Control circuit and interleave power supply

Abstract

To provide a control circuit capable of monitoring a load without depending on the cycle of an AC power supply without increasing the number of terminals, requiring no new parts or wiring, and capable of easily switching whether or not a slave converter is stopped under a light load without increasing the number of terminals.SOLUTION: A control circuit includes a load state determination unit 120, an on-trigger generation unit 130, a gate control unit 150, a drive unit 160, and an interleave signal generation unit 170. The load state determination unit 120 outputs load state information determined based on the error amplifier output voltage to the interleave signal generation unit 170. The on-trigger generation unit 130 generates an on-trigger and outputs it to the gate control unit 150. The interleave signal generation unit 170 outputs an interleave signal including information on whether or not to stop slave switch control circuits 200a, 200b based on the load state information and the control signal output information to a slave converter 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a control circuit and an interleaved power supply. [Background technology]

[0002] Conventionally, there is known a critical-type interleaved power supply that controls a PFC circuit using multiple converter stages, which monitors the load state and stops all stages except the first stage when the load is light, thereby improving conversion efficiency (see, for example, Patent Document 1).

[0003] The interleaved power supply described in Patent Document 1 includes three converters (a main converter and two sub converters), each of which has an inductor, a switch, and a rectifier. The interleaved power supply described in Patent Document 1 monitors the load state based on input side information (e.g., inductor current, input voltage, input current, etc.) or output side information (e.g., output voltage, output current, etc.), and operates only the main converter when the load is light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-019558 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, (1) as in the case of the interleaved power supply described in Patent Document 1, when the load state is monitored based on information on the input side (e.g., inductor current, input voltage, input current, etc.), an additional circuit and a terminal for sending an automatic stop signal to the control circuit of the slave converter are required to monitor the load state. Also, when multiple slave converters are provided and each converter has its own control circuit, it is necessary to transmit the automatic stop signal of the slave converter between adjacent converters, and a new terminal is required for this purpose. Therefore, in these cases, there is a problem that the number of terminals of the control circuit of the main converter increases, which may cause problems such as an increase in size or the need for design changes.

[0006] Also, (2) in the interleaved power supply described in Patent Document 1, when the load state is monitored based on information on the input side (e.g., inductor current, input voltage, input current, etc.), depending on the cycle of the AC power supply (particularly when the input voltage is in a valley), the secondary converter may stop unintentionally despite the heavy load. Therefore, there is a demand for a control circuit that monitors the load independently of the cycle of the AC power supply.

[0007] On the other hand, (3) in the interleaved power supply described in Patent Document 1, when the load condition is monitored based on output side information (e.g., output voltage, output current, etc.), the output side information needs to be converted and input to the control circuit. In this case, new components and wiring are required to obtain the output side information, which results in a problem of a complex circuit configuration.

[0008] Furthermore, (4) when ripple reduction is required even under light load or when the load changes suddenly from light to heavy, it is sometimes not desirable to stop the sub-converter, so there is a demand for an interleaved power supply that can easily switch whether or not the sub-converter is stopped under light load. However, in this case, a separate circuit is required to switch whether or not the sub-converter is stopped, which poses the problem of an increase in the number of terminals in the control circuit of the main converter.

[0009] Therefore, the present invention has been made in consideration of the above circumstances, and aims to provide a control circuit that (1) is less likely to cause problems such as an increase in the number of terminals of the control circuit of the main converter, which increases the size, or which is less likely to cause problems such as the need for design changes due to the increase in the number of terminals, (2) is capable of monitoring the load without depending on the cycle of the AC power supply, (3) does not require new components or wiring to obtain information on the output side, and therefore does not complicate the circuit configuration, and (4) is capable of easily switching whether or not the slave converter is stopped under light load without increasing the number of terminals of the control circuit of the main converter. Also, an object of the present invention is to provide an interleaved power supply having such a control circuit. [Means for solving the problem]

[0010] The control circuit of the present invention includes a main converter having a main switch that performs a switching operation, and a slave converter having a slave switch that performs switching with a predetermined phase difference with respect to the switching operation of the main switch, and is a control circuit for controlling the switching operation of the main switch for an interleaved power supply that forms a master-slave relationship between the main converter and the slave converter. The control circuit includes a load condition determination unit, an on-trigger generation unit, a gate control unit, a drive unit, and an interleave signal generation unit, and the load condition determination unit determines a load condition based on an error amplifier output voltage generated by a voltage based on an output voltage, and outputs the determined load condition information to the interleave converter. The error amplifier output voltage is supplied to the gate control unit, and the on-trigger generation unit outputs an on-trigger to the gate control unit, the gate control unit outputs a control signal having an on-width calculated based on the error amplifier output voltage to the drive unit with a predetermined phase difference and outputs control signal output information to the interleave signal generation unit, the drive unit turns the main switch on and off based on the control signal, and the interleave signal generation unit outputs an interleave signal to the slave converter, the interleave signal including information on whether to stop a slave switch control circuit that controls the switching operation of the slave switch based on the load state information and the control signal output information.

[0011] The interleaved power supply of the present invention comprises a main converter having a main switch that performs switching operation, and a slave converter having a slave switch that switches with a predetermined phase difference relative to the switching operation of the main switch, and is an interleaved power supply that forms a master-slave relationship between the main converter and the slave converter, and is characterized in that a main switch control circuit that controls the switching operation of the main switch is a control circuit as described in any of claims 1 to 4, and outputs an interleaved signal including information on whether to stop the slave switch control circuit that controls the switching operation of the slave switch to the slave switch control circuit, and the slave switch control circuit determines whether to stop the slave switch control circuit based on an interleaved input signal when the interleaved signal is input to the slave switch control circuit. Effect of the Invention

[0012] According to the control circuit and interleaved power supply of the present invention, the interleaved signal generating unit outputs an interleaved signal including information on 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 (slave converter) based on the load state information and the control signal output information, so there is no need to provide the control circuit with a terminal for sending an automatic stop signal to the slave switch control circuit. Therefore, it is possible to prevent problems such as an increase in the number of terminals of the control circuit of the main converter, which results in an increase in size, or an increase in the number of terminals, which requires a change in design, from occurring. Even if multiple slave converters are provided and each converter has its own control circuit, it is possible to determine whether or not to stop the slave switch control circuit by the interleave signal, so there is no need to provide terminals for transmitting the automatic stop signal of the slave converter between adjacent converters, and therefore there is no need to increase the number of terminals of the slave switch control circuit.

[0013] Furthermore, according to the control circuit and interleaved power supply of the present invention, the load state determination unit generates load state information based on the error amplifier output voltage, which is generated by a voltage based on the output voltage, and outputs the load state information to the interleaved signal generation unit, so that the load state can be determined without depending on the cycle of the AC power supply. Therefore, it is possible to prevent the secondary converter from stopping unintentionally despite a heavy load, as in the case where the load state is monitored based on information on the input side (e.g., inductor current, input voltage, input current, etc.), and it is possible to provide a control circuit that monitors the load without depending on the cycle of the AC power supply.

[0014] According to the control circuit and interleaved power supply of the present invention, the load state determination unit determines the load state based on the error amplifier output voltage generated by a voltage based on the output voltage, and outputs the determined load state information to the interleave signal generation unit, and the interleave signal generation unit outputs an interleave signal including information on whether or not to stop the slave switch control circuit that controls the switching operation of the slave switch based on the load state information and the control signal output information to the slave switch control circuit (slave converter), so that the error amplifier output voltage that has conventionally been used to correct the on-width can be used to determine whether or not to stop the slave switch control circuit. Therefore, no new components or wiring are required to obtain information on the output side, and the circuit configuration can be prevented from becoming complicated.

[0015] According to the control circuit and interleaved power supply of the present invention, the interleave signal generating unit outputs an interleave signal including information on whether or not to stop the slave switch control circuit that controls the switching operation of the slave switch based on the load state information and the control signal output information to the slave switch control circuit, so that even when it is not desired to stop the slave converter, such as when reducing ripple even under light load or when there is a sudden change from light load to heavy load, it is possible to easily switch whether or not the slave converter is stopped by adjusting the interleave signal. In addition, there is no need for a circuit that switches whether or not the slave converter is stopped, and the number of terminals of the control circuit of the main converter is not increased. Therefore, it is possible to easily switch whether or not the slave converter is stopped under light load without increasing the number of terminals of the control circuit of the main converter. [Brief description of the drawings]

