiparallel to each SW element QH1, QL1, QH2, QL2. The

  In each of the power supply systems P1 and P2, the drive circuits KL1 and KL2 that drive the SW elements QL1 and QL2 of the lower arm are connected to the high potential side of the second power supply E2 on the high potential side of the power supply terminal. The potential side is connected to the low potential side of the SW elements QL1 and QL2, respectively. Further, the drive circuits KH1 and KH2 for driving the upper arm SW elements QH1 and QH2, respectively, are connected to the high potential side of the second power supply E2 via the BS circuits B1 and B2, respectively. Are connected to the low potential sides of the SW elements QH1 and QH2, respectively.

  Further, the BS circuits B1 and B2 for increasing the voltage applied to the upper arm drive circuits KH1 and KH2 include diodes D1 and D2 and capacitive elements C1 and C2, respectively. The diodes D1, D2 are respectively inserted in the forward direction from the high potential side of the second power supply E2 toward the high potential side of the power supply terminals of the drive circuits KH1, KH2. Capacitance elements C1 and C2 have one end connected to the cathode side of diodes D1 and D2, and the other end connected to the low potential side of the power supply terminals of drive circuits KH1 and KH2.

  On the other hand, the charge replenishment circuit F1 included in the power supply device 10 of FIG. 6 which is a block configuration unit not included in the power supply device 90 of FIG. 16 can be embodied as follows.

  For example, as shown in the circuit diagram of the power supply device 10a of FIG. 7, the charge replenishment circuit F1a includes two switch elements (hereinafter abbreviated as S elements) S1 and S2, a third capacitive element C3, It can be composed of three diodes D3 and a fourth diode D4. The two S elements S1 and S2 connected in series are a connection point N1 of two SW elements QH1 and QL1 of the first power supply system P1 and a connection point N2 of two SW elements QH2 and QL2 of the second power supply system P2. It is inserted in the route connecting One end of the capacitive element C3 is connected to the connection point N3 of the two S elements S1 and S2, and the other end is connected to the high potential side of the second power supply E2. The diode D3 is inserted in the forward direction from the high potential side of the second power supply E2 toward the other end of the capacitive element C3. The diode D4 is inserted in the forward direction from the other end of the third capacitive element toward the high potential side of the power supply terminal of the drive circuit KH1 of the first power supply system P1. Of the two S elements S1 and S2 connected in series, the first S element S1 on the output (connection point N1) side of the first power supply system P1 is the control signal IH2 for the upper arm of the second power supply system P2. Is turned on and off in the same manner in synchronization with the control signal IH2. Further, the second S element S2 on the output (connection point N2) side of the second power supply system P2 receives the control signal IL2 of the lower arm of the second power supply system P2, and is similarly synchronized with the control signal IL2. It is configured to turn on and off.

  The above-described power supply devices 10 and 10a shown in FIGS. 6 and 7 are power supply devices configured to increase the voltage applied to the upper arm drive circuits KH1 and KH2 by the BS circuits B1 and B2, and have a plurality of power supply systems. Have. Then, at least two power supply systems P1 and P2 are driven at different periods. In the power supply devices 10 and 10a configured to increase the voltage applied to the drive circuit of the upper arm by the BS circuits B1 and B2, the upper arm of each of the plurality of power supply systems is provided with only one second power supply E2 for the drive circuit. And the lower arm drive circuits can be operated. For this reason, a power supply is simplified and it can be set as a small and cheap electric power supply apparatus.

  On the other hand, in the case of a power supply device using a BS circuit, with the basic configuration alone, like the power supply devices 90 and 90a shown in FIGS. 16 and 17, the upper arm drive circuit can operate normally. There are time constraints. As described with reference to FIGS. 1 to 5, the BS circuit is charged when the lower arm SW element is ON, and the accumulated charge is driven when the upper arm SW element is ON. Consumed by the circuit. Therefore, if the ON time of the upper arm becomes longer, the electric charge stored in the BS circuit continues to decrease, and finally the SW element is turned OFF without maintaining a sufficient gate potential.

