Expandable scalable power supply system

Abstract

A power supply system (100) comprises an MPU (20), a plurality of power conversion circuits (11–14), and a plurality of scale control circuits (31, 32). The MPU (20) supplies a digital switching driving signal (PWM11) to the power conversion circuit (11) and supplies a digital switching driving signal (PWM13) to the power conversion circuit (13). The scale control circuit (31) comprises a CR circuit, and generates and supplies to the power conversion circuit (12) a switching driving signal (PWM12) that is delayed relative to the digital switching driving signal (PWM11). The scale control circuit (32) comprises a CR circuit, and generates and supplies to the power conversion circuit (14) a switching driving signal (PWM14) that is delayed relative to the digital switching driving signal (PWM13).

Description

[Technical field]

[0001] The present invention relates to a power supply system having a plurality of power conversion circuits, and more particularly to a scalable power supply system. [Background technology]

[0002] Patent Document 1 describes a switching power supply device. The switching power supply device described in Patent Document 1 includes a plurality of pulse compensators. The plurality of pulse compensators generate individual pulse signals that drive a plurality of power conversion circuits. The plurality of pulse compensators cause the phases of the plurality of individual pulse signals to differ, thereby realizing multi-phase operation.

[0003] Patent Document 2 describes a multiphase DC-DC converter. The multiphase DC-DC converter described in Patent Document 2 includes a plurality of delay circuits. The plurality of delay circuits delay the PWM drive signal output by the control circuit. The control circuit and the plurality of delay circuits supply the PWM drive signal and the delayed PWM drive signal to the converter drive unit connected in the subsequent stage, respectively. This realizes multiphase drive.

[0004] Patent Document 3 describes a DCDC converter. The DCDC converter in Patent Document 3 includes a phase controller. The phase controller detects the state of the DCDC converter and dynamically changes the number of drive phases. The phase controller provides the number of drive phases to a distributor, which distributes one pulse signal to multiple pulse signals set with a phase difference according to the number of drive phases, and provides the multiple pulse signals to a driver IC. This realizes multi-phase drive.

[0005] Patent Document 4 describes a power supply semiconductor device. The power supply semiconductor device described in Patent Document 4 includes multiple drive ICs with timers. The multiple drive ICs with timers are connected in a ring shape and send trigger signals in sequence. Based on the trigger signals, the multiple drive ICs with timers control switching while shifting the time in sequence. This achieves multi-phase driving.

[0006] Patent Document 5 describes a multi-phase DC-DC converter. The multi-phase DC-DC converter described in Patent Document 5 includes a phase control unit and a pulse distribution unit. The phase control unit sets the number of drive phases and provides it to the pulse distribution unit. The pulse distribution unit distributes multiple pulses included in one drive signal to multiple drive signals according to the number of drive phases so that the pulses do not overlap. This realizes multi-phase drive. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-176606 A [Patent Document 2] JP 2015-146711 A [Patent Document 3] JP 2014-87185 A [Patent Document 4] JP 2013-94058 A [Patent Document 5] JP 2010-119117 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, in each of the devices shown in the above-mentioned Patent Documents 1 to 5, the configuration for generating a plurality of pulse signals (PWM drive signals) according to the number of phases is complicated, and a special custom IC must be designed each time.

[0009] In addition, interleaved distribution circuits have been proposed in the past, but because the signal frequency decreases according to the number of distributions, the transient response deteriorates and the circuit cannot be used depending on the control range of the converter's operating frequency. This problem can be solved by increasing the frequency of the input signal according to the number of distributions, but in many cases this cannot be achieved due to the upper limit of the operating frequency of the control circuit made of semiconductors.

[0010] Therefore, an object of the present invention is to provide a scale-up scalable power supply system that has a simple configuration, can suppress a decrease in power conversion efficiency, and can achieve multi-phase drive according to the number of power conversion circuits to be driven without being limited by the number of drive outputs of the control IC. [Means for solving the problem]

[0011] The scale-up scalable power supply system of the present invention includes a plurality of power conversion circuits, a power management control circuit, and an extended control circuit. Each of the plurality of power conversion circuits includes an inductor, a power semiconductor circuit including a switching element that controls a current flowing through the inductor, and a drive unit that drives the switching element. The power management control circuit generates a first digital switching drive signal to be provided to a first power semiconductor circuit in the plurality of power semiconductor circuits.

[0012] The extended control circuit is electrically connected between the power management control circuit and a second power semiconductor circuit different from the first power semiconductor circuit in the plurality of power semiconductor circuits. The extended control circuit generates a second switching drive signal from the first digital switching drive signal and provides the second switching drive signal to the second power semiconductor circuit. The extended control circuit has a voltage-time conversion circuit that sets a predetermined signal delay time for the first digital switching drive signal to generate the second switching drive signal.

[0013] The voltage-time conversion circuit has a threshold signal conversion circuit that determines a signal delay time using a time constant and a threshold voltage of a CR circuit that is made up of a resistor and a capacitor.

[0014] The expansion control circuit sets the phase of the second analog switching drive signal, which is the basis of the second switching drive signal, using the time constant of the CR circuit of the threshold signal conversion circuit. The expansion control circuit sets the on-time width of the second switching drive signal to be the same as the on-time width of the first digital switching drive signal, using the threshold voltage of the threshold signal conversion circuit and the second analog switching signal after the phase is set. The expansion control circuit determines the number of the multiple power conversion circuits according to the total number of signals obtained by adding the first number of signals of the first digital switching drive signal to the second number of signals of the second switching drive signal.

[0015] In this configuration, a second switching drive signal that is out of phase with the first digital switching drive signal and has the same on-time width as the first digital switching drive signal is generated from a first digital switching drive signal output from one power management control circuit. The first digital switching drive signal and the second switching drive signal are each provided to separate power conversion circuits, thereby achieving multi-phase drive.

[0016] Furthermore, since the second switching drive signal is a delayed version of the first digital switching drive signal, the switching frequency is maintained without decreasing even if the number of power conversion circuits increases.

[0017] Furthermore, the extended control circuit that generates the second switching drive signal is a CR circuit made up of a resistor and a capacitor, and therefore has a simple configuration. Effect of the Invention

