WO2022190855A1

WO2022190855A1 - Switching power supply device, switch control device, vehicle-mounted device, and vehicle

Info

Publication number: WO2022190855A1
Application number: PCT/JP2022/007206
Authority: WO
Inventors: 慎吾橋口
Original assignee: ローム株式会社
Priority date: 2021-03-09
Filing date: 2022-02-22
Publication date: 2022-09-15
Also published as: JPWO2022190855A1

Abstract

This switching power supply device comprises first to sixth switches, a capacitor, and a control unit configured to control on/off of each of the first to sixth switches. The control unit is configured to provide: a first period for turning on the fifth switch, turning on the first switch, turning off the second switch, turning off the fourth switch, and turning off the sixth switch; and a second period for turning on the second switch, turning off the first switch, turning off the third switch, turning on the fourth switch, and turning off the fifth switch.

Description

Switching power supply device, switch control device, in-vehicle equipment, and vehicle

The invention disclosed in this specification relates to a switching power supply device that steps down an input voltage to an output voltage, a switch control device, an in-vehicle device, and a vehicle.

The DC-DC converter proposed in Patent Document 1 has a switched capacitor circuit, and improves efficiency by turning on a high-side switch included in the switched capacitor circuit with zero-volt switching.

JP 2010-148288 A

However, in the DC-DC converter proposed in Patent Document 1, the output voltage is 1/4 of the input voltage, and if the input voltage fluctuates, the output voltage also fluctuates and the output voltage cannot be stabilized.

A switching power supply device disclosed in this specification includes first to sixth switches, a capacitor, and a control unit configured to control on/off of each of the first to sixth switches. Prepare. The first switch is configured such that a first terminal of the first switch can be connected to an application terminal of an input voltage, and a second terminal of the first switch is connected to a first terminal of the second switch and a first terminal of the capacitor. configured to be connectable to The second switch is configured such that the second end of the second switch is connectable to the first end of the third switch and the first end of the first inductor. The third switch is configured such that a second terminal of the third switch can be connected to a low voltage application terminal lower than the input voltage. The fourth switch is configured such that a first end of the fourth switch is connectable to a second end of the capacitor and a first end of the fifth switch, and a second end of the fourth switch is connected to the low voltage. It is configured to be connectable to the application end. The fifth switch is configured such that the second end of the fifth switch is connectable to the first end of the sixth switch and the first end of the second inductor. The sixth switch is configured such that a second end of the sixth switch can be connected to the low voltage application end. a first period in which the control unit turns on the fifth switch, turns on the first switch, turns off the second switch, turns off the fourth switch, and turns off the sixth switch; and a second period during which the second switch is turned on, the first switch is turned off, the third switch is turned off, the fourth switch is turned on, and the fifth switch is turned off. be done.

The switch control device disclosed in this specification is part of a switching power supply device that includes first to sixth switches and a capacitor. The first switch is configured such that a first terminal of the first switch can be connected to an application terminal of an input voltage, and a second terminal of the first switch is connected to a first terminal of the second switch and a first terminal of the capacitor. configured to be connectable to The second switch is configured such that the second end of the second switch is connectable to the first end of the third switch and the first end of the first inductor. The third switch is configured such that a second terminal of the third switch can be connected to a low voltage application terminal lower than the input voltage. The fourth switch is configured such that a first end of the fourth switch is connectable to a second end of the capacitor and a first end of the fifth switch, and a second end of the fourth switch is connected to the low voltage. It is configured to be connectable to the application end. The fifth switch is configured such that the second end of the fifth switch is connectable to the first end of the sixth switch and the first end of the second inductor. The sixth switch is configured such that a second end of the sixth switch can be connected to the low voltage application end. The switch control device is configured to control on/off of each of the first to sixth switches, turns on the fifth switch, turns on the first switch, turns off the second switch, a first period in which the fourth switch is turned off and the sixth switch is turned off; a period in which the second switch is turned on, the first switch is turned off, the third switch is turned off, and the fourth switch is turned off; and a second period during which the fifth switch is turned on and the fifth switch is turned off.

The in-vehicle equipment disclosed in this specification includes the switching power supply device configured as described above or the switch control device configured as described above.