  As means for solving the above problems, for example, it is conceivable to increase the amount of charge that can be accumulated in the BS circuit, but in this case, the cost increases. Further, if the switching period of the SW elements of the upper arm and the lower arm is shortened while keeping the amount of charge that can be accumulated in the BS circuit, the cost is not increased, but in this case, the SW loss increases.

  For this reason, in the power supply devices 10 and 10a shown in FIGS. 6 and 7 described above, the first power supply system P1 driven with a long cycle has the charge replenishment circuits F1 and F1a connected to the second power supply E2. It has a configuration. Then, the charge replenishment circuits F1 and F1a receive the control signals IH2 and IL2 of the second power supply system P2 driven with a short cycle, and repeat charge charging and discharging at timings based on the control signals IH2 and IL2. Charge is supplied to the BS circuit B1 of the one power supply system P1. Thus, the charge replenishment circuits F1 and F1a continue to replenish charges to the BS circuit B1 of the first power supply system P1 by the control signals IH2 and IL2 of the second power supply system P2 that are driven in a short cycle. For this reason, it is possible to keep the SW element QH1 of the upper arm of the first power supply system P1 driven at a long cycle ON. As described above, the power supply apparatuses 10 and 10a are freed from the restriction on the maximum ON time during which the upper arm drive circuit can operate normally.

  The operation of the power supply apparatus according to the present invention will be described in more detail using the power supply apparatus 10a shown in FIG. 7 as an example.

  FIG. 8 is a diagram illustrating an example of a timing chart of the power supply device 10a of FIG. In FIG. 8, the control signals IL1, IH1, IL2, and IH2, the output voltages V1 and V2, and the voltage VC1 of the capacitive element C1 in the BS circuit B1 of the first power supply system P1 and the capacitive element of the charge replenishment circuit F1a shown in FIG. Each waveform of the voltage VC3 of C3 is shown. The waveforms of the control signals IL1, IH1, IL2, and IH2 shown in the timing chart of FIG. 8 and the output voltage V2 of the second power supply system P2 that is driven in a short cycle are exactly the same as those shown in FIG. It is. Further, in the chart of the voltage VC1 in FIG. 8, the voltage waveform of the voltage VC1 shown in FIG. 1 of the power supply device 90a is indicated by a dotted line for comparison.

  9 to 12 show the operation mode of the power supply apparatus 10a at each timing (LH), (LL), (LD), (HH), (HL), and (HD) shown in the chart of FIG. FIG. Similar to FIGS. 1 to 5, the left symbol in parentheses indicating the operation mode indicates the operation of the first power supply system. Symbol H indicates a mode in which the upper arm control signal is ON, symbol L indicates a mode in which the lower arm control signal is ON, and symbol D indicates a dead time mode.

  As shown in FIG. 8, three timings (LH), (LL), and (LD) in which the left sign in the parenthesis is L are in the first power supply system of long cycle driving, and the control signal IH1 of the upper arm is This is an operation mode in which the lower arm control signal IL1 is ON. In each of these operation modes, as shown in FIGS. 9 (LH), (LL) and FIG. 10 (LD), the upper arm SW element QH1 is turned off in the first power supply system of long cycle drive. Yes, the lower arm SW element QL1 is in the ON state. Therefore, the connection point N1 between the two SW elements QH1 and QL1 is at a low potential (ground potential, output voltage V1 is 0). Accordingly, the capacitive element C1 of the BS circuit B1 has a path through the diode D1 of the BS circuit B1 and the charge replenishment circuit F1a indicated by a broken line arrow in any of the operation modes (LH), (LL), and (LD). Charging is carried out through two paths through the diodes D3 and D4.