[0016] [Figure 1] 1 is a circuit diagram showing an interleaved power supply 1 according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram shown for explaining a main switch control circuit 100 (reader) according to the first embodiment. [Diagram 3] 3A and 3B are diagrams for explaining the automatic stop function of the slave converter 30 (follower) of the first embodiment. FIG. 3A is a timing chart of the leader and follower, and FIG. 3B is a schematic diagram showing the relationship between the interleaved signal IL_OUT, the interleaved input signal IL_IN, and the interleaved signal detection threshold voltage VIL_IN1. Note that each waveform is drawn diagrammatically, and the high-level values ​​of different waveforms do not necessarily match. For example, the high-level voltage values ​​of the leader's IL_OUT and the follower's interleaved input signal IL_IN appear to be the same, but in reality, the follower's interleaved input signal IL_IN is a divided version of the leader's interleaved signal IL_OUT, and is therefore smaller than the high-level voltage value of the leader's IL_OUT. [Figure 4] 1 is a circuit diagram showing an interleaved power supply 2 according to a first modified example. [Diagram 5]5A and 5B are diagrams for explaining the operation of the slave converter 30 (follower) of the modified example 1. Fig. 5A is a timing chart of the leader and follower, and Fig. 5B is a schematic diagram showing the relationship between the interleaved signal IL_OUT, the interleaved input signal IL_IN, and the interleaved signal detection threshold voltage VIL_IN1. [Figure 6] 6A is a diagram for explaining the automatic stop function of the slave converter 30 (follower) of embodiment 2. Fig. 6A is a timing chart of the leader and follower, and Fig. 6B is a schematic diagram 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. [Figure 7] 7A and 7B are diagrams for explaining the operation of the slave converter 30 (follower) of the modified example 2. Fig. 7A is a timing chart of the leader and follower, and Fig. 7B is a schematic diagram 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. [Figure 8] 8A is a schematic diagram showing the relationship between the COMP voltage and the load state in embodiment 3. Fig. 8A is a schematic diagram showing the relationship between the COMP voltage and the load state determination threshold voltage, and Fig. 8B is a timing chart showing the relationship between the COMP voltage, the gate output voltage OUT, and the interleaved signal IL_OUT. [Figure 9] This is a schematic diagram showing the relationship between the high-level voltage value (IL_OUT threshold value) VIL_OUT of the leader's interleaved signal, the high-level voltage value (IL_IN generation voltage) IL_IN of the interleaved input signal, the interleaved signal detection threshold voltages (IL_IN threshold values) VIL_IN1 and VIL_IN2, and the high-level voltage values ​​(IL_OUT threshold values) VIL_OUT1 and VIL_OUT2 of the follower's interleaved signal in embodiment 3. [Figure 10]10A and 10B are diagrams showing the automatic stop function of the slave converters 30 and 40 (followers 1 and 2) in embodiment 3. Fig. 10A is a timing chart of the leader and followers, and Fig. 10B is a schematic diagram shown to explain the operations of the leader, follower 1, and follower 2 in a heavy load state. [Figure 11] 11A and 11B are diagrams showing the automatic stop function of slave converters 30 and 40 (followers 1 and 2) in embodiment 3. Fig. 11A is a schematic diagram shown to explain the operation of the leader, follower 1, and follower 2 in light load state 1, and Fig. 11B is a schematic diagram shown to explain the operation of the leader, follower 1, and follower 2 in light load state 2. [Figure 12] 13 is a diagram illustrating an automatic stop function of slave converters 30 and 40 (followers 1 and 2) in Modification 3. FIG. [Figure 13] 13A is a diagram showing the automatic stop function of the slave converters 30, 40 (followers 1, 2) in the modified example 3. Fig. 13A is a timing chart of the leader and followers, and Fig. 13B is a schematic diagram showing the relationship between the interleaved signals and the interleaved input signal IL_IN of the leader, follower 1, and follower 2 and the threshold voltage. [Figure 14] FIG. 11 is a circuit diagram showing an interleaved power supply 2 according to a fourth embodiment. [Figure 15] FIG. 13 is a schematic diagram showing the relationship between the interleaved signal and the interleaved input signal IL_IN and the threshold voltage of the leader, follower 1, and follower 2 in the fourth embodiment. [Figure 16] 16A and 16B are diagrams illustrating the automatic stop function of the slave converters 30 and 40 (followers 1 and 2) of embodiment 4. Fig. 16A is a schematic diagram shown to explain the automatic stop function of the leader, follower 1, and follower 2 in a heavy load state, Fig. 16B is a schematic diagram shown to explain the automatic stop function of the leader, follower 1, and follower 2 in a light load state 2, and Fig. 16C is a schematic diagram shown to explain the automatic stop function of the leader, follower 1, and follower 2 in a light load state 1. [Figure 17]FIG. 13 is a schematic diagram showing the relationship between the interleaved signal and the interleaved input signal IL_IN and the threshold voltage of the leader, follower 1, and follower 2 in the fifth embodiment. [Figure 18] 18A and 18B are diagrams illustrating the automatic stop function of the slave converters 30 and 40 (followers 1 and 2) of embodiment 5. Fig. 18A is a schematic diagram shown to explain the automatic stop function of the leader, follower 1, and follower 2 in a heavy load state, Fig. 18B is a schematic diagram shown to explain the automatic stop function of the leader, follower 1, and follower 2 in a light load state 2, and Fig. 18C is a schematic diagram shown to explain the automatic stop function of the leader, follower 1, and follower 2 in a light load state 1. [Figure 19] FIG. 13 is a block diagram for explaining a main switch control circuit 101 (reader) according to a sixth embodiment. [Figure 20] 20 is a schematic graph shown to explain load state determination threshold voltages Vcomp1, Vcomp2 in the sixth embodiment. [Figure 21] 21(a) and 21(b) are circuit diagrams for explaining an input voltage monitoring circuit according to embodiment 6. FIG. [Figure 22] FIG. 11 is a block diagram showing a main switch control circuit 100a according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The control circuit and interleaved power supply of the present invention will be described below based on the embodiment 1 shown in the drawings. Note that the embodiment described below does not limit the invention according to the claims. Also, not all of the elements and combinations thereof described in the embodiment are necessarily essential to the solution of the present invention.

[0018] [Embodiment 1] 1. Configuration of the interleaved power supply 1 according to the first embodiment The interleaved power supply 1 according to the first embodiment 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 rectifier circuit 10, a main converter 20 having a main switch Q1 that performs switching operation, secondary converters 30 and 40 having secondary switches Q2 and Q3 that perform switching in a state having a phase difference with respect to the switching operation of the main switch Q1, and an output capacitor C3.

[0019] In the interleaved power supply 1, a main converter 20 and sub converters 30, 40 are connected in parallel between a rectifier circuit 10 and an output capacitor C3, and the main converter 20 and the sub converters 30, 40 form a master-slave relationship.

[0020] The rectifier circuit 10 includes a bridge diode BD that, for example, full-wave rectifies the AC current of a commercial power source to make it a pulsating current, and a smoothing capacitor C2.

[0021] (1) Configuration of main converter 20 The main converter 20 (leader) comprises an inductor L1, an auxiliary winding L4, a main switch Q1, a diode D1, and a main switch control circuit 100 (corresponding to the control circuit of the present invention), and the inductor L1, the main switch Q1, and the diode D1 form a boost chopper circuit.

[0022] In the first embodiment, the main switch Q1 is a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), but may be an IGBT or other suitable switch element. Any suitable inductor may be used as the inductor L1, and any suitable diode may be used as the diode D1. The same applies to the slave switches Q2, Q3, inductors L2, L3, and diodes D2, D3 described later.

[0023] 1 and 2, the main switch control circuit 100 outputs a control signal for controlling the main switch Q1 to the gate electrode of the main switch Q1, and also outputs an interleave signal to the slave converter 30. The main switch control circuit 100 has eight terminals, namely, 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.

[0024] The Vcc terminal is connected to the external power supply Vcc and receives power from the external power supply Vcc. The OUT terminal is connected to the gate electrode of the main switch Q1 and outputs a signal to the gate electrode that controls the on / off of the main switch Q1. The GND terminal is grounded.

[0025] The ZC terminal is connected to the auxiliary winding L4 and detects the inductor current IL flowing through the inductor L1.

[0026] The OCL terminal is connected to a resistor R3 and a capacitor C7, and is connected to the midpoint between the source electrode of the main switch Q1 and the resistor R2 via the resistor R3. The OCL terminal is used to monitor whether an overcurrent flows through the main switch Q1 by monitoring a voltage determined by the resistor R2. The IL_OUT terminal is connected to the IL_IN terminal of the slave switch control circuit 200a (follower).

[0027] The COMP terminal is connected to the output terminal of the error amplifier 110, which is connected to the capacitor C6. The main switch control circuit 100 uses the voltage of the COMP terminal to determine the ON width of the main switch Q1 and control the gate output voltage. The FB terminal is connected to the capacitor C5 and resistors R4 and R5. The voltage obtained by dividing the output voltage by resistors R4 and R5 is input to the FB terminal.

[0028] Next, the internal configuration of the main switch control circuit 100 will be described. 2, the main switch control circuit 100 (leader) has an error amplifier (FB_Amp) 110, a load state determination unit 120, an on-trigger generation unit 130, an on-width calculation unit 140, a gate control unit 150, a drive unit 160, and an interleave signal generation unit 170. In addition, although not shown, it has an overvoltage detection unit (not shown) that detects whether the output voltage of the interleaved power supply 1 is an overvoltage by comparing whether the FB voltage of the FB terminal is greater than a predetermined value.

[0029] The error amplifier 110 detects an error between the voltage obtained by dividing the output voltage by resistors R4 and R5 and a reference voltage, and determines the charge / discharge current of the capacitor C6 at the COMP terminal based on the error. This determines the COMP terminal voltage (COMP voltage), and the on-width is determined so as to keep the output voltage constant.

[0030] The load condition determination unit 120 generates load condition information based on an error amplifier output voltage (COMP voltage) generated by a voltage based on the output voltage (a voltage obtained by dividing the output voltage Vo), and outputs the load condition information to the interleave signal generation unit 170.

[0031] The load condition determination unit 120 determines the load condition based on whether the error amplifier output voltage (COMP voltage) exceeds load condition determination threshold voltages Vcomp1, Vcomp2 (see FIG. 3(a)). Specifically, the load condition determination unit 120 determines that the load is light when the COMP voltage falls below the load condition determination threshold voltage Vcomp1, and determines that the load has returned to heavy when the COMP voltage recovers and exceeds Vcomp2. The load condition determination threshold voltage Vcomp2 when the COMP voltage is increasing is greater than the load condition determination threshold voltage Vcomp1 when the COMP voltage is decreasing.