[0018] According to the present invention, it is possible to provide a scale-expandable scalable power supply system that realizes multi-phase drive that has a simple configuration in which an extension circuit is connected to a control IC, consumes little power in the extension circuit to suppress a decrease in power conversion efficiency, and can flexibly respond to an increase in current according to the number of power conversion circuits to be driven without being limited by the number of drive outputs of the control IC, thereby enabling the scale of the output power capacity to be expanded. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a circuit block diagram showing an example of a power supply system according to the first embodiment. [Diagram 2] FIG. 2 is a circuit diagram illustrating an example of a configuration of the extension control circuit according to the first embodiment. [Diagram 3] FIG. 3 is a waveform diagram showing an example of the switching drive signal and the gate voltage signal. [Figure 4] 4(A) and 4(B) are functional block diagrams showing an example of the effectiveness of the power supply system according to the first embodiment of the present invention. [Diagram 5] FIG. 5 is a circuit block diagram showing an extended control circuit portion of a power supply system according to the second embodiment. [Figure 6] FIG. 6 is a waveform diagram showing an example of the switching drive signal and the gate voltage signal. [Figure 7] FIG. 7 is a circuit block diagram showing an extended control circuit portion of a power supply system according to the third embodiment. [Figure 8] FIG. 8 is a waveform diagram showing an example of the switching drive signal and the gate voltage signal. [Figure 9] FIG. 9 is a circuit block diagram illustrating an example of a power supply system according to the fourth embodiment. [Figure 10] FIG. 10 is a waveform diagram showing an example of the switching drive signal and the gate voltage signal. [Figure 11] FIG. 11 is a circuit block diagram showing an example of a power supply system according to the fifth embodiment. [Figure 12]FIG. 12 is a waveform diagram showing an example of the switching drive signal and the gate voltage signal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] In this application, the term "expandable power supply system" refers to a power supply system in which the number of power conversion circuits used for multi-phase driving can be set to a desired number. For example, the term refers to a power supply system in which the number of power conversion circuits required for the system can be appropriately set to achieve a desired output current value at a desired output voltage value with high efficiency. In the following, the scale-expandable power supply system is simply referred to as a power supply system.

[0021] [First embodiment] A power supply system according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a circuit block diagram showing an example of the power supply system according to the first embodiment.

[0022] As shown in FIG. 1, the power supply system 100 includes a plurality of power conversion circuits 11-14 (power conversion circuit 11, power conversion circuit 12, power conversion circuit 13, power conversion circuit 14), an MPU 20, and a plurality of extension control circuits 31-32 (extension control circuit 31, extension control circuit 32). In this embodiment, the number of power conversion circuits is four, but the configuration of this embodiment can be applied if there are two or more power conversion circuits. Also, the number of extension control circuits is two, but this can be set according to the number of power conversion circuits and the number of digital switching drive signals that can be output from the MPU 20 with different phases.

[0023] (Schematic configuration of power supply system 100) The power supply system 100 includes a common input terminal Pin and a common output terminal Pout. The common input terminal Pin is connected to an external DC voltage source (input power supply). The power supply system 100 receives a DC input voltage Vin from the common input terminal Pin. The common output terminal Pout is connected to a load Ro. The voltage of the common output terminal Pout becomes the output voltage Vout of the power supply system 100.

[0024] The MPU 20 is connected to a common input terminal Pin and is supplied with power through the common input terminal Pin. In practice, a regulator or the like is connected to the power input terminal of the MPU 20 and power is supplied through the regulator. This power supply line is connected to the ground reference potential through an input capacitor Ci1.

[0025] The MPU 20 is a programmable micro processing unit and is realized by an IC that realizes a multi-phase controller, etc. The MPU 20 corresponds to the "power management control circuit" of the present invention.

[0026] The MPU 20 is connected to the power conversion circuit 11 and the power conversion circuit 13 .

[0027] An input terminal of the extension control circuit 31 is connected to the connection line between the MPU 20 and the power conversion circuit 11, and an output terminal of the extension control circuit 31 is connected to the power conversion circuit 12. An input terminal of the extension control circuit 32 is connected to the connection line between the MPU 20 and the power conversion circuit 13, and an output terminal of the extension control circuit 32 is connected to the power conversion circuit 14.

[0028] The power conversion circuits 11-14 are connected to a common input terminal Pin and are supplied with power through the common input terminal Pin. The power supply line of the power conversion circuit 11 is connected to the ground reference potential through an input capacitor Ci1. The power supply line of the power conversion circuit 12 is connected to the ground reference potential through an input capacitor Ci2. The power supply line of the power conversion circuit 13 is connected to the ground reference potential through an input capacitor Ci3. The power supply line of the power conversion circuit 14 is connected to the ground reference potential through an input capacitor Ci4.

[0029] The output terminal of power conversion circuit 11, the output terminal of power conversion circuit 12, the output terminal of power conversion circuit 13, and the output terminal of power conversion circuit 14 are connected to each other at an output common node and connected to a common output terminal Pout through the output common node.

[0030] The power conversion circuits 11-14 each individually and in parallel execute a power conversion operation of converting an input voltage Vin into an output voltage Vout. The power conversion circuits 11-14 have the same circuit configuration.

[0031] 1, the power conversion circuit 11 includes a driving unit 110, a switching element Q1H, a switching element Q1L, and an inductor L1. The driving unit 110, the switching element Q1H, and the switching element Q1L are formed, for example, by an integrated FET-integrated PWM control IC (analog circuit IC). The circuit unit consisting of the driving unit 110, the switching element Q1H, and the switching element Q1L corresponds to the "power semiconductor circuit" of the present invention.

[0032] The driving unit 110 is connected to a common input terminal Pin and is supplied with power through the common input terminal Pin. The driving unit 110 is connected to the MPU 20. The gates of the switching elements Q1H and Q1L are connected to the driving unit 110.

[0033] The drain of the switching element Q1H is connected to the common input terminal Pin. The source of the switching element Q1H and the drain of the switching element Q1L are connected. The source of the switching element Q1L is connected to the ground reference potential. One end of the inductor L1 is connected to the node of the switching element Q1H and the switching element Q1L, and the other end of the inductor L1 is connected to the output common node.

[0034] The power conversion circuit 12 includes a drive unit 120, a switching element Q2H, a switching element Q2L, and an inductor L2. The drive unit 120, the switching element Q2H, and the switching element Q2L are formed, for example, by an integrated FET-integrated PWM control IC (analog circuit IC). The circuit unit consisting of the drive unit 120, the switching element Q2H, and the switching element Q2L corresponds to the "power semiconductor circuit" of the present invention.

[0035] The driving unit 120 is connected to a common input terminal Pin and is supplied with power through the common input terminal Pin. The driving unit 120 is connected to the extension control circuit 31. The gate of the switching element Q2H and the gate of the switching element Q2L are connected to the driving unit 120.

[0036] The drain of the switching element Q2H is connected to the common input terminal Pin. The source of the switching element Q2H and the drain of the switching element Q2L are connected. The source of the switching element Q2L is connected to the ground reference potential. One end of the inductor L2 is connected to the node of the switching element Q2H and the switching element Q2L, and the other end of the inductor L2 is connected to the output common node.

[0037] The power conversion circuit 13 includes a drive unit 130, a switching element Q3H, a switching element Q3L, and an inductor L3. The drive unit 130, the switching element Q3H, and the switching element Q3L are formed, for example, by an integrated FET-integrated PWM control IC (analog circuit IC). The circuit unit consisting of the drive unit 130, the switching element Q3H, and the switching element Q3L corresponds to the "power semiconductor circuit" of the present invention.

[0038] The driver 130 is connected to a common input terminal Pin and is supplied with power through the common input terminal Pin. The driver 130 is connected to the MPU 20 by a line separate from that of the driver 110. The gates of the switching elements Q3H and Q3L are connected to the driver 130.

[0039] The drain of switching element Q3H is connected to the common input terminal Pin. The source of switching element Q3H and the drain of switching element Q3L are connected. The source of switching element Q3L is connected to the ground reference potential. One end of inductor L3 is connected to the node of switching element Q3H and switching element Q3L, and the other end of inductor L3 is connected to the output common node.

