Switching converter, its controller circuit, and electronic equipment using the same

Abstract

To provide a switching converter without RHPZ (Right Half Plane Zero).SOLUTION: An inductor L1 is connected between a switching node SW and an output line 104. A first switch SW1 and a second switch SW2 are connected in series between an input line 102 and a ground line 106. A third switch SW3 is connected between the switching node SW and the input line 102. A flying capacitor C1 is connected between both ends of the third switch SW3 and the first switch SW1. A controller IC 200A drives the first to third switches SW1 to SW3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a switching converter.

Background Art

[0002] To generate a voltage higher than the power supply voltage, a boost converter is used. The boost converter can boost the input voltage V IN to any voltage level according to the switching duty cycle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The boost converter has a transfer function with a right half plane zero (RHPZ). The RHPZ causes various constraints in applications where the inductor value is large and the output current is large.

[0005] The present disclosure has been made in such a situation, and one of its exemplary purposes is to provide a switching converter having no RHPZ.

Means for Solving the Problems

[0006] A switching converter according to an aspect of the present disclosure includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch connected between the switching node and the input line, a flying capacitor connected across the third switch and the first switch, and a controller circuit for driving the first switch to the third switch.

[0007] Another aspect of the present disclosure is a controller circuit of a switching converter. The switching converter includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch connected between the switching node and the input line, and a flying capacitor connected across the third switch and the first switch. The controller circuit includes a state control unit that alternately repeats a first state in which the second switch and the third switch are on and the first switch is off, and a second state in which the second switch and the third switch are off and the first switch is on, and a drive circuit that drives the first switch to the third switch in response to an output of the state control unit.

[0008] Yet another aspect of the present disclosure is a switching converter. The switching converter includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch and a fourth switch connected in series between the input line and the switching node, a flying capacitor connected between both ends of the third switch and the first switch, a fifth switch connected between the switching node and the ground line, and a controller circuit for driving the first switch to the fifth switch.

[0009] Yet another aspect of the present disclosure is a controller circuit of a switching converter. The switching converter includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch and a fourth switch connected in series between the input line and the switching node, a flying capacitor connected between both ends of the third switch and the first switch, and a fifth switch connected between the switching node and the ground line. The controller circuit includes a state control unit that alternately repeats a first state in which the first switch and the fourth switch are off and the second switch, the third switch, and the fifth switch are on, and a second state in which the first switch and the fourth switch are on and the second switch, the third switch, and the fifth switch are off, and a drive circuit that drives the first switch to the fifth switch according to the output of the state control unit.

[0010] In addition, combinations of the above components arbitrarily, and components and expressions mutually replaced between methods, apparatuses, systems, etc. are also effective as aspects of the present invention.

Advantages of the Invention

[0011] According to certain aspects of the present disclosure, a switching converter without an RHPZ can be provided.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0013] (Overview of the Embodiment) An overview of some exemplary embodiments of the present disclosure will be described. This overview is for the purpose of providing a basic understanding of the embodiments as a prelude to the detailed description that follows, and simplifies and describes some concepts of one or more embodiments. It does not limit the scope of the invention or disclosure. This overview is not an all-inclusive overview of all possible embodiments, nor is it intended to identify important elements of all embodiments or to delineate the scope of some or all aspects. For convenience, "one embodiment" may be used to refer to one embodiment (example or variation) or multiple embodiments (examples or variations) disclosed herein.

[0014] A switching converter according to one embodiment includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch connected between the switching node and the input line, a flying capacitor connected between both ends of the third switch and the first switch, and a controller circuit for driving the third switch and the first switch.

[0015] According to this configuration, the voltage of the switching node can be switched between two voltages of 2×V IN and V IN , and the output voltage V OUT can be changed within the range of V IN ~2×V IN according to the duty cycle of the switching, thus realizing a boost operation. On the other hand, since the switching converter has a buck topology, there is no RHPZ.

[0016] Also, in a normal boost converter, the closer the boost ratio is to 1, the higher the efficiency. However, in the above configuration, the efficiency is higher when the boost ratio is close to 2. Therefore, when operating at a boost ratio close to 2, the efficiency can also be improved compared to a conventional boost converter.

