Control circuit and interleaved power supply

Abstract

A control circuit according to the present invention is provided with a load state determination unit (120) that outputs load state information determined on the basis of an error amplifier output voltage to an interleaving signal generation unit (170), an on-trigger generation unit (130) that outputs the load state information to the interleaving signal generation unit (170), a gate control unit (150) that controls the on-trigger generation unit (130), and a drive unit (160) that drives the on-trigger generation unit (130). A turn-on trigger generation unit (130) generates a turn-on trigger and outputs the turn-on trigger to a gate control unit (150), and an interleaving signal generation unit (170) outputs, to a sub-converter (30), an interleaving signal including information on whether to stop sub-switch control circuits (200a, 200b) on the basis of load state information and control signal output information. According to the control circuit of the present invention, the load can be monitored without increasing the number of terminals or depending on the cycle of the AC power supply, new components and wiring are not required, and switching can be easily performed on whether the sub-converter is stopped or not when the load is light without increasing the number of terminals.

Description

TECHNICAL FIELD

[0001] The present application relates to a control circuit and an interleaved power supply. BACKGROUND

[0002] This application claims priority based on Japanese Patent Application No. 2023-170201 filed on September 29, 2023, the entire contents of which are incorporated herein by reference.

[0003] In the past, in a critical type interleaved power supply that controls a PFC circuit by a multi-stage converter, an interleaved power supply that monitors a load state and stops stages other than a first stage at a light load to improve conversion efficiency is known (for example, refer to Patent Literature 1).

[0004] The interleaved power supply described in Patent Literature 1 includes three converters (a main converter and two sub-converters) each having an inductor, a switch, and a rectifier. The interleaved power supply described in Patent Literature 1 monitors a load state based on information on the input side (for example, an inductor current, an input voltage, an input current, etc.) or information on the output side (for example, an output voltage, an output current, etc.), and at a light load, only the main converter is made to operate.

[0005]

Prior Art Documents

[0006]

Patent Literature 1

[0007] However, (1) in the case of the interleaved power supply described in Patent Literature 1, in the case of monitoring a load state based on information on the input side (for example, an inductor current, an input voltage, an input current, etc.), in order to monitor the load state, an additional terminal for transmitting an automatic stop signal to an additional circuit and a control circuit of a sub-converter is required. In addition, in the case of having a plurality of sub-converters and having a control circuit in each converter, an automatic stop signal of a sub-converter needs to be transmitted between adjacent converters, and thus an additional terminal is required. Therefore, in these cases, since the number of terminals of the control circuit of the main converter increases, there is a problem that a large size, a design change, and the like can occur.

[0008] Further, (2) in the interleaved power supply described in Patent Literature 1, in the case of monitoring a load state based on information on the input side (for example, an inductor current, an input voltage, an input current, etc.), according to the cycle of an alternating current power supply (particularly, when the input voltage reaches a valley), there is a possibility that a sub-converter is unintentionally stopped even though it is a heavy load. Therefore, a control circuit that monitors a load regardless of the cycle of the alternating current power supply is required.

[0009] On the other hand, (3) in the interleaved power supply described in Patent Document 1, in the case where the load state is monitored based on the information on the output side (for example, output voltage, output current, and the like), the information on the output side needs to be converted and input to the control circuit, and therefore in this case, in order to obtain the information on the output side, new components and wiring are required, and thus the circuit structure becomes complicated.

[0010] Further, (4) in the case where the fluctuation is reduced at the time of light load or in the case where the load suddenly changes from light load to heavy load, there are cases where it is not intended to intentionally stop the sub-converter, and therefore an interleaved power supply capable of easily switching whether the sub-converter is stopped at the time of light load is required. However, in this case, a circuit for switching whether the sub-converter is stopped needs to be additionally provided, and the number of terminals of the control circuit of the main converter increases.

[0011] Therefore, the present application is achieved in view of the above-described circumstances, and aims to provide a control circuit which (1) is not likely to cause adverse circumstances such as an increase in the number of terminals of the control circuit of the main converter, an increase in size, a need for design change, and the like, (2) is capable of monitoring a load without depending on the period of an alternating-current power supply, (3) does not need new components and wiring for obtaining information on the output side, and is not likely to cause a complicated circuit structure, and (4) is capable of easily switching whether the sub-converter is stopped at the time of light load without increasing the number of terminals of the control circuit of the main converter. Further, the present application aims to provide an interleaved power supply having such a control circuit. SUMMARY

[0012] The control circuit of the present application is used to control an interleaved power supply having: a main converter having a main switch that performs switching operation; and a sub-converter having a sub-switch that performs switching operation in a state having a phase difference with respect to the switching operation of the main switch, the main converter and the sub-converter constituting a master-slave relationship, the switching operation of the sub-switch of the interleaved power supply, characterized in that: the control circuit includes: a load state determination section that determines a load state based on an error amplifier output voltage generated based on an output voltage, outputs the determined load state information to an interleaving signal generation section, a conduction trigger generation section that generates a conduction trigger and outputs it to a gate control section, the gate control section that outputs a control signal having a conduction width calculated based on the error amplifier output voltage to the drive section with a predetermined phase difference based on the conduction trigger, and outputs control signal output information to the interleaving signal generation section, the drive section that performs conduction / cutoff of the main switch based on the control signal, and the interleaving signal generation section that outputs an interleaving signal to the sub-converter based on the load state information and the control signal output information, the interleaving signal containing information of whether to stop a sub-switch control circuit that controls the switching operation of the sub-switch.

[0013] The interleaved power supply of the present application has: a main converter having a main switch that performs switching operation; and a sub-converter having a sub-switch that performs switching operation in a state having a phase difference with respect to the switching operation of the main switch, the main converter and the sub-converter constituting a master-slave relationship, characterized in that: a main switch control circuit for controlling the switching operation of the main switch is the control circuit of any one of claims 1 to 4, which outputs an interleaving signal containing information of whether to stop a sub-switch control circuit that controls the switching operation of the sub-switch to the sub-switch control circuit, and the sub-switch control circuit determines whether to stop the sub-switch control circuit based on an interleaving input signal when the interleaving signal is input to the sub-switch control circuit.

[0014] Effects of the Invention

[0015] According to the control circuit and the interleaved power supply of the present application, since the interleaving signal generation section outputs an interleaving signal containing information of whether to stop a sub-switch control circuit that controls the switching operation of the sub-switch to the sub-switch control circuit based on the load state information and the control signal output information, it is possible to prevent the occurrence of adverse situations such as an increase in the number of terminals of the control circuit of the main converter, resulting in an increase in size, or an increase in the number of terminals requiring a change in design.

[0016] In addition, since it is possible to determine whether to stop the sub-switch control circuit by the interleaving signal even when a plurality of sub-converters are provided and each of the converters has a control circuit, it is possible to not provide a terminal for transmitting an automatic stop signal of the sub-converters between adjacent converters. Therefore, it is possible to not increase the number of terminals of the sub-switch control circuit.

[0017] Further, according to the control circuit and the interleaved power supply of the present application, since the load state determining section generates the load state information based on the error amplifier output voltage generated based on the output voltage and outputs the load state information to the interleaving signal generating section, it is possible to determine the load state without depending on the period of the alternating current power supply. Therefore, it is possible to prevent the sub-converters from being stopped unintentionally regardless of the heavy load, as in the case of monitoring the load state based on the information on the input side (for example, the inductor current, the input voltage, the input current, and the like), and it is a control circuit capable of monitoring the load without depending on the period of the alternating current power supply.

[0018] According to the control circuit and the interleaved power supply of the present application, since the load state determining section determines the load state based on the error amplifier output voltage generated based on the output voltage, outputs the determined load state information to the interleaving signal generating section, and the interleaving signal generating section outputs the interleaving signal containing the information of the sub-switch control circuit that controls the switching operation of the sub-switch based on the load state information and the control signal output information to the sub-switch control circuit (the sub-converter), it is possible to use the error amplifier output voltage for correcting the on-width in the past for determining whether to stop the switching control circuit. Therefore, it is not necessary to additionally provide a new component and a wiring for acquiring the information on the output side, and it is possible to prevent the circuit structure from being complicated.

[0019] According to the control circuit and the interleaved power supply of the present application, since the interleaving signal generating section outputs the interleaving signal containing the information of the sub-switch control circuit that controls the switching operation of the sub-switch based on the load state information and the control signal output information to the sub-switch control circuit, it is possible to easily switch whether to stop the sub-converter by adjusting the interleaving signal even when the load is light, as in the case of reducing the ripple or the case of suddenly changing from the light load to the heavy load, or even when it is not intended to intentionally stop the sub-converter. In addition, it is not necessary to additionally provide a circuit for switching whether to stop the sub-converter, and the number of terminals of the control circuit of the main converter is not increased. Therefore, it is possible to easily switch whether to stop the sub-converter when the load is light without increasing the number of terminals of the control circuit of the main converter. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a circuit diagram of the interleaved power supply 1 of Embodiment 1.

[0021] Figure 2is a block diagram for explaining the main switch control circuit 100 (Leader) according to Embodiment 1.

[0022] Figure 3 is a graph for explaining the automatic stop function of the slave converter 30 (Follower) of Embodiment 1. Figure 3 (a) is a timing chart of the Leader and the Follower, Figure 3 (b) is a schematic view showing the relationship between the interleaved signal IL_OUT, the interleaved input signal IL_IN, and the interleaved signal detection threshold voltage VIL_IN1. In addition, each waveform is schematically illustrated, and the value of the high level between different waveforms is not consistently constant. For example, the Leader IL_OUT and the interleaved input signal IL_IN of the Follower appear to have the same high level voltage value, but actually, since the interleaved input signal IL_IN of the Follower divides the signal after the interleaved signal IL_OUT of the Leader, the voltage value of the high level of the Leader IL_OUT is smaller.

[0023] Figure 4 is a circuit diagram of the interleaved power supply 2 related to Modified Example 1.

[0024] Figure 5 is a graph for explaining the operation of the slave converter 30 (Follower) of Modified Example 1. Figure 5 (a) is a timing chart of the Leader and the Follower, Figure 5 (b) is a schematic view showing the relationship between the interleaved signal IL_OUT, the interleaved input signal IL_IN, and the interleaved signal detection threshold voltage VIL_IN1.