[0032] The on-trigger generating section 130 generates an on-trigger and outputs it to the gate control section 150 .

[0033] The on-width calculation unit 140 calculates the on-width of the main switch Q1 so as to keep the output voltage constant based on the COMP voltage, and outputs it as on-width information to the gate control unit 150. Specifically, the on-width of the main switch Q1 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 unit 140, since it is preferable to increase the inductor current IL in a heavy load state, the on-width is widened by increasing the COMP voltage. On the other hand, since it is not necessary to increase the inductor current IL in a light load state, the on-width is narrowed by lowering the COMP voltage.

[0034] The gate control unit 150 outputs a control signal having an on-width calculated based on the COMP voltage to the drive unit 160 with a predetermined phase difference based on an on-trigger, and outputs control signal output information synchronized with the control signal to the interleave signal generation unit 170.

[0035] The driving unit 160 outputs a switching pulse for turning on and off the main switch Q1 based on a control signal from the gate control unit 150 to the gate electrode of the main switch Q1 via a gate output terminal OUT.

[0036] The interleave signal generating unit 170 outputs an interleave signal to the slave switch control circuits 200a and 200b based on the load state information and the control signal output information. The interleave signal includes information on whether or not to stop the slave switch control circuits 200a and 200b (follower 1, follower 2) that control the switching operations of the slave switches Q2 and Q3.

[0037] The interleave signal generating unit 170 has an interleave output voltage adjusting unit, and outputs an interleave signal IL_OUT whose voltage value at high level has been adjusted to the slave switch control circuit 200a as information on whether or not to stop the slave switch control circuits 200a, 200b. Specifically, the interleave signal is output to the slave switch control circuit 200a so that the high level voltage value when it is determined that the state is a light load state is lower than the high level voltage value when it is determined that the state is a heavy load state.

[0038] The interleave signal is synchronized with the control signal, and the high level voltage value during heavy load is the same as the high level voltage value of the control signal.

[0039] (2) Configuration of the Slave Converter 30 and the Slave Switch Control Circuit 200a The slave converter 30 includes an inductor L2, an auxiliary winding L5, a slave switch Q2, a diode D2, and a slave switch control circuit 200a. The inductor L2, the slave switch Q2, and the diode D2 form a boost chopper circuit.

[0040] The slave switch control circuit 200a is a control circuit that controls the switching operation of the slave switch Q2. The slave switch control circuit 200a basically has the same configuration as the main switch control circuit 100, but differs in that an IL_IN terminal is provided instead of the FB terminal of the main switch control circuit 100, an IL_OUT terminal is provided instead of the COMP terminal, and a VIS terminal that is not connected to anything is provided instead of the IL_OUT terminal.

[0041] The IL_IN terminal of the slave switch control circuit 200a is connected to resistors R9 and R10 and a capacitor C11. The resistor R9 is provided between the IL_IN terminal and the IL_OUT terminal of the master switch control circuit 100, and the interleaved signal is divided by the resistors R9 and R10 and input to the IL_IN terminal.

[0042] The slave switch control circuit 200a judges whether to stop the slave switch control circuit 200a based on the interleaved input signal IL_IN (a signal obtained by dividing the interleaved signal IL_OUT by resistors R9 and R10) when the interleaved signal IL_OUT is input to the slave switch control circuit 200a. Specifically, when the high-level voltage value of the interleaved input signal IL_IN is greater than a predetermined interleaved signal detection threshold voltage VIL_IN1, the slave converter 30 performs normal interleaving operation, and when the high-level voltage value of the interleaved input signal IL_IN is less than the predetermined interleaved signal detection threshold voltage VIL_IN1, the slave converter 30 stops the interleaved operation. When the slave converter 30 stops the interleaved operation, it does not output the gate output voltage OUT and the interleaved signal (see the gate output voltage OUT and the interleaved signal IL_OUT of the follower in FIG. 3).

[0043] (3) Configuration of the Slave Converter 40 and the Slave Switch Control Circuit 200b The slave converter 40 includes an inductor L3, an auxiliary winding L6, a slave switch Q3, a diode D3, and a slave switch control circuit 200b, and the inductor L3, the slave switch Q3, and the diode D3 form a boost chopper circuit. The slave converter 40 and the slave switch control circuit 200b have the same configuration as the slave converter 30 and the slave switch control circuit 200a, except that the IL_OUT terminal that outputs the interleaved signal is not connected.

[0044] The slave switch control circuit 200b determines whether or not to stop the slave switch control circuit 200b based on an interleaved input signal IL_IN (a signal obtained by dividing the interleaved signal IL_OUT by resistors R14 and R15) when the interleaved signal IL_OUT is input to the slave switch control circuit 200b.

[0045] Specifically, when the high-level voltage value of the interleaved input signal IL_IN is greater than a predetermined interleaved signal detection threshold voltage, the slave converter 40 performs normal interleaving operation, and when the high-level voltage value of the interleaved input signal IL_IN is less than the predetermined interleaved signal detection threshold voltage, the slave converter 40 stops the interleaved operation. The interleaved signal detection threshold voltage of the slave switch control circuit 200b may be the same as or different from the interleaved signal detection threshold voltage VIL_IN1 of the slave switch control circuit 200a.

[0046] 2. Operation of the control circuit 100 and the interleaved power supply 1 according to the first embodiment Next, the operation of the control circuit 100 and the interleaved power supply 1 according to the first embodiment will be described with reference to Fig. 3. For ease of explanation, the explanation will be limited to the main converter 20 (leader) and the slave converter 30 (follower).

[0047] (1) Heavy load condition When the leader's COMP voltage exceeds the load state determination threshold voltage Vcomp1 (see FIG. 3(a) COMP voltage), the load state determination unit 120 determines that the load state is heavy. 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 drops, the on width of the gate output voltage OUT and the interleave signal IL_OUT becomes shorter in response to the voltage value of the COMP voltage.

[0048] The period of the interleave signal IL_OUT is synchronized with the gate output voltage OUT. The high-level voltage value is VIL1.

[0049] In the first embodiment, the interleaved signal IL_OUT output from the leader is divided by a voltage divider circuit formed by resistors R9 and R10 of the slave converter 30 in Fig. 1 and input via the IL_IN terminal of the slave switch control circuit 200a. Therefore, the high-level voltage value of the interleaved input signal IL_IN is VIL1_D (see Fig. 3(b)).

[0050] In a heavy load state, the high-level voltage value VIL_D of the interleaved input signal IL_IN is greater than the interleaved signal detection threshold voltage VIL_IN1, and the follower (sub-converter 30) continues the interleaved operation.

[0051] The gate output voltage OUT of the follower rises when the interleaved input signal IL_IN turns off, and falls after remaining on for the same period as the interleaved input signal IL_IN was on. Therefore, the period is shifted and an interleaved operation is performed. The follower also generates an interleaved signal IL_OUT and outputs the interleaved signal IL_OUT to the slave converter 40 in the subsequent stage.

[0052] (2) Light load condition When the leader's COMP voltage becomes equal to or lower than the load state determination threshold voltage Vcomp1 and does not exceed the load state determination threshold voltage Vcomp2 even if the COMP voltage is in the recovery stage (see COMP voltage in FIG. 3(a)), the load state determination unit 120 determines that the load state is light. During this time, the gate output voltage OUT is repeatedly turned on and off at a predetermined cycle, although the on-width is shorter than in the case of a heavy load. The load condition determination threshold voltage Vcomp2 is higher than the load condition determination threshold voltage Vcomp1.

[0053] The interleave signal IL_OUT is synchronized with the gate output voltage OUT. The interleave signal generating unit 170 outputs to the slave switch control circuit 200a, as information on whether or not to stop the slave switch control circuit 200a, an interleave signal that has been adjusted so that the high-level voltage value when it is determined that the load state is light is lower than the high-level voltage value when it is determined that the load state is heavy.

[0054] That is, in a light load state, the interleaved signal IL_OUT is output to the follower, the high level voltage value of which is adjusted to VIL2 lower than VIL1 when the heavy load state is determined.

[0055] As in the case of a heavy load state, the interleaved signal IL_OUT output from the leader is divided by a voltage divider circuit formed by resistors R9 and R10 of the slave converter 30 and input via the IL_IN terminal of the slave switch control circuit 200a. Therefore, the high-level voltage value of the interleaved input signal IL_IN is divided, and the high-level voltage value becomes VIL2_D (see FIG. 3(b)).

[0056] In a light load state, the high-level voltage value VI2_D of the interleaved input signal IL_IN becomes smaller than the interleaved signal detection threshold voltage VIL_IN1. Therefore, in the follower (sub-converter 30), the gate output voltage OUT becomes low level, and the follower stops the interleaving operation. In addition, the interleaved signal IL_OUT becomes low level, and the interleaved operation of the next and subsequent sub-converters (followers, sub-converter 40 in the first embodiment) is also stopped.

[0057] (3) Heavy load condition When the leader's COMP voltage rises again and becomes equal to or higher than the load state determination threshold voltage Vcomp2, the load state determination unit 120 determines that the load state is heavy. The operation is the same as that in the above (1) heavy load state, and the follower resumes interleaving operation.

