Power supply circuit and power supply module

Abstract

The present disclosure provides a power supply circuit and a power supply module that can easily configure a power supply circuit having the required performance to suit various types of power generation elements. [Solution] The power supply circuit 120 is a power supply circuit including multiple analog circuit blocks. The power supply circuit 120 includes a first analog circuit block, a second analog circuit block that operates independently of the first analog circuit block based on a common index with the first analog circuit block, and a third analog circuit block that operates independently of the first analog circuit block and the second analog circuit block. The first analog circuit block, the second analog circuit block, and the third analog circuit block operate independently without directly exchanging signals with each other.

Description

[Technical Field]

[0001] The present disclosure relates to a power supply circuit including a plurality of analog circuit blocks, and a power supply module. [Background technology]

[0002] In recent years, wireless sensor nodes have been developed that operate standalone in factories, farms, etc., acquiring necessary information and transmitting it to a server, etc. As a power source for operating the wireless sensor nodes, it is being considered to use power generation elements that convert renewable energy (also known as environmental energy) such as light, heat, vibration, and wind into electricity.

[0003] For example, a power generation element that converts mechanical vibration energy into electrical energy is disclosed in JP 2011-517277 A (Patent Document 1). In order to drive a sensor or the like with the power generated by the power generation element, a power supply circuit is required to stably supply power from the power generation element to the sensor or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2011-517277 Summary of the Invention [Problem to be solved by the invention]

[0005] However, power supply circuits must be developed individually for each combination of power generation element (environmental harvesting element) that converts environmental energy into electricity and wireless sensor node. Therefore, developing individual power supply circuits to drive wireless sensor nodes to match the various types of power generation elements would result in small-lot, multi-variety development, which would increase design costs and become an obstacle to the widespread use of wireless sensor nodes.

[0006] Furthermore, if individual power supply circuits are developed to suit various types of power generation elements, it is possible to obtain power supply circuits with high performance (for example, low power consumption performance) for specific power generation elements, but the circuit configuration becomes complex and the power supply circuit does not have the expandability to add other power generation elements, etc. On the other hand, if a power supply circuit is made general-purpose so that it can be adapted to various types of power generation elements, it will not be able to obtain the required performance.

[0007] Therefore, an object of the present disclosure is to provide a power supply circuit and a power supply module that can easily configure a power supply circuit having the required performance in accordance with various types of power generation elements. [Means for solving the problem]

[0008] A power supply circuit according to one embodiment of the present disclosure is a power supply circuit including a plurality of analog circuit blocks. The power supply circuit includes a first analog circuit block, a second analog circuit block that operates independently of the first analog circuit block based on a common index with the first analog circuit block, and a third analog circuit block that operates independently of the first analog circuit block and the second analog circuit block. The first analog circuit block, the second analog circuit block, and the third analog circuit block operate independently without directly exchanging signals with each other.

[0009] A power supply module according to one embodiment of the present disclosure includes a plurality of power generating elements and the power supply circuit described above. [Effects of the Invention]

[0010] According to the present disclosure, the first analog circuit block, the second analog circuit block, and the third analog circuit block operate independently without directly transferring signals to each other, making it possible to easily configure a power supply circuit with the required performance to suit various types of power generation elements. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 1 is a block diagram of a power supply module according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram for explaining control of a power supply circuit. [Figure 3] 1 is a diagram for explaining distributed control of a power supply circuit according to an embodiment; [Figure 4] FIG. 10 is another diagram for explaining distributed control of the power supply circuit according to the embodiment. [Figure 5] 3A and 3B are diagrams for explaining an internal rhythm of the power supply circuit according to the embodiment; [Figure 6] FIG. 10 is a diagram for explaining the control timing of a power supply circuit to be compared. [Figure 7] FIG. 10 is a circuit diagram of a power supply module according to a modified example. [Figure 8] FIG. 10 is a diagram illustrating an example of standby power of a power supply circuit according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] A power supply circuit according to an embodiment and a power supply module including the power supply circuit will be described in detail below with reference to the drawings. Note that the same reference numerals in the drawings indicate the same or corresponding parts. Below, a power supply circuit capable of extracting power from a power generation element (environmental harvesting element) that converts environmental energy into electric power will be described as an example. However, the power supply circuit is not limited to applications to power generation elements that convert environmental energy into electric power, and can be similarly applied to various types of power generation elements other than energy harvesting elements.