[0025] Figure 6 is a graph for explaining the automatic stop function of the slave converter 30 (Follower) of Embodiment 2. Figure 6 (a) is a timing chart of the Leader and the Follower, Figure 6 (b) is a schematic view showing the relationship between the interleaved signal IL_OUT, the interleaved input signal IL_IN, the interleaved signal detection threshold voltage VIL_IN1, and the interleaved operation stop threshold voltage VIL_IN1_stop.

[0026] Figure 7 is a graph for explaining the operation of the slave converter 30 (Follower) of Modified Example 2. Figure 7 (a) is a timing chart of the Leader and the Follower, Figure 7 (b) is a schematic view showing the relationship between the interleaved signal IL_OUT, the interleaved input signal IL_IN, the interleaved signal detection threshold voltage VIL_IN1, and the interleaved operation stop threshold voltage VIL_IN1_stop.

[0027] Figure 8is a diagram showing the relationship between the COMP voltage and the load state of Embodiment 3. Figure 8 (a) is a diagram showing the relationship between the COMP voltage and the load state determination threshold voltage, Figure 8 (b) is a timing chart showing the relationship between the COMP voltage, the gate output voltage OUT, and the interleaved signal IL_OUT.

[0028] Figure 9 is a diagram showing the relationship between the high-level voltage value of the interleaved signal of the master (IL_OUT threshold value) VIL_OUT, the high-level voltage value of the interleaved input signal (IL_IN generation voltage) IL_IN, the interleaved signal detection threshold voltage (IL_IN threshold value) VIL_IN1, VIL_IN2, the high-level voltage value of the follower interleaved signal (IL_OUT threshold value) VIL_OUT1, and VIL_OUT2 in Embodiment 3.

[0029] Figure 10 is a diagram showing the automatic stop function of the sub-converters 30, 40 (followers 1, 2) of Embodiment 3. Figure 10 (a) is a timing chart of the master and the followers, Figure 10 (b) is a diagram for explaining the operation of the master, the follower 1, and the follower 2 in a heavy load state.

[0030] Figure 11 is a diagram showing the automatic stop function of the sub-converters 30, 40 (followers 1, 2) of Embodiment 3. Figure 11 (a) is a diagram for explaining the operation of the master, the follower 1, and the follower 2 in a light load state 1, Figure 10 (b) is a diagram for explaining the operation of the master, the follower 1, and the follower 2 in a light load state 2.

[0031] Figure 12 is a diagram of the automatic stop function of the sub-converters 30, 40 (followers 1, 2) of Modification 3.

[0032] Figure 13 is a diagram of the automatic stop function of the sub-converters 30, 40 (followers 1, 2) of Modification 3. Figure 13 (a) is a timing chart of the master and the followers, Figure 13 (b) is a diagram showing the relationship between the interleaved signal and the interleaved input signal IL_IN and the threshold voltage of the master, the follower 1, and the follower 2.

[0033] Figure 14 is a circuit diagram of the interleaved power supply 2 of Embodiment 4.

[0034] Figure 15is a schematic diagram of the interleaved signals of the master, the follower 1 and the follower 2 and the relationship between the interleaved input signal IL_IN and the threshold voltage of Embodiment 4.

[0035] Figure 16 is a graph of the automatic stop function of the slave converter 30, 40 (follower 1, 2) of Embodiment 4. Figure 16 (a) is a schematic diagram for explaining the automatic stop function of the master, the follower 1 and the follower 2 in a heavy load state, Figure 16 (b) is a schematic diagram for explaining the automatic stop function of the master, the follower 1 and the follower 2 in a light load state 2, Figure 16 (c) is a schematic diagram for explaining the automatic stop function of the master, the follower 1 and the follower 2 in a light load state 1.

[0036] Figure 17 is a schematic diagram of the interleaved signals of the master, the follower 1 and the follower 2 and the relationship between the interleaved input signal IL_IN and the threshold voltage of Embodiment 5.

[0037] Figure 18 is a graph of the automatic stop function of the slave converter 30, 40 (follower 1, 2) of Embodiment 5. Figure 18 (a) is a schematic diagram for explaining the automatic stop function of the master, the follower 1 and the follower 2 in a heavy load state, Figure 18 (b) is a schematic diagram for explaining the automatic stop function of the master, the follower 1 and the follower 2 in a light load state 2, Figure 18 (c) is a schematic diagram for explaining the automatic stop function of the master, the follower 1 and the follower 2 in a light load state 1.

[0038] Figure 19 is a block diagram for explaining the master switch control circuit 101 (master) of Embodiment 6.

[0039] Figure 20 is a schematic diagram for explaining the load state determination threshold voltages Vcomp1 and Vcomp2 of Embodiment 6.

[0040] Figure 21 is a circuit diagram of the input voltage monitoring circuit of Embodiment 6, Figure 21 (a) and Figure 21 (b) are example diagrams of the input voltage monitoring circuit.

[0041] Figure 22 is a block diagram of the master switch control circuit 100a involved in the modification example 3. DETAILED DESCRIPTION

[0042] The following describes the control circuit and the interleaved power supply of the present application based on Embodiment 1 shown in the drawings. The embodiments described below do not limit the application of the appended claims. In addition, not all of the elements and combinations thereof described in the embodiments are essential to the solution means of the present application.

[0043] [Embodiment 1]

[0044] 1. Embodiment 1 relates to the structure of the interleaved power supply 1

[0045] The interleaved power supply 1 of Embodiment 1 is an interleaved power supply in which a plurality of converters are connected in multiple stages. As shown in FIG. 1, the interleaved power supply 1 includes a rectifying circuit 10, a main converter 20 having a main switch Ql that performs a switching operation, sub-converters 30, 40 having sub-switches Q2, Q3 that perform switching with a phase difference with respect to the switching operation of the main switch Ql, and an output capacitor C3. Figure 1

[0046] In the interleaved power supply 1, the main converter 20 and the sub-converters 30, 40 are connected in parallel between the rectifying circuit 10 and the output capacitor C3, and a master-slave relationship is established between the main converter 20 and the sub-converters 30, 40.

[0047] The rectifying circuit 10 has, for example, a bridge diode BD and a smoothing capacitor C2 that full-wave rectify an alternating current of a commercial power supply and make it into a pulsating current.

[0048] (1) Structure of the main converter 20

[0049] The main converter 20 (main director) includes an inductor LI, an auxiliary winding L4, a main switch Ql, a diode DI, and a main switch control circuit 100 (corresponding to the control circuit of the present application), and constitutes a boost chopper circuit with the inductor LI, the main switch Ql, and the diode DI.

[0050] The main switch Ql is a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) in Embodiment 1, but can also be an IGBT, and other appropriate switching elements can also be used. The inductor LI can use an appropriate inductor, and the diode DI can also use an appropriate diode. The same applies to the sub-switches Q2, Q3, the inductors L2, L3, and the diodes D2, D3 described later.

[0051] As shown in FIG. 2 and FIG. 3, the main switch control circuit 100 outputs a control signal that controls the main switch Ql to the gate of the main switch Ql, and outputs an interleaving signal to the sub-converters 30. The main switch control circuit 100 has eight terminals, a Vcc terminal, an OUT terminal, a GND terminal, a ZC terminal, an OCL terminal, an IL_OUT terminal, a COMP terminal, and an FB terminal. Figure 1 Figure 2 As shown in FIG. 2 and FIG. 3, the main switch control circuit 100 outputs a control signal that controls the main switch Ql to the gate of the main switch Ql, and outputs an interleaving signal to the sub-converters 30. The main switch control circuit 100 has eight terminals, a Vcc terminal, an OUT terminal, a GND terminal, a ZC terminal, an OCL terminal, an IL_OUT terminal, a COMP terminal, and an FB terminal.​​

[0052] The Vcc terminal is connected to the external power supply Vcc, receiving power from Vcc. The OUT terminal is connected to the gate electrode of the main switch Q1, outputting a signal to the gate electrode to control the on / off state of the main switch Q1. The GND terminal is grounded.

[0053] The ZC terminal is connected to the auxiliary winding L4 and detects the current IL flowing through the inductor L1.

[0054] The OCL terminal is connected to resistor R3 and capacitor C7, and is connected via resistor R3 to the source of main switch Q1 and the midpoint of resistor R2. The OCL terminal is used to monitor whether there is overcurrent flowing in main switch Q1 by monitoring the voltage determined by resistor R2. The IL_OUT terminal is connected to the IL_IN terminal on the secondary switch control circuit 200a (follower).

[0055] The COMP terminal is connected to the output terminal of the error amplifier 110, which is connected to capacitor C6. The main switch control circuit 100 uses the voltage at the COMP terminal to determine the conduction width of the main switch Q1 and control the gate output voltage. The FB terminal is connected to capacitor C5 and resistors R4 and R5. The voltage obtained by dividing the output voltage through resistors R4 and R5 is input to the FB terminal.

[0056] Next, the internal structure of the main switch control circuit 100 will be described.

[0057] like Figure 2 As shown, the main switch control circuit 100 (the main power supply) includes an error amplifier (FB_Amp) 110, a load state determination unit 120, a conduction trigger generation unit 130, a conduction width calculation unit 140, a gate control unit 150, a drive unit 160, and an interleaved signal generation unit 170. Additionally, although not shown, it includes an overvoltage detection unit (not shown), which detects whether the output voltage of the interleaved power supply 1 is overvoltage by comparing whether the FB voltage at the FB terminal is greater than a predetermined value.

[0058] Error amplifier 110 compares the output voltage with the voltage divided by resistors R4 and R5 and a reference voltage to detect the error, and determines the charging and discharging current of capacitor C6 at the COMP terminal based on this error. In this way, the COMP terminal voltage (COMP voltage) is determined, and the conduction width is determined to keep the output voltage constant.

[0059] The load status determination unit 120 generates load status information based on the error amplifier output voltage (COMP voltage) generated by dividing the output voltage Vo, and outputs it to the interleaved signal generation unit 170.