[0017] In one embodiment, the controller circuit may alternately repeat a first state in which the second switch and the third switch are on and the first switch is off, and a second state in which the second switch and the third switch are off and the first switch is on. In the first state, the flying capacitor is charged with the input voltage V IN . In the second state, the voltage Vc (= V IN ) of the flying capacitor is added to the input voltage V IN , and a voltage of 2 × V IN can be generated at the switching node.

[0018] In one embodiment, the first switch to the third switch may be N-channel MOSFETs.

[0019] The controller circuit according to one embodiment controls a switching converter. The switching converter to be controlled includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch connected between the switching node and the input line, and a flying capacitor connected between both ends of the third switch and the first switch. The controller circuit includes a state control unit that alternately repeats a first state in which the second switch and the third switch are on and the first switch is off, and a second state in which the second switch and the third switch are off and the first switch is on, and a drive circuit that drives the first switch to the third switch according to the output of the state control unit.

[0020] According to this configuration, the voltage of the switching node can be switched between two voltages of 2 × V IN and V IN . According to the duty cycle of the switching, the output voltage V OUT can be adjusted to V IN to 2 × V INIt can be changed within the range, and thus the boost operation can be realized. On the other hand, since the switching converter has a buck topology, there is no RHPZ, and thus the phase compensation of the controller circuit becomes easier compared to the boost converter.

[0021] A switching converter according to an embodiment includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch and a fourth switch connected in series between the input line and the switching node, a flying capacitor connected between both ends of the third switch and the first switch, a fifth switch connected between the switching node and the ground line, and a controller circuit for driving the first switch to the fifth switch.

[0022] According to this configuration, the voltage of the switching node can be switched between two voltages of 2×V IN and 0V, and the output voltage V OUT can be changed within the range of 0 to 2×V IN according to the duty cycle of the switching, and thus the buck-boost operation (buck operation and boost operation) can be realized. On the other hand, since the switching converter has a buck topology, there is no RHPZ.

[0023] Also, in a normal boost converter, the closer the boost ratio is to 1, the higher the efficiency. However, in the above configuration, the efficiency is higher when the boost ratio is close to 2. Therefore, when operating at a boost ratio close to 2, the efficiency can also be improved compared to the conventional boost converter.

[0024] In one embodiment, the controller circuit may alternately repeat a first state in which the first switch and the fourth switch are off and the second switch, the third switch, and the fifth switch are on, and a second state in which the first switch and the fourth switch are on and the second switch, the third switch, and the fifth switch are off. In the first state, the flying capacitor is charged with the input voltage V IN , and 0V is generated at the switching node. In the second state, the voltage Vc (= V IN ) of the flying capacitor is added to the input voltage V IN , and a voltage of 2×V IN can be generated at the switching node.

[0025] In one embodiment, the first switch to the fifth switch may be N-channel MOSFETs.

[0026] A controller circuit according to one embodiment controls a switching converter. The switching converter to be controlled includes an input line, an output line, a ground line, a switching node, an inductor connected between the switching node and the output line, an output capacitor connected to the output line, a first switch and a second switch connected in series between the input line and the ground line, a third switch and a fourth switch connected in series between the input line and the switching node, a flying capacitor connected between both ends of the third switch and the first switch, and a fifth switch connected between the switching node and the ground line. The controller circuit includes a state control unit that alternately repeats a first state in which the first switch and the fourth switch are off and the second switch, the third switch, and the fifth switch are on, and a second state in which the first switch and the fourth switch are on and the second switch, the third switch, and the fifth switch are off, and a drive circuit that drives the first switch to the fifth switch according to the output of the state control unit.

[0027] According to this configuration, the voltage of the switching node is 2×V INIt can be switched with two voltages of 0V and 2V. According to the duty cycle of the switching, the output voltage V OUT can be varied in the range of 0 to 2×V IN , and thus the buck-boost operation can be realized. On the other hand, since the switching converter has a buck topology, there is no RHPZ, and thus the phase compensation of the controller circuit is easier compared to the buck-boost converter.