The vehicle disclosed in this specification includes the vehicle-mounted device configured as described above and a battery that supplies power to the vehicle-mounted device.

According to the invention disclosed in this specification, it is possible to change the relationship between the input voltage and the output voltage in the switching power supply.

FIG. 1 is a diagram showing the configuration of a switching power supply device according to one embodiment. FIG. 2 is a time chart showing a first operation example of the switching power supply device according to one embodiment. FIG. 3 is a diagram showing the current flowing through the switching power supply device according to one embodiment. FIG. 4 is a diagram showing the current flowing through the switching power supply device according to one embodiment. FIG. 5 is a diagram showing the current flowing through the switching power supply device according to one embodiment. FIG. 6 is a diagram showing the current flowing through the switching power supply device according to one embodiment. FIG. 7 is a diagram showing the current flowing through the switching power supply device according to one embodiment. FIG. 8 is a diagram showing the current flowing through the switching power supply device according to one embodiment. FIG. 9 is a time chart showing a second operation example of the switching power supply device according to one embodiment. FIG. 10 is a time chart showing a third operation example of the switching power supply device according to one embodiment. FIG. 11 is an external view showing one configuration example of a vehicle.

In this specification, a MOS transistor is defined as a gate structure that includes a layer made of a conductor or a semiconductor such as polysilicon with a low resistance value, an insulating layer, and a P-type, N-type, or intrinsic semiconductor. layer” refers to a transistor consisting of at least three layers. In other words, the structure of the gate of a MOS transistor is not limited to a three-layer structure of metal, oxide, and semiconductor.

<Structure of switching power supply device according to one embodiment>
FIG. 1 is a diagram showing the configuration of a switching power supply device according to one embodiment. A switching power supply device 1 (hereinafter referred to as "switching power supply device 1") according to one embodiment is a switching power supply device that steps down an input voltage VIN to an output voltage VOUT. The switching power supply 1 includes a control unit CNT1, first to sixth switches SW1 to SW6, a capacitor C1, a first inductor L1, a second inductor L2, an output capacitor COUT, and an output feedback unit FB1. Prepare.

The control unit CNT1 controls on/off of the first to sixth switches SW1 to SW6 based on the output of the output feedback unit FB1. In other words, the control unit CNT1 is a switch control device that controls ON/OFF of the first to sixth switches SW1 to SW6.

The first switch SW1 is configured such that a first end can be connected to the application end of the input voltage VIN, and a second end is configured to be connectable to the first end of the capacitor C1 and the first end of the second switch SW2. The first switch SW1 conducts/disconnects a current path between the application terminal of the input voltage VIN and the first connection node N1. The first connection node N1 is a node to which the second end of the first switch SW1, the first end of the second switch SW2, and the first end of the capacitor C1 are connected. For example, a P-channel MOS transistor, an N-channel MOS transistor, or the like can be used as the first switch SW1. For example, when an N-channel MOS transistor is used for the first switch SW1, the switching power supply device 1 may be provided with a bootstrap circuit or the like to generate a voltage higher than the input voltage VIN.

The second switch SW2 is configured such that the second end can be connected to the first end of the third switch SW3 and the first end of the first inductor L1. The second switch SW2 conducts/disconnects the current path between the first connection node N1 and the third connection node N3. The third connection node N3 is a node to which the second end of the second switch SW2, the first end of the third switch SW3, and the first end of the first inductor L1 are connected. For example, a P-channel MOS transistor, an N-channel MOS transistor, or the like can be used as the second switch SW2. For example, if an N-channel MOS transistor is used for the second switch SW2, the switching power supply 1 may be provided with a bootstrap circuit or the like to generate a voltage higher than the input voltage VIN.

The third switch SW3 is configured so that the second end can be connected to the ground potential application end. The third switch SW3 conducts/disconnects the current path between the third connection node N3 and the ground potential. For example, an N-channel MOS transistor or the like can be used as the third switch SW3.

A first end of the fourth switch SW4 is connectable to the second end of the capacitor C1 and the first end of the fifth switch SW5, and a second end is connectable to the ground potential application end. The fourth switch SW4 conducts/disconnects the current path between the second connection node N2 and the ground potential. The second connection node N2 is a node to which the second terminal of the capacitor C1, the first terminal of the fourth switch SW4, and the first terminal of the fifth switch SW5 are connected. For example, an N-channel MOS transistor or the like can be used as the fourth switch SW4.