[0060] The load state determination section 120 determines the load state based on whether the error amplifier output voltage (COMP voltage) exceeds the load state determination threshold voltages Vcomp1, Vcomp2 (refer to FIG. 2) (a). Specifically, the load state determination section 120 determines that the load is light when the COMP voltage is lower than the load state determination threshold voltage Vcomp1, and determines that the load returns to heavy when the COMP voltage recovers and exceeds Vcomp2. The load state determination threshold voltage Vcomp2 when the COMP voltage increases is larger than the load state determination threshold voltage Vcomp1 when the COMP voltage decreases. Figure 3

[0061] The on trigger generation section 130 generates an on trigger and outputs it to the gate control section 150.

[0062] The on width calculation section 140 calculates the on width of the main switch Ql based on the COMP voltage to maintain the output voltage constant, and outputs it to the gate control section 150 as on width information. Specifically, the on width of the main switch Ql is determined by the charge / discharge voltage of the capacitor C6 connected to the COMP terminal which is the error amplifier output voltage terminal. In the on width calculation section 140, it is preferable to make the inductor current IL large in the heavy load state, and therefore the on width is widened by making the capacitor voltage high. On the other hand, in the light load state, the inductor current IL can not be increased, and therefore the on width is narrowed by lowering the COMP voltage.

[0063] The gate control section 150 outputs a control signal having an on width calculated based on the COMP voltage to the drive section 160 with a prescribed phase difference based on the on trigger, and outputs control signal output information synchronized with the control signal to the interleaved signal generation section 170.

[0064] The drive section 160 outputs a switching pulse for turning on / off the main switch Ql to the gate electrode of the main switch Ql via the gate output terminal OUT based on the control signal from the gate control section 150.

[0065] The interleaved signal generation section 170 outputs an interleaved signal to the sub-switch control circuits 200a, 200b based on the load state information and the control signal output information. The interleaved signal contains information on whether to stop the sub-switch control circuits 200a, 200b (follower 1, follower 2) which control the switching operation of the sub switches Q2, Q3.

[0066] ​The interleaved signal generation section 170 has an interleaved output voltage adjustment section that outputs, as information for stopping the sub-switch control circuits 200a and 200b, an interleaved signal IL_OUT whose voltage value at the time of outputting a high level to the sub-switch control circuit 200a is adjusted. Specifically, an interleaved signal whose voltage value at the time of outputting a high level when the light load state is determined is adjusted to be lower than the voltage value at the time of outputting a high level when the heavy load state is determined is output to the sub-switch control circuit 200a.

[0067] The interleaved signal is synchronized with the control signal, and the voltage value of the high level at the time of the heavy load is the same as the voltage value of the high level of the control signal.

[0068] (2) Structure of the sub-converter 30 and the sub-switch control circuit 200a

[0069] The sub-converter 30 includes the inductor L2, the auxiliary winding L5, the sub-switch Q2, the diode D2, and the sub-switch control circuit 200a, and constitutes a boost chopper circuit with the inductor L2, the sub-switch Q2, and the diode D2.

[0070] The sub-switch control circuit 200a is a control circuit that controls the switching operation of the sub-switch Q2.

[0071] The sub-switch control circuit 200a basically has the same structure as the main switch control circuit 100, but differs in that the IL_IN terminal is provided instead of the FB terminal of the main switch control circuit 100, the IL_OUT terminal is provided instead of the COMP terminal, and the VIS terminal that is not connected to any part is provided instead of the IL_OUT terminal.

[0072] The IL_IN terminal of the sub-switch control circuit 200a is connected to the resistors R9 and R10 and the capacitor C11. The resistor R9 is arranged between the IL_IN terminal and the IL_OUT terminal of the main switch control circuit 100, and the interleaved signal is divided by the resistors R9 and R10 to be input to the IL_IN terminal.

[0073] The secondary switch control circuit 200a determines whether to stop based on the interleaved input signal IL_IN (the interleaved signal IL_OUT is the signal divided by resistors R9 and R10) when the interleaved signal IL_OUT is input to the secondary switch control circuit 200a. Specifically, when the high-level voltage value of the interleaved input signal IL_IN is greater than the specified interleaved signal detection threshold voltage VIL_IN1, the secondary converter 30 performs normal interleaving operation; when the high-level voltage value of the interleaved input signal IL_IN is less than the specified interleaved signal detection threshold voltage VIL_IN1, the secondary converter 30 stops the interleaving operation. When the interleaving operation is stopped, the secondary converter 30 does not output the gate output voltage OUT and the interleaved signal (see reference). Figure 3 The follower's gate output voltage OUT and interleaved signal IL_OUT).

[0074] (3) Structure of the secondary converter 40 and the secondary switch control circuit 200b

[0075] The secondary converter 40 includes an inductor L3, an auxiliary winding L6, a secondary switch Q3, a diode D3, and a secondary switch control circuit 200b. The inductor L3, secondary switch Q3, and diode D3 form a boost chopper circuit. The secondary converter 40 and secondary switch control circuit 200b have the same structure as the secondary converter 30 and secondary switch control circuit 200a, except that they do not have the IL_OUT terminal connected to the interleaved output signal.

[0076] The secondary switch control circuit 200b determines whether to stop based on the interleaved input signal IL_IN (the interleaved signal is the signal after IL_OUT is divided by resistors R14 and R15) when the interleaved signal IL_OUT is input to the secondary switch control circuit 200b.

[0077] Specifically, when the high-level voltage of the interleaved input signal IL_IN is greater than the specified interleaved signal detection threshold voltage, the sub-converter 40 performs normal interleaving operation; when the high-level voltage of the interleaved input signal IL_IN is less than the specified interleaved signal detection threshold voltage, the sub-converter 40 stops interleaving operation. The interleaved signal detection threshold voltage of the sub-switch control circuit 200b can be the same as or different from the interleaved signal detection threshold voltage VIL_IN1 of the sub-switch control circuit 200a.

[0078] 2. Embodiment 1 relates to the operation of the control circuit 100 and the interleaved power supply 1

[0079] Next, based on Figure 3 The operation of the control circuit 100 and the alternating power supply 1 involved in Embodiment 1 will be explained. For the sake of simplicity, the explanation will focus on the main converter 20 (master converter) and the sub-converter 30 (follower converter).

[0080] (1) Heavy load state

[0081] When the COMP voltage of the master controller exceeds the load state determination threshold voltage VCOMP1 (refer to Figure 3 (a) comp voltage), the load state determination section 120 determines that it is a heavy load state. When the COMP voltage is constant, the gate output voltage OUT is turned on and off at a constant cycle, and when the COMP voltage decreases, the on width of the gate output voltage OUT and the interleaved signal IL_OUT become short corresponding to the voltage value of the COMP voltage.

[0082] The cycle of the interleaved signal IL_OUT is synchronized with the gate output voltage OUT. The voltage value of the high level is VIL1.

[0083] In Embodiment 1, the interleaved signal IL_OUT output from the master controller is Figure 1 divided by the voltage dividing circuit composed of resistors R9 and R10 of the sub-converter 30, and input via the IL_IN terminal of the sub-switching control circuit 200a. Therefore, the voltage value of the high level of the interleaved input signal IL_IN is VIL1_D (refer to Figure 3 (b) of Embodiment 1).

[0084] In the heavy load state, the high level voltage value VIL_D of the interleaved input signal IL_IN is higher than the interleaved signal detection threshold voltage VIL_IN1, and the follower (sub-converter 30) continues the interleaved operation.

[0085] The gate output voltage OUT of the follower rises at the timing when the interleaved input signal IL_IN is turned off, and decreases after the on state continues for the same period as the period when the interleaved input signal IL_IN is turned on. Therefore, the cycle is shifted, and the interleaved operation is performed. Also, the interleaved signal IL_OUT is generated, and the interleaved signal IL_OUT is output to the sub-converter 40 of the subsequent stage.

[0086] (2) Light load state

[0087] When the COMP voltage of the master controller is below the load state determination threshold voltage VCOMP1, and the COMP voltage is in the recovery phase and does not exceed the load state determination threshold voltage Vcomp2 (refer to Figure 3 (a) comp voltage), the load state determination section 120 determines that it is a light load state. During this period, the gate output voltage OUT is repeatedly turned on and off at a prescribed cycle, although the on width is shorter than that in the heavy load case.

[0088] In addition, the load state determination threshold voltage Vcomp2 is higher than the load state determination threshold voltage Vcomp1.

[0089] The stagger signal IL_OUT is synchronized with the gate output voltage OUT. As information of whether or not to stop the sub-switch control circuit 200a, the stagger signal generation section 170 outputs the stagger signal to the sub-switch control circuit 200a, which is adjusted to have a voltage value of a high level lower when the light load state is determined than when the heavy load state is determined.

[0090] That is, in the light load state, the stagger signal IL_OUT output to the follower is adjusted to have a voltage value of VIL2 lower than VIL1 when the heavy load state is determined.

[0091] As in the case of the heavy load state, the stagger signal IL_OUT output from the leader is divided by the voltage division circuit composed of resistors R9 and R10 of the sub-converter 30, and is input via the IL_IN terminal of the sub-switch control circuit 200a. Therefore, the voltage value of the high level of the stagger input signal IL_IN is divided, and the voltage value of the high level is VIL2_D (see (b) of FIG. 10). Figure 3

[0092] In the light load state, the voltage value VI2_D of the high level of the stagger input signal IL_IN is smaller than the stagger signal detection threshold voltage VIL_IN1. Therefore, in the follower (sub-converter 30), the gate output voltage OUT goes to the low level, and thus the follower stops the stagger operation. In addition, the stagger signal IL_OUT goes to the low level, and the stagger operation of the sub-converter (follower, in Embodiment 1, the sub-converter 40) after the next stage also stops.

[0093] (3) Heavy load state

[0094] The COMP voltage of the leader rises again, and when the load state determination threshold voltage Vcomp2 or more, the load state determination section 120 determines the heavy load state. The operation proceeds in the same manner as in the above (1) heavy load state, and the follower starts the stagger operation again.