[0058] 3. Effects of the control circuit 100 and the interleaved power supply 1 according to the first embodiment According to the control circuit 100 and the interleaved power supply 1 of the first embodiment, the interleave signal generating unit 170 outputs an interleave signal including information on whether or not to stop the slave switch control circuits 200a, 200b that control the switching operations of the slave switches Q2, Q3 to the slave switch control circuit 200a (slave converter 30) based on the load state information and the control signal output information, so that it is not necessary to provide the control circuit 100 with a terminal for sending an automatic stop signal to the slave switch control circuit 200a. Therefore, it is possible to prevent problems such as an increase in the number of terminals of the control circuit 100 of the main converter 20, which results in an increase in size, or an increase in the number of terminals, which results in a need for a design change. Even if multiple slave converters are provided and each converter has its own control circuit, it is possible to determine whether to stop the slave converters 30 and 40 using the interleave signal, so there is no need to provide new terminals for transmitting the automatic stop signal of the slave converter between adjacent converters. Therefore, there is no need to increase the number of terminals of the slave switch control circuits 200a and 200b.

[0059] Furthermore, according to the control circuit 100 and the interleaved power supply 1 of the first embodiment, the load state determination unit 120 generates load state information based on the error amplifier output voltage (COMP voltage) generated by a voltage based on the output voltage and outputs the information to the interleaved signal generation unit 170, so that the load state can be determined without depending on the cycle of the AC power supply. Therefore, it is possible to prevent the secondary converter from stopping unintentionally despite a heavy load, as in the case where the load state is monitored based on information on the input side (e.g., inductor current, input voltage, input current, etc.), and it is possible to provide a control circuit that monitors the load without depending on the cycle of the AC power supply.

[0060] Moreover, according to the control circuit 100 and the interleaved power supply 1 of the first embodiment, the load state determination unit 120 determines the load state based on the error amplifier output voltage (COMP voltage) generated by the voltage based on the output voltage, and outputs the determined load state information to the interleave signal generation unit 170, and the interleave signal generation unit 170 outputs an interleave signal including information on whether or not to stop the slave switch control circuits 200a and 200b that control the switching operations of the slave switches Q2 and Q3 based on the load state information and the control signal output information to the slave switch control circuit 200a, so that the error amplifier output voltage (COMP voltage), which has been conventionally used to correct the ON width, can be used to determine whether or not to stop the slave switch control circuits 200a and 200b. Therefore, no new components or wiring are required to obtain information on the output side, and the circuit configuration can be prevented from becoming complicated.

[0061] In addition, according to the control circuit 100 and the interleaved power supply 1 of the first embodiment, the interleave signal generating unit 170 outputs an interleave signal including information on whether or not to stop the slave switch control circuits 200a and 200b that control the switching operations of the slave switches Q2 and Q3 to the slave switch control circuit 200a based on the load state information and the control signal output information, so that even when it is not desired to stop the slave converters 30 and 40, such as when reducing ripples even under light load or when the load suddenly changes from light to heavy, it is possible to easily switch whether or not the slave converters 30 and 40 are stopped by adjusting the interleave signal. In addition, a circuit for switching whether or not the slave converters 30 and 40 are stopped is not required, and the number of terminals of the control circuit 100 of the main converter 20 is not increased. Therefore, it is possible to easily switch whether or not the slave converter is stopped under light load without increasing the number of terminals of the control circuit 100 of the main converter.

[0062] Furthermore, according to the control circuit 100 and interleaved power supply 1 of embodiment 1, the interleave signal generating unit 170 outputs an interleave signal with an adjusted high-level voltage value during light load to the slave switch control circuits 200a, 200b as information on whether or not to stop the slave switch control circuits 200a, 200b. Therefore, it is possible to communicate that the interleave operation of the slave converter is to be stopped by changing the high-level voltage value of the interleave signal without increasing the number of terminals of the control circuit 100 of the main converter 20.

[0063] Furthermore, according to the control circuit 100 and interleaved power supply 1 of embodiment 1, the interleave signal generating unit 170 outputs an interleave signal to the slave switch control circuits 200a, 200b, in which the high-level voltage value during light load is adjusted to be a lower voltage value than the high-level voltage value during heavy load, as information on whether or not to stop the slave switch control circuits 200a, 200b. Therefore, by simply keeping the high-level voltage value low, it is possible to easily communicate to the slave converters 30, 40 whether or not to stop the interleaved operation.

[0064] Incidentally, when the interleaving operation of the slave converters 30 and 40 stops, the load on the main converter 20 increases, causing the COMP voltage to rise. As a result, it becomes difficult to accurately determine the load state, and there is a risk that the follower stop may be unintentionally released. On the other hand, according to the control circuit 100 and the interleaving power supply 1 according to the first embodiment, the load state determination threshold voltage Vcomp2 when the error amplifier output voltage is increasing is greater than the load state determination threshold voltage Vcomp1 when the error amplifier output voltage is decreasing. Therefore, even when the interleaving operation of the slave converters 30 and 40 stops and the COMP voltage rises due to an increase in the load on the main converter 20, the load state determination unit 120 can accurately determine the load state and prevent the unintentional release of the follower stop.

[0065] According to the interleaving power supply 1 according to the first embodiment, since the slave converters 30 and 40 have voltage dividing circuits (resistors R9 and R10, resistors R14 and R15) that divide the interleaving signal IL_OUT, it is possible to adjust whether to stop the slave switch control circuit that controls the switching operation of the slave switches.

[0066] According to the interleaving power supply 1 according to the first embodiment, as slave converters, a plurality of slave converters are provided, and at least one (two in the first embodiment) of the plurality of slave converters has a voltage dividing circuit that divides the interleaving signal. Therefore, it is possible to select whether to perform automatic stop of the follower.

[0067] Also, according to the interleaving power supply 1 according to the first embodiment, since VIL1_D > VIL_IN1 and VIL2_D < VIL_IN1 are satisfied, the interleaving operation of the slave converters 30 and 40 can be stopped only by changing the high-level voltage value of the interleaving signal IL_OUT between heavy load and light load.

[0068] [Modification Example 1] The control circuit and interleaved power supply 2 according to the first modification basically have the same configuration as the control circuit 100 and interleaved power supply 1 according to the first embodiment, but differ from the control circuit 100 and interleaved power supply 1 according to the first embodiment in that the slave converter is not automatically stopped. As shown in Fig. 4, the slave converters 30, 40 of the interleaved power supply 2 according to the first modification have no resistors R10, R15 that were present in the first embodiment, and do not have a voltage divider circuit.

[0069] (1) Heavy load condition The control circuit and the interleaved power supply 2 according to the first modification basically operate in the same manner as in the first embodiment, but the interleaved signal IL_OUT output from the leader is not divided. Therefore, the high-level voltage value of the interleaved input signal IL_IN input to the follower is VIL1 (see FIG. 5(a) and FIG. 5(b)).

[0070] Since the high-level voltage value VIL1 of the interleaved input signal IL_IN is greater than the interleaved signal detection threshold voltage VIL_IN1, the follower (the secondary converter 30) continues the interleaved operation.

[0071] (2) Light load condition Even in a light load state, the interleaved signal IL_OUT output from the leader is not divided. Therefore, the high-level voltage value of the interleaved input signal IL_IN input to the follower is VIL2.

[0072] Since the high-level voltage value VIL2 of the interleaved input signal IL_IN is greater than the interleaved signal detection threshold voltage VIL_IN1, the follower (sub-converter 30) continues the interleaved operation. In this way, by inputting the interleaved signal to the sub-converter 30 (follower) without dividing it, the sub-converter can be prevented from stopping even under a light load.

[0073] As described above, the control circuit and interleaved power supply 2 according to Modification 1 are different from the control circuit 100 and interleaved power supply 1 according to Embodiment 1 in that the slave converter is not automatically stopped. However, similar to the case of the control circuit 100 and interleaved power supply 1 according to Embodiment 1, the load determination unit generates load state information based on the error amplifier output voltage generated by the voltage based on the output voltage, and outputs it to the interleaved signal generation unit. The interleaved signal generation unit outputs an interleaved signal including information on whether to stop the slave switch control circuit that controls the switching operation of the slave switch based on the load state information and the control signal output information. Therefore, (1) problems such as an increase in the number of terminals of the control circuit of the main converter and an increase in size, or an increase in the number of terminals and the need for a design change are less likely to occur, (2) it is possible to monitor the load without depending on the cycle of the AC power supply, (3) new components and wiring for obtaining output side information are not required, and the circuit configuration is less likely to become complicated, and (4) it is a control circuit that can easily switch whether the slave converter stops or not during light load without increasing the number of terminals of the control circuit of the main converter.

[0074] Also, according to the control circuit 100 and interleaved power supply 2 according to Modification 1, since VIL1 > VIL2 > VIL_IN1 is satisfied, it is possible not to stop the slave converter even during light load.

[0075] Also, as can be seen from Embodiment 1 and Modification 1, by satisfying VIL1 > VIL2 > VIL_IN1, and VIL1_D > VIL_IN1, and VIL2_D < VIL_IN1, not only can it be selected whether to maintain the interleaved operation of the slave converter in the light load state, but also it is possible to determine whether to maintain the interleaved operation in the light load state with a relatively simple change of whether to incorporate the voltage division or not. Therefore, it is a control circuit with high versatility.

[0076] In addition, the control circuit 100 and the interleaved power supply 2 of the modified example 1 have the same configuration as the control circuit 100 and the interleaved power supply 1 of the first embodiment except that they do not automatically stop the slave converter, and therefore have the relevant effects among the effects of the control circuit 100 and the interleaved power supply 1 of the first embodiment.