The fifth switch SW5 is configured such that the second end can be connected to the first end of the sixth switch SW6 and the first end of the second inductor. The fifth switch SW5 conducts/interrupts the current path between the second connection node N2 and the fourth connection node N4. The fourth connection node N4 is a node to which the second end of the fifth switch, the first end of the sixth switch SW6, and the first end of the second inductor are connected. For example, an N-channel MOS transistor or the like can be used as the fifth switch SW5.

The sixth switch SW6 is configured so that the second end can be connected to the ground potential application end. The sixth switch SW6 conducts/disconnects the current path between the fourth connection node N4 and the ground potential. For example, an N-channel MOS transistor or the like can be used as the sixth switch SW6.

The output capacitor COUT has a first end connectable to the second end of the first inductor L1, the second end of the second inductor L2, and the output terminal OUT, and the second end connectable to the ground potential application end. configured to An output voltage VOUT applied to the output terminal OUT is supplied to a load LD1 connected to the output terminal OUT.

The output feedback unit FB1 generates and outputs a feedback signal according to the output voltage VOUT. As the output feedback unit FB1, for example, a resistance voltage dividing circuit or the like that divides the output voltage VOUT by resistance to generate a feedback signal can be used. Further, for example, the output feedback unit FB1 may be configured to acquire the output voltage VOUT and output the output voltage VOUT itself as a feedback signal. In addition to the feedback signal corresponding to the output voltage VOUT, the output feedback unit FB1 also generates and outputs a feedback signal corresponding to the current flowing through the first inductor L1 and the current flowing through the second inductor L2. good too. Current mode control is enabled by the output feedback unit FB1 also generating a feedback signal according to the current flowing through the first inductor L1 and the current flowing through the second inductor L2.

The control unit CNT1 controls on/off of the first to sixth switches SW1 to SW6. More specifically, the control unit CNT1 controls ON/OFF of the first to sixth switches SW1 to SW6 based on the feedback signal output from the output feedback unit FB1.

A case where the input voltage VIN is set to 48V and the ground potential is set to 0V will be described below as an example.

<First Operation Example of Switching Power Supply According to One Embodiment>
FIG. 2 is a time chart showing a first operation example of the switching power supply device 1. FIG. In this specification, the direction from one end (third connection node N3 side) of the first inductor L1 to the other end (output terminal OUT side) is defined as the positive direction of the current IL1 flowing through the first inductor L1. The direction from one end (fourth connection node N4 side) of the two-inductor L2 to the other end (output terminal OUT side) is the positive direction of the current IL2 flowing through the second inductor L2. The control unit CNT1 sets the length of the first period P1 and the length of the second period P2 according to the feedback signal output from the output feedback unit FB1. Thereby, the relationship between the input voltage VIN and the output voltage VOUT in the switching power supply device 1 can be changed. The lighter the load LD1, the shorter the length of the first period P1 and the length of the second period P2.

The control unit CNT1 complementarily controls the ON/OFF of the first switch SW1 and the fourth switch SW4 at a duty of 50% in each cycle PD. Each cycle PD has the same fixed value.

During the period in which the first switch SW1 is on and the fourth switch SW4 is off (period from timing t1 to timing t5), the capacitor C1 and the input terminal are electrically connected, and the capacitor C1 and the ground potential are electrically connected. Since they are not directly connected, the voltage V1 at the first connection node N1 is 48V and the voltage V2 at the second connection node N2 is 24V.

On the other hand, during the period in which the first switch SW1 is off and the fourth switch SW4 is on (period from timing t5 to timing t1 of the next cycle), the capacitor C1 is electrically connected to the ground potential. Since the capacitor C1 and the input terminal are not electrically connected, the voltage V1 at the first connection node N1 is 24V and the voltage V2 at the second connection node N2 is 0V.

In the first period P1 (period from timing t3 to timing t4), the control unit CNT1 turns on the fifth switch SW5, turns on the first switch SW1, turns off the second switch SW2, and turns off the fourth switch SW4. off, and the sixth switch SW6 is turned off. As a result, a current flows from the input terminal to the output capacitor COUT and the output terminal OUT via the first switch SW1, the capacitor C1, the fifth switch SW5, and the second inductor L2 (see FIG. 3).