[0040] The power conversion circuit 14 includes a driving unit 140, a switching element Q4H, a switching element Q4L, and an inductor L4. The driving unit 140, the switching element Q4H, and the switching element Q4L are formed, for example, by an integrated FET-integrated PWM control IC (analog circuit IC). The circuit unit consisting of the driving unit 140, the switching element Q4H, and the switching element Q4L corresponds to the "power semiconductor circuit" of the present invention.

[0041] The driving unit 140 is connected to the common input terminal Pin and is supplied with power through the common input terminal Pin. The driving unit 140 is connected to the extension control circuit 32. The gate of the switching element Q4H and the gate of the switching element Q4L are connected to the driving unit 140.

[0042] The drain of switching element Q4H is connected to the common input terminal Pin. The source of switching element Q4H and the drain of switching element Q4L are connected. The source of switching element Q4L is connected to the ground reference potential. One end of inductor L4 is connected to the node of switching element Q4H and switching element Q4L, and the other end of inductor L4 is connected to the output common node.

[0043] The common output terminal Pout is connected to the ground reference potential through an output capacitor Co.

[0044] The output voltage Vout of the common output terminal Pout is fed back to the MPU 20 via a voltage feedback circuit vFB. At this time, although detailed circuitry is omitted, the voltage feedback circuit vFB converts the output voltage Vout into a voltage that can be input by the MPU 20 and feeds it back to the MPU 20.

[0045] Although detailed circuits are omitted, the multiple power conversion circuits 11 detect the inductor current of inductor L1 and feed back the inductor current detection value of inductor L1 to the MPU 20 through an individual current feedback circuit iFB11. The multiple power conversion circuits 12 detect the inductor current of inductor L2 and feed back the inductor current detection value of inductor L2 to the MPU 20 through an individual current feedback circuit iFB12. The multiple power conversion circuits 13 detect the inductor current of inductor L3 and feed back the inductor current detection value of inductor L3 to the MPU 20 through an individual current feedback circuit iFB13. The multiple power conversion circuits 14 detect the inductor current of inductor L4 and feed back the inductor current detection value of inductor L4 to the MPU 20 through an individual current feedback circuit iFB14.

[0046] (Detailed explanation of multi-phase drive) The MPU20 generates a digital switching drive signal PWM11 for the power conversion circuit 11 and a digital switching drive signal PWM13 for the power conversion circuit 13. The digital switching drive signal PWM11 and the digital switching drive signal PWM13 are rectangular wave signals. The digital switching drive signal PWM11 and the digital switching drive signal PWM13 have the same frequency and a predetermined phase difference (not the same phase). In this case, since the number of power conversion circuits to which the MPU20 outputs switching drive signals is two, the phase difference between the digital switching drive signal PWM11 and the digital switching drive signal PWM13 is set to, for example, 180° (=360° / 2). The digital switching drive signal PWM11 and the digital switching drive signal PWM13 correspond to the "first digital switching drive signal" of the present invention.

[0047] The MPU 20 outputs the digital switching drive signal PWM11 to the drive unit 110 of the power conversion circuit 11, and outputs the digital switching drive signal PWM13 to the drive unit 130 of the power conversion circuit 13. At this time, the MPU 20 outputs the digital switching drive signal PWM11 and the digital switching drive signal PWM13 in synchronization with each other.

[0048] The extension control circuit 31 generates an analog switching drive signal PWM12 (symbol not shown) based on the digital switching drive signal PWM11, and outputs it to the drive unit 120 of the power conversion circuit 12. Although details will be described later, the analog switching drive signal PWM12 is a signal in which the rising and falling edges of a rectangular pulse are slower than those of the digital switching drive signal PWM11.

[0049] At this time, the extension control circuit 31 generates the analog switching drive signal PWM12 so that the on-time width of the analog switching drive signal PWM12 is the same as the on-time width of the digital switching drive signal PWM11. More specifically, the extension control circuit 31 generates the analog switching drive signal PWM12 so that the time difference between the on-voltage threshold value THon and the off-voltage threshold value THoff in the drive unit 120 of the power conversion circuit 12 is the same as the on-time width of the digital switching drive signal PWM11.

[0050] Moreover, the extension control circuit 31 sets the on-time of the analog switching drive signal PWM12 to be delayed by a predetermined time with respect to the on-time of the digital switching drive signal PWM11. The phase difference between the digital switching drive signal PWM11 and the analog switching drive signal PWM12 is set shorter than the phase difference between the digital switching drive signal PWM11 and the digital switching drive signal PWM13 (the phase difference between the two digital switching drive signals). The analog switching drive signal PWM12 corresponds to the "second switching drive signal" of the present invention.

[0051] The extension control circuit 32 generates an analog switching drive signal PWM14 (symbol not shown) based on the digital switching drive signal PWM13, and outputs it to the drive unit 140 of the power conversion circuit 14. Although details will be described later, the analog switching drive signal PWM14 is a signal in which the rising and falling edges of a rectangular pulse are slower than those of the digital switching drive signal PWM13.

[0052] At this time, the extension control circuit 32 generates the analog switching drive signal PWM14 so that the on-time width of the analog switching drive signal PWM14 is the same as the on-time width of the digital switching drive signal PWM13. More specifically, the extension control circuit 32 generates the analog switching drive signal PWM14 so that the time difference between the on-voltage threshold value THon and the off-voltage threshold value THoff in the drive unit 140 of the power conversion circuit 14 is the same as the on-time width of the digital switching drive signal PWM13.

[0053] The extension control circuit 31 also sets the ON time of the analog switching drive signal PWM12 to be delayed by a predetermined time with respect to the ON time of the digital switching drive signal PWM11. This delay time is set so that the phase difference between the digital switching drive signal PWM13 and the analog switching drive signal PWM14 is shorter than the phase difference between the digital switching drive signal PWM13 and the digital switching drive signal PWM11 (the phase difference between the two digital switching drive signals). The analog switching drive signal PWM14 corresponds to the "second switching drive signal" of the present invention.

[0054] The driving unit 110 of the power conversion circuit 11 generates gate voltage signals for the switching element Q1H and the switching element Q1L using the digital switching drive signal PWM11. The gate voltage signal of the switching element Q1H is synchronized with the digital switching drive signal PWM11 and is a signal with a different voltage level in the Hi state. The gate voltage signal of the switching element Q1L is an inverted signal of the switching element Q1H.

[0055] The driver 120 of the power conversion circuit 12 generates gate voltage signals for the switching element Q2H and the switching element Q2L using the analog switching drive signal PWM12. The gate voltage signal for the switching element Q2H is a square wave signal determined by the voltage of the analog switching drive signal PWM12, an on-voltage threshold THon, and an off-voltage threshold THoff. The gate voltage signal for the switching element Q2L is an inverted signal of the switching element Q2H.

[0056] The driver 130 of the power conversion circuit 13 generates gate voltage signals for the switching element Q3H and the switching element Q3L using the digital switching drive signal PWM 13. The gate voltage signal for the switching element Q3H is synchronized with the digital switching drive signal PWM 13 and has a different voltage level in the Hi state. The gate voltage signal for the switching element Q3L is an inverted signal of the switching element Q3H.