[0077] [Embodiment 2] The control circuit and interleaved power supply of embodiment 2 basically have the same configuration as the control circuit 100 and interleaved power supply 1 of embodiment 1, but differ from the control circuit 100 and interleaved power supply 1 of embodiment 1 in that the high-level voltage value of the interleaved signal in a light load state is higher than the high-level voltage value in a heavy load state.

[0078] 4, the circuit configuration of the control circuit and the interleaved power supply (not shown) according to the second embodiment is similar to that of the interleaved power supply 2 according to the first modification. That is, the secondary converters 30 and 40 do not have a voltage dividing circuit.

[0079] In the follower, an interleaved signal detection threshold voltage VIL_IN1 and an interleaved operation stop threshold voltage VIL_IN1_stop are provided for the interleaved input signal IL_IN, and whether or not to stop the slave switch control circuit is determined depending on whether the high-level voltage value of the interleaved input signal IL_IN is within the range from a predetermined interleaved signal detection threshold voltage VIL_IN1 to a predetermined interleaved operation stop threshold voltage VIL_IN1_stop.

[0080] (1) Heavy load condition The control circuit and the interleaved power supply according to the second embodiment basically operate in the same manner as in the first embodiment, but the high-level voltage value of the interleaved signal IL_OUT is VIL1. And, since the voltage is not divided, the high-level voltage value of the interleaved input signal input to the follower remains at VIL1 (see FIG. 6(a) and FIG. 6(b)).

[0081] Since the high-level voltage value VIL1 of the interleaved input signal IL_IN is within the range from the interleaved signal detection threshold voltage VIL_IN1 to the predetermined interleaved operation stop threshold voltage VIL_IN1_stop, the follower maintains the interleaved operation, i.e., outputs the gate output voltage OUT and outputs the interleaved signal to the next converter.

[0082] (2) Light load condition Even in a light load state, the interleaved signal IL_OUT output from the leader is not divided. Therefore, the high-level voltage value of the interleaved input signal IL_IN input to the follower is VIL2.

[0083] 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 level, and the output of the interleaved signal to the next-stage converter is stopped.

[0084] As described above, the control circuit and interleaved power supply of embodiment 2 differ from the control circuit 100 and interleaved power supply 1 of embodiment 1 in that the high-level voltage value of the interleaved signal in a light load state is higher than the high-level voltage value in a heavy load state. However, like the control circuit 100 and interleaved power supply 1 of embodiment 1, (1) it is less likely to cause problems 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, which would require design changes, (2) it is possible to monitor the load without depending on the cycle of the AC power supply, (3) it does not require new components or wiring to obtain information on the output side, and the circuit configuration is less likely to become complicated, and (4) it is a control circuit that can easily switch whether or not the sub-converter is stopped under a light load without increasing the number of terminals of the control circuit of the main converter.

[0085] Furthermore, according to the control circuit and interleaved power supply of embodiment 2, the interleaved signal generating unit 170 outputs to the slave switch control circuit 200a, as information on whether or not to stop the slave switch control circuits 200a, 200b, an interleaved signal adjusted so that the high-level voltage value VIL2 when a light load state is determined is higher than the high-level voltage value VIL1 when a heavy load state is determined. Therefore, it is possible to stop the interleaved operation of the follower in a light load state without a voltage divider circuit.

[0086] The control circuit and interleaved power supply of embodiment 2 have the same configuration as the control circuit 100 and interleaved power supply 1 of embodiment 1 except that the high-level voltage value of the interleaved signal in a light load state is higher than the high-level voltage value in a heavy load state, and therefore have the relevant effects among the effects of the control circuit 100 and interleaved power supply 1 of embodiment 1.

[0087] [Variation 2] The control circuit and interleaved power supply according to the second modification basically have the same configuration as the control circuit and interleaved power supply according to the second embodiment, but differs from the control circuit and interleaved power supply according to the second embodiment in that the slave converter is not automatically stopped. The slave converters 30 and 40 of the interleaved power supply according to the second modification have a voltage divider circuit, similar to the case of the interleaved power supply 1 according to the first embodiment shown in FIG.

[0088] (1) Heavy load condition When a heavy load state is determined, the high-level voltage value of the interleaved signal IL_OUT output from the leader is VIL1 (see Figures 7(a) and 7(b)). In the second modification, the interleaved input signal IL_IN is voltage-divided, so that the high-level voltage value of the interleaved input signal IL_IN input to the follower is VIL1_D (see Figure 7(b)).

[0089] Since the high-level voltage value VIL1_D of the interleaved input signal IL_IN is greater than the interleaved signal detection threshold voltage VIL_IN1 and less than the interleaved operation stop threshold voltage VIL_IN1_stop, the follower (sub-converter 30) continues the interleaved operation.

[0090] (2) Light load condition Even in a light load state, the interleaved signal IL_OUT output from the leader is voltage divided. Therefore, the high-level voltage value of the interleaved input signal IL_IN input to the follower is VIL2_D.

[0091] Since the high-level voltage value VIL2_D of the interleaved input signal IL_IN is greater than the interleaved signal detection threshold voltage VIL_IN1 and less than the interleaved operation stop threshold voltage VIL_IN1_stop, the follower (sub-converter 30) continues the interleaved operation. In this way, by dividing the interleaved signal to the slave converter 30 (follower), it is possible to prevent the slave converter from being stopped even under a light load.

[0092] As described above, the control circuit and interleaved power supply of variant example 2 differ from the control circuit and interleaved power supply of embodiment 2 in that the slave converter is not automatically stopped. However, like the control circuit and interleaved power supply of embodiment 1, (1) it is less likely to cause problems such as an increase in the number of terminals of the main converter control circuit resulting in an increase in size or a need for design changes due to the increased number of terminals, (2) it is possible to monitor the load without depending on the cycle of the AC power supply, (3) it does not require new components or wiring to obtain information on the output side, and the circuit configuration is less likely to become complicated, and (4) it is a control circuit that can easily switch whether or not the slave converter is stopped under light load without increasing the number of terminals of the main converter control circuit.

[0093] Furthermore, according to the control circuit and interleaved power supply of variant example 2, since VIL_IN1_stop>VIL1_D>VIL_IN1 and VIL_IN1_stop>VIL2_D>VIL_IN1 are satisfied, it is possible to prevent the secondary converter from being stopped even under a light load.

[0094] Furthermore, as can be seen from the second embodiment and the second modification, by satisfying VIL1>VIL_IN1_stop>VIL2>VIL_IN1, and also VIL_IN1_stop>VIL1_D>VIL_IN1 and VIL_IN1_stop>VIL2_D>VIL_IN1, not only can it be selected whether to maintain the interleaved operation of the slave converter in a light load state, but also it can be determined whether to maintain the interleaved operation in a light load state by a relatively simple change of whether or not to incorporate a voltage divider circuit in the converter. Therefore, a highly versatile control circuit is obtained.

[0095] In addition, the control circuit and interleaved power supply of variant example 2 have the same configuration as the control circuit and interleaved power supply of embodiment 2 except that they do not automatically stop the slave converter, and therefore have the relevant effects among the effects of the control circuit and interleaved power supply of embodiment 2.

[0096] [Embodiment 3] The control circuit and interleaved power supply of embodiment 3 basically have the same configuration as the control circuit 100 and interleaved power supply 1 of embodiment 1, but differs from the control circuit 100 and interleaved power supply 1 of embodiment 1 in that it provides three load states in the load state determination.

[0097] The circuit configurations of the control circuit and the interleaved power supply (not shown) according to the third embodiment are similar to those shown in Fig. 1. That is, the secondary converters 30 and 40 are provided with voltage dividing circuits.

[0098] In the load condition determination unit 120 of the follower, four load condition determination threshold voltages Vcomp1, Vcomp2, Vcomp3, and Vcomp4 are provided for the error amplifier output voltage (COMP voltage) (see FIG. 8(a)). The load condition determination threshold voltages Vcomp1 and Vcomp3 are threshold voltages for determining the load condition when the COMP voltage becomes small, and the load condition determination threshold voltages Vcomp2 and Vcomp4 are threshold voltages for determining the load condition when the COMP voltage becomes large.

[0099] The magnitude relationship between the load state determination threshold voltages Vcomp1, Vcomp2, Vcomp3, and Vcomp4 is as follows: Vcomp1 <Vcomp2<Vcomp3<Vcomp4である。

[0100] When the COMP voltage decreases, if it exceeds Vcomp3, it is determined to be in a heavy load state, and if it is equal to or less than Vcomp3 and exceeds Vcomp1, it is determined to be in light load state 2. When the COMP voltage becomes equal to or less than Vcomp1 and the COMP voltage begins to recover but is less than Vcomp2, it is determined to be in light load state 1. Also, when the COMP voltage increases, if the COMP voltage is equal to or greater than Vcomp2 and less than Vcomp4, it is determined to be in light load state 2, and if it is equal to or greater than Vcomp4, it is determined to be in a heavy load state.

[0101] In the third embodiment, the high-level voltage value of the interleaved signal is changed depending on the load state. That is, the high-level voltage value of the interleaved signal is VIL1 in a heavy load state, VIL3 in a light load state 2, and VIL2 in a light load state 1. The magnitude relationship of each voltage value is VIL1>VIL3>VIL2.

[0102] The slave switch control circuit (follower) is provided with a first interleaved signal detection threshold voltage VIL_IN1 and a second interleaved signal detection threshold voltage VIL_IN2 lower than the first interleaved signal detection threshold voltage VIL_IN1 (see FIG. 9).