During the first ON period O1 (period from timing t1 to timing t2), the control unit CNT1 turns on the sixth switch SW6. At the start time (timing t1) of the first ON period O1, the current IL2 flowing through the second inductor L2 is zero. Since the third switch SW3 is turned on during the first ON period O1, the current IL2 flowing through the second inductor L2 becomes a negative current (see FIG. 4). At timing t2, when the third switch SW3 is turned off, the voltage V4 at the fourth connection node N4 rises.

By providing the first ON period O1 in which the sixth switch SW6 is turned ON before the fifth switch SW5 is turned ON, the potential difference between both ends of the fifth switch SW5 when the fifth switch SW5 is turned ON at timing t3 is reduced. Since it can be made (ideally zero), the efficiency of the switching power supply device 1 can be improved.

When the first period P1 ends, the control unit CNT1 turns off the fifth switch SW5 and turns on the sixth switch SW6. The control unit CNT1 keeps the sixth switch SW6 on until the current IL2 flowing through the second inductor L2 decreases to zero. As a result, a current flows from the ground potential to the output capacitor COUT and the output terminal OUT via the sixth switch SW6 and the second inductor L2 (see FIG. 5). Therefore, the switching power supply 1 includes a second current detector (not shown) that detects the current IL2 flowing through the second inductor L2. As the second detection unit, for example, a current detection unit that detects the current IL2 flowing through the second inductor L2 by detecting the current flowing through the sixth switch SW6 based on the potential difference between both ends of the sixth switch SW6 can be used. This is because the current flowing through the sixth switch SW6 can be regarded as the current IL2 flowing through the second inductor L2 when the fifth switch SW5 is off and the sixth switch SW6 is on.

The voltage V4 at the fourth connection node N4 is generated from the voltage V2 at the second connection node N2 by switching the fifth switch SW5 and the sixth switch SW6 described above.

In the second period P2 (period from timing t7 to timing t8), the control unit CNT1 turns on the second switch SW2, turns off the first switch SW1, turns off the third switch SW3, and turns off the fourth switch SW4. turn on and turn off the fifth switch SW5. As a result, a current flows from the ground potential to the output capacitor COUT and the output terminal OUT via the fourth switch SW4, the capacitor C1, the second switch SW2, and the first inductor L1 (see FIG. 6).

When the second period P2 ends, the control unit CNT1 turns off the second switch SW2 and turns on the third switch SW3. The control unit CNT1 keeps the third switch SW3 on until the current IL1 flowing through the first inductor L1 decreases to zero. As a result, a current flows from the ground potential to the output capacitor COUT and the output terminal OUT via the third switch SW3 and the first inductor L1 (see FIG. 7). Therefore, the switching power supply device 1 includes a first current detection section (not shown) that detects the current IL1 flowing through the first inductor L1. As the first detection unit, for example, a current detection unit that detects the current IL1 flowing through the first inductor L1 by detecting the current flowing through the third switch SW3 based on the potential difference across the third switch SW3 can be used. This is because when the second switch SW2 is off and the third switch SW3 is on, the current flowing through the third switch SW3 can be regarded as the current IL1 flowing through the first inductor L1.

The voltage V3 at the third connection node N3 is generated from the voltage V1 at the first connection node N1 by switching the second switch SW2 and the third switch SW3 described above.

Then, the control unit CNT1 provides a second ON period O2 (a period from timing t5 to timing t6) for turning on the third switch SW3 before turning on the second switch SW2. At the start of the second ON period O2 (timing t5), the current IL1 flowing through the first inductor L1 is zero. During the second ON period O2, the third switch SW3 is turned on, so the current IL2 flowing through the second inductor L2 becomes a negative current (see FIG. 8). Then, when the second ON period O2 ends, the third switch SW3 is turned off, so the voltage V3 at the third connection node N3 rises. As a result, the potential difference across the second switch SW2 when the second switch SW2 is turned on can be reduced (ideally to zero), so that the efficiency of the switching power supply 1 can be improved.