[0057] The driver 140 of the power conversion circuit 14 generates gate voltage signals for the switching element Q4H and the switching element Q4L using the analog switching drive signal PWM14. The gate voltage signal for the switching element Q4H is a square wave signal determined by the voltage of the analog switching drive signal PWM14, an on-voltage threshold THon, and an off-voltage threshold THoff. The gate voltage signal for the switching element Q4L is an inverted signal of the switching element Q2H.

[0058] By such control (processing) of the MPU 20, the extension control circuit 31, the extension control circuit 32, and the multiple drivers 110, 120, 130, 140, the gate voltage signal of the switching element Q1H of the power conversion circuit 11, the gate voltage signal of the switching element Q2H of the power conversion circuit 12, the gate voltage signal of the switching element Q3H of the power conversion circuit 13, and the gate voltage signal of the switching element Q4H of the power conversion circuit 14 have the same frequency, the same on-time width, and a predetermined phase difference between them. Similarly, the gate voltage signal of the switching element Q1L of the power conversion circuit 11, the gate voltage signal of the switching element Q2L of the power conversion circuit 12, the gate voltage signal of the switching element Q3L of the power conversion circuit 13, and the gate voltage signal of the switching element Q4L of the power conversion circuit 14 have the same frequency, the same on-time width, and a predetermined phase difference between them.

[0059] As a result, the power conversion circuits 11-14 perform power conversion operations with their phases shifted from one another. Therefore, the power supply system 100 performs power conversion operations using multi-phase driving, and can output a desired output voltage Vout and a desired output current to the load Ro with high efficiency while suppressing a decrease in power conversion efficiency.

[0060] (Detailed explanation of the extension control circuits 31 and 32) Fig. 2 is a circuit diagram showing an example of the configuration of the extension control circuit according to the first embodiment. In Fig. 2, the extension control circuit 31 is shown, but the extension control circuit 32 has the same basic circuit configuration.

[0061] The extension control circuit 31 includes a resistor R311, a resistor R312, a capacitor C31, and a diode D31.

[0062] The resistor R312 and the diode D31 are connected in series. More specifically, the cathode of the diode D31 and one end of the resistor R312 are connected together.

[0063] The series circuit of the resistor R312 and the diode D31 is connected in parallel to the resistor R311. More specifically, one end of the series circuit of the resistor R312 and the diode D31 on the diode D31 side (the anode of the diode D31) is connected to one end of the resistor R311. The other end of the series circuit of the resistor R312 and the diode D31 on the resistor R312 side (the other end of the resistor R312) is connected to the other end of the resistor R311.

[0064] A node between one end of the resistor R311 and the anode of the diode D31 is connected to a connection line between the MPU 20 and the power conversion circuit 11 (a line through which the digital switching drive signal PWM11 is transmitted).

[0065] The node at the other end of the resistor R311 and the other end of the resistor R312 is connected to the ground reference potential through the capacitor C31. The terminal of the capacitor C31 opposite to the ground reference potential side and the node at the other end of the resistor R311 and the other end of the resistor R312 are connected to the power conversion circuit 12 (more specifically, the drive unit 120 of the power conversion circuit 12).

[0066] With this circuit configuration, the extension control circuit 31 configures a CR time constant circuit using the resistance component of the circuit including the resistors R311, R312, and diode D31, and the capacitance of the capacitor C31.

[0067] As a result, the digital switching drive signal PWM11 and the analog switching drive signal PWM12 have the following relationship. Fig. 3 is a waveform diagram showing an example of the switching drive signal and the gate voltage signal. Fig. 3 shows, from the top, the digital switching drive signal PWM11, the analog switching drive signal PWM12, the gate voltage signal V1H, and the gate voltage signal V2H.

[0068] As described above, the digital switching drive signal PWM11 is a signal generated by the MPU 20 and supplied to the power conversion circuit 11. The digital switching drive signal PWM11 is a square wave signal with a predetermined frequency and an on-time width Ton1, as shown in Fig. 3. Although not shown in Fig. 3, the digital switching drive signal PWM11 may have some high-frequency noise superimposed thereon depending on the situation.

[0069] The analog switching drive signal PWM12 is an output signal of the extension control circuit 31, which receives the digital switching drive signal PWM11 as an input. The extension control circuit 31 is a CR time constant circuit as described above.

[0070] 3, the analog switching drive signal PWM12 rises with a delay from the rise time of the digital switching drive signal PWM11 and falls with a delay from the fall time of the digital switching drive signal PWM11 in accordance with the CR time constant. The rise characteristic (waveform) and fall characteristic (waveform) of the analog switching drive signal PWM12 are set by the resistance value of the resistor R311 and the resistance value of the resistor R312 of the extension control circuit 31 and the capacitance of the capacitor C31.

[0071] Here, the extension control circuit 31 sets the rise time constant of the extension control circuit 31 so that the analog switching drive signal PWM12 reaches the on-voltage threshold value THon after the delay time τ from the rise time of the digital switching drive signal PWM11. Furthermore, the extension control circuit 31 sets a fall time constant such that the on-time width Ton2 of the analog switching drive signal PWM12 becomes the same as the on-time width Ton1 of the digital switching drive signal PWM11. That is, the extension control circuit 31 functions as the "voltage-time conversion circuit" and the "threshold signal conversion circuit" of the present invention.

[0072] When the voltage of the switching drive signal PWM12 rises to the on-voltage threshold THon, the drive unit 120 of the power conversion circuit 12 transitions the voltage of the gate voltage signal V2H from the low state (VL) to the high state (VH) (see FIG. 3). Then, when the voltage of the analog switching drive signal PWM12 drops to the off-voltage threshold THoff, the drive unit 120 transitions the voltage of the gate voltage signal V2H from the high state (VH) to the low state (VL) (see FIG. 3).

[0073] On the other hand, when the digital switching drive signal PWM11 changes from the Low state to the Hi state, the drive unit 110 of the power conversion circuit 11 synchronizes with this and transitions the voltage of the gate voltage signal V1H from the Low state (VL) to the Hi state (VH) (see FIG. 3). Then, thereafter, when the digital switching drive signal PWM11 changes from the Hi state to the Low state, the drive unit 110 synchronizes with this and transitions the voltage of the gate voltage signal V1H from the Hi state (VH) to the Low state (VL) (see FIG. 3).

[0074] The analog switching drive signal PWM12 is generated as described above by using the digital switching drive signal PWM11. As a result, the gate voltage signal V2H to the switching element Q2H of the power conversion circuit 12 becomes a signal with the same frequency, a predetermined delay time τ, and an on-time width Ton2 having the same time length as the on-time width Ton1, as compared with the gate voltage signal V1H to the switching element Q1H of the power conversion circuit 11, as shown in FIG.

[0075] Therefore, the power conversion circuits 12 and 11 perform power conversion operations with a predetermined phase difference (time difference τ), and multi-phase driving by the power conversion circuits 11 and 12 is realized.