[0103] When the interleave input signal IL_IN is equal to or higher than the first interleave signal detection threshold voltage VIL_IN1, the interleave operation continues and an interleave signal whose high-level voltage value is the same level as the high-level voltage value of the interleave signal IL_OUT output from the reader is output. When the interleave input signal IL_IN is smaller than the first interleave signal detection threshold voltage VIL_IN1 and greater than or equal to the second interleave signal detection threshold voltage VIL_IN2, the interleave operation continues, but an interleave signal whose high-level voltage value is lower than the high-level voltage value of the interleave signal IL_OUT output from the reader is output. When the interleave input signal IL_IN is smaller than the second interleave signal detection threshold voltage VIL_IN2, the interleave operation is stopped.

[0104] (1) Heavy load condition The high-level voltage value of the interleaved signal IL_OUT output from the leader is VIL1, and since the slave converter 30 is provided with a voltage divider circuit, the high-level voltage value of the interleaved input signal IL_IN input to the follower is VIL1_D (see Figures 9 and 10(a)).

[0105] Because the high-level voltage value VIL1_D of the interleaved input signal IL_IN exceeds the first interleaved signal detection threshold voltage VIL_IN1, the slave converter 30 continues the interleaved operation and outputs to the slave converter 40 a voltage value VIL_OUT1 at the same level as the high-level voltage value of the interleaved signal IL_OUT output from the leader.

[0106] In follower 2 (sub-converter 40), the high-level voltage value of the interleaved signal IL_OUT output from follower 1 becomes VIL_OUT1 (see FIG. 10). This is then divided and input, so that the high-level voltage value of the interleaved input signal IL_IN of follower 2 becomes VIL_OUT1_D (see FIG. 10(b)).

[0107] Since the value of VIL_OUT1_D exceeds the first interleaved signal detection threshold voltage VIL_IN1, the slave converter 40 continues the interleaved operation and outputs to the slave converter 40 a voltage value VIL_OUT1 at the same level as the high-level voltage value of the interleaved signal IL_OUT output from the leader.

[0108] (2) Light load condition 2 In a light load state, the high-level voltage value of the interleaved signal IL_OUT output from the leader is VIL3, and since a voltage divider circuit is provided in the slave converter 30 in embodiment 3, the high-level voltage value of the interleaved input signal VIL_IN input to the follower becomes VIL3_D (see Figures 9 and 10(a)).

[0109] The high-level voltage value VIL3_D of the interleaved input signal IL_IN is equal to or lower than the first interleaved signal detection threshold voltage VIL_IN1 and is equal to or higher than the second interleaved signal detection threshold voltage VIL_IN2. In this case, the slave converter 30 continues the interleaving operation and outputs to the slave converter 40 an interleaved signal IL_OUT having a high-level voltage value VIL_OUT2 lower than the high-level voltage value of the interleaved signal IL_OUT output from the leader (see FIG. 11(a)).

[0110] In follower 2 (sub converter 40), the interleaved signal IL_OUT output from follower 1 is voltage-divided and input, so that the high-level voltage value of the interleaved input signal of follower 2 becomes VIL_OUT2_D (see FIG. 11(b)).

[0111] Since the high-level voltage value VIL_OUT2_D of the interleaved input signal of follower 2 falls below the first interleaved signal detection threshold voltages VIL_IN1 and VIL_IN2 of follower 2, the interleaving operation of follower 2 stops.

[0112] Therefore, in the light load state 2, the main converter 20 and the slave converter 30 can be operated, and some of the slave converters (the slave converter 40) can be stopped.

[0113] (3) Light load condition 1 In the light load state 1, the high level voltage value of the interleaved signal IL_OUT output from the leader is VIL2. In the third embodiment, since the slave converter 30 is provided with a voltage divider circuit, the high level voltage value of the interleaved input signal IL_IN input to the follower 1 is VIL2_D (see FIG. 9 and FIG. 10(a)).

[0114] The voltage value VIL2_D falls below the first interleaved signal detection threshold voltage VIL_IN1 and the second interleaved signal detection threshold voltage VIL_IN2. In this case, the gate output voltage OUT and the interleaved signal IL_OUT of the secondary converter 30 become low level, and the interleaving operation stops (see FIG. 11(b)).

[0115] In follower 2 (slave converter 40), since the interleave signal IL_OUT is not output from follower 1, follower 2 does not turn on.

[0116] Therefore, in the light load state 2, only the main converter 20 is operated and all the sub converters are stopped.

[0117] Thus, the control circuit and interleaved power supply according to the third embodiment differ from the control circuit 100 and interleaved power supply 1 according to the first embodiment in that three load states are provided in the load state judgment. However, like the control circuit 100 and interleaved power supply 1 according to the first embodiment, the load judgment unit generates load state information based on the error amplifier output voltage generated by a voltage based on the output voltage and outputs it to the interleaved signal generation unit, and the interleaved signal generation unit outputs an interleaved signal including information on whether or not to stop the slave switch control circuit that controls the switching operation of the slave switch based on the load state information and the control signal output information to the slave switch control circuit. Therefore, (1) it is unlikely that problems such as an increase in the number of terminals of the control circuit of the main converter, which results in an increase in size, or an increase in the number of terminals, which results in a need for design changes, will occur, (2) it is possible to monitor the load regardless of the cycle of the AC power supply, (3) new components and wiring are not required to obtain information on the output side, and the circuit configuration is unlikely to become complicated, and (4) it is possible to easily switch whether or not the slave converter is stopped under a light load without increasing the number of terminals of the control circuit of the main converter.

[0118] According to the control circuit and interleaved power supply of embodiment 3, by adopting the above-mentioned configuration, all the slave converters can be stopped in light load state 1, and in light load state 2, all or a predetermined number of the multiple slave converters can be stopped.

[0119] In addition, the control circuit and interleaved power supply of embodiment 3 have the same configuration as the control circuit 100 and interleaved power supply 1 of embodiment 1 except for the fact that three load states are provided in the load state determination, and therefore have the relevant effects among the effects possessed by the control circuit 100 and interleaved power supply 1 of embodiment 1.

[0120] [Variation 3] The control circuit and interleaved power supply of variant example 3 basically have the same configuration 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 it does not automatically stop the slave converter.

[0121] In the circuit configuration of the control circuit and the interleaved power supply 3 according to the third modification, a voltage divider circuit is not formed in either of the secondary converters 30 and 40, similar to the circuit configuration in FIG.

[0122] In the heavy load state, the high-level voltage value of the interleaved signal IL_OUT output from the leader 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. 12).

[0123] In the third modification, neither of the secondary converters 30, 40 has a voltage divider circuit formed therein, so the interleaved input signal IL_IN input to the secondary converter 30 is the same as the interleaved output signal. The high-level voltage values ​​VIL1, VIL3, and 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 secondary converter 30 continues the interleaved operation regardless of the load state (see FIGS. 12 and 13).

[0124] Moreover, since the voltage values ​​VIL1, VIL3, and 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 high-level voltage values ​​of the interleaved signals output to the secondary converter 40 are all voltage values ​​close to the voltage value VIL1. Therefore, the secondary converter 40 (and, if a secondary converter is further connected, the secondary converter) also continues the interleaved operation.

[0125] In this way, the control circuit and interleaved power supply according to the third modification differ from the control circuit and interleaved power supply according to the third embodiment in that the slave converter is not automatically stopped. However, like the control circuit and interleaved power supply according to the third embodiment, the load determination unit generates load state information based on the error amplifier output voltage generated by a voltage based on the output voltage and outputs it to the interleaved signal generation unit, and the interleaved signal generation unit outputs an interleaved signal including information on 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 based on the load state information and the control signal output information. Therefore, (1) it is unlikely that problems 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, resulting in the need for design changes, will occur, (2) it is possible to monitor the load regardless of the cycle of the AC power supply, (3) new components and wiring are not required to obtain information on the output side, and the circuit configuration is unlikely to become complicated, and (4) it is possible to easily switch whether or not the slave converter is stopped under a light load without increasing the number of terminals of the control circuit of the main converter.

[0126] The control circuit and interleaved power supply according to the third modification can maintain the interleaved operation regardless of the load state by adopting the above-mentioned configuration.

[0127] In addition, the control circuit and interleaved power supply of variant example 3 have the same configuration as the control circuit and interleaved power supply of embodiment 3 except that the control circuit and interleaved power supply do not automatically stop the slave converter, and therefore have the relevant effects among the effects of the control circuit and interleaved power supply of embodiment 3.

[0128] [Embodiment 4] The control circuit and interleaved power supply 3 of embodiment 4 basically have the same configuration 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 slave converter 30 performs an automatic stop function for interleaved operation, while the slave converter 40 does not perform an automatic stop function for interleaved operation.

[0129] In the interleaved power supply 3 according to the third embodiment, the secondary converter 30 has a voltage dividing circuit formed by resistors R9 and R10, while the secondary converter 40 does not have a voltage dividing circuit (see FIG. 14).

[0130] (1) Heavy load condition As in the third embodiment, the high-level voltage value of the interleaved signal IL_OUT output from the leader is VIL1. In the fourth embodiment, since the slave converter 30 has a voltage divider circuit, the high-level voltage value of the interleaved input signal IL_IN input to the follower 1 (second stage) is VIL1_D (see FIG. 15).

[0131] The voltage value VIL1_D is higher than the first interleaved signal detection threshold voltage VIL_IN1. Therefore, the follower 1 continues the interleaving operation and outputs the interleaved signal IL_OUT of the high-level voltage value VIL_OUT1, which is the same level as the high-level voltage value of the leader's interleaved signal IL_OUT, to the follower 2 (see FIG. 16(a)).