[0028] In one embodiment, the controller circuit may be integrally integrated on a single semiconductor substrate. "Integral integration" includes cases where all components of the circuit are formed on the semiconductor substrate and cases where the main components of the circuit are integrally integrated. Some resistors, capacitors, etc. may be provided outside the semiconductor substrate for adjusting circuit constants. By integrating the circuit on one chip, the circuit area can be reduced and the characteristics of the circuit elements can be kept uniform.

[0029] (Embodiment) Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and duplicate explanations will be omitted as appropriate. Also, the embodiments are illustrative and not restrictive, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0030] In this specification, the phrase "member A is in a state of being connected to member B" includes not only the case where member A and member B are physically directly connected, but also the case where member A and member B are indirectly connected via other members that do not substantially affect their electrical connection state or impair the functions and effects achieved by their connection.

[0031] Similarly, the phrase "member C is provided between member A and member B" includes not only the case where member A and member C, or member B and member C are directly connected, but also the case where they are indirectly connected via other members that do not substantially affect their electrical connection state or impair the functions and effects achieved by their combination.

[0032] Also, the statement "signal A (voltage, current) is responsive to signal B (voltage, current)" means that signal A has a correlation with signal B. Specifically, it means (i) when signal A is signal B, (ii) when signal A is proportional to signal B, (iii) when signal A is obtained by level-shifting signal B, (iv) when signal A is obtained by amplifying signal B, (v) when signal A is obtained by inverting signal B, or (vi) any combination thereof, etc. Those skilled in the art will understand that the scope of "responsive to" is determined according to the types and uses of signals A and B.

[0033] The vertical and horizontal axes of the waveform diagrams and time charts referred to in this specification are appropriately enlarged or reduced for ease of understanding, and each waveform shown is also simplified, exaggerated, or emphasized for ease of understanding.

[0034] (Embodiment 1) FIG. 1 is a circuit diagram of a switching converter 100A according to Embodiment 1. The switching converter 100A boosts the input voltage V of the input line 102 IN and generates an output voltage V after boosting on the output line 104 OUT . The switching converter 100A includes a flying capacitor C1, an output capacitor C2, an inductor L1, first switches SW1 to third switches SW3, resistors R1, R2, and a controller IC (Integrated Circuit) 200A.

[0035] Inductor L1 is connected between the switching node SW and the output line 104. Output capacitor C2 is connected to the output line 104. The first switch SW1 and the second switch SW2 are connected in series between the input line 102 and the ground line 106. The third switch SW3 is connected between the switching node SW and the input line 102. Flying capacitor C1 is connected between both ends of the third switch SW3 and the first switch SW1. In this embodiment, the first switch SW1 to the third switch SW3 are N-channel MOSFETs.

[0036] The first switch SW1 to the third switch SW3 and the flying capacitor C1 are referred to as a switching circuit 110A.

[0037] Controller IC200A drives the first switch SW1 to the third switch SW3, and generates a switching voltage V IN and 2×V IN at the switching node SW to take two voltage levels V SW .

[0038] For example, controller IC200A alternately repeats the first state φ1 and the second state φ2. · First state φ1 The second switch SW2 and the third switch SW3: ON The first switch SW1: OFF · Second state φ2 The second switch SW2 and the third switch SW3: OFF The first switch SW1: ON

[0039] Controller IC200A includes a drive circuit 210A, a state control unit 220A, and a feedback circuit 230, and is a functional IC integrated on a single semiconductor substrate. The gate pins G1 to G3 of controller IC200A are connected to the gates of the first switch SW1 to the third switch SW3. Also, a feedback signal V corresponding to the output voltage V OUT of the switching converter 100A is input to the feedback pin FB of controller IC200A.FB is fed back. Resistors R1 and R2 divide the output voltage V OUT and generate a feedback signal V FB .

[0040] Resistors R1 and R2 may be integrated into the controller IC200A. Also, the plurality of switches SW1 to SW3 may be integrated into the controller IC200A.