[0076] Similarly, by providing the extended control circuit 32, the relationship (frequency, phase, on-time width) between the digital switching drive signal PWM13 supplied to the power conversion circuit 13 and the analog switching drive signal PWM14 supplied to the power conversion circuit 14 becomes similar to that between the digital switching drive signal PWM11 and the analog switching drive signal PWM12.

[0077] As described above, the digital switching drive signal PWM11 and the digital switching drive signal PWM13 have the same frequency and on-time width, and have a predetermined phase difference.

[0078] This enables power supply system 100 to achieve multi-phase driving by a plurality of power conversion circuits 11-14.

[0079] Furthermore, as described above, the extension control circuits 31 and 32 are realized by time constant circuits including resistors and capacitors, thereby enabling the power supply system 100 to achieve multi-phase driving with a simple circuit configuration.

[0080] That is, power supply system 100 has a simple configuration, suppresses a decrease in power conversion efficiency, and can achieve multi-phase drive according to the number of power conversion circuits to be driven.

[0081] Furthermore, the extension control circuit 31 includes a series circuit of a resistor R312 and a diode D31 as a resistance component that determines the time constant. This allows the extension control circuit 31 to set the rising time constant and the falling time constant to be different from each other. Therefore, the extension control circuit 31 can more easily and reliably set the delay time of the analog switching drive signal PWM12 relative to the digital switching drive signal PWM11 to a desired time and set the ON time width to the same at the same time. Similarly, the extension control circuit 32 can more easily and reliably set the delay time of the analog switching drive signal PWM14 relative to the digital switching drive signal PWM13 to a desired time and set the ON time width to the same at the same time.

[0082] Furthermore, since the extension control circuit 31 is a CR circuit in which the capacitor C31 is connected to the ground reference potential, it also functions as a low-pass filter. As a result, even if high-frequency noise is superimposed on the digital switching drive signal PWM11, the extension control circuit 31 can suppress this harmonic noise. As a result, the analog switching drive signal PWM12 has a smooth waveform with high-frequency noise suppressed. Therefore, malfunction of the drive unit 120 can be suppressed.

[0083] Similarly, even if high-frequency noise is superimposed on the digital switching drive signal PWM13, the extension control circuit 32 can suppress this harmonic noise. As a result, the analog switching drive signal PWM14 has a smooth waveform with suppressed high-frequency noise. Therefore, malfunction of the drive unit 140 can be suppressed.

[0084] As a result, power supply system 100 can achieve multi-phase drive with a simple configuration and high operational reliability with malfunctions suppressed.

[0085] (Application example of the configuration of the power supply system 100) Figures 4(A) and 4(B) are functional block diagrams showing an example of the effectiveness of the power supply system according to the first embodiment of the present invention. Figure 4(A) is a diagram showing one aspect corresponding to an increase in the number of phases when the configuration of the present invention is used, and Figure 4(B) is a diagram showing one aspect corresponding to an increase in the number of phases when a conventional configuration is used. Figures 4(A) and 4(B) show a case where a 4-phase output MPU is used.

[0086] In the conventional configuration, when multi-phase driving is realized by eight power conversion circuits 11-18, as shown in Fig. 4(B), a four-phase output MPU 20A supplies switching drive signals to four power conversion circuits 11-14, and a four-phase output MPU 20B supplies water supply drive signals to four power conversion circuits 15-18. Then, synchronization control signals and the like are transmitted and received between MPU 20A and MPU 20B to perform synchronization processing. This realizes eight-phase multi-phase driving.

[0087] On the other hand, as shown in FIG. 4(A), in the present invention, by using multiple extended control circuits 31-34, a 4-phase output MPU 20 supplies switching drive signals to eight power conversion circuits 11-18, thereby achieving 8-phase multiphase drive.

[0088] In this way, by using the configuration of the present invention, it is possible to drive a larger number of power conversion circuits in a multi-phase manner than the number of phases that can be output by one MPU 20. That is, the scale of the power supply system can be expanded according to the desired number of power conversion circuits without increasing the number of MPUs. More specifically, the power supply system of the present invention has a simple configuration in which an extension circuit is connected to a control IC, and the power consumption of the extension circuit is small, so that a decrease in power conversion efficiency can be suppressed. Furthermore, the power supply system of the present invention can flexibly respond to an increase in current according to the number of power conversion circuits to be driven without being limited by the number of drive outputs of the control IC, and can expand the scale of the output power capacity.

[0089] In this case, the expanded control circuit is realized by a CR circuit having a simple circuit configuration consisting of resistors, diodes, and capacitors, so the circuit configuration is not complex and the number of phases in the multi-phase drive can be increased and the scale of the power supply system can be expanded with a relatively simple configuration.

[0090] [Second embodiment] A power supply system according to a second embodiment of the present invention will be described with reference to the drawing. Fig. 5 is a circuit block diagram showing an extended control circuit portion of the power supply system according to the second embodiment.

[0091] 5, the power supply system 100A according to the second embodiment differs from the power supply system 100 according to the first embodiment in the configuration of the extended control circuit. Other configurations of the power supply system 100A are similar to those of the power supply system 100, and descriptions of similar parts will be omitted.

[0092] The power supply system 100A includes an extension control circuit 31L. Note that, instead of the extension control circuit 32 of the power supply system 100, the power supply system 100A includes an extension control circuit 32L (not shown) having a similar configuration to the extension control circuit 31L.

[0093] The extension control circuit 31L differs from the extension control circuit 31 according to the first embodiment in that a logic circuit 310 is added. Other configurations of the extension control circuit 31L are similar to those of the extension control circuit 31.

[0094] The extension control circuit 31L includes a resistor R311, a resistor R312, a capacitor C31, a diode D31, and a logic circuit 310.

[0095] The resistor R312 and the diode D31 are connected in series. The series circuit of the resistor R312 and the diode D31 is connected in parallel to the resistor R311.

[0096] A node between one end of the resistor R311 and the anode of the diode D31 is connected to a connection line between the MPU 20 and the power conversion circuit 11 (a line through which the digital switching drive signal PWM11 is transmitted).

[0097] The node at the other end of the resistor R311 and the other end of the resistor R312 is connected to the ground reference potential through a capacitor C31.

[0098] A terminal of the capacitor C31 opposite to the ground reference potential side and a node of the other end of the resistor R311 and the other end of the resistor R312 are connected to an input terminal of the logic circuit 310.

[0099] An output terminal of the logic circuit 310 is connected to the power conversion circuit 12 (more specifically, to the driver 120 of the power conversion circuit 12).

[0100] As described above, the resistor R311, the resistor R312, the capacitor C31, and the diode D31 configure a CR circuit, which outputs an analog switching drive signal PWM12.

[0101] The logic circuit 310 is configured using, for example, an AND circuit, a comparator, and the like. The logic circuit 310 receives the analog switching drive signal PWM12 and performs binarization processing using an on-voltage threshold value THon and an off-voltage threshold value THoff. As a result, the logic circuit 310 generates a digital switching drive signal PWM12D consisting of a square wave signal. The logic circuit 310 outputs the digital switching drive signal PWM12D to the drive unit 120 of the power conversion circuit 12.