[0013] (Embodiment) 1 is a block diagram of a power supply module 100 according to an embodiment. The power supply module 100 includes a power generating element 110 and a power supply circuit 120. The power supply module 100 extracts power generated by the power generating element 110 using the power supply circuit 120 and supplies the power to a load circuit (not shown), such as a sensor.

[0014] The power generating element 110 is, for example, a thermoelectric power generating element. A thermoelectric power generating element is an element that can extract, as electric power, the thermoelectromotive force generated by applying a temperature difference between thermoelectric conversion materials such as two different types of metals or p-type and n-type semiconductors. Alternatively, the power generating element 110 is, for example, an electromagnetic vibration power generating element including a vibrator. An electromagnetic vibration power generating element is an element that can extract electric power by vibrating a vibrator using environmental vibrations to change the magnetic flux.

[0015] The power supply circuit 120 can extract power from the power generation element 110 and charge the charging elements 22-24 with power. The power generation element 110, which converts environmental energy into power, cannot always generate stable power, so the generated power is charged to the charging elements 22-24 to stably drive load circuits such as sensors and the power supply circuit 120 itself. The charging elements 22-24 are, for example, capacitors or batteries. The charging element 22 is for an external application and is controlled to approximately 2.7 V, while the charging elements 23 and 24 are for the power supply circuit 120 and are controlled to approximately 4.2 V and approximately 1.0 V, respectively.

[0016] The power supply circuit 120 is composed of multiple analog circuit blocks, including a power supply management circuit block 10, a charge management circuit block 20, and a voltage conversion circuit block 30. In this disclosure, an analog circuit block refers to a unit including at least one analog circuit. The power supply management circuit block 10 is an analog circuit block (first analog circuit block) that starts up the power supply circuit 120, and includes a startup switch circuit 11 and a startup circuit 12. The startup switch circuit 11 uses the power charged in the charging element 24 to start up the power supply circuit 120 via the startup circuit 12.

[0017] The charge management circuit block 20 is an analog circuit block (second analog circuit block) that includes charging elements 22 to 24 and manages the power to be charged to the charging elements 22 to 24, and includes a selector circuit 21. The selector circuit 21 switches between charging and not charging the charging elements 22 to 24 based on the voltages of the charging elements 22 to 24. Note that the charging elements 22 to 24 are not limited to being included in the charge management circuit block 20, and may be provided separately from the charge management circuit block 20 and connected to the charge management circuit block 20.

[0018] The voltage conversion circuit block 30 is an analog circuit block (third analog circuit block) that includes an inductor and converts the voltage input from the power generation element 110 and outputs it to the charging elements 22 to 24, and includes a rectifier circuit 31 and a DC-DC conversion circuit 32. The rectifier circuit 31 is a circuit that converts AC power generated by the power generation element 110 into DC power. Note that if the power generation element 110 is a power generation element that generates DC power, the voltage conversion circuit block 30 does not need to include the rectifier circuit 31. The DC-DC conversion circuit 32 is a circuit that converts the voltage input from the power generation element 110 into a voltage suitable for charging the charging elements 22 to 24. The DC-DC conversion circuit 32 may be a circuit that uses a switching capacitor instead of an inductor.

[0019] Furthermore, in the power supply circuit 120, the power management circuit block 10 and the charge management circuit block 20 operate independently of each other using the internal power supply voltage as a common index, and the voltage conversion circuit block 30 operates autonomously at an internal rhythm different from that of the charge management circuit block 20. In other words, the power supply circuit 120 performs distributed control in which the power management circuit block 10, the charge management circuit block 20, and the voltage conversion circuit block 30 operate independently without directly exchanging signals with each other. Note that the internal rhythm is not necessarily limited to a periodic rhythm, and may be a non-periodic rhythm as long as they can operate independently.