[0041] The state control unit 220A is control logic that generates control signals S1 to S3 that define the on and off states of the first switch SW1 to the third switch SW3, and controls the state of the switching converter 100A.

[0042] The drive circuit 210A drives the first switch SW1 to the third switch SW3 according to the outputs S1 to S3 of the state control unit 220A. The drive circuit 210A includes three drivers Dr1 to Dr3.

[0043] The feedback circuit 230 controls the time ratio of the first state φ1 and the second state φ2 so that the error between the feedback signal V FB and the reference voltage V REF approaches zero. The feedback circuit 230 can be configured in the same way as a general DC / DC converter, and can include, for example, a pulse width modulator or a pulse frequency modulator. Also, the control method is not particularly limited, and it may be a voltage mode controller, a peak current mode or average current mode controller, or a ripple control, specifically a hysteresis control (Bang-Bang control) or a controller with a fixed bottom detection on-time or a fixed peak detection off-time.

[0044] The above is the configuration of the switching converter 100A. Next, its operation will be described.

[0045] Figure 2 is an equivalent circuit diagram of the switching converter 100A in the first state φ1 of FIG. 1. In the first state φ1, the second switch SW2 and the third switch SW3 are on, and the first switch SW1 is off. In the first state φ1, V SW =V IN and the flying capacitor C1 is charged with the input voltage V IN . That is, the voltage Vc across both ends of the flying capacitor C1 is equal to the input voltage V IN .

[0046] The voltage ΔV L1 across both ends of the inductor L1 in the first state φ1 is ΔV L1 =V IN -V OUT and becomes a negative voltage. Therefore, the current I L of the inductor L1 decreases with time at a slope of (V IN -V OUT ) / L.

[0047] Figure 3 is an equivalent circuit diagram of the switching converter 100A in the second state φ2 of FIG. 1. In the second state φ2, the second switch SW2 and the third switch SW3 are off, and the first switch SW1 is on. In the second state φ2, V SW =2×V IN .

[0048] The voltage ΔV L2 across both ends of the inductor L1 in the second state φ2 is ΔV L2 =2×V IN -V OUT and becomes a positive voltage. Therefore, the current I L of the inductor L1 increases with time at a slope of (2×V IN -V OUT ) / L.

[0049] Figure 4 is an operating waveform diagram of the switching converter 100A of FIG. 1. The coil current I L flowing through the inductor L1 is shown in FIG. 4. In the second state φ2, the coil current I L increases. The time of the second state φ2 is t ONWhen it is set as such, the coil current I L The increase amount ΔI ON is ΔI ON =(2×V IN -V OUT ) / L×t ON becomes as follows.

[0050] In the first state φ1, the coil current I L decreases. When the time of the first state φ1 is t OFF When it is set as such, the coil current I L The decrease amount ΔI OFF (absolute value) is ΔI OFF =|(V IN -V OUT )| / L×t OFF =(V OUT -V IN ) / L×t OFF becomes as follows.

[0051] In the steady state, when the average value of the coil current I L is constant, ΔI ON =ΔI OFF holds. Therefore, Equation (1) is obtained. (2×V IN -V OUT ) / L×t ON =(V OUT -V IN ) / L×t OFF …(1)

[0052] When the duty cycle d is d=t ON / (t ON +t OFF ) is set as such, Equation (2) is obtained. V OUT =(1 + d)·V IN

[0053] That is, by changing the duty cycle d in the range of 0 to 1, the output voltage V OUT is adjusted from V IN to 2×VIN It can be changed between them, and a boosting operation can be realized.

[0054] The above is the operation of the switching converter 100A. Next, its advantages will be described.

[0055] Referring to FIG. 1. When comparing the switching converter 100A with a general buck converter (Buck converter), in the general buck converter, the switching voltage V at one end of the inductor L1 SW is switched between 0V and V IN , while in the switching converter 100A of FIG. 1, the switching voltage V SW is switched between V IN and 2×V IN . The switching converter 100A can be understood as replacing the high-side transistor (switching transistor) and the low-side transistor (synchronous rectifier transistor) of the buck converter with the switching circuit 110A. That is, the switching converter 100A can boost the voltage, but its circuit topology is the same as that of the buck converter, and thus it does not have an RHPZ. This makes phase compensation easier when designing the controller IC200A. That is, the feedback circuit 230 in FIG. 1 can be configured in the same way as the feedback circuit of the buck converter.