The controller CNT1 always turns on the fourth switch SW4 when turning on the second switch SW2 so that both ends of the capacitor Cr are in a low impedance state when turning on the second switch SW2. there is

Similarly, the control unit CNT1 always turns on the first switch SW1 when turning on the fifth switch SW5 so that both ends of the capacitor Cr are in a low impedance state when turning on the fifth switch SW5. ing.

Further, the control unit CNT1 makes the length of the first period P1 and the length of the second period P2 equal in each cycle PD in order to keep the potential difference across the capacitor Cr substantially constant.

<Second Operation Example of Switching Power Supply According to One Embodiment>
FIG. 9 is a time chart showing a second operation example of the switching power supply device 1. FIG. Hereinafter, in the second operation example, description of the same operations as in the first operation example will be omitted, and operations different from the first operation example will be described.

In the second operation example, the control unit CNT1 does not complementarily on/off control the first switch SW1 and the fourth switch SW4 at a duty of 50% in each period PD.

In the second operation example, the control unit CNT1 turns on the first switch SW1 and the fifth switch SW5 at the same time, and turns off the first switch SW1 and the fifth switch SW5 at the same time. Also, in the second operation example, the controller CNT1 turns on the fourth switch SW4 and the second switch SW2 at the same time, and turns off the fourth switch SW4 and the second switch SW2 at the same time.

When both the fifth switch SW5 and the sixth switch SW6 are off, that is, when the fourth connection node N4 is in a high impedance state, the voltage V4 at the fourth connection node N4 tries to maintain the same value as the output voltage VOUT. However, when the second switch SW2 is turned on while the fourth connection node N4 is in the high-impedance state, the body diode formed across the fifth switch SW5 draws electric charges from the fourth connection node N4, The voltage V4 at the fourth connection node N4 drops to 0V. The body diode formed between both ends of the fifth switch SW5 has an anode on the side of the fourth connection node N4 and a cathode on the side of the second connection node N2. Since the voltage V4 at the fourth connection node N4 becomes lower than the output voltage VOUT, the current IL2 flowing through the second inductor L2 becomes a negative current. When the second switch SW2 is turned off, electric charges are supplied from the fourth connection node N4 to the second connection node N2 through the body diode formed between both ends of the fifth switch SW5. voltage V2 rises to 24V. As the voltage V2 at the second connection node N2 rises, the voltage V1 at the first connection node N1 rises to 48V. As a result, the potential difference across the first switch SW1 when the first switch SW1 is turned on can be reduced (ideally to zero). Therefore, in the second operation example, the efficiency of the switching power supply device 1 can be improved more than in the first operation example.

When using the fifth switch SW5 having no body diode formed between both ends thereof, or when using the fifth switch SW5 having a low current capability of the body diode formed between both ends of the switch SW5, the fifth switch SW5 is connected in parallel. A diode may be provided.

<Third Operation Example of Switching Power Supply According to One Embodiment>
FIG. 10 is a time chart showing a third operation example of the switching power supply device 1. FIG. Hereinafter, in the third operation example, the description of the same operations as in the second operation example will be omitted, and the operations different from the second operation example will be described.

In the third operation example, as in the second operation example, when the second switch SW2 is turned off, the second connection node N2 is connected from the fourth connection node N4 via the body diode formed between both ends of the fifth switch SW5. is supplied with charge. Although the voltage V2 at the second connection node N2 rises, it does not reach 24V. As the voltage V2 at the second connection node N2 rises, the voltage V1 at the first connection node N1 rises, but does not reach 48V. When the first switch SW1 is turned on, the voltage V2 at the second connection node N2 rises to 24V and the voltage V2 at the first connection node N1 rises to 48V.

Although the third operation example is not as good as the second operation example, the efficiency of the switching power supply 1 can be improved more than the first operation example.

<Application>
Next, application examples of the switching power supply device 1 described above will be described. FIG. 11 is an external view showing a configuration example of a vehicle in which the in-vehicle device is mounted. The vehicle X of this configuration example is equipped with onboard devices X11 to X17 and a battery (not shown) that supplies power to these onboard devices X11 to X17.