[0020] The power supply circuit 120 according to this embodiment and the power supply module 100 including the power supply circuit 120 are intended for use as a power source for wireless sensor nodes such as IoT (Internet of Things) devices. Therefore, a power generating element that converts environmental energy into electric power is used as the power generating element 110, and the power supply circuit 120 must efficiently extract electric power from the power generating element 110 and charge the charging elements 22-24 at the required voltage. However, when designing a power supply circuit using conventional design techniques, control is performed by directly exchanging signals between circuits or circuit blocks, which necessitates optimizing the circuit configuration of the entire power supply circuit depending on the type of power generating element, resulting in a problem of increased design costs. Figure 2 is a schematic diagram for explaining the control of the power supply circuit.

[0021] FIG. 2(a) is a block diagram of a power supply module 200 in which the power supply circuit 220 is designed using a conventional design method. The power supply module 200 includes a power generation element 210 and a power supply circuit 220. The power supply circuit 220 is composed of multiple analog circuit blocks, and includes a startup switch circuit 211 and a startup circuit 212 as analog circuit blocks that start the power supply circuit 220. The power supply circuit 220 also includes a selector circuit 221 as an analog circuit block that manages the power to be charged to the charging elements 222 to 224. The power supply circuit 220 also includes a rectifier circuit 231 and a DC-DC conversion circuit 232 as analog circuit blocks that convert the voltage input from the power generation element 210 and output it to the charging elements 222 to 224. The charging element 222 is for an external application and is controlled to approximately 2.7 V, while the charging elements 223 and 224 are for the power supply circuit 220 and are controlled to approximately 4.2 V and approximately 1.0 V, respectively.

[0022] In the power supply circuit 220, as shown in FIG. 2(a), control is performed by directly exchanging signals between circuits. Specifically, the start-up switch circuit 211 passes an ON signal to the start-up circuit 212 to operate the start-up circuit 212 using the power charged in the charging element 224. The start-up circuit 212 passes an ON signal to the rectifier circuit 231 to start the power supply circuit 220. The DC-DC conversion circuit 232 passes an ON signal or a STOP signal to the selector circuit 221 based on a Ready signal from the selector circuit 221. As described above, in the power supply circuit 220, direct exchange of signals between circuits is required between circuits, so it is necessary to optimize the circuit configuration of the entire power supply circuit. Furthermore, if the power supply circuit 220 is made more functional so that it can simultaneously extract power from multiple power generation elements, the design of the power supply circuit 220 becomes more complex.

[0023] Therefore, the power supply circuit 120 according to this embodiment employs distributed control inspired by biological control systems. Although biological motor control systems are purely analog systems, each component has a high degree of autonomy, allowing the brain to stably control the entire system with minimal information. Figure 2(b) is a block diagram of a power supply module 100 including the power supply circuit 120 according to this embodiment. To address the aforementioned issues, the power supply circuit 120 employs distributed control, in which analog circuit blocks operate independently without directly passing signals between them. Therefore, in Figure 2(b), arrows within each analog circuit represent the idea that processing is completed within each analog circuit. In this way, the power supply circuit 120 simplifies the circuit configuration and reduces design costs by allowing each analog circuit block to operate autonomously, like a biological control system.

[0024] Furthermore, if the power supply circuit 120 can operate each analog circuit block autonomously, it will be possible to change the analog circuit block unit according to the type of power generating element. In this way, adopting distributed control technology in the power supply circuit 120 makes it easier to design the power supply circuit 120 to ensure compatibility with various types of power generating elements and scalability that allows expansion in analog circuit block units. In other words, it is possible to realize a design platform that can be designed by assembling the power supply circuit 120 in analog circuit block units.

[0025] Next, specific control for autonomously operating each analog circuit block will be described. FIG. 3 is a diagram for explaining distributed control of a power supply circuit 120 according to an embodiment. The waveform shown in FIG. 3(a) shows how the power management circuit block 10 and the charge management circuit block 20 operate independently of each other using the internal power supply voltage as a common index. On the other hand, the waveform shown in FIG. 3(b) shows how the power management circuit block and the charge management circuit block in a comparative power supply circuit (for example, the power supply circuit 220 in FIG. 2(a)) depend on each other and directly exchange signals. Note that the horizontal axis in FIGS. 3(a) and 3(b) represents time, and the vertical axis represents voltage.