[0095] 3. Embodiment 1 relates to the effects of the control circuit 100 and the interleaved power supply 1

[0096] ​According to the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the sub-switch Q2 is generated by the interleaved signal generation section 170 based on the load state information and the control signal output information, and the interleaved signal including information of whether or not to stop the sub-switch control circuit 200a, 200b for controlling the switching operation of Q3 is output to the sub-switch control circuit 200a (sub-converter 30), it is not necessary to provide a terminal for transmitting the automatic stop signal to the sub-switch control circuit 200a in the control circuit 100. Therefore, it is possible to prevent the number of terminals of the control circuit 100 of the main converter 20 from increasing and the size from becoming large, or the number of terminals from increasing and the design from being changed, and the like.

[0097] In addition, since it is possible to determine whether or not to stop the sub-converters 30, 40 by the interleaved signal even in the case where a plurality of sub-converters are provided and the control circuit is provided in each of the converters, it is not necessary to provide a terminal for transmitting the automatic stop signal of the sub-converters between the adjacent converters. Therefore, it is possible to prevent the number of terminals of the sub-switch control circuit 200a, 200b from increasing.

[0098] Further, according to the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the load state information is generated by the load state determination section 120 based on the error amplifier output voltage (COMP voltage) generated based on the output voltage and is output to the interleaved signal generation section 170, it is possible to determine the load state independently of the period of the AC power supply. Therefore, it is possible to prevent the sub-converters from being stopped unintentionally regardless of the heavy load, as in the case where the load state is monitored based on the information on the input side (for example, the inductor current, the input voltage, the input current, and the like), and it is a control circuit capable of monitoring the load independently of the period of the AC power supply.

[0099] In addition, according to the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the load state information is determined by the load state determination section 120 based on the error amplifier output voltage (COMP voltage) generated based on the output voltage, and is output to the interleaved signal generation section 170, and the interleaved signal including information of whether or not to stop the sub-switch control circuit 200a, 200b for controlling the switching operation of the sub-switches Q2, Q3 is output to the sub-switch control circuit 200a based on the load state information and the control signal output information, it is possible to use the output voltage (COMP voltage) of the error amplifier for correcting the on-width in the past for determining whether or not to stop the sub-switch control circuit 200a, 200b. Therefore, it is possible to prevent the circuit structure from becoming complicated without providing an additional component and a wiring for acquiring the information on the output side.

[0100] In addition, according to the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the interleaved signal generation section 170 outputs the interleaved signal including information on whether to stop the sub-switch control circuits 200a, 200b including the switching operation of the control sub-switches Q2, Q3 to the sub-switch control circuits 200a, 200b based on the load state information and the control signal output information, it is possible to easily switch whether to stop the sub-converters 30, 40 by adjusting the interleaved signal even in a case where it is not intended to stop the sub-converters 30, 40 as in a case of alleviating fluctuation or a case of suddenly changing from a light load to a heavy load. In addition, it is not necessary to additionally provide a circuit for switching whether to stop the sub-converters 30, 40, and the number of terminals of the control circuit 100 of the main converter 20 is not increased. Thus, it is possible to simply switch whether to stop the sub-converters in a light load without increasing the number of terminals of the control circuit 100 of the main converter.

[0101] In addition, according to the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the interleaved signal generation section 170 outputs the interleaved signal in which the voltage value of the high level in a light load is adjusted to the sub-switch control circuits 200a, 200b as information on whether to stop the sub-switch control circuits 200a, 200b, it is possible to convey whether to stop the interleaved operation of the sub-converters by changing the voltage value of the high level of the interleaved signal without increasing the number of terminals of the control circuit 100 of the main converter 20.

[0102] In addition, according to the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the interleaved signal generation section 170 outputs the interleaved signal in which the voltage value of the high level in a light load is adjusted to a voltage value lower than the voltage value of the high level in a heavy load to the sub-switch control circuits 200a, 200b as information on whether to stop the sub-switch control circuits 200a, 200b, it is possible to simply convey whether to stop the interleaved operation of the sub-converters 30, 40 to the sub-converters 30, 40 by simply suppressing the voltage value of the high level to be lower.

[0103] In addition, when the interleaved operation of the sub-converters 30, 40 is stopped, the COMP voltage rises due to an increase in the load of the main converter 20, and thus it is difficult to correctly determine the load state, and it is likely that the stop of the follower is unintentionally released. In contrast, according to the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the load state determination threshold voltage Vcomp2 when the error amplifier output voltage increases is greater than the load state determination threshold voltage Vcomp1 when the error amplifier output voltage decreases, the load state determination section 120 is able to accurately determine the load state even in a case where the interleaved operation of the sub-converters 30, 40 is stopped and the COMP voltage rises due to an increase in the load of the main converter 20, and thus it is possible to prevent the stop of the follower from being unintentionally released.

[0104] According to the interleaved power supply 1 according to Embodiment 1, since the sub-converters 30, 40 have the voltage dividing circuit (resistors R9 and R10, resistors R14 and R15) that divides the voltage of the interleaved signal IL_OUT, it is possible to adjust whether to stop the sub-switch control circuit that controls the switching operation of the sub-switch.

[0105] According to the interleaved power supply 1 according to Embodiment 1, since the sub-converters 30, 40 have the voltage dividing circuit (resistors R9 and R10, resistors R14 and R15) that divides the voltage of the interleaved signal IL_OUT, it is possible to adjust whether to stop the sub-switch control circuit that controls the switching operation of the sub-switch.

[0106] According to the interleaved power supply 1 according to Embodiment 1, since the sub-converters 30, 40 have the voltage dividing circuit (resistors R9 and R10, resistors R14 and R15) that divides the voltage of the interleaved signal IL_OUT, it is possible to adjust whether to stop the sub-switch control circuit that controls the switching operation of the sub-switch.

[0107] [Modified Example 1]

[0108] The control circuit and the interleaved power supply 2 according to Modified Example 1 basically have the same structure as the control circuit 100 and the interleaved power supply 1 according to Embodiment 1, but are different from the control circuit 100 and the interleaved power supply 1 according to Embodiment 1 in that the automatic stop of the sub-converters is not performed. As shown in FIG. 10, in the sub-converters 30, 40 of the interleaved power supply 2 according to Modified Example 1, the resistors R10, R15 present in Embodiment 1 are deleted, and the voltage dividing circuit is not provided. Figure 4

[0109] (1) Heavy load state

[0110] The control circuit and the interleaved power supply 2 according to Modified Example 1 perform substantially the same operation as in Embodiment 1, but the interleaved signal IL_OUT output from the master follower is not divided. Therefore, the voltage value of the high level of the interleaved input signal IL_IN input to the follower becomes VIL1 (see (a) and (b) of FIG. 11). Figure 5 (a) and Figure 5 (b).

[0111] Since the voltage value VIL1 of the high level of the interleaved input signal IL_IN is higher than the interleaved signal detection threshold voltage VIL_IN1, the follower (sub-converter 30) continues the interleaving operation.

[0112] (2) Light load state

[0113] Even in the light load state, the interleaved signal IL_OUT output from the master follower is not divided. Therefore, the voltage value of the high level of the interleaved input signal IL_IN input to the follower is VIL2.​

[0114] Since the high level voltage value VIL2 of the interleaved input signal IL_IN is larger than the interleaved signal detection threshold voltage VIL_IN1, the follower (sub-converter 30) continues the interleaving operation. In this way, by inputting the interleaved signal to the sub-converter 30 (follower) without voltage division, the sub-converter can be continued without stopping even in a light load.

[0115] In this way, although the control circuit and the interleaved power supply 2 of the modified example 1 differ from the control circuit 100 and the interleaved power supply 1 of the embodiment 1 in that the automatic stop of the sub-converter is not performed, like the control circuit 100 and the interleaved power supply 1 of the embodiment 1, since the load determination section generates the load state information based on the error amplifier output voltage generated based on the output voltage and outputs to the interleaved signal generation section, and the interleaved signal generation section outputs the interleaved signal including the information of the sub-switch control circuit which controls the switching operation of the sub-switch whether to stop to the sub-switch control circuit based on the load state information and the control signal output information, (1) the increase in the number of terminals of the control circuit of the main converter and the increase in the size or the change in the design due to the increase in the number of terminals of the control circuit of the main converter are less likely to occur, (2) the load can be monitored without depending on the period of the alternating current power supply, (3) a new component and wiring for acquiring the information on the output side are not required, and the circuit structure is less likely to become complicated, and (4) whether to stop the sub-converter in a light load can be switched easily without increasing the number of terminals of the control circuit of the main converter.

[0116] Further, according to the control circuit 100 and the interleaved power supply 2 of the modified example 1, since VIL1 > VIL2 > VIL_IN1 is satisfied, the sub-converter can be continued without stopping even in a light load.

[0117] In addition, as is clear from the embodiment 1 and the modified example 1, since VIL1 > VIL2 > VIL_IN1 is satisfied, VIL1_D > VIL_IN1 is satisfied, and VIL2_D < VIL_IN1 is satisfied, not only whether to maintain the interleaving operation of the sub-converter in a light load state can be selected, but also whether to maintain the interleaving operation in a light load state can be determined by a simple change such as incorporating or not incorporating the voltage division circuit. Therefore, it is a control circuit with high versatility.

[0118] In addition, since the control circuit 100 and the interleaved power supply 2 involved in the modified example 1 have the same structure as the control circuit 100 and the interleaved power supply 1 involved in the embodiment 1 except that the automatic stop of the sub-converter is not performed, the same effects as the control circuit 100 and the interleaved power supply 1 involved in the embodiment 1 are obtained.

[0119]

Embodiment 2

[0120] The control circuit and interleaved power supply involved in Embodiment 2 have basically the same structure as the control circuit 100 and interleaved power supply 1 involved in Embodiment 1, but they differ from the control circuit 100 and interleaved power supply 1 involved in Embodiment 1 in that the voltage value of the high level of the interleaved signal in the light load state is higher than the voltage value of the high level in the heavy load state.

[0121] like Figure 4 As shown, the control circuit and interleaved power supply (not shown) of Embodiment 2 have the same circuit structure as the interleaved power supply 2 in Modified Example 1. That is, the sub-converters 30 and 40 do not have voltage divider circuits.