  Further, regarding the capacitive element C3 of the charge replenishment circuit F1a, in the operation mode (LH) of FIG. 9, the S element S1 is turned on in synchronization with the control signal IH2, and the S element S2 is turned off in synchronization with the control signal IL2. Therefore, the connection point N3 (lower potential of the capacitive element C3) between the two S elements S1 and S2 is low potential (ground potential) via the SW element QL1 and S element S1 of the lower arm of the first power supply system. The output voltage V1 becomes 0). Accordingly, the capacitive element C3 of the charge replenishment circuit F1a is charged through the path indicated by the broken line arrow. Conversely, in the operation mode (LL) of FIG. 9, the S element S1 is turned off in synchronization with the control signal IH2, and the S element S2 is turned on in synchronization with the control signal IL2. Therefore, in this case, the connection point N3 between the two S elements S1 and S2 is low potential (ground potential, output voltage V2 is 0 via the SW element QL2 and S element S2 of the lower arm of the second power supply system. ) For this reason, the capacitive element C3 of the charge replenishment circuit F1a is similarly charged through the path indicated by the dashed arrow. Since the charging is completed in an extremely short time, when the charge is accumulated in the capacitive elements C1 and C3 until the saturated state, the charged state by the saturated charge is only continued thereafter. Further, in the operation mode (LD) of FIG. 10 in which the second power supply system is dead time, the two S elements S1 and S2 are turned off and the charging of the capacitive element C3 is stopped, but the charged state by the saturated charge remains as it is. Will continue.

  As described above, in the power supply device 10a of FIG. 7, the charging of the capacitive element C1 of the BS circuit B1 is continued in the period in which the SW element QL1 of the lower arm is in the ON state in the first power supply system of long cycle driving. In addition, charging of the capacitive element C3 of the charge supply circuit F1a is continued. For this reason, the voltages VC1 and VC3 of the capacitive elements C1 and C3 during this period are maintained in a high voltage state due to the charges accumulated up to the saturation state as shown in the lower two stages of FIG.

  As shown in FIG. 8, three timings (HH), (HL), and (HD) with the left symbol in parentheses being H are the first power supply system of long cycle driving, and the control signal IH1 of the upper arm is This is an operation mode in which the lower arm control signal IL1 is OFF. In these operation modes, as shown in FIGS. 11 (HH), (HL) and FIG. 12 (HD), the SW element QH1 of the upper arm is turned on in the first power supply system of long cycle driving. Yes, the SW element QL1 of the lower arm is in the OFF state. Accordingly, the connection point N1 between the two SW elements QH1 and QL1 becomes a high potential (the potential of the first power supply E1 via the upper arm SW element QH1), and the high potential output voltage V1 is output from the output terminal OUT1 to the load. Supplied.

  In the period when the upper arm SW element QH1 is in the ON state, in the conventional power supply device 90a described with reference to FIGS. 1 to 5, the discharge of the charge accumulated in the capacitive element C1 and the current consumption in the drive circuit KH1 The voltage VC1 of the capacitive element C1 continued to decrease. On the other hand, the power supply apparatus 10a having the charge replenishment circuit F1a shown in FIG. 7 operates as follows.

  As shown in FIGS. 11 (HH), (HL) and FIG. 12 (HD), in the period when the SW element QH1 of the upper arm is in the ON state, the discharge of the charge accumulated in the capacitive element C1 and the drive circuit KH1 Current consumption is continued in the same manner as the conventional power supply device 90a. However, paying attention to the capacitive element C3 of the charge supply circuit F1a, in the operation mode (HH) of FIG. 11, the S element S1 is turned on in synchronization with the control signal IH2, and the S element S2 is turned off in synchronization with the control signal IL2. To do. For this reason, the electric charge stored in the capacitive element C3 is discharged through the path indicated by the broken-line arrow through the diode D4. Therefore, in the drive circuit KH1, charges are supplied from both the capacitive element C1 of the BS circuit B1 and the capacitive element C3 of the charge replenishment circuit F1a. Accordingly, during the operation mode (HH), the voltage VC1 of the capacitor C1 decreases more slowly than when the charge replenishment circuit F1a is not provided. Next, in the operation mode (HL) of FIG. 11, the S element S1 is turned off in synchronization with the control signal IH2, and the S element S2 is turned on in synchronization with the control signal IL2. Accordingly, the connection point N3 between the two S elements S1 and S2 becomes a low potential (the ground potential and the output voltage V2 are 0) via the SW element QL2 and the S element S2 of the lower arm of the second power supply system. For this reason, the capacitive element C3 of the charge replenishment circuit F1a is charged through the diode D3 along the path indicated by the broken line arrow. Since the charging is completed in a very short time, when the charge is accumulated in the capacitive element C3 until the saturated state, the charged state by the saturated charge is only continued thereafter. Therefore, as shown in the lowermost stage of FIG. 8, the voltage VC3 of the capacitive element C3 is instantaneously restored to near the voltage of the second power supply E2 when the control signal IH2 is turned on, and is high until the control signal IH2 is turned off. State is maintained. Further, in the operation mode (HD) of FIG. 12 in which the second power supply system is dead time, the two S elements S1 and S2 are turned off, and the charging of the capacitive element C3 is stopped, but the control signal IH2 is turned on. Until then, the high voltage state is maintained.