[0026] First, in region A shown in Figure 3(b), when power is supplied from the power generation element 210 and the voltage VC1 of the charging element 224 monitored by the power management circuit block reaches approximately 1.1 V, the power management circuit block raises the internal power supply voltage VDD1 to the voltage VC1 of the charging element 224 and activates the power supply circuit 220. On the other hand, when the voltage VC1 of the charging element 224 monitored by the power management circuit block falls below approximately 0.9 V, the internal power supply voltage VDD1 drops and the power supply circuit 220 shuts down. After the power supply circuit 220 starts up, signals are directly exchanged between the power management circuit block and the charging management circuit block to control the voltage VC1 of the charging element 224 to be approximately 1.0 V. Specifically, when the voltage VC1 of the charging element 224 drops below approximately 1.0 V (region B), the power management circuit block passes a signal to the charging management circuit block to supply power from the power generation element 210 or another charging element 224 to the charging element 224 whose voltage has dropped below approximately 1.0 V. On the other hand, when the voltage VC1 of the charging element 224 exceeds approximately 1.1 V, the power management circuit block passes a signal to the charging management circuit block to stop supplying power from the power generation element or another charging element 224 to the charging element 224 whose voltage has exceeded approximately 1.1 V. In this way, in the comparative power supply circuit 220, signals are exchanged directly between the power management circuit block and the charging management circuit block, and control is performed while interdependent on each other.

[0027] However, in the power supply circuit 120 according to this embodiment, the power management circuit block 10 and the charge management circuit block 20 operate independently of each other, using the internal power supply voltage VDD1 (the voltage VC1 of the charging element 24) as a common index. The internal power supply voltage VDD1 at which the power management circuit block 10 starts up is linked to the voltage VC1 of the charging element 24. Specifically, as shown in FIG. 3(a), the power management circuit block 10 operates independently based on the power generation thresholds (approximately 0.9V and approximately 1.05V) using the voltage VC1 of the charging element 24. On the other hand, the charge management circuit block 20 operates independently based on the charge management thresholds (approximately 0.95V and approximately 1.1V) using the internal power supply voltage VDD1 (the voltage VC1 of the charging element). In this embodiment, the range between the upper threshold (approximately 1.05 V) and the lower threshold (approximately 0.9 V) for power generation and the range between the upper threshold (approximately 1.1 V) and the lower threshold (approximately 0.95 V) for charge management partially overlap, but they do not necessarily have to overlap. Also, in this embodiment, the upper threshold (approximately 1.05 V) for power generation is lower than the upper threshold (approximately 1.1 V) for charge management, but this magnitude relationship does not necessarily have to be satisfied. On the other hand, in this embodiment, the lower threshold (approximately 0.9 V) for power generation is lower than the lower threshold (approximately 0.95 V) for charge management, but this magnitude relationship must always be satisfied.

[0028] In this way, the power supply circuit 120 performs distributed control, controlling the power management circuit block 10 and the charge management circuit block 20 based on their respective thresholds using the internal power supply voltage VDD1 (the voltage VC1 of the charging element 24). In other words, the power management circuit block 10 and the charge management circuit block 20 perform closed control within their respective analog circuit blocks using a common index, performing local control similar to reflexes in the control systems of living organisms. To achieve this type of distributed control, for example, the power management circuit block 10 and the charge management circuit block 20 can be controlled using two hysteresis comparators. Note that to implement control using two hysteresis comparators as an analog circuit, it is sufficient to use, for example, two Schmitt trigger circuits.

[0029] Here, the power management circuit block 10 (first analog circuit block) includes a voltage monitor circuit (first voltage monitor circuit) that monitors the voltage VC1 of the charging element 24, for example, in the start-up circuit 12. Unlike the power management circuit block 10, the charge management circuit block 20 (second analog circuit block) includes a voltage monitor circuit (second voltage monitor circuit) that monitors the internal power supply voltage VDD1 (voltage VC1 of the charging element) of the charge management circuit block 20, for example, in the selector circuit 21.