When the switching power supply device 1 described above is installed in the vehicle X, it is required to suppress radiation noise in the AM band so as not to adversely affect the reception of AM radio broadcasts. Therefore, it is desirable that the control unit CNT1 generates a voltage of 1.8 MHz or more and 2.1 MHz or less at the first connection node N1. That is, it is desirable to set the reciprocal (switching frequency) of the fixed value of each cycle PD to 1.8 MHz or more and 2.1 MHz or less. This is because if the switching frequency is less than 1.8 MHz, radiation noise in the AM band increases, and if the switching frequency is greater than 2.1 MHz, the switching loss exceeds the allowable range.

The in-vehicle device X11 is an engine control unit that performs engine-related controls (injection control, electronic throttle control, idling control, oxygen sensor heater control, auto-cruise control, etc.).

The in-vehicle device X12 is a lamp control unit that controls lighting and extinguishing of HID [high intensity discharged lamp] and DRL [daytime running lamp].

The in-vehicle device X13 is a transmission control unit that performs controls related to the transmission.

The in-vehicle device X14 is a body control unit that performs controls related to the movement of the vehicle X (ABS [anti-lock brake system] control, EPS [electric power steering] control, electronic suspension control, etc.).

The in-vehicle device X15 is a security control unit that controls driving such as door locks and security alarms.

In-vehicle equipment X16 is electronic equipment that is built into vehicle X at the factory shipment stage as standard equipment or manufacturer options, such as wipers, electric door mirrors, power windows, electric sunroofs, electric seats, and air conditioners.

The in-vehicle device X17 is an electronic device that the user arbitrarily attaches to the vehicle X, such as an in-vehicle A/V [audio/visual] device, a car navigation system, and an ETC [Electronic Toll Collection System].

It should be noted that the switching power supply device 1 described above can be incorporated in any of the in-vehicle devices X11 to X17.

<Points to note>
In addition to the above-described embodiment, the configuration of the present invention can be modified in various ways without departing from the gist of the invention. The above embodiments should be considered illustrative in all respects and not restrictive, and the technical scope of the present invention is indicated by the scope of claims rather than the description of the above embodiments. It should be understood that all modifications that fall within the meaning and range of equivalents of the claims are included.

For example, in the above embodiment, the potential difference across the capacitor C1 is kept constant by aligning the length of the first period P1 and the length of the second period P2 in each cycle. However, for example, the length of the first period P1 and the length of the second period P2 are not made the same. The configuration may be such that the ratio with the length of the two periods P2 is adjusted.

Further, in the above embodiment, the timing when the fifth switch SW5 is turned on and the timing when the current IL2 flowing through the second inductor L2 becomes zero are the same timing (timing t3), but the fifth switch SW5 is turned on. The timing may be before the timing at which the current IL2 flowing through the second inductor L2 becomes zero, or after the timing at which the current IL2 flowing through the second inductor L2 becomes zero. However, if the fifth switch SW5 turns on before the current IL2 flowing through the second inductor L2 becomes zero, the fifth switch SW5 will not be zero volt switching. Therefore, it is desirable that the fifth switch SW5 is turned on at the same time as the current IL2 flowing through the second inductor L2 becomes zero or after the current IL2 flowing through the second inductor L2 becomes zero.

In the above embodiment, both the third switch SW3 and the sixth switch SW6 are turned on during the period from the timing t5 to the timing t6, but after the sixth switch SW6 is turned off (after the timing t6). The third switch SW3 may be turned on immediately. A capacitor C1 is arranged between the second switch SW2 and the third switch SW3 and the fifth switch SW5 and the sixth switch SW6, and the switching operation of the second switch SW2 and the third switch SW3 and the switching operation of the fifth switch SW5 and the fifth switch SW5 are arranged. This is because it is independent of the switching operation of the 6-switch SW6. However, providing a period in which both the third switch SW3 and the sixth switch SW6 are ON as in the above embodiment improves the temporal efficiency of switching control. It is desirable to provide a period during which both SW6 are on.