[0102] 6 is a waveform diagram showing an example of the switching drive signal and the gate voltage signal, which shows, from the top, the digital switching drive signal PWM11, the analog switching drive signal PWM12, the digital switching drive signal PWM12D, the gate voltage signal V1H, and the gate voltage signal V2H.

[0103] By including the extended control circuit 31L, as shown in FIG. 7, the digital switching drive signal PWM12D supplied to the power conversion circuit 12 becomes a signal having the same frequency, the same on-time width, and a phase difference as the digital switching drive signal PWM11 supplied to the power conversion circuit 11.

[0104] Thus, like power supply system 100, power supply system 100A has a simple configuration, suppresses a decrease in power conversion efficiency, and can achieve multi-phase drive according to the number of power conversion circuits to be driven.

[0105] Furthermore, in power supply system 100A, rectangular wave signals that have the same waveform but have a phase difference are supplied to multiple power conversion circuits 11-14, which can further suppress malfunctions of multiple power conversion circuits 11-14.

[0106] [Third embodiment] A power supply system according to a third embodiment of the present invention will be described with reference to the drawings. Fig. 7 is a circuit block diagram showing an extended control circuit portion of the power supply system according to the third embodiment. Fig. 8 is a waveform diagram showing an example of a switching drive signal and a gate voltage signal. Fig. 8 shows, from the top, a digital switching drive signal PWM11, an analog switching drive signal PWM12, a gate voltage signal V1H, and a gate voltage signal V2H.

[0107] 7, the power supply system 100B according to the third embodiment differs from the power supply system 100 according to the first embodiment in the configuration of the extended control circuit. Other configurations in the power supply system 100B are similar to those in the power supply system 100, and descriptions of similar parts will be omitted.

[0108] The power supply system 100B includes an extension control circuit 31S. Note that, instead of the extension control circuit 32 of the power supply system 100, the power supply system 100B includes an extension control circuit 32S (not shown) having a similar configuration to the extension control circuit 31S.

[0109] The extension control circuit 31S differs from the extension control circuit 31 according to the first embodiment in that the resistor R312 and the diode D31 are omitted. Other configurations of the extension control circuit 31S are the same as those of the extension control circuit 31.

[0110] Even with this configuration, by appropriately setting the resistance value of resistor R311 and the capacitance of capacitor C31, the phase difference between the gate voltage signal V1H to the switching element Q1H of the power conversion circuit 11 and the gate voltage signal V2H to the switching element Q2H of the power conversion circuit 12 can be set to a predetermined value (a value other than 0) as shown in Figure 8.

[0111] Thus, like power supply system 100, power supply system 100B has a simple configuration, suppresses a decrease in power conversion efficiency, and can achieve multi-phase drive according to the number of power conversion circuits to be driven.

[0112] Furthermore, power supply system 100B can achieve a simpler circuit configuration than power supply system 100.

[0113] [Fourth embodiment] A power supply system according to a fourth embodiment of the present invention will be described with reference to the drawings. Fig. 9 is a circuit block diagram showing an example of the power supply system according to the fourth embodiment. Fig. 10 is a waveform diagram showing an example of a switching drive signal and a gate voltage signal. Fig. 10 shows, from the top, a digital switching drive signal PWM11, an analog switching drive signal PWM12, a digital switching drive signal PWM12D, an analog switching drive signal PWM13, a digital switching drive signal PWM13D, a gate voltage signal V1H, a gate voltage signal V2H, and a gate voltage signal V3H.

[0114] 9, the power supply system 100C according to the fourth embodiment differs from the power supply system 100A according to the second embodiment in that a plurality of extended control circuits are cascaded. Other basic configurations of the power supply system 100C are similar to the basic circuit configuration of the power supply system 100A, and a description of similar parts will be omitted.

[0115] In the example shown in FIG. 9, the power supply system 100C is a system that drives more than eight power conversion circuits in a multiphase manner.

[0116] The power supply system 100C includes a plurality of power conversion circuits 11-18 and a plurality of extension control circuits 31L-36L.

[0117] The power conversion circuits 11-18 have the same circuit configuration. The extension control circuits 31L-36L have the same circuit configuration. The extension control circuits 31L-36L have the same circuit configuration as the extension control circuit 31L shown in the second embodiment.

[0118] The MPU 20 is connected to the power conversion circuit 11 and the power conversion circuit 15 via separate connection lines.

[0119] An input terminal of the extension control circuit 31L is connected to a connection line between the MPU 20 and the power conversion circuit 11. An output terminal of the extension control circuit 31L is connected to the power conversion circuit 12.

[0120] An input terminal of the extension control circuit 32L is connected to an output terminal of the extension control circuit 31 L. An output terminal of the extension control circuit 32L is connected to the power conversion circuit 13.

[0121] An input terminal of the extension control circuit 33L is connected to an output terminal of the extension control circuit 32L. An output terminal of the extension control circuit 33L is connected to the power conversion circuit 14.

[0122] An input terminal of the extension control circuit 34L is connected to a connection line between the MPU 20 and the power conversion circuit 15. An output terminal of the extension control circuit 34L is connected to the power conversion circuit 16.

[0123] An input terminal of the extension control circuit 35L is connected to an output terminal of the extension control circuit 34L. An output terminal of the extension control circuit 35L is connected to the power conversion circuit 17.

[0124] An input terminal of the extension control circuit 36L is connected to an output terminal of the extension control circuit 35L. An output terminal of the extension control circuit 36L is connected to the power conversion circuit 18.

[0125] The MPU 20 outputs (supplies) a digital switching drive signal PWM11 to the power conversion circuit 11. The MPU 20 also outputs (supplies) a digital switching drive signal PWM15 to the power conversion circuit 15. The digital switching drive signal PWM15 is a signal having a predetermined phase difference with respect to the digital switching drive signal PWM11.

[0126] This phase difference is determined by the number of power conversion circuits to which the MPU 20 directly outputs digital switching drive signals, with reference to the number of power conversion circuits to be multiphase-driven in the power supply system 100C. For example, in the case of multiphase-driving 36 power conversion circuits, if the number of power conversion circuits to which the MPU 20 directly outputs digital switching drive signals is four, the phase difference is set to 90°.

[0127] The extension control circuit 31L receives the digital switching drive signal PWM11 as an input, generates an analog switching drive signal PWM12, and generates a digital switching drive signal PWM12D from the analog switching drive signal PWM12, as shown in FIG. 10. The extension control circuit 31L outputs the digital switching drive signal PWM12D to the power conversion circuit 12.

[0128] The extension control circuit 32L receives the digital switching drive signal PWM12D as an input, generates an analog switching drive signal PWM13, and generates a digital switching drive signal PWM13D from the analog switching drive signal PWM13, as shown in FIG. 10. The extension control circuit 32L outputs the digital switching drive signal PWM13D to the power conversion circuit 13.

[0129] The extension control circuit 33L receives the digital switching drive signal PWM13D as an input, and generates a digital switching drive signal PWM14D, similar to the extension control circuits 31L and 32L. The extension control circuit 33L outputs the digital switching drive signal PWM14D to the power conversion circuit 14.