  During the operation mode (HL) in which the capacitive element C3 is charged, the capacitive element C1 of the BS circuit B1 continues to be discharged, and the voltage VC1 continues to decrease. However, at the moment when the control signal IH2 is turned on next and the operation mode (HH) shown in FIG. 11 is entered, the capacitive element C1 of the BS circuit B1 and the capacitive element C3 of the charge replenishing circuit F1a are connected in parallel. For this reason, the voltage VC1 of the capacitive element C1 that has continued to decrease is instantaneously restored to near the voltage VC3 of the capacitive element C3. The voltages VC1 and VC3 of the capacitive elements C1 and C3 gradually decrease due to current consumption in the drive circuit KH1 during the subsequent operation mode (HH).

  As described above, in the power supply device 10a of FIG. 7, the discharge of the capacitive element C1 of the BS circuit B1 is continued during the period in which the SW element QH1 of the upper arm is in the ON state in the first power supply system of long cycle driving. Is done. However, in the power supply device 10a, charging and discharging of the capacitive element C3 of the charge replenishment circuit F1a are repeated at the timing based on the control signals IH2 and IL2 during this period. For this reason, the voltage VC1 of the capacitive element C1 of the power supply device 10a does not drop below the threshold voltage Vth necessary for the operation of the drive circuit KH1 as it does in the power supply device 90a of FIG. The vertical movement is repeated within a predetermined range during the period.

  As described above, in the power supply device 10a of FIG. 7, the charge replenishment circuit F1a is repeatedly charged and discharged at a timing based on the control signals IH2 and IL2 of the second power supply system P2 driven in a short cycle, Charges are continuously supplied to the BS circuit B1 of the first power supply system P1. For this reason, it becomes possible to continue to turn on the SW element QH1 of the upper arm of the first power supply system P1 driven with a long cycle, and it is freed from the restriction of the maximum ON time during which the upper arm drive circuit can operate normally. .

  Further, the power supply device 10a of FIG. 7 and the conventional drive circuit in which the BS circuit of Patent Document 1 described above includes the first capacitor and the second capacitor are used in a power supply system that is driven in a short cycle. This is common in that the charge is continuously supplied to the long-cycle BS circuit. However, the power supply device 10a differs from the drive circuit of Patent Document 1 in the following points. In other words, in the conventional drive circuit, the second capacitor that replenishes the first phase (long cycle drive) first capacitor is connected to the output point of the other phase (short cycle drive) SW element connected to the first power supply E1. One end was connected. Therefore, as described above, in the conventional driving circuit, when the SW element of the lower arm of the own phase is ON and the SW element of the upper arm of the other phase is turned ON, the first power supply E1 is set to a high voltage. However, there is a problem that a charging path exceeding the withstand voltage of the self-phase driving circuit is formed.

  On the other hand, the charge replenishment circuit F1a in the power supply device 10a of FIG. 7 is connected to the second power supply E2 for the drive circuit, and controls the drive circuit of the second power supply system P2 that is driven in a short cycle. Based on the signals IH2 and IL2, charge charging and discharging are repeated. For this reason, in the power supply apparatus 10a, unlike the conventional driving circuit described above, even when the first power supply E1 is set to a high voltage, a charging path that causes a problem with the breakdown voltage is not formed. .

  As described above, the power supply devices 10 and 10a described above are small power supply devices that do not increase cost and SW loss, and do not affect the withstand voltage of the upper arm drive circuit. The long SW element is a power supply device that can operate normally.