[0122] The follower provides an interleaved signal detection threshold voltage VIL_IN1 and an interleaved action stop threshold voltage VIL_IN1_stop for interleaving the input signal IL_IN. It determines whether to stop the secondary switch control circuit based on whether the high-level voltage value of the interleaved input signal IL_IN is within the range from the specified interleaved signal detection threshold voltage VIL_IN1 to the specified interleaved action stop threshold voltage VIL_IN1_stop.

[0123] (1) Heavy load condition

[0124] The control circuit and interleaved power supply involved in Embodiment 2 operate essentially the same as in Embodiment 1, but the high-level voltage value of the interleaved signal IL_OUT is VIL1. Furthermore, since no voltage division is performed, the high-level voltage value of the interleaved input signal input to the follower remains VIL1 (see reference). Figure 6 (a) and Figure 6 (b)).

[0125] Because the high-level voltage VIL1 of the interleaved input signal IL_IN is within the range from the interleaved signal detection threshold voltage VIL_IN1 to the specified interleaved operation stop threshold voltage VIL_IN1_stop, the follower maintains interleaved operation. That is, the output gate output voltage OUT is maintained, and the interleaved signal is output to the next stage converter.

[0126] (2) Light load condition

[0127] Even under light load conditions, the interleaved signal IL_OUT output from the master circuit is not divided. Therefore, the high-level voltage of the interleaved input signal IL_IN input to the follower is VIL2.

[0128] Since the high-level voltage value VIL2 of the interleaved input signal IL_IN is greater than the interleaved operation stop threshold voltage VIL_IN1_stop, the follower (sub-converter 30) stops the interleaved operation. That is, the gate output voltage OUT becomes low, and the interleaved signal is not output to the next stage converter.

[0129] As such, although the control circuit and the interleaved power supply of Embodiment 2 differ from the control circuit 100 and the interleaved power supply 1 of Embodiment 1 in that the voltage value of the high level of the interleaved signal in the light load state is higher than that in the heavy load state, like the control circuit 100 and the interleaved power supply 1 of Embodiment 1, (1) the number of terminals of the control circuit of the main converter does not easily increase, and the size does not easily become large, the number of terminals does not easily increase, and design change is not required, (2) the load is monitored regardless of the period of the alternating current power supply, (3) a new component and a wiring for acquiring the output side information are not required, and the circuit structure does not easily become complex, and (4) the number of terminals of the control circuit of the main converter does not increase, and whether or not the sub-converter stops can be easily switched in the light load state.

[0130] Further, according to the control circuit and the interleaved power supply of Embodiment 2, since the interleaved signal generation section 170 outputs the interleaved signal whose voltage value VIL2 of the high level when the light load state is determined is higher than the voltage value VIL1 of the high level when the heavy load state is determined to the sub-switch control circuit 200a as information whether or not to stop the sub-switch control circuit 200a, 200b, the interleaved operation of the follower can be stopped in the light load state without the voltage dividing circuit.

[0131] Further, since the control circuit and the interleaved power supply according to Embodiment 2 have the same structure as the control circuit 100 and the interleaved power supply 1 of Embodiment 1 except that the voltage value of the high level of the interleaved signal in the light load state is higher than that in the heavy load state, the control circuit 100 and the interleaved power supply 1 of Embodiment 1 also have the same effects.

[0132]

Modified Example 2

[0133] The control circuit and the interleaved power supply according to Modified Example 2 basically have the same structure as the control circuit and the interleaved power supply of Embodiment 2, but differ from the control circuit and the interleaved power supply of Embodiment 2 in that the automatic stop of the sub-converter is not performed. The sub-converter 30, 40 of the interleaved power supply according to Modified Example 2 has the same structure as the sub-converter 30, 40 of Embodiment 2. Figure 1 Like the interleaved power supply 1 of Embodiment 1 illustrated in FIG. 1, the interleaved power supply according to Modified Example 2 has the voltage dividing circuit.

[0134] (1) Heavy load state

[0135] When the heavy load state is determined, the voltage value of the high level of the interleaved signal IL_OUT output from the master controller is VIL1 (refer to Figure 7 (a) and Figure 7 (b). In Modification 2, since the interleaved input signal IL_IN is divided, the voltage value of the high level of the interleaved input signal IL_IN input to the follower becomes VIL1_D (refer to Figure 7 (b).

[0136] Since the high level voltage value VIL1_D of the interleaved input signal IL_IN is larger than the interleaved signal detection threshold voltage VIL_IN1 and smaller than the interleaved action stop threshold voltage VIL_IN1_stop, the follower (the slave converter 30) maintains the interleaved action.

[0137] (2) Light load state

[0138] Even in the light load state, the interleaved signal IL_OUT output from the master controller is divided. Therefore, the voltage value of the high level of the interleaved input signal IL_IN input to the follower is VIL2_D.

[0139] Since the high level voltage value VIL2_D of the interleaved input signal IL_IN is larger than the interleaved signal detection threshold voltage VIL_IN1 and smaller than the interleaved action stop threshold voltage VIL_IN1_stop, the follower (the slave converter 30) maintains the interleaved action.

[0140] As such, by dividing the interleaved signal to the slave converter 30 (the follower), the slave converter can be maintained without being stopped even in the light load state.

[0141] As such, although the control circuit and the interleaved power supply of Modification 2 are different from those of Embodiment 2 in that the automatic stop of the slave converter is not performed, like the control circuit and the interleaved power supply of Embodiment 1, (1) the increase in the number of terminals of the control circuit of the master converter does not easily cause the increase in the size or the increase in the number of terminals requiring the design change and the like, (2) the load can be monitored without depending on the period of the alternating current power supply, (3) a new component and wiring for acquiring the information on the output side are not required, and the circuit structure is not easily complicated, and (4) whether the slave converter is stopped or not can be switched easily at the light load without increasing the number of terminals of the control circuit of the master converter.

[0142] In addition, according to the control circuit and the interleaved power supply of Modification 2, since VIL_IN1_stop > VIL1_D > VIL_IN1 and VIL_IN1_stop > VIL2_D > VIL_IN1 are satisfied, the slave converter can be maintained without being stopped even at the light load.

[0143] In addition, as is apparent from Embodiment 2 and Modified Example 2, by satisfying VIL1 > VIL_IN1_stop > VIL2 > VIL_IN1, and satisfying VIL_IN1_stop > VIL1_D > VIL_IN1, and satisfying VIL_IN1_stop > VIL2_D > VIL_IN1, not only can it be selected whether to maintain the sub-converter interleaving operation in the light load state, but also it can be determined whether to maintain the interleaving operation in the light load state by a simple change of embedding or not embedding the voltage dividing circuit in the converter. Therefore, it is a control circuit having high versatility.

[0144] In addition, since the control circuit and the interleaving power supply of Modified Example 2 have the same structure as the control circuit and the interleaving power supply of Embodiment 2 except for the point that the automatic stop of the sub-converter is not performed, it has the effects corresponding to the effects possessed by the control circuit and the interleaving power supply of Embodiment 2.

[0145]

Embodiment 3

[0146] Embodiment 3 relates to a control circuit and an interleaving power supply which basically have the same structure as the control circuit 100 and the interleaving power supply 1 of Embodiment 1, but differ from the control circuit 100 and the interleaving power supply 1 of Embodiment 1 in that three load state are acquired by the load state determination.

[0147] The circuit structure of the control circuit and the interleaving power supply (not shown) of Embodiment 3 is the same as that of Embodiment 1. That is, the sub-converters 30, 40 are provided with voltage dividing circuits. Figure 1

[0148] In the load state determination section 120 of the follower, four load state determination threshold voltages Vcomp1, Vcomp2, Vcomp3, Vcomp4 are set for the error amplifier output voltage (COMP voltage) (refer to FIG. 12 (a)). Figure 8 (a)). The load state determination threshold voltages Vcomp1, Vcomp3 are threshold voltages for determining the load state when the comp voltage becomes small, and the load state determination threshold voltages Vcomp2, Vcomp4 are threshold voltages for determining the load state when the comp voltage becomes large.

[0149] The magnitude relationship between the load state determination threshold voltages Vcomp1, Vcomp2, Vcomp3, Vcomp4 is Vcomp1 < Vcomp2 < Vcomp3 < Vcomp4.

[0150] ​When the COMP voltage becomes small, the COMP voltage is determined to be in the heavy load state when it exceeds Vcomp3, and in the light load state 2 when it is equal to or smaller than Vcomp3 and exceeds Vcomp1. When the COMP voltage is equal to or smaller than Vcomp1, the COMP voltage starts to recover but is lower than Vcomp2, and is determined to be in the light load state 1. Also, when the COMP voltage becomes large, the COMP voltage is determined to be in the light load state 2 when it is equal to or larger than Vcomp2 and lower than Vcomp4, and in the heavy load state when it is equal to or larger than Vcomp4.

[0151] In Embodiment 3, the high level voltage value of the stagger signal is changed based on the load state. That is, the high level voltage value of the stagger signal is VIL1 in the heavy load state, VIL3 in the light load state 2, and VIL2 in the light load state 1. Also, the magnitude relation of each voltage value is VIL1 > VIL3 > VIL2.

[0152] The sub-switch control circuit (follower) is provided with a first stagger signal detection threshold voltage VIL_IN1 and a second stagger signal detection threshold voltage VIL_IN2 lower than the first stagger signal detection threshold voltage VIL_IN1 (see Figure 9 ).

[0153] When the stagger input signal IL_IN is equal to or larger than the first stagger signal detection threshold voltage VIL_IN1, the stagger operation is continued, and the high level voltage value is the same as that of the stagger signal IL_OUT output from the reader.

[0154] When the stagger input signal IL_IN is smaller than the first stagger signal detection threshold voltage VIL_IN1 and equal to or larger than the second stagger signal detection threshold voltage VIL_IN2, the stagger operation is continued, but the output high level voltage value is lower than that of the stagger signal IL_OUT output from the master.

[0155] When the stagger input signal IL_IN is smaller than the second stagger signal detection threshold voltage VIL_IN2, the stagger operation is stopped.

[0156] (1) Heavy load state

[0157] The high level voltage value of the stagger signal IL_OUT output from the master is VIL1, and since a voltage dividing circuit is provided in the sub-converter 30, the high level voltage value of the stagger input signal IL_IN input to the follower becomes VIL1_D (see Figure 9 and Figure 10 (a).