[0056] Also, in a normal boost converter (Boost converter), the closer the boost ratio is to 1, the higher the efficiency, but in the switching converter 100A, the efficiency is higher when the boost ratio is close to 2 times. Therefore, when operating at a boost ratio close to 2, the efficiency can also be improved compared with the conventional boost converter.

[0057] (Embodiment 2) FIG. 5 is a circuit diagram of a switching converter 100B according to Embodiment 2. The switching converter 100B boosts or buck-boosts the input voltage V of the input line 102 IN and outputs the boosted or buck-boosted output voltage V to the output line 104 OUTis generated. The switching converter 100B includes a flying capacitor C1, an output capacitor C2, an inductor L1, first to fifth switches SW1 to SW5, resistors R1 and R2, and a controller IC (Integrated Circuit) 200B.

[0058] The inductor L1 is connected between the switching node SW and the output line 104. The output capacitor C2 is connected to the output line 104.

[0059] The switching circuit 110B includes the first to fifth switches SW1 to SW5 and the flying capacitor C1. The switching circuit 110B has a configuration in which the fourth switch SW4 and the fifth switch SW5 are added to the switching circuit 110A of FIG. 1. The first switch SW1 and the second switch SW2 are connected in series between the input line 102 and the ground line 106. The third switch SW3 and the fourth switch SW4 are connected between the input line 102 and the switching node SW. The fifth switch SW5 is connected between the switching node SW and the ground line 106. The flying capacitor C1 is connected between both ends of the third switch SW3 and the first switch SW1. In the present embodiment, the first to fifth switches SW1 to SW5 are N-channel MOSFETs.

[0060] The controller IC200B drives the first to fifth switches SW1 to SW5 and generates a switching voltage V IN that takes two voltage levels of 0V and 2×V SW at the switching node SW.

[0061] For example, the controller IC200B alternately repeats the first state φ1 and the second state φ2. · First state φ1 First switch SW1, fourth switch SW4: OFF Second switch SW2, third switch SW3, fifth switch SW5: ON · Second state φ2 First switch SW1 and fourth switch SW4: ON Second switch SW2, third switch SW3, and fifth switch SW5: OFF

[0062] Controller IC200B includes a drive circuit 210B, a state control unit 220B, and a feedback circuit 230, and is a functional IC integrated on a single semiconductor substrate. The gate pins G1 to G5 of controller IC200B are connected to the gates of the first switch SW1 to the fifth switch SW5. Also, a feedback signal V OUT corresponding to the output voltage V FB of the switching converter 100B is fed back to the feedback pin FB of controller IC200B. Resistors R1 and R2 divide the output voltage V OUT to generate a feedback signal V FB .

[0063] Resistors R1 and R2 may be integrated into controller IC200B. Also, the plurality of switches SW1 to SW5 may be integrated into controller IC200B.

[0064] The state control unit 220B generates control signals S1 to S5 that define the on and off states of the first switch SW1 to the fifth switch SW5, and controls the state of the switching converter 100B.

[0065] The drive circuit 210B drives the first switch SW1 to the fifth switch SW5 according to the outputs S1 to S5 of the state control unit 220B. The drive circuit 210B includes three drivers Dr1 to Dr5.

[0066] The feedback circuit 230 controls the time ratio of the first state φ1 and the second state φ2 so that the error between the feedback signal V FB and the reference voltage V REF approaches zero. The feedback circuit 230 can be configured in the same way as a general DC / DC converter.

[0067] The above is the configuration of the switching converter 100B. Subsequently, its operation will be described.

[0068] Figure 6 is an equivalent circuit diagram of the first state φ1 of the switching converter 100B in FIG. 5. In the first state φ1, the second switch SW2, the third switch SW3, and the fifth switch SW5 are on, and the first switch SW1 and the fourth switch SW4 are off. In the first state φ1, V SW = 0V, and the flying capacitor C1 is charged by the input voltage V IN . That is, the voltage Vc across both ends of the flying capacitor C1 is equal to the input voltage V IN .