  Next, details of the above-described power supply apparatuses 10 and 10a will be described in more detail.

  Since the S elements S1 and S2 of the charge replenishment circuit F1a in the power supply device 10a of FIG. 7 are switched at the same speed as the SW elements QH2 and QL2, they are preferably composed of transistor elements (hereinafter abbreviated as T elements). The T element may be, for example, a MOS transistor element (hereinafter abbreviated as M element) or a bipolar transistor element.

  FIG. 13 is a circuit diagram of the power supply apparatus 10b, and is a diagram illustrating a circuit configuration example in which the S elements S1 and S2 of the charge replenishment circuit F1a in the power supply apparatus 10a of FIG. 7 are M elements M1 and M2.

  In the charge replenishment circuit F1b of the power supply apparatus 10b shown in FIG. 13, a fifth diode D5 is further provided for the M elements M1 and M2 having the same configuration and function as the S elements S1 and S2 shown in FIG. It has been added. The diode D5 is for cutting off the current path of the parasitic diode associated with the M elements M1 and M2, and is connected to the two SW elements QH2 of the second power supply system P2 from the connection point N3 of the two M elements M1 and M2. It is inserted in the forward direction toward the connection point N2 of QL2. As described above, when the M elements M1 and M2 are employed as the S elements S1 and S2 in the power supply device 10a of FIG. 7, the current paths of the parasitic diodes associated with the M elements M1 and M2 are cut off. It is preferable to add a diode D5 shown in FIG.

  FIG. 14 and FIG. 15 are circuit diagrams of the power supply devices 10c and 10d, respectively, showing a modification of the power supply device 10a shown in FIG.

  In the power supply device 10a of FIG. 7, the S element S1 on the first power supply system P1 (connection point N1) side and the S element S2 on the second power supply system P2 (connection point N2) side in the charge replenishment circuit F1a are respectively The configuration was as follows. That is, the S element S1 on the connection point N1 side is turned on and off in the same manner in synchronization with the control signal IH2 of the upper arm of the second power supply system P2. Further, the S element S2 on the connection point N2 side is turned on and off in the same manner in synchronization with the control signal IL2 of the lower arm of the second power supply system P2.

  On the other hand, the control signal IH2 for the upper arm and the control signal IL2 for the lower arm in the second power supply system P2 are turned on and off in a complementary manner, so that the connection configuration of the power supply devices 10c and 10d shown in FIGS. It is possible to adopt.

  In the power supply device 10c of FIG. 14, only the control signal IH2 of the upper arm of the second power supply system P2 is used for controlling the S elements S1 and S2 of the charge replenishment circuit F1c. The S element S1 on the connection point N1 side inputs the control signal IH2 for the upper arm of the second power supply system P2 as it is, and the S element S2 on the connection point N2 side supplies the second power supply via the inverter I1. An inverted signal of the control signal IH2 for the upper arm of the system P2 is input.

  Conversely, in the power supply device 10d of FIG. 15, only the control signal IL2 for the lower arm of the second power supply system P2 is used for controlling the S elements S1 and S2 of the charge replenishment circuit F1d. The S element S1 on the connection point N1 side inputs an inverted signal of the control signal IL2 of the lower arm of the second power supply system P2 via the inverter I2, and the S element S2 on the connection point N2 side The control signal IL2 for the lower arm of the power supply system P2 is input as it is.

  Even in the connection configuration of the S elements S1 and S2 shown in FIG. 14 and FIG. 15, the charge replenishment circuits F1c and F1d repeatedly charge and discharge charges at a timing based on the control signal of the second power supply system P2 having a short cycle. Then, charge is replenished to the BS circuit B1 of the long-cycle first power supply system P1.

  As described above, the above-described power supply apparatus is a small-sized power supply apparatus that does not increase cost and SW loss, and has a long ON time without affecting the withstand voltage of the upper arm drive circuit. The device is a power supply device that can also operate normally.

  Therefore, the power supply apparatus is suitable as a vehicle-mounted power supply apparatus that is required to be small and low-cost and that integrates a plurality of power supply systems that are driven at various cycles.