[0158] Since the voltage value VIL1_D of the high level of the interleaved input signal IL_IN exceeds the first interleaved signal detection threshold voltage VIL_IN1, the slave converter 30 continues the interleaving operation and outputs a voltage value VIL_OUT1 of the same level as the voltage value of the high level of the interleaved signal IL_OUT output from the master to the slave converter 40.

[0159] In the follower 2 (the slave converter 40), the voltage value of the high level of the interleaved signal IL_OUT output from the follower 1 is VIL_OUT1 (refer to Figure 10 ). Then, since this voltage is divided and input, the voltage value of the high level of the interleaved input signal IL_IN of the follower 2 is VIL_OUT1_D (refer to Figure 10 (b)).

[0160] Since the value of VIL_OUT1_D exceeds the first interleaved signal detection threshold voltage VIL_IN1, the slave converter 40 continues the interleaving operation and outputs a voltage value VIL_OUT1 of the same level as the voltage value of the high level of the interleaved signal IL_OUT output from the master to the slave converter 40.

[0161] (2) Light load state 2

[0162] In the light load state, the voltage value of the high level of the interleaved signal IL_OUT output from the master is VIL3, and in the embodiment 3, a voltage dividing circuit is provided in the slave converter 30, and thus the voltage value of the high level of the interleaved input signal VIL_IN of the input follower is VIL3_D (refer to Figure 9 and Figure 10 (a)).

[0163] The voltage value VIL3_D of the high level of the interleaved input signal IL_IN is not more than the first interleaved signal detection threshold voltage VIL_IN1 and not less than the second interleaved signal detection threshold voltage VIL_IN2.

[0164] In this case, the slave converter 30 continues the interleaving operation and outputs an interleaved signal IL_OUT of a voltage value VIL_OUT2 of a high level lower than the voltage value of the high level of the interleaved signal IL_OUT output from the master to the slave converter 40 (refer to Figure 11 (a)).

[0165] In the follower 2 (the slave converter 40), since the interleaved signal IL_OUT output from the follower 1 is divided and input, the voltage value of the high level of the interleaved input signal of the follower 2 becomes VIL_OUT2_D (refer to Figure 11 (b)).

[0166] Since the high level voltage value of the interleaved input signal to the follower 2 is lower than the first and second interleaved signal detection threshold voltages VIL_IN1 and VIL_IN2 of the follower 2, the interleaving operation of the follower 2 is stopped.

[0167] Therefore, in the light load state 2, the main converter 20 and the sub-converters 30 can be operated, and a part of the plurality of sub-converters (the sub-converter 40) can be stopped.

[0168] (3) Light load state 1

[0169] In the light load state 1, the voltage value of the high level of the interleaved signal IL_OUT output from the master is VIL2. In the embodiment 3, since the voltage dividing circuit is provided in the sub-converter 30, the voltage value of the high level of the interleaved input signal IL_IN input to the follower 1 is VIL2_D (refer to Figure 9 and Figure 10 (a).

[0170] The voltage value VIL2_D is lower than the first and second interleaved signal detection threshold voltages VIL_IN1 and VIL_IN2. In this case, the sub-converter 30 gate output voltage OUT and the interleaved signal IL_OUT are low, and the interleaving operation is stopped (refer to Figure 11 (b).

[0171] In the follower 2 (the sub-converter 40), since the interleaved signal IL_OUT is not output from the follower 1, the follower 2 is not turned on.

[0172] Therefore, in the light load state 2, only the main converter 20 can be operated and all of the plurality of sub-converters can be stopped.

[0173] As such, although the control circuit and the interleaved power supply according to Embodiment 3 set three load states in the load state determination, like the control circuit 100 and the interleaved power supply 1 according to Embodiment 1, since the load determination section generates the load state information based on the error amplifier output voltage generated based on the output voltage and outputs to the interleaved signal generation section, and the interleaved signal generation section outputs the interleaved signal including the information of the sub-switch control circuit including whether to stop the switching operation of the sub-switch to the sub-switch control circuit based on the load state information and the control signal output information, (1) the number of terminals of the control circuit of the main converter does not easily increase and the size does not easily increase, or the number of terminals increases and the design needs to be changed, and the like, (2) the load can be monitored without depending on the period of the alternating current power supply, (3) a new component and wiring for acquiring the information on the output side are not needed, and the circuit structure does not easily become complicated, and (4) whether to stop the sub-converters at the light load can be easily switched without increasing the number of terminals of the control circuit of the main converter.

[0174] According to the control circuit and the interleaved power supply according to Embodiment 3, by adopting the above structure, all of the sub-converters can be stopped at the light load state 1, and all of the sub-converters or a prescribed number of sub-converters among the plurality of sub-converters can be stopped at the light load state 2.

[0175] In addition, the control circuit and the interleaved power supply according to Embodiment 3 have the same structure as the control circuit 100 and the interleaved power supply 1 according to Embodiment 1 except for the point that three load states are set in the load state determination, and thus have the effects of the control circuit 100 and the interleaved power supply 1 according to Embodiment 1.

[0176]

Variation 3

[0177] The control circuit and the interleaved power supply according to Variation 3 basically have the same structure as the control circuit and the interleaved power supply according to Embodiment 3, but differ from the control circuit and the interleaved power supply according to Embodiment 3 in that the automatic stop of the sub-converters is not performed.

[0178] The control circuit and the interleaved power supply according to Variation 3 have the same circuit configuration as the control circuit and the interleaved power supply according to Embodiment 3, and Figure 4 like the control circuit and the interleaved power supply according to Embodiment 1, the voltage dividing circuit is not formed in the sub-converters 30 and 40.

[0179] In the heavy load state, the voltage value of the high level of the interleaved signal IL_OUT output from the master director is VIL1, in the light load state 2, it is VIL3, and in the light load state 1, it is VIL2. The magnitude relationship of the respective voltage values is VIL1 > VIL3 > VIL2 (see FIG. 6). Figure 12 .

[0180] In Modification 3, since neither of the sub-converters 30, 40 forms a voltage dividing circuit, the interleaved input signal IL_IN input to the sub-converters 30 is the same as the interleaved output signal. The high level voltage values VIL1, VIL3, VIL2 of the interleaved input signal IL_IN are all higher than the first interleaved signal detection threshold voltage VIL_IN1 and the second interleaved signal detection threshold voltage VIL_IN2. Therefore, the sub-converters 30 continue the interleaved operation regardless of the load state (see FIG. 6). Figure 12 and Figure 13 ).

[0181] In addition, since the voltage values VIL1, VIL3, VIL2 are all higher than the first interleaved signal detection threshold voltage VIL_IN1 and the second interleaved signal detection threshold voltage VIL_IN2, the voltage values of the high level of the interleaved signal output to the sub-converters 40 are all voltage values close in size to the voltage value VIL1. Therefore, the sub-converters 40 (the sub-converters in the case where the sub-converters are connected) also continue the interleaved operation.

[0182] As such, although the control circuit and the interleaved power supply of Modification 3 differ from the control circuit and the interleaved power supply of Embodiment 3 in that the automatic stop of the sub-converters is not performed, like the control circuit and the interleaved power supply of Embodiment 3, since the load determination section generates the load state information based on the error amplifier output voltage generated based on the output voltage and outputs the load state information to the interleaved signal generation section, and the interleaved signal generation section outputs the interleaved signal including the information of whether to stop the switching operation of the sub-switch control circuit of the sub-switches to the sub-switch control circuit based on the load state information and the control signal output information, (1) the increase in the number of terminals of the control circuit of the main converter and the increase in the size or the change in the design due to the increase in the number of terminals of the control circuit of the main converter are less likely to occur, (2) the load can be monitored without depending on the period of the alternating current power supply, (3) a new component and a new wiring for acquiring the information on the output side are not required, and the circuit structure is less likely to become complicated, and (4) the sub-converters can be switched on and off at the time of light load without increasing the number of terminals of the control circuit of the main converter.

[0183] According to the control circuit and the interleaved power supply of Modification 3, by adopting the above-described configuration, the interleaved operation can be maintained regardless of the load state.

[0184] In addition, the control circuit and the interleaved power supply of Modification 3 have the same structure as the control circuit and the interleaved power supply of Embodiment 3 except for the point that the automatic stop of the sub-converters is not performed, and thus have effects corresponding to the effects of the control circuit and the interleaved power supply of Embodiment 3.

[0185]

Embodiment 4

[0186] Embodiment 4 relates to a control circuit and interleaved power supply 3 having substantially the same structure as the control circuit and interleaved power supply of Embodiment 3, but differs from the control circuit and interleaved power supply of Embodiment 3 in that the sub-converter 30 performs the automatic stop function of interleaved operation, and the sub-converter 40 does not perform the automatic stop of interleaved operation.

[0187] In the interleaved power supply 3 of Embodiment 3, the sub-converter 30 has a voltage dividing circuit composed of resistors R9 and R10, and the sub-converter 40 does not have a voltage dividing circuit (see Figure 14 ).

[0188] (1) Heavy load state

[0189] As in the case of Embodiment 3, the voltage value of the high level of the interleaved signal IL_OUT output from the master director is VIL1. In Embodiment 4, since the sub-converter 30 has a voltage dividing circuit, the voltage value of the high level of the interleaved input signal IL_IN input to the follower 1 (second stage) is VIL1_D (see Figure 15 ).

[0190] The voltage value VIL1_D is higher than the first interleaved signal detection threshold voltage VIL_IN1. Therefore, the follower 1 continues the interleaved operation, and outputs the interleaved signal IL_OUT of the high level voltage value VIL_OUT1 which is the same level as the voltage value of the high level of the interleaved signal IL_OUT of the master director to the follower 2 (see Figure 16 (a).

[0191] In Embodiment 4, since the sub-converter 40 does not have a voltage dividing circuit, the voltage value of the high level of the interleaved input signal IL_IN input to the follower 2 (third stage) remains VIL_OUT1. Since the voltage value VIL_OUT1 is higher than the first interleaved signal detection threshold voltage VIL_IN1, the follower 1 continues the interleaved operation.