The switching power supply device (1) described above is configured to control ON/OFF of the first to sixth switches (SW1 to SW6), the capacitor (C1), and the first to sixth switches. a control unit (CNT1), wherein the first switch is configured such that a first end of the first switch can be connected to an input voltage application end, and a second end of the first switch is connected to a second switch; The second switch is configured to be connectable to a first end and a first end of the capacitor, wherein the second switch connects a second end of the second switch to a first end of the third switch and a first end of the first inductor. the third switch is configured such that a second end of the third switch can be connected to a low voltage application end lower than the input voltage; one end of the capacitor is connectable to the second end of the capacitor and the first end of the fifth switch; the second end of the fourth switch is connectable to the low voltage application end; The switch is configured such that the second end of the fifth switch is connectable to the first end of the sixth switch and the first end of the second inductor, and the sixth switch connects the second end of the sixth switch to the first end of the second inductor. The controller is configured to be connectable to the low voltage application end, the controller turns on the fifth switch, turns on the first switch, turns off the second switch, turns off the fourth switch, a first period in which the sixth switch is turned off, the second switch is turned on, the first switch is turned off, the third switch is turned off, the fourth switch is turned on, and the fifth switch is turned on; and a second off period (first configuration).

The switching power supply device having the first configuration can change the relationship between the input voltage and the output voltage.

In the switching power supply device having the first configuration, the control unit is configured to provide a first ON period for turning on the sixth switch before turning on the fifth switch (second configuration ).

In the switching power supply device having the second configuration, the potential difference between both ends of the fifth switch can be reduced (ideally zero) when the fifth switch is turned on, so efficiency can be improved.

In the switching power supply device having the first or second configuration, the control section is configured to provide a second ON period for turning on the third switch before turning on the second switch (second 3).

In the switching power supply device having the third configuration, the potential difference between both ends of the second switch can be reduced (ideally zero) when the second switch is turned on, so efficiency can be improved.

In the switching power supply device having any one of the first to third configurations, the controller always turns on the fourth switch when turning on the second switch, and turns on the fifth switch when turning on the fifth switch. A configuration (fourth configuration) may be employed in which the first switch is always turned on.

The switching power supply device having the fourth configuration can put both ends of the capacitor Cr into a low impedance state when turning on the second switch. Further, the switching power supply device having the fourth configuration can bring both ends of the capacitor into a low impedance state when turning on the fifth switch.

In the switching power supply device having any one of the first to fourth configurations, the control unit is configured to match the length of the first period and the length of the second period in each cycle (fifth configuration ).

The switching power supply device having the fifth configuration can keep the potential difference across the capacitor constant.

In the switching power supply device having any one of the first to fifth configurations, the control unit simultaneously turns on the first switch and the fifth switch, simultaneously turns off the first switch and the fifth switch, and A configuration (sixth configuration) may be employed in which the fourth switch and the second switch are turned on at the same time, and the fourth switch and the second switch are turned off at the same time.

In the switching power supply device having the sixth configuration, the potential difference between both ends of the first switch can be reduced (ideally zero) when the first switch is turned on, so efficiency can be improved.

The switch control device (CNT1) described above includes first to sixth switches (SW1 to SW6) and a capacitor (C1). the second end of the first switch is connectable to the first end of the second switch and the first end of the capacitor, and the second switch is configured to be connectable to the application end of the second switch is connectable to the first end of the third switch and the first end of the first inductor, the third switch being configured such that the second end of the third switch is lower than the input voltage; a first end of the fourth switch is connectable to a second end of the capacitor and a first end of the fifth switch; The second ends of four switches are connectable to the low voltage application end, and the fifth switch is configured such that the second ends of the fifth switches are connected to the first end of the sixth switch and the first end of the second inductor. a second end of the sixth switch is connectable to the low voltage application end, wherein the switching power supply (1) comprises: configured to control on/off of each of the first to sixth switches, turning on the fifth switch, turning on the first switch, turning off the second switch, and turning off the fourth switch a first period during which the sixth switch is turned off, the second switch is turned on, the first switch is turned off, the third switch is turned off, the fourth switch is turned on, and the fifth period is turned off; and a second period during which the switch is turned off (seventh configuration).

The switch control device having the seventh configuration can change the relationship between the input voltage and the output voltage in the switching power supply device.

The vehicle-mounted devices (X11 to X17) described above have a configuration (eighth configuration) including the switching power supply device having any one of the first to sixth configurations or the switch control device having the seventh configuration.

The vehicle-mounted device having the eighth configuration can change the relationship between the input voltage and the output voltage in the switching power supply.