[0030] The power supply circuit 120 autonomously generates the internal power supply voltage VDD1 in the power management circuit block 10, and autonomously controls the internal power supply voltage VDD1 (voltage VC1 of the charging element) within the charge management threshold (approximately 0.95 V and approximately 1.1 V) in the charge management circuit block 20. In region A shown in FIG. 3(a), power is supplied from the power generation element 110, and when the voltage VC1 of the charging element 24 of the charge management circuit block 20 reaches approximately 1.05 V, the internal power supply voltage VDD1 is activated. On the other hand, in region B, if the internal power supply voltage VDD1 falls below the lower threshold (approximately 0.9 V) for power generation even when power is supplied from the power generation element 110 to the power management circuit block 10, the power management circuit block 10 drops the internal power supply voltage VDD1 and stops the power supply circuit 120.

[0031] 4 is another diagram illustrating distributed control of the power supply circuit 120 according to the embodiment. The waveforms shown in FIG. 4(a) show how the power management circuit block 10 and the charge management circuit block 20 operate independently of each other, using the internal power supply voltage as a common index. On the other hand, the waveforms shown in FIG. 4(b) show how the power management circuit block and the charge management circuit block in a comparative power supply circuit (e.g., the power supply circuit 220 in FIG. 2(a)) depend on each other and perform control by directly exchanging signals with each other. Note that the horizontal axis in FIGS. 4(a) and 4(b) represents time, and the vertical axis represents voltage.

[0032] First, in region C shown in FIG. 4(b), power is supplied from the charging element 224 via a circuit startup boost circuit included in the startup circuit 212. When the voltage VC2 of the charging element 223 detected by the power management circuit block reaches approximately 4.3 V, the internal power supply voltage VDD2 rises to the voltage VC2 of the charging element 223, and the power supply circuit 220 is started. Meanwhile, when the internal power supply voltage VDD2 of the power management circuit block (voltage VC2 of the charging element 223) reaches approximately 4.0 V, the internal power supply voltage VDD2 falls, and the power supply circuit 220 is shut down. After the power supply circuit 220 is started, the power management circuit block and the charging management circuit block exchange signals directly with each other to control the internal power supply voltage VDD2 monitored by the power management circuit block to be approximately 4.2 V. Specifically, when the internal power supply voltage VDD2 (voltage VC2 of the charging element 223) falls below approximately 4.1 V (region B), the power management circuit block sends a signal to the charging management circuit block to supply power from the power generation element to the power management circuit block. On the other hand, when the internal power supply voltage VDD2 monitored by the power management circuit block exceeds approximately 4.4 V, the power management circuit block sends a signal to the power management circuit block to stop the supply of power from the power generation element to the power management circuit block. In this way, in the comparative power supply circuit 220, signals are exchanged directly between the power management circuit block and the charge management circuit block, and they perform control dependent on each other.

[0033] However, in the power supply circuit 120 according to this embodiment, the power management circuit block 10 and the charge management circuit block 20 operate independently of each other, using the internal power supply voltage VDD2 (voltage VC2 of the charging element 23) as a common index. The internal power supply voltage VDD2 of the power management circuit block 10 is linked to the voltage VC2 of the charging element of the charge management circuit block 20. Specifically, as shown in FIG. 4(a), the power management circuit block 10 operates independently based on the power generation thresholds (approximately 4.0 V and approximately 4.3 V) using the voltage VC2 of the charging element 23 (internal power supply voltage VDD2). On the other hand, the charge management circuit block 20 operates independently based on the charge management thresholds (approximately 4.1 V and approximately 4.4 V) using the internal power supply voltage VDD2 (voltage VC2 of the charging element). In this embodiment, the range between the upper threshold (approximately 4.3 V) and the lower threshold (approximately 4.0 V) for power generation and the range between the upper threshold (approximately 4.4 V) and the lower threshold (approximately 4.1 V) for charge management partially overlap, but they do not necessarily have to overlap. Also, in this embodiment, the upper threshold (approximately 4.3 V) for power generation is lower than the upper threshold (approximately 4.4 V) for charge management, but this magnitude relationship does not necessarily have to be satisfied. On the other hand, in this embodiment, the lower threshold (approximately 4.0 V) for power generation is lower than the lower threshold (approximately 4.1 V) for charge management, but this magnitude relationship must always be satisfied.