[0192] In addition, assuming that the follower 3 of the fourth stage is provided, the interleaved signal IL_OUT of the high level voltage value VIL_OUT1 which is the same level as the voltage value of the high level of the interleaved signal IL_OUT of the master director is output.

[0193] (2) Light load state 2

[0194] As in Embodiment 3, the voltage value of the high level of the interleaved signal IL_OUT output from the master director is VIL3. In Embodiment 4, since the sub-converter 30 has a voltage dividing circuit, the voltage value of the high level of the interleaved input signal IL_IN input to the follower 1 (second stage) is VIL3_D (see Figure 15 ).

[0195] The voltage value VIL3_D is higher than the first cross signal detection threshold voltage VIL_IN1. Therefore, the follower 1 continues the cross operation and outputs the cross signal IL_OUT of the high level voltage value VIL_OUT1 which is the same level as the high level voltage value of the cross signal IL_OUT of the dominant to the follower 2 (third stage) (refer to Figure 16 (b).

[0196] In Embodiment 4, since the sub-converter 40 does not have the voltage dividing circuit, the voltage value of the high level of the cross input signal IL_IN input to the follower 2 (third stage) is maintained as VIL_OUT1. Since the voltage value VIL_OUT1 is higher than the first cross signal detection threshold voltage VIL_IN1, the follower 1 continues the cross operation.

[0197] In addition, assuming that the follower 3 of the fourth stage is provided, the cross signal IL_OUT of the high level voltage value VIL_OUT1 which is the same level as the high level voltage value of the cross signal IL_OUT of the dominant is output to the follower 3.

[0198] (3) Light load state 1

[0199] As in Embodiment 3, the high level voltage value of the cross signal IL_OUT output from the dominant is VIL2. In Embodiment 4, since the sub-converter 30 has the voltage dividing circuit, the voltage value of the high level of the cross input signal IL_IN input to the follower 1 (second stage) is VIL2_D (refer to Figure 15 ).

[0200] The voltage value VIL2_D is lower than the second cross signal detection threshold voltage VIL_IN2. Therefore, the follower 1 stops the cross operation and does not output the cross signal IL_OUT (refer to Figure 16 (c).

[0201] Since the cross signal is not output to the follower 2 (third stage), the follower 2 also stops the cross operation.

[0202] Therefore, in the heavy load state and the light load state 2, all the converters are caused to operate, but in the case of the light load state 1, only the main converter (dominant) can be caused to operate.

[0203] As such, while the control circuit and the interleaved power supply according to Embodiment 4 differ from the control circuit and the interleaved power supply according to Embodiment 3 in that the sub-converter 30 performs the automatic stop function of the interleaved operation and the sub-converter 40 does not perform the automatic stop of the interleaved operation, as with the control circuit and the interleaved power supply according to Embodiment 3, (1) the increase in the number of terminals of the control circuit of the main converter and the increase in the size or the change in the design due to the increase in the number of terminals of the control circuit of the main converter are less likely to occur, (2) the load can be monitored without depending on the period of the alternating current power supply, (3) a new component and wiring for acquiring information on the output side are not required and the circuit structure is less likely to become complicated, and (4) the switching of whether to stop the sub-converter at the light load can be easily performed without increasing the number of terminals of the control circuit of the main converter.

[0204] Further, according to the control circuit and the interleaved power supply according to Embodiment 4, since the above-described structure is employed, in the case of the light load state 1, the automatic stop of the sub-converter can be performed by only the main converter, and in the case of the heavy load state and the light load state 2, all the converters can perform the interleaved operation.

[0205] In addition, in the control circuit and the interleaved power supply according to Embodiment 4, the sub-converter 30 performs the automatic stop function of the interleaved operation, but the sub-converter 40 has the same structure as the control circuit and the interleaved power supply according to Embodiment 3 except for the point that the sub-converter 40 does not perform the automatic stop of the interleaved operation, and thus has the effects corresponding to the effects of the control circuit and the interleaved power supply according to Embodiment 3.

[0206]

Embodiment 5

[0207] The control circuit and the interleaved power supply according to Embodiment 5 basically have the same structure as the control circuit and the interleaved power supply according to Embodiment 4, but the operation in the light load state 2 differs from the control circuit and the interleaved power supply according to Embodiment 4. In addition, the operation in the heavy load state and the light load state 1 is the same as that according to Embodiment 4, and thus the description thereof is omitted.

[0208] As in Embodiment 4, in the light load state 2, the high-level voltage value of the interleaved signal IL_OUT output from the main director is VIL3. In Embodiment 4, since the sub-converter 30 has the voltage dividing circuit, the high-level voltage value of the interleaved input signal IL_IN input to the follower 1 (the second stage) is VIL3_D (see Figure 17 ).

[0209] The voltage value VIL3_D is lower than the second interleaved signal detection threshold voltage VIL_IN2. Therefore, the follower 1 stops the interleaved operation and does not output the interleaved signal IL_OUT (see Figure 18 (b).

[0210] Therefore, in the heavy load state, all the converters are made to act, but in the light load state 1 and the light load state 2, only the main converter (the leader) can be made to act.

[0211] In addition, in a case where the voltage value VIL3_D is higher than the second interleaved signal detection threshold voltage VIL_IN2 and lower than the first interleaved signal detection threshold voltage VIL_IN1, both the follower 1 and the follower 2 perform interleaved action.

[0212] As such, although the operation of the control circuit and the interleaved power supply in the light load state 2 according to the embodiment 5 is different from that of the control circuit and the interleaved power supply according to the embodiment 4, like the control circuit and the interleaved power supply according to the embodiment 4, since the load determination section generates the load state information based on the error amplifier output voltage generated based on the output voltage and outputs the load state information to the interleaved signal generation section, and the interleaved signal generation section outputs the interleaved signal including the information of the sub-switch control circuit including whether to stop the switching action of the control sub-switch to the sub-switch control circuit based on the load state information and the control signal output information, (1) the increase in the number of terminals of the control circuit of the main converter and the increase in the size or the change in the design due to the increase in the number of terminals of the control circuit of the main converter are less likely to occur, (2) the load can be monitored without depending on the period of the alternating current power supply, (3) a new component and a new wiring for acquiring the information on the output side are not required, and the circuit structure is less likely to become complicated, and (4) whether to stop the sub-converter at the time of light load can be switched easily without increasing the number of terminals of the control circuit of the main converter.

[0213] In addition, the control circuit and the interleaved power supply according to the embodiment 5 have the same structure as the control circuit and the interleaved power supply according to the embodiment 4 in terms of the operation other than the operation in the light load state 2, and thus have the effects corresponding to the effects of the control circuit and the interleaved power supply according to the embodiment 4.

[0214]

Embodiment 6

[0215] The control circuit 101 and the interleaved power supply according to the embodiment 6 basically have the same structure as the control circuit 100 and the interleaved power supply 1 according to the embodiment 1, but differ from the control circuit 100 and the interleaved power supply 1 according to the embodiment 1 in that the load state determination threshold voltage varies based on the input voltage.

[0216] In the embodiment 1, as described above, Figure 20(c) shown, load state determination threshold voltages Vcomp1, Vcomp2 that are independent of the input voltage are used, but in Embodiment 6, the load state determination threshold voltages Vcomp1, Vcomp2 are adjusted based on the input voltage. Specifically, adjustment is made by reducing the load state determination threshold voltages Vcomp1, Vcomp2 when the input voltage exceeds a prescribed input voltage threshold voltage (refer to Figure 20 (a)), or linearly reducing the load state determination threshold voltages Vcomp1, Vcomp2 as the input voltage increases (refer to Figure 20 (b)).

[0217] The load state determination section 120 is connected to the front stage or the rear stage of the rectifier circuit 10 via an input voltage monitoring terminal, and input voltage information after voltage division of the input voltage is input (refer to Figure 19 ). Specifically, voltage information after voltage division input to the input voltage monitoring terminal can be input from the two power supply lines connected to the power source AC-IN and the rectifier circuit 10 (refer to Figure 21 (a)), or the two power supply lines connected from the rectifier circuit 10 to the main converter 20, from which voltage information after voltage division input to the input voltage monitoring terminal is input.

[0218] As such, although Embodiment 6 differs from the case of the control circuit 100 and the interleaved power supply 1 of Embodiment 1 in that the load state determination threshold voltages vary based on the input voltage, as with the case of the control circuit 100 and the interleaved power supply 1 of Embodiment 1, since the load determination section generates load state information based on the error amplifier output voltage generated from the output voltage and outputs it to the interleaved signal generation section, and the interleaved signal generation section outputs an interleaved signal containing information of the sub-switch control circuit including whether or not to stop the switching action of the sub-switch control circuit based on the load state information and the control signal output information to the sub-switch control circuit, therefore, (1) it is less likely to cause the terminal number of the control circuit of the main converter to increase and become larger in size, or the terminal number to increase and require design changes and the like, (2) it is possible to monitor the load without depending on the period of the alternating current power supply, (3) it is not necessary to have new components and wiring for acquiring information on the output side, and the circuit structure is less likely to become complex, (4) it is possible to easily switch whether or not to stop the sub-converter at light load without increasing the terminal number of the control circuit of the main converter.

[0219] In the interleaved power supply, even at the same conduction width (COMP voltage), a large difference in output power occurs between the case of a high input voltage and the case of a low input voltage. In contrast, according to the control circuit and the interleaved power supply of Embodiment 6, the load state determination section 120 adjusts the load state determination threshold voltage based on the input voltage, and thus it is possible to reduce the difference in output power (load) for which the follower is determined to be stopped.

[0220] In addition, the control circuit and the interleaved power supply according to Embodiment 6 have the same structure as the control circuit 100 and the interleaved power supply 1 of Embodiment 1 except that the load state determination threshold voltage varies based on the input voltage, and thus have the effects of the control circuit 100 and the interleaved power supply 1 of Embodiment 1.

[0221] The present application has been described above based on each of the above embodiments, but the present application is not limited to the above Embodiment 1. It can be implemented in various ways without departing from the scope of the concept, and for example, the following modifications can also be made.

[0222] (1) The positions, connections, numbers, and the like described in each of the above embodiments (including each of the modified examples) are examples, and can be changed within a range that does not impair the effects of the present application.