[0132] In the fourth embodiment, since the slave converter 40 does not have a voltage divider circuit, the high-level voltage value of the interleaved input signal IL_IN input to the follower 2 (third stage) remains at 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. If a fourth-stage follower 3 is provided, it outputs an interleaved signal IL_OUT having a high-level voltage value VIL_OUT1 that is the same as the high-level voltage value of the leader's interleaved signal IL_OUT.

[0133] (2) Light load condition 2 As in the third embodiment, the high-level voltage value of the interleaved signal IL_OUT output from the leader is VIL3. In the fourth embodiment, since the slave converter 30 has a voltage divider circuit, the high-level voltage value of the interleaved input signal IL_IN input to the follower 1 (second stage) is VIL3_D (see FIG. 15).

[0134] The voltage value VIL3_D is higher than the first interleaved signal detection threshold voltage VIL_IN1. Therefore, the follower 1 continues the interleaving operation and outputs the interleaved signal IL_OUT of the high-level voltage value VIL_OUT1, which is the same level as the high-level voltage value of the leader's interleaved signal IL_OUT, to the follower 2 (see FIG. 16(b)).

[0135] In the fourth embodiment, since the slave converter 40 does not have a voltage divider circuit, the high-level voltage value of the interleaved input signal IL_IN input to the follower 2 (third stage) remains at 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. If a fourth-stage follower 3 is provided, the follower 3 receives an interleaved signal IL_OUT having a high-level voltage value VIL_OUT1 that is the same as the high-level voltage value of the leader interleaved signal IL_OUT.

[0136] (3) Light load condition 1 As in the third embodiment, the high-level voltage value of the interleaved signal IL_OUT output from the leader is VIL2. In the fourth embodiment, since the slave converter 30 has a voltage divider circuit, the high-level voltage value of the interleaved input signal IL_IN input to the follower 1 (second stage) is VIL2_D (see FIG. 15).

[0137] The voltage value VIL2_D is lower than the second interleaved signal detection threshold voltage VIL_IN2. Therefore, the follower 1 stops the interleaving operation and does not output the interleaved signal IL_OUT (see FIG. 16(c)).

[0138] Since the interleave signal is not output to follower 2 (third stage), follower 2 also stops interleave operation.

[0139] Therefore, in heavy load condition and light load condition 2, all converters are operated, but in light load condition 1, only the main converter (leader) can be operated.

[0140] Thus, the control circuit and interleaved power supply of embodiment 4 differs from the control circuit and interleaved power supply of embodiment 3 in that the slave converter 30 performs an automatic stop function of the interleaved operation while the slave converter 40 does not perform an automatic stop function of the interleaved operation. However, like the control circuit and interleaved power supply of embodiment 3, (1) it is less likely to cause problems 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 resulting in the need for design changes, (2) it is possible to monitor the load without depending on the cycle of the AC power supply, (3) new components and wiring are not required to obtain information on the output side, and the circuit configuration is less likely to become complicated, and (4) it is a control circuit that can easily switch whether or not the slave converter is stopped under light load without increasing the number of terminals of the control circuit of the main converter.

[0141] Furthermore, with the control circuit and interleaved power supply of embodiment 4, as configured as described above, in the case of light load condition 1, only the main converter is operated and the sub converter is automatically stopped, and in the case of heavy load condition and light load condition 2, all converters can be operated in an interleaved manner.

[0142] In addition, the control circuit and interleaved power supply of embodiment 4 have the same configuration as the control circuit and interleaved power supply of embodiment 3, except that the slave converter 30 performs an automatic stopping function of the interleaved operation, but the slave converter 40 does not perform an automatic stopping function of the interleaved operation, and therefore have the corresponding effects among the effects of the control circuit and interleaved power supply of embodiment 3.

[0143] [Embodiment 5] The control circuit and interleaved power supply according to the fifth embodiment basically have the same configuration as the control circuit and interleaved power supply according to the fourth embodiment, but the operation in the light load state 2 is different from that of the control circuit and interleaved power supply according to the fourth embodiment. Note that the operation in the heavy load state and the light load state 1 is the same as that of the fourth embodiment, and therefore the description thereof will be omitted.

[0144] As in the fourth embodiment, in the light load state 2, the high level voltage value of the interleaved signal IL_OUT output from the leader is VIL3. In the fourth embodiment, since the slave converter 30 has a voltage divider circuit, the high level voltage value of the interleaved input signal IL_IN input to the follower 1 (second stage) is VIL3_D (see FIG. 17).

[0145] The voltage value VIL3_D is lower than the second interleaved signal detection threshold voltage VIL_IN2. Therefore, the follower 1 stops the interleaving operation and does not output the interleaved signal IL_OUT (see FIG. 18(b)).

[0146] Therefore, in heavy load conditions, all converters are operated, but in light load conditions 1 and 2, only the main converter (leader) can be operated.

[0147] When 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 follower 1 and follower 2 perform the interleaved operation.

[0148] In this way, the operation of the control circuit and interleaved power supply according to embodiment 5 in the light load state 2 is different from that of the control circuit and interleaved power supply according to embodiment 4. However, as in the case of the control circuit and interleaved power supply according to embodiment 4, the load determination unit generates load state information based on the error amplifier output voltage generated by a voltage based on the output voltage and outputs it to the interleaved signal generation unit, and the interleaved signal generation unit outputs an interleaved signal including information on 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 based on the load state information and the control signal output information. Therefore, (1) it is unlikely that problems 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, which requires a change in design, will occur, (2) it is possible to monitor the load regardless of the cycle of the AC power supply, (3) new components and wiring are not required to obtain information on the output side, and the circuit configuration is unlikely to become complicated, and (4) it is possible to easily switch whether or not the slave converter is stopped during a light load without increasing the number of terminals of the control circuit of the main converter.

[0149] In addition, the control circuit and interleaved power supply of embodiment 5 have the same configuration as the control circuit and interleaved power supply of embodiment 4 except for the operation in light load state 2, and therefore have the relevant effects among the effects of the control circuit and interleaved power supply of embodiment 4.

[0150] [Embodiment 6] The control circuit 101 and interleaved power supply of embodiment 6 basically have the same configuration as the control circuit 100 and interleaved power supply 1 of embodiment 1, but differs from the control circuit 100 and interleaved power supply 1 of embodiment 1 in that the load state determination threshold voltage varies depending on the input voltage.

[0151] In the first embodiment, as shown in Fig. 20(c), the load state determination threshold voltages Vcomp1, Vcomp2 that are independent of the input voltage are used, but in the sixth embodiment, the load state determination threshold voltages Vcomp1, Vcomp2 are adjusted based on the input voltage. Specifically, the load state determination threshold voltages Vcomp1, Vcomp2 are adjusted to be smaller when the input voltage exceeds a predetermined input voltage threshold voltage (see Fig. 20(a)), and the load state determination threshold voltages Vcomp1, Vcomp2 are adjusted to be linearly decreased as the input voltage increases (see Fig. 20(b)).

[0152] The load state determination unit 120 is connected to the front or rear stage of the rectifier circuit 10 via an input voltage monitoring terminal, and receives input voltage information obtained by dividing the input voltage (see FIG. 19). Specifically, the load state determination unit 120 may be connected to two power supply lines connected from the power source AC-IN to the rectifier circuit 10, and the input voltage information may be divided therefrom and input to the input voltage monitoring terminal (see FIG. 21(a)), or may be connected to two power supply lines connected from the rectifier circuit 10 to the main converter 20, and the input voltage information may be divided therefrom and input to the input voltage monitoring terminal (see FIG. 21(b)).

[0153] Thus, the control circuit and interleaved power supply according to the sixth embodiment differ from the control circuit 100 and interleaved power supply 1 according to the first embodiment in that the load state determination threshold voltage varies depending on the input voltage. However, like the control circuit 100 and interleaved power supply 1 according to the first embodiment, the load determination unit generates load state information based on the error amplifier output voltage generated by a voltage based on the output voltage and outputs it to the interleaved signal generation unit, and the interleaved signal generation unit outputs an interleaved signal including information on whether or not to stop the slave switch control circuit that controls the switching operation of the slave switch based on the load state information and the control signal output information to the slave switch control circuit. Therefore, (1) it is unlikely that problems such as an increase in the number of terminals of the control circuit of the main converter, which results in an increase in size, or an increase in the number of terminals, which results in a need for design changes, will occur, (2) it is possible to monitor the load regardless of the cycle of the AC power supply, (3) new components and wiring are not required to obtain information on the output side, and the circuit configuration is unlikely to become complicated, and (4) it is possible to easily switch whether or not the slave converter is stopped under a light load without increasing the number of terminals of the control circuit of the main converter.

[0154] Incidentally, in an interleaved power supply, even with the same ON width (COMP voltage), a large difference occurs in output power between the case of a high input voltage and the case of a low input voltage. In contrast, in the control circuit and interleaved power supply according to the sixth embodiment, the load condition determination unit 120 adjusts the load condition determination threshold voltage based on the input voltage, so that the difference in output power (load) at which it is determined that the follower should be stopped can be reduced.

[0155] In addition, the control circuit and interleaved power supply of embodiment 6 have the same configuration as the control circuit 100 and interleaved power supply 1 of embodiment 1 except that the load state determination threshold voltage varies depending on the input voltage, and therefore have the relevant effects among the effects of the control circuit 100 and interleaved power supply 1 of embodiment 1.