[0069] The voltage ΔV L1 across both ends of the inductor L1 in the first state φ1 is ΔV L1 = -V OUT , resulting in a negative voltage. Therefore, the current I L of the inductor L1 decreases with time at a slope of (-V OUT ) / L.

[0070] Figure 7 is an equivalent circuit diagram of the second state φ2 of the switching converter 100B in FIG. 5. In the second state φ2, the second switch SW2, the third switch SW3, and the fifth switch SW5 are off, and the first switch SW1 and the fourth switch SW4 are on. In the second state φ2, V SW = 2 × V IN .

[0071] The voltage ΔV L2 across both ends of the inductor L1 in the second state φ2 is ΔV L2 = 2 × V IN - V OUT , resulting in a positive voltage. Therefore, the current I L of the inductor L1 increases with time at a slope of (2 × V IN - V OUT ) / L.

[0072] Figure 8 is an operation waveform diagram of the switching converter 100B in FIG. 5. In FIG. 8, the coil current I flowing through the inductor L1L is shown. In the second state φ2, the coil current I L increases. When the time of the second state φ2 is t ON , the increase amount ΔI L of the coil current I ON is ΔI ON =(2×V IN -V OUT ) / L×t ON as follows.

[0073] In the first state φ1, the coil current I L decreases. When the time of the first state φ1 is t OFF , the decrease amount ΔI L (absolute value) of the coil current I OFF is ΔI OFF =|-V OUT | / L×t OFF =V OUT / L×t OFF as follows.

[0074] In the steady state, when the average value of the coil current I L is constant, ΔI ON =ΔI OFF holds. Therefore, Equation (3) is obtained. (2×V IN -V OUT ) / L×t ON =V OUT / L×t OFF …(3)

[0075] When the duty cycle d is d=t ON / (t ON +t OFF ) then Equation (4) is obtained. V OUT =2d·V IN

[0076] That is, by changing the duty cycle d in the range of 0 to 1, the output voltage V OUTis changed between 0 and 2×V IN and the buck-boost operation can be realized.

[0077] The above is the operation of the switching converter 100B. Next, its advantages will be described.

[0078] Referring to FIG. 5, when comparing the switching converter 100B with a general buck converter (Buck converter), in the general buck converter, the switching voltage V at one end of the inductor L1 SW switches between 0V and V IN while in the switching converter 100B of FIG. 5, the switching voltage V SW switches between 0V and 2×V IN . The switching converter 100B can be understood as replacing the high-side transistor (switching transistor) and the low-side transistor (synchronous rectifier transistor) of the buck converter with the switching circuit 110B. That is, the switching converter 100B can perform buck-boost operation, but its circuit topology is the same as that of the buck converter, and thus it does not have an RHPZ. This makes phase compensation easier when designing the controller IC200B. That is, the feedback circuit 230 in FIG. 5 can be configured in the same way as the feedback circuit of the buck converter.

[0079] Also, in a normal buck-boost converter (Buck-Boost converter), the closer the boost ratio is to 1, the higher the efficiency, but in the switching converter 100B, the efficiency is higher when the boost ratio is close to 2 times. Therefore, when operating at a boost ratio close to 2, the efficiency can also be improved compared to the conventional buck-boost converter.

[0080] (Modification example) The above-described embodiments are examples, and those skilled in the art will understand that various modifications are possible for the combination of each of these constituent elements and each processing process. Hereinafter, such modification examples will be described.

[0081] In Embodiment 1, the controller IC200A switches the switching circuit 110A between the first state φ1 and the second state φ2 alternately, but the present disclosure is not limited thereto. For example, in a light load state, in addition to the first state φ1 and the second state φ2, a three-state switching among the first state φ1, the second state φ2, and the third state φ3 may be performed. In the third state φ3, all the switches SW1 to SW3 are off.