[0130] As a result of this processing, the digital switching drive signal PWM12D becomes a signal that is delayed by a predetermined phase difference relative to the digital switching drive signal PWM11, the digital switching drive signal PWM13D becomes a signal that is delayed by a predetermined phase difference relative to the digital switching drive signal PWM12D, and the digital switching drive signal PWM14D becomes a signal that is delayed by a predetermined phase difference relative to the digital switching drive signal PWM13D.

[0131] In this way, the power supply system 100C can generate a plurality of digital switching drive signals PWM12D, PWM13D, and PWM14D that are delayed in sequence using one digital switching drive signal PWM11, and supply these signals to the plurality of power conversion circuits 11-14, respectively.

[0132] Similarly, the extension control circuit 34L receives the digital switching drive signal PWM15 as an input, generates a digital switching drive signal PWM16D, and outputs it to the power conversion circuit 16. The extension control circuit 35L receives the digital switching drive signal PWM16D as an input, generates a digital switching drive signal PWM17D, and outputs it to the power conversion circuit 17. The extension control circuit 36L receives the digital switching drive signal PWM17D as an input, generates a digital switching drive signal PWM18D, and outputs it to the power conversion circuit 18.

[0133] In this way, the power supply system 100C can generate a plurality of digital switching drive signals PWM16D, PWM17D, and PWM18D that are delayed in sequence using one digital switching drive signal PWM15, and supply these signals to the plurality of power conversion circuits 15-18, respectively.

[0134] As described above, by providing the configuration of power supply system 100C, four or more power conversion circuits can be driven in multiphase using one digital switching drive signal output from MPU 20. As a result, power supply system 100C can achieve multiphase driving without unnecessarily increasing the number of MPUs 20 even in a configuration that requires more power conversion circuits.

[0135] Furthermore, since the multiple expansion control circuits 31L-36L use CR circuits, the power supply system 100C can be configured as an expandable power supply system with a simple circuit configuration.

[0136] In the above configuration, for example, in the case where 20 power conversion circuits are driven in a multiphase manner, and the number of power conversion circuits to which the MPU20 directly outputs digital switching drive signals is four (for example, in FIG. 9, when digital switching drive signals are directly supplied to the power conversion circuits 191 and 192 not shown), the phase difference between the digital switching drive signals PWM11 and PWM15 is set to, for example, 360° / 20×4 (the number of power conversion circuits driven based on one digital switching drive signal PWM11, PWM15)=72°. In addition, the phase difference between the digital switching drive signal PWM15 and the digital switching drive signal PWM19 (drive signal to the power conversion circuit 191 not shown) is also set to, for example, 72°. The phase difference between the digital switching drive signal PWM19 (drive signal to the power conversion circuit 191, not shown) and the digital switching drive signal PWM20 (drive signal to the power conversion circuit 192, not shown) is set to, for example, 18°. Furthermore, the phase difference between the digital switching drive signal PWM20 (drive signal to the power conversion circuit 192, not shown) and the digital switching drive signal PWM11 is set to, for example, 18°. As a result, when 20 power conversion circuits are used, the balance of power supply is improved and the decrease in power conversion efficiency can be further suppressed.

[0137] [Fifth embodiment] A power supply system according to a fifth embodiment of the present invention will be described with reference to the drawings. Fig. 11 is a circuit block diagram showing an example of the power supply system according to the fifth embodiment. Fig. 12 is a waveform diagram showing an example of a switching drive signal and a gate voltage signal. Fig. 12 shows, from the top, a digital switching drive signal PWM11, an analog switching drive signal PWM12, a digital switching drive signal PWM12D, an analog switching drive signal PWM13, a digital switching drive signal PWM13D, a gate voltage signal V1H, a gate voltage signal V2H, and a gate voltage signal V3H.

[0138] 11, the power supply system 100D according to the fifth embodiment differs from the power supply system 100A according to the second embodiment in that a plurality of extended control circuits are connected in parallel. Other basic configurations of the power supply system 100D are similar to the basic circuit configuration of the power supply system 100A, and a description of similar parts will be omitted.

[0139] In the example shown in FIG. 11, the power supply system 100C is a system that drives more than six power conversion circuits in a multiphase manner.

[0140] The power supply system 100D includes a plurality of power conversion circuits 11-16 and a plurality of extension control circuits 31L-34L.

[0141] The power conversion circuits 11-16 have the same circuit configuration. The extension control circuits 31L-34L have the same circuit configuration. The extension control circuits 31L-34L have the same circuit configuration as the extension control circuit 31L shown in the second embodiment, but each has a different CR time constant setting.

[0142] The MPU 20 is connected to the power conversion circuit 11 and the power conversion circuit 14 via separate connection lines.

[0143] An input terminal of the extension control circuit 31L is connected to a connection line between the MPU 20 and the power conversion circuit 11. An output terminal of the extension control circuit 31L is connected to the power conversion circuit 12.

[0144] An input terminal of the extension control circuit 32L is connected to a connection line between the MPU 20 and the power conversion circuit 11. An output terminal of the extension control circuit 32L is connected to the power conversion circuit 13.

[0145] An input terminal of the extension control circuit 33L is connected to a connection line between the MPU 20 and the power conversion circuit 14. An output terminal of the extension control circuit 33L is connected to the power conversion circuit 15.

[0146] An input terminal of the extension control circuit 34L is connected to a connection line between the MPU 20 and the power conversion circuit 14. An output terminal of the extension control circuit 34L is connected to the power conversion circuit 16.

[0147] The MPU 20 outputs (supplies) a digital switching drive signal PWM11 to the power conversion circuit 11. The MPU 20 also outputs (supplies) a digital switching drive signal PWM14 to the power conversion circuit 14. The digital switching drive signal PWM14 is a signal having a predetermined phase difference with respect to the digital switching drive signal PWM11. Note that the phase difference is set based on the same principle as in the above-mentioned fourth embodiment, and therefore a description thereof will be omitted.

[0148] The extension control circuit 31L receives the digital switching drive signal PWM11 as an input, generates an analog switching drive signal PWM12, and generates a digital switching drive signal PWM12D from the analog switching drive signal PWM12, as shown in FIG. 11. The extension control circuit 31L outputs the digital switching drive signal PWM12D to the power conversion circuit 12.

[0149] The extension control circuit 32L receives the digital switching drive signal PWM11 as an input, generates an analog switching drive signal PWM13, and generates a digital switching drive signal PWM13D from the analog switching drive signal PWM13, as shown in FIG. 11. The extension control circuit 32L outputs the digital switching drive signal PWM13D to the power conversion circuit 13.

[0150] 12, the analog switching drive signal PWM13 has a waveform different from that of the analog switching drive signal PWM12. More specifically, the analog switching drive signal PWM13 reaches the ON voltage threshold THon later than the analog switching drive signal PWM12. Also, the analog switching drive signal PWM13 reaches the OFF voltage threshold THoff later than the analog switching drive signal PWM12.

[0151] However, the time difference between the on-voltage threshold THon and the off-voltage threshold THoff in the analog switching drive signal PWM13 is set to be the same as the time difference between the on-voltage threshold THon and the off-voltage threshold THoff in the analog switching drive signal PWM12.