The vehicle described above has a configuration (ninth configuration) including the vehicle-mounted device of the eighth configuration and a battery that supplies power to the vehicle-mounted device.

The vehicle (X) having the ninth configuration can change the relationship between the input voltage and the output voltage in the switching power supply.

1 switching power supply device according to one embodiment C1 capacitor COUT output capacitor CNT1 control unit FB1 output feedback unit L1 first inductor L2 second inductor LD1 load SW1 to SW6 first to sixth switches X vehicle X11 to X17 onboard equipment

Claims

first to sixth switches, a capacitor, and a controller configured to control on/off of each of the first to sixth switches;
The first switch is configured such that a first terminal of the first switch can be connected to an application terminal of an input voltage, and a second terminal of the first switch is connected to a first terminal of the second switch and a first terminal of the capacitor. configured to connect to
the second switch is configured such that a second end of the second switch can be connected to a first end of the third switch and a first end of the first inductor;
The third switch is configured such that a second terminal of the third switch can be connected to a low voltage application terminal lower than the input voltage,
The fourth switch is configured such that a first end of the fourth switch is connectable to a second end of the capacitor and a first end of the fifth switch, and a second end of the fourth switch is connected to the low voltage. configured to be connectable to the applying end,
the fifth switch is configured such that a second end of the fifth switch can be connected to a first end of the sixth switch and a first end of a second inductor;
The sixth switch is configured such that a second terminal of the sixth switch can be connected to the low voltage application terminal,
The control unit
a first period during which the fifth switch is turned on, the first switch is turned on, the second switch is turned off, the fourth switch is turned off, and the sixth switch is turned off;
a second period during which the second switch is turned on, the first switch is turned off, the third switch is turned off, the fourth switch is turned on, and the fifth switch is turned off;
A switching power supply configured to provide a
The control unit
2. The switching power supply device according to claim 1, configured to provide a first ON period during which said sixth switch is turned ON before said fifth switch is turned ON.
The control unit
3. The switching power supply device according to claim 1, wherein a second ON period for turning on said third switch is provided before said second switch is turned on.
The control unit
4. The device according to any one of claims 1 to 3, wherein the fourth switch is always turned on when the second switch is turned on, and the first switch is always turned on when the fifth switch is turned on. The switching power supply device according to any one of claims 1 to 3.
The control unit
5. The switching power supply device according to claim 1, wherein the length of said one period and the length of said second period are made equal in each period.
The control unit
simultaneously turning on the first switch and the fifth switch and simultaneously turning off the first switch and the fifth switch;
6. The switching power supply device according to claim 1, wherein said fourth switch and said second switch are turned on simultaneously, and said fourth switch and said second switch are turned off simultaneously.
comprising first to sixth switches and a capacitor,
The first switch is configured such that a first terminal of the first switch can be connected to an application terminal of an input voltage, and a second terminal of the first switch is connected to a first terminal of the second switch and a first terminal of the capacitor. configured to connect to
the second switch is configured such that a second end of the second switch can be connected to a first end of the third switch and a first end of the first inductor;
The third switch is configured such that a second terminal of the third switch can be connected to a low voltage application terminal lower than the input voltage,
The fourth switch is configured such that a first end of the fourth switch is connectable to a second end of the capacitor and a first end of the fifth switch, and a second end of the fourth switch is connected to the low voltage. configured to be connectable to the applying end,
the fifth switch is configured such that a second end of the fifth switch can be connected to a first end of the sixth switch and a first end of a second inductor;
The sixth switch is a part of a switching power supply device configured such that a second end of the sixth switch can be connected to the low voltage application end,
configured to control on/off of each of the first to sixth switches;
a first period during which the fifth switch is turned on, the first switch is turned on, the second switch is turned off, the fourth switch is turned off, and the sixth switch is turned off;
a second period during which the second switch is turned on, the first switch is turned off, the third switch is turned off, the fourth switch is turned on, and the fifth switch is turned off;
A switch control device configured to provide a
An in-vehicle device comprising the switching power supply device according to any one of claims 1 to 6 or the switch control device according to claim 7.
An in-vehicle device according to claim 8;
a battery that supplies power to the in-vehicle device;
a vehicle.