[0082] In Embodiment 2, the controller IC200B switches the switching circuit 110B between the first state φ1 and the second state φ2 alternately, but the present disclosure is not limited thereto. For example, in a light load state, in addition to the first state φ1 and the second state φ2, a three-state switching among the first state φ1, the second state φ2, and the third state φ3 may be performed. In the third state φ3, all the switches SW1 to SW5 are off.

[0083] In Embodiment 1 or Embodiment 2, although the plurality of switches SW1 to SW5 are constituted by transistors, some of the switches may be diodes.

[0084] (Application) FIG. 9 is a diagram showing an example of an electronic device 700 including the switching converter 100. The electronic device 700 includes an internal circuit 710 and a power supply circuit 720. The internal circuit 710 may include a CPU (Central Processing Unit), a memory, an interface circuit for a LAN (Local Area Network), and the like. The power supply circuit 710 boosts (or steps down) the input voltage V IN and supplies it to the internal circuit 710. The above-described buck-boost converter 100 can be used as the power supply circuit 720.

[0085] The electronic device 700 is not limited to a server, and may be an in-vehicle device. Alternatively, the electronic device 700 may be an industrial device, an OA (Office Automation) device, or a consumer device such as an audio device.

[0086] Embodiments are examples, and it is understood by those skilled in the art that there are various variations in each of the constituent elements and combinations of each processing process, and such variations are also included in the present disclosure and can constitute the scope of the present invention.

Explanation of Signs

[0087] 100 Switching Converter 102 Input Line 104 Output Line 106 Ground Line 110 Switching Circuit 200 Controller IC 210 Drive Circuit 220 State Control Unit 230 Feedback Circuit SW1 First Switch SW2 Second Switch SW3 Third Switch SW4 Fourth Switch SW5 Fifth Switch C1 Flying Capacitor C2 Output Capacitor L1 Inductor

Claims

1. An input line, An output line, A ground line, A switching node, An inductor connected between the switching node and the output line, An output capacitor connected to the output line, A flying capacitor, A first switch having one end connected to the input line and the other end connected to the first end of the flying capacitor, A second switch having one end connected to the first end of the flying capacitor and the other end directly connected to the ground line, A third switch having one end connected to the input line and the other end connected to the second end of the flying capacitor, A fourth switch having one end connected to the second end of the flying capacitor and the other end connected to the switching node, A fifth switch having one end connected to the switching node and the other end directly connected to the ground line, A controller circuit for driving the first switch to the fifth switch, A switching converter comprising the same.

2. The controller circuit is configured to: A first state in which the first switch and the fourth switch are off, and the second switch, the third switch, and the fifth switch are on; A second state in which the first switch and the fourth switch are on, and the second switch, the third switch, and the fifth switch are off; The switching converter according to claim 1, wherein the first state and the second state are alternately repeated.

3. The first switch to the fifth switch according to claim 1 or 2 are N-channel MOSFETs.

4. A controller circuit of a switching converter, The switching converter includes: An input line, An output line, A ground line, A switching node, An inductor connected between the switching node and the output line, An output capacitor connected to the output line, A flying capacitor, A first switch having one end connected to the input line and the other end connected to the first end of the flying capacitor, A second switch having one end connected to the first end of the flying capacitor and the other end directly connected to the ground line, A third switch having one end connected to the input line and the other end connected to the second end of the flying capacitor, A fourth switch having one end connected to the second end of the flying capacitor and the other end connected to the switching node, A fifth switch having one end connected to the switching node and the other end directly connected to the ground line, is provided, The controller circuit includes a first state in which the first switch and the fourth switch are off, and the second switch, the third switch, and the fifth switch are on, and a second state in which the first switch and the fourth switch are on, and the second switch, the third switch, and the fifth switch are off, and a state control unit that alternately repeats these states, A drive circuit that drives the first switch to the fifth switch in response to the output of the state control unit, A controller circuit comprising.

5. The controller circuit according to claim 4, which is integrally integrated on one semiconductor substrate.

6. A switching converter comprising the controller circuit according to claim 4 or 5.

7. An electronic device comprising the switching converter according to any one of claims 1, 2, and 6.

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