[0156] Although the present invention has been described based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiment 1. It can be embodied in various forms without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0157] (1) The positions, connections, quantities, etc. described in the above embodiments (including the modified examples; the same applies below) are merely examples and may be changed without impairing the effects of the present invention.

[0158] (2) In each of the above embodiments, two stages of slave converters are provided (three stages in total), but the present invention is not limited to this. One stage of slave converters (two stages in total) may be provided, or three or more stages of slave converters (four or more stages in total) may be provided. Furthermore, when three or more stages of slave converters (four or more stages in total) are provided, the number of converters having an automatic stop function may be appropriately determined, such as by providing three or more interleave signal detection threshold voltages in the slave converters to stop the second stage onwards, or by stopping the third stage onwards.

[0159] (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 invention is not limited to this. A light load state 3, a light load state 4, etc. may be selected more finely. In this case, the number of load state determination threshold voltages may be determined to be six or eight.

[0160] (4) In the above-mentioned embodiment 1, the on-trigger is output from the on-trigger generating unit 130 to the gate control unit 150, not from the outside, but the present invention is not limited to this. The main switch control circuit 100 may further include a zero current detection unit 180 that detects the timing when the inductor current becomes zero, the on-trigger generating unit may generate an on-trigger based on the timing detected by the zero current detection unit 180 and output it to the gate control unit 150, and the gate control unit 150 may output a control signal to the gate control unit 150 at the timing when the inductor current becomes zero based on the on-trigger (see the control circuit 100a according to the third modification, FIG. 22). In this case, the main converter 20 and the sub converters 30, 40 all perform current criticality operation.

[0161] (5) In the above embodiment 1, the critical point of the input current of the slave converter is detected by detecting the choke current of the inductor using an auxiliary winding arranged opposite the inductor, but the present invention is not limited to this. The critical point of the input current of the slave converter may be detected by detecting a zero voltage point from the drain voltage of the master switch or the slave switch. [Explanation of symbols]

[0162] 1, 2, 3... interleaved power supply, 20... main converter, 30, 40... slave converter, 100... main switch control circuit (leader), 200a, 200b... slave switch control circuit (follower), 120... load state determination unit, 130... on-trigger generation unit, 140... on-width calculation unit, 150... gate control unit, 160... drive unit, 170... interleaved signal generation unit, Q1... main switch, Q2, Q3... slave switches

Claims

1. A control circuit for controlling the switching operation of the main switch for an interleaved power supply including a main converter having a main switch that performs a switching operation, and a slave converter having a slave switch that performs switching with a predetermined phase difference with respect to the switching operation of the main switch, the control circuit comprising: the control circuit includes a load state determination unit, an on-trigger generation unit, a gate control unit, a drive unit, and an interleave signal generation unit; The load condition determination unit determines a load condition based on an error amplifier output voltage generated by a voltage based on an output voltage, and outputs the determined load condition information to the interleave signal generation unit; the on-trigger generating unit generates an on-trigger and outputs it to the gate control unit; the gate control unit outputs a control signal having an on-width calculated based on the error amplifier output voltage to the drive unit with a predetermined phase difference based on the on-trigger, and outputs control signal output information to the interleave signal generation unit; The drive unit turns the main switch on and off based on the control signal, The control circuit is characterized in that the interleave signal generating unit outputs an interleave signal including information on whether or not to stop a slave switch control circuit that controls the switching operation of the slave switch based on the load state information and the control signal output information to the slave converter.

2. 2. The control circuit according to claim 1, wherein the interleave signal generation unit outputs the interleave signal, the voltage value of which is adjusted when at a high level, to the slave switch control circuit as information on whether or not to stop the slave switch control circuit.

3. 3. The control circuit according to claim 2, wherein the interleave signal generating unit outputs to the slave switch control circuit, as information on whether or not to stop the slave switch control circuit, the interleave signal being adjusted so that a high-level voltage value when it is determined that the load state is light is lower than a high-level voltage value when it is determined that the load state is heavy.

4. 3. The control circuit according to claim 2, wherein the interleave signal generating unit outputs to the slave switch control circuit, as information on whether or not to stop the slave switch control circuit, the interleave signal being adjusted so that a high-level voltage value when it is determined that the load state is light is higher than a high-level voltage value when it is determined that the load state is heavy.

5. the load condition determination unit determines a load condition based on whether or not the error amplifier output voltage exceeds a load condition determination threshold voltage; 5. The control circuit according to claim 1, wherein the load condition determination threshold voltage when the error amplifier output voltage is increasing is greater than the load condition determination threshold voltage when the error amplifier output voltage is decreasing.

6. the load condition determination unit determines a load condition based on whether or not the error amplifier output voltage exceeds a load condition determination threshold voltage; 5. The control circuit according to claim 1, wherein the load condition determination unit adjusts the load condition determination threshold voltage based on an input voltage.

7. A zero current detection unit detects a timing when the inductor current becomes zero, the on-trigger generating unit generates the on-trigger based on the timing detected by the zero current detecting unit and outputs the on-trigger to the gate control unit; 5. The control circuit according to claim 1, wherein the gate control unit outputs the control signal to the gate control unit at a timing when an inductor current becomes zero based on the on-trigger.

8. An interleaved power supply comprising: a main converter having a main switch that performs a switching operation; and a slave converter having a slave switch that performs switching with a predetermined phase difference with respect to the switching operation of the main switch, wherein a master-slave relationship is formed between the main converter and the slave converter, A main switch control circuit that controls a switching operation of the main switch is a control circuit according to any one of claims 1 to 4, and outputs an interleave signal including information on whether or not to stop a slave switch control circuit that controls a switching operation of the slave switch to the slave switch control circuit; 11. The interleaved power supply according to claim 10, wherein the slave switch control circuit judges whether or not to stop the slave switch control circuit based on an interleave input signal when the interleave signal is input to the slave switch control circuit.

9. 9. The interleaved power supply according to claim 8, wherein the secondary converter has a voltage dividing circuit for dividing the interleaved signal.

10. The slave converter includes a plurality of slave converters, 9. The interleaved power supply according to claim 8, wherein at least one of the plurality of slave converters includes a voltage divider circuit that divides the interleaved signal.

11. the slave switch control circuit determines whether to stop the slave switch control circuit depending on whether a high-level voltage value of the interleaved input signal exceeds a predetermined interleaved signal detection threshold voltage; When the load state determination unit determines that the load is heavy, the high-level voltage value of the interleaved signal output from the main switch control circuit is set to VIL1, and when the load state determination unit determines that the load is light, the high-level voltage value of the interleaved signal output from the main switch control circuit is set to VIL2, and the interleaved signal detection threshold voltage is set to VIL_IN1. VIL1>VIL2>VIL_IN1 is satisfied, In the case where a voltage divider circuit is disposed in the slave converter, and the interleaved signal is divided by the voltage divider circuit and input to the slave switch control circuit, if the load condition determination unit determines that the load is heavy, the high level voltage value of the interleaved input signal is set to VIL1_D, and if the load condition determination unit determines that the load is light, the high level voltage value of the interleaved input signal is set to VIL2_D, 9. The interleaved power supply according to claim 8, wherein the voltage divider circuits are arranged so as to satisfy VIL1_D>VIL_IN1 and VIL2_D<VIL_IN1.

12. the slave switch control circuit determines whether to stop the slave switch control circuit depending on whether a high-level voltage value of the interleaved input signal is within a range from a predetermined interleaved signal detection threshold voltage to a predetermined interleaved operation stop threshold voltage; When the load state determination unit determines that the load is heavy, the high-level voltage value of the interleaved signal output from the main switch control circuit is set to VIL1, and when the load state determination unit determines that the load is light, the high-level voltage value of the interleaved signal output from the main switch control circuit is set to VIL2, 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 the case where a voltage divider circuit is disposed in the slave converter, and the interleaved signal is divided by the voltage divider circuit and input to the slave switch control circuit, if the load condition determination unit determines that the load is heavy, the high level voltage value of the interleaved input signal is set to VIL1_D, and if the load condition determination unit determines that the load is light, the high level voltage value of the interleaved input signal is set to VIL2_D, 9. The interleaved power supply according to claim 8, wherein the voltage divider circuits are arranged so as to satisfy VIL_IN1_stop>VIL1_D>VIL_IN1 and VIL_IN1_stop>VIL2_D>VIL_IN1.

13. The slave converter includes a plurality of slave converters, Each of the slave switch control circuits in the slave converter 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 for the interleaved signal; In a case where the interleave signal is directly input to the slave switch control circuit, or in a case where a voltage divider circuit is arranged in the slave converter and the interleave signal is divided by the voltage divider circuit and input to the slave switch control circuit, (1) When the high-level voltage value of the interleaved input signal exceeds a first interleaved signal detection threshold voltage, the slave switch control circuit causes a slave converter having the slave switch control circuit to continue an interleaved operation and outputs an interleaved signal having a voltage value equal to the high-level voltage value of the interleaved signal output from the main switch control circuit; (2) When the high-level voltage value of the interleaved input signal is equal to or lower than a first interleaved signal detection threshold voltage and equal to or higher than a second interleaved signal detection threshold voltage, the slave switch control circuit causes the slave converter having the slave switch control circuit to continue the interleaved operation and outputs an interleaved signal having a voltage value at a level lower than the high-level voltage value of the interleaved signal output from the main switch control circuit; (3) When the high-level voltage value of the interleaved signal is less than a second interleaved signal detection threshold voltage, the slave switch control circuit causes the slave converter having the slave switch control circuit to stop the interleaved operation and to stop outputting the interleaved signal.

9. An interleaved power supply as claimed in claim 8.

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