[0223] (2) In each of the above embodiments, two sub-converters (three in total) are provided, but the present application is not limited to this. One sub-converter (two in total) can be provided, or three or more sub-converters (four or more in total) can be provided. In the case where three or more sub-converters (four or more in total) are provided, three or more interleaving signal detection threshold voltages can be provided in the sub-converters, and the second stage or later can be stopped, or the third stage or later can be stopped, and the number of converters having the automatic stop function can be appropriately determined.

[0224] (3) In each of the above embodiments, the load state is divided into a heavy load state, a light load state 1, and a light load state 2, but the present application is not limited to this. A light load state 3, a light load state 4, and the like can be more finely selected. In this case, the load state determination threshold voltage can be determined to be six or eight.

[0225] (4) In Embodiment 1 described above, the conduction trigger is output from the conduction trigger generating section 130 to the gate control section 150, not from the outside, but the present application is not limited to this. It can also be configured such that the main switch control circuit 100 further has a zero current detection section 180 that detects the timing at which the inductor current is zero current, the conduction trigger generating section generates the conduction trigger based on the timing detected by the zero current detection section 180, and outputs it to the gate control section 150, and the gate control section 150 outputs the control signal to the gate control section 150 at the timing at which the inductor current is zero current based on the conduction trigger (see the control circuit 100a of Modification 3, Figure 22 ). In this case, both the main converter 20 and the auxiliary converters 30, 40 perform current-critical operation.

[0226] (5) In Embodiment 1 described above, the critical point of the input current of the auxiliary converter is detected by detecting the choke coil current of the inductor using the auxiliary winding disposed opposite the inductor, but the present application is not limited to this. It can also be configured such that the critical point of the input current of the auxiliary converter is detected by detecting the zero voltage point based on the drain voltage of the main switch or the auxiliary switch.

[0227]

Explanation of Symbols

[0228] 1, 2, 3... interleaved power supply; 20... main converter; 30, 40... auxiliary converter; 100... main switch control circuit (main director); 200a, 200b... auxiliary switch control circuit (follower); 120... load state determination section; 130... conduction trigger generating section; 140... conduction width calculation section; 150... gate control section; 160... drive section; 170... interleaved signal generating section; Q1... main switch; Q2, Q3... auxiliary switch.

Claims

1. A control circuit for controlling an interleaved power supply having: a main converter having a main switch that performs switching operation; and a sub-converter having a sub-switch that performs switching operation in a state having a phase difference with respect to the switching operation of the main switch, the switching operation of the sub-switch of the sub-converter being controlled between the main converter and the sub-converter in a master-slave relationship, characterized by: the control circuit including: a load state determination section, an on trigger generation section, a gate control section, a drive section, and an interleaving signal generation section, wherein the load state determination section determines a load state based on an error amplifier output voltage generated based on an output voltage, and outputs load state information determined to the interleaving signal generation section, the on trigger generation section generates an on trigger and outputs to the gate control section, the gate control section outputs a control signal having an on width calculated based on the error amplifier output voltage to the drive section with a prescribed phase difference based on the on trigger, and outputs control signal output information to the interleaving signal generation section, the drive section performs on-off of the main switch based on the control signal, and the interleaving signal generation section outputs an interleaving signal to the sub-converter based on the load state information and the control signal output information, the interleaving signal containing information of whether to stop a sub-switch control circuit that controls the switching operation of the sub-switch.

2. The control circuit according to claim 1, characterized in that: the interleaving signal generation section outputs the interleaving signal with a voltage value at a high level adjusted as the information of whether to stop the sub-switch control circuit to the sub-switch control circuit.

3. The control circuit according to claim 2, characterized in that: the interleaving signal generation section outputs the interleaving signal as the information of whether to stop the sub-switch control circuit to the sub-switch control circuit, the interleaving signal being adjusted so that a voltage value of a high level when a light load state is determined is lower than a voltage value of a high level when a heavy load state is determined.

4. The control circuit according to claim 2, characterized in that: the interleaving signal generation section outputs the interleaving signal as the information of whether to stop the sub-switch control circuit to the sub-switch control circuit, the interleaving signal being adjusted so that a voltage value of a high level when a light load state is determined is higher than a voltage value of a high level when a heavy load state is determined.

5. The control circuit according to any one of claims 1 to 4, characterized in that: the load state determination section determines a load state based on whether the error amplifier output voltage exceeds a load state determination threshold voltage, and the load state determination threshold voltage when the error amplifier output voltage is increased is greater than the load state determination threshold voltage when the error amplifier output voltage is decreased.

6. The control circuit according to any one of claims 1 to 4, characterized in that: the load state determination section determines a load state based on whether the error amplifier output voltage exceeds a load state determination threshold voltage, and the load state determination threshold voltage when the error amplifier output voltage is increased is less than the load state determination threshold voltage when the error amplifier output voltage is decreased. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The load state determination section adjusts the load state determination threshold voltage based on an input voltage.

7. The control circuit according to any one of claims 1 to 4, characterized by Further comprising: a zero current detection section that detects a timing at which the inductor current becomes zero current, wherein the conduction trigger generation section generates the conduction trigger based on the timing detected by the zero current detection section and outputs the conduction trigger to the gate control section, the gate control section outputs the control signal to the gate control section at the timing at which the inductor current becomes zero current based on the conduction trigger.

8. An interleaved power supply comprising: a main converter having a main switch that performs switching operation; and a slave converter having a slave switch that performs switching operation in a state having a phase difference with respect to the switching operation of the main switch, the main converter and the slave converter constituting a master-slave relationship therebetween, characterized in that: a main switch control circuit for controlling the switching operation of the main switch is the control circuit according to any one of claims 1 to 4, and outputs an interleaving signal containing information of whether or not to stop the slave switch control circuit that controls the switching operation of the slave switch to the slave switch control circuit, the slave switch control circuit determines whether or not to stop the slave switch control circuit based on an interleaving input signal when the interleaving signal is input to the slave switch control circuit.

9. The interleaved power supply according to claim 8, characterized in that: the slave converter has a voltage dividing circuit that divides the interleaving signal.

10. The interleaved power supply according to claim 8, characterized in that: as the slave converter, a plurality of slave converters are provided, at least one of the plurality of slave converters has a voltage dividing circuit that divides the interleaving signal.

11. The interleaved power supply according to claim 8, characterized in that: the slave switch control circuit judges whether or not to stop the slave switch control circuit based on whether or not a voltage value of a high level of the interleaving input signal exceeds a prescribed interleaving signal detection threshold voltage, when the load state determination section determines that the load is heavy, the voltage value of the high level of the interleaving signal output from the main switch control circuit is set to VILl, when the load state determination section determines that the load is light, the voltage value of the high level of the interleaving signal output from the main switch control circuit is set to VIL2, and the interleaving signal detection threshold voltage is set to VIL_INl, and VILl > VIL2 > VIL_INl is satisfied, in a case where the slave converter is provided with a voltage dividing circuit that divides the interleaving signal and inputs the interleaving signal to the slave switch control circuit, when the load state determination section determines that the load is heavy, the voltage value of the high level of the interleaving input signal is set to VILl_D, when the load state determination section determines that the load is light, the voltage value of the high level of the interleaving input signal is set to VIL2_D, and the voltage dividing circuit is set so that VILl_D > VIL_INl and VIL2_D < VIL_INl are satisfied.

12. The interleaved power supply according to claim 8, characterized in that: the sub-switch control circuit judges whether to stop the sub-switch control circuit based on whether the voltage value of the high level of the interleaved input signal is within a range from a prescribed interleaved signal detection threshold voltage to a prescribed interleaved operation stop threshold voltage, when the load state judging section judges that the load is heavy, the voltage value of the high level of the interleaved signal output from the main switch control circuit is set to VIL1, when the load state judging section judges that the load is light, the voltage value of the high level of the interleaved signal output from the main switch control circuit is set to VIL2, and when the interleaved signal detection threshold voltage is set to VIL_IN1 and the interleaved operation stop threshold voltage is set to VIL_IN1_stop, VIL2 > VIL_IN1_stop > VIL1 > VIL_IN1 is satisfied, in a case where a voltage dividing circuit is provided in the slave converter and the interleaved signal is divided by the voltage dividing circuit and input to the sub-switch control circuit, when the load state judging section judges that the load is heavy, the voltage value of the high level of the interleaved input signal is set to VIL1_D, and when the load state judging section judges that the load is light, the voltage value of the high level of the interleaved input signal is set to VIL2_D, the voltage dividing circuit is arranged so that VIL_IN1_stop > VIL1_D > VIL_IN1 and VIL_IN1_stop > VIL2_D > VIL_IN1 are satisfied.

13. The interleaved power supply according to claim 8, wherein: a plurality of slave converters are provided as the slave converters, the sub-switch control circuit of each of the slave converters is provided with a first interleaved signal detection threshold voltage and a second interleaved signal detection threshold voltage lower than the first interleaved signal detection threshold voltage, in a case where the interleaved signal is directly input to the sub-switch control circuit or in a case where a voltage dividing circuit is provided in the slave converter and the interleaved signal is divided by the voltage dividing circuit and input to the sub-switch control circuit, (1) in a case where the voltage value of the high level of the interleaved input signal exceeds the first interleaved signal detection threshold voltage, the sub-switch control circuit causes the slave converter having the sub-switch control circuit to continue the interleaved operation and outputs an interleaved signal having a voltage value at the same level as the voltage value of the high level of the interleaved signal output from the main switch control circuit, (2) in a case where the voltage value of the high level of the interleaved input signal is not more than the first interleaved signal detection threshold voltage and not less than the second interleaved signal detection threshold voltage, the sub-switch control circuit causes the slave converter having the sub-switch control circuit to continue the interleaved operation and outputs an interleaved signal having a voltage value at a lower level than the voltage value of the high level of the interleaved signal output from the main switch control circuit, (3) In a case where the voltage value of the high level of the interleaved signal is less than a second interleaved signal detection threshold voltage, the sub-switch control circuit stops interleaved operation of the sub-converter having the sub-switch control circuit, and stops output of the interleaved signal.

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