[0152] This is achieved by making the CR time constant of the extension control circuit 32L different from that of the extension control circuit 31L.

[0153] Through this processing, the digital switching drive signal PWM12D becomes a signal that is delayed by a predetermined phase difference with respect to the digital switching drive signal PWM11, and the digital switching drive signal PWM13D becomes a signal that is delayed by a predetermined phase difference with respect to the digital switching drive signal PWM12D.

[0154] In this way, the power supply system 100D can generate a plurality of digital switching drive signals PWM12D, PWM13D that are delayed in sequence using one digital switching drive signal PWM11, and supply these signals to the plurality of power conversion circuits 11-13, respectively.

[0155] Similarly, the extension control circuit 33L receives the digital switching drive signal PWM14 as an input, generates a digital switching drive signal PWM15D, and outputs it to the power conversion circuit 15. The extension control circuit 34L receives the digital switching drive signal PWM15D as an input, generates a digital switching drive signal PWM16D, and outputs it to the power conversion circuit 16.

[0156] In this manner, the power supply system 100D can generate a plurality of digital switching drive signals PWM15D, PWM16D that are delayed in sequence using a single digital switching drive signal PWM14, and supply these signals to the plurality of power conversion circuits 14-16, respectively.

[0157] As described above, by providing the configuration of power supply system 100D, it is possible to perform multiphase driving of three or more power conversion circuits using one digital switching drive signal output from MPU 20. As a result, power supply system 100D can achieve multiphase driving without unnecessarily increasing the number of MPUs 20 even in a configuration that requires more power conversion circuits.

[0158] Furthermore, since the multiple expansion control circuits 31L-34L use CR circuits, the power supply system 100D can be configured as an expandable power supply system with a simple circuit configuration.

[0159] In the power supply system 100D, instead of the multiple extension control circuits 31L-34L, a configuration similar to the extension control circuit 31 shown in the first embodiment can be adopted. In other words, the power supply system 100D can also be applied to a configuration that does not use the logic circuit 310. This allows the power supply system 100D to realize an even simpler circuit configuration.

[0160] In the above-described embodiments, the on-time width of the digital switching drive signal output by the MPU 20 is set to be the same as the on-time width of the switching drive signal output by the extended control circuit. However, this is a value set by, for example, the number of power conversion circuits to be multiphase-driven. For example, in the power supply system 100 according to the first embodiment, the MPU 20 can adjust the on-time width based on the feedback voltage of the output voltage Vout and the feedback current from the multiple power conversion circuits 11-14. In this case, if the on-time width of the digital switching drive signal output from the MPU 20, the on-voltage threshold value THon and the off-voltage threshold value THoff set in the extended control circuits 31 and 32, the time of the on-voltage threshold value THon, and the time of the off-voltage threshold value THoff are appropriately set based on the feedback current from the multiple power conversion circuits 11-14, it is also possible to adjust the current balance in the multiple power conversion circuits 11-14.

[0161] Furthermore, the MPU 20 has an input terminal for a PMBus signal, and can determine the number of power conversion circuits to be multiphase-driven and set the on-time width according to the voltage and current specified by the PMBus signal.

[0162] Furthermore, the configurations of the above-described embodiments can be combined as appropriate, and effects according to each combination can be achieved. [Explanation of symbols]

[0163] 100, 100A, 100B, 100C, 100D: Power supply system 110, 120, 130, 140: Drive unit 11-18, 191, 192: Power conversion circuits 20, 20A, 20B: MPU 31, 31L, 31S, 32, 32L, 32S, 33L, 34L, 35L, 36L: Expansion control circuit 310: Logic circuits C31: Capacitor Ci1, Ci2, Ci3, Ci4: Input capacitors Co: Output capacitor D31: Diode L1, L2, L3, L4: Inductors Pin: Common input terminal Pout: Common output terminal Q1H, Q2H, Q3H, Q4H: switching elements Q1L, Q2L, Q3L, Q4L: switching elements R311, R312: Resistor Ro: Load

Claims

1. A plurality of power conversion circuits each including an inductor, a switching element that controls a current flowing through the inductor, and a power semiconductor circuit that includes a drive unit that drives the switching element; a power management control circuit that generates a first digital switching drive signal for a first power semiconductor circuit in the plurality of power semiconductor circuits; an extension control circuit electrically connected between the power management control circuit and a second power semiconductor circuit different from the first power semiconductor circuit in the plurality of power semiconductor circuits, the extension control circuit generating a second switching drive signal from the first digital switching drive signal and providing the second switching drive signal to the second power semiconductor circuit; Equipped with The power management control circuit generates a plurality of first digital switching drive signals having different phases based on the number of a plurality of power conversion circuits that directly output the first digital switching drive signals, and outputs the plurality of first digital switching drive signals to different extension control circuits in synchronization with each other; Each of the expansion control circuits comprises: a voltage-time conversion circuit that sets a predetermined signal delay time for the first digital switching drive signal to generate the second switching drive signal; The voltage-time conversion circuit includes: a threshold signal conversion circuit for determining the signal delay time using a time constant and a threshold voltage of a CR circuit composed of a resistor and a capacitor; The expansion control circuit includes: setting a phase of a second analog switching drive signal that is a basis of the second switching drive signal using a time constant of the CR circuit of the threshold signal conversion circuit; using the threshold voltage of the threshold signal conversion circuit and the second analog switching signal after the phase is set, the ON time width of the second switching drive signal is set to be equal to the ON time width of the first digital switching drive signal; determining the number of the plurality of power conversion circuits according to a total number of signals obtained by adding a first number of signals of the first digital switching drive signal to a second number of signals of the second switching drive signal; A scalable power supply system.

2. the threshold signal conversion circuit includes a logic circuit that sets a phase and an on-time width of the second switching drive signal and outputs the second switching drive signal as a digital switching drive signal.

2. The scale-expandable scalable power supply system according to claim 1.

3. a resistance setting circuit for setting the resistance of the CR circuit; The resistance setting circuit includes: a first resistor element, a second resistor element, and a rectifying element; a series circuit of the second resistance element and the rectifying element is connected in parallel to the first resistance element; 3. The scale-expandable scalable power supply system according to claim 1 or 2.

4. The extension control circuit is a plurality of The plurality of expansion control circuits are cascaded.

3. The scale-expandable scalable power supply system according to claim 1 or 2.

5. The extension control circuit is a plurality of The plurality of extension control circuits are connected in parallel.

3. The scale-expandable scalable power supply system according to claim 1 or 2.

6. The power management control circuit is composed of a multi-phase controller.

3. The scale-expandable scalable power supply system according to claim 1 or 2.

7. the power management control circuit is capable of receiving a PMBus signal and executing control in response to the PMBus signal; 3. The scale-expandable scalable power supply system according to claim 1 or 2.

8. The power management control circuit is configured by a programmable MPU.

2. The scale-expandable scalable power supply system according to claim 1.

9. The plurality of power conversion circuits detect an inductor current of the inductor provided in each of the power conversion circuits and feed the detected inductor current back to the power management control circuit.

2. The scale-expandable scalable power supply system according to claim 1.

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