10, 10a to 10d, 90, 90a Power supply device E1, E2 Power supply P1, P2 Power supply system QH1, QL1, QH2, QL2 SW element KH1, KL1, KH2, KL2 Drive circuit IH1, IL1, IH2, IL2 Control signal B1 , B2 BS circuit F1, F1a to F1d Charge replenishment circuit D1 to D5 Diode C1 to C3 Capacitance element S1, S2 S element M1, M2 M element

Claims (9)

A power supply that includes two switching elements (hereinafter abbreviated as SW elements) connected in series with an upper arm and a lower arm that are connected to a first DC power source, and that outputs power to a load from a connection point of the two SW elements. A device,
Two drive circuits, upper arm and lower arm, which are connected to a direct current second power supply, input control signals of the two SW elements and output gate signals, and voltages applied to the upper arm drive circuit A plurality of power supply systems composed of a bootstrap circuit (hereinafter abbreviated as a BS circuit) that enhances power and the two SW elements,
At least two power supply systems of the plurality of power supply systems are driven with different periods, and a first power supply system driven with a long period includes a charge replenishment circuit connected to the second power source. Have
The charge replenishment circuit inputs the control signal of the second power supply system that is driven in a short cycle, repeats charge charging and discharging at a timing based on the control signal, and sends the charge signal to the BS circuit of the first power supply system. An electric power supply device configured to replenish electric charges. The drive circuit is
The high potential side of the power supply terminal is connected to the high potential side of the second power supply, the low potential side of the power supply terminal is connected to the low potential side of the SW element,
The BS circuit is
A diode inserted in the forward direction from the high potential side of the second power supply toward the high potential side of the power supply terminal of the drive circuit, one end connected to the cathode side of the diode, and the other end connected to the power supply of the drive circuit The power supply device according to claim 1, wherein the power supply device includes a capacitive element connected to a low potential side of the terminal. The charge replenishment circuit comprises:
Two switch elements connected in series (hereinafter referred to as S element) inserted in a path connecting the connection point of two SW elements of the first power supply system and the connection point of two SW elements of the second power supply system Abbreviated) and
A third capacitive element having one end connected to the connection point of the two S elements and the other end connected to the high potential side of the second power supply;
A third diode inserted in a forward direction from the high potential side of the second power supply toward the other end of the third capacitive element;
A fourth diode inserted in the forward direction from the other end of the third capacitive element toward the high potential side of the power supply terminal of the drive circuit of the first power supply system;
Of the two S elements,
The first S element on the output side of the first power supply system is turned on and off in the same manner in synchronization with the control signal of the SW element of the upper arm of the second power supply system,
The second S element on the output side of the second power supply system is configured to be turned on and off in the same manner in synchronization with the control signal of the SW element of the lower arm of the second power supply system. The power supply device according to claim 2. The S element is
The power supply device according to claim 3, comprising a transistor element (hereinafter abbreviated as T element). The T element comprises a MOS transistor element (hereinafter abbreviated as M element),
5. The power according to claim 4, wherein a fifth diode is inserted in a forward direction from a connection point of the two M elements toward a connection point of two SW elements of the second power supply system. Feeding device. The first S element inputs a control signal of the SW element of the upper arm of the second power supply system,
The power supply according to any one of claims 3 to 5, wherein the second S element is configured to input a control signal of a SW element of a lower arm of the second power supply system. apparatus. The first S element inputs a control signal of the SW element of the upper arm of the second power supply system,
The said 2S element is comprised so that the inversion signal of the control signal of the SW element of the upper arm of the said 2nd electric power supply system may be input, The Claim 3 thru | or 5 characterized by the above-mentioned. Power supply equipment. The first S element receives an inverted signal of the control signal of the SW element of the lower arm of the second power supply system,
The power supply according to any one of claims 3 to 5, wherein the second S element is configured to input a control signal of a SW element of a lower arm of the second power supply system. apparatus.   The power supply apparatus according to any one of claims 1 to 8, wherein the power supply apparatus is for vehicle use.

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