[0034] In this way, the power supply circuit 120 is configured so that the power management circuit block 10 and the charge management circuit block 20 use the internal power supply voltage as a common index, and each operates based on a different threshold. In other words, the power management circuit block 10 and the charge management circuit block 20 use a common index to perform closed control within their respective analog circuit blocks, similar to the reflex control systems of living organisms, enabling autonomous operation without the need for signals to be exchanged between the analog circuit blocks. Note that the common index that can be used in the power supply circuit 120 is not limited to the internal power supply voltage, and may also be information such as a compensation voltage, an external power supply voltage, or the installation environment.

[0035] As shown in FIGS. 3 and 4, a configuration for autonomously operating individual analog circuit blocks includes control similar to the reflexes of biological control systems, as well as control similar to the internal rhythm (Central Pattern Generator) of biological control systems. FIG. 5 is a diagram illustrating the internal rhythm of a power supply circuit according to an embodiment. FIG. 5(a) shows a circuit diagram of a charge management circuit block 20 and a voltage conversion circuit block 30 to illustrate an example of distributed control using the internal rhythm in a power supply circuit 120. Since it is assumed that power is supplied from three different types of power generating elements, three inductors are used in the voltage conversion circuit block 30. FIG. 6 is a diagram illustrating the control timing of a comparative power supply circuit. FIG. 6(a) shows a circuit diagram of a charge management circuit block 240 and a voltage conversion circuit block 230 to illustrate the control timing of a comparative power supply circuit (e.g., the power supply circuit 220 of FIG. 2(a)).

[0036] 6(a), three switches SW2 are connected in series to each of the three charging elements 222 to 224. In the voltage conversion circuit block 230, inductors 233 to 235 and a switch SW1 are connected to each of three wires. Each of the three wires of the voltage conversion circuit block 230 is electrically connected to each of the three charging elements 222 to 224 via the switch SW2.

[0037] The timing of charging the charging elements 222-224 in the circuit configuration of the charging management circuit block 240 and voltage conversion circuit block 230 shown in Fig. 6(a) will be explained using the timing chart in Fig. 6(b). First, when switch SW1 is ON, current flows to each of the inductors 233-235, and the inductor current rises. When switch SW1 is OFF and switch SW2 is ON, current flows from each of the inductors 233-235 to the charging management circuit block 240, and the inductor current falls. At the timing (region D) when this inductor current falls, each of the charging elements 222-224 is charged, and the capacitor voltage (Cap voltage) of each of the charging elements 222-224 rises.

[0038] As described above, in the comparative power supply circuit 220, in order to charge each of the charging elements 222 to 224 with the current of each of the inductors 233 to 235, it is necessary to switch the switch SW2 from the OFF state to the ON state at the timing when the switch SW1 switches from the ON state to the OFF state. Therefore, in the comparative power supply circuit 220 shown in Fig. 6(a), it is necessary to exchange a signal (synchronization signal) between the charge management circuit block 240 and the voltage conversion circuit block 230 in order to synchronize the control timing of the switch SW1 and the switch SW2.

[0039] 5(a), a switch SW2 is connected in series to each of three charging elements 22-24, and the ends of the three switches SW2 are combined and electrically connected to a voltage conversion circuit block 30. In the voltage conversion circuit block 30, inductors 33-35, diodes 36-38, and a switch SW1 are connected to three wires, respectively. The diodes 36-38 are elements for preventing current from flowing from the charging management circuit block 20 to the voltage conversion circuit block 30, and may be switching elements such as transistors.

[0040] The timing of charging the charging elements 22-24 in the circuit configuration of the charging management circuit block 20 and voltage conversion circuit block 30 shown in Fig. 5(a) will be explained using the timing chart in Fig. 5(b). First, when switch SW1 is ON, current flows to each of the inductors 33-35, and the inductor current rises. When switch SW1 is OFF, if any switch SW2 is ON, current flows from each of the inductors 33-35 to the charging management circuit block 20, and the inductor current falls. At the timing (region D) when this inductor current falls, each of the charging elements 22-24 is charged, and the capacitor voltage (Cap voltage) of each of the charging elements 22-24 rises.

[0041] In this way, the power supply circuit 120 controls switches SW1 and SW2 to charge each of the charging elements 22-24 with the current of each of the inductors 33-35. However, in the power supply circuit 120 shown in FIG. 5(a), the control timing of switches SW1 and SW2 is not synchronized (asynchronous). Switch SW1 operates autonomously with an internal rhythm based on the current of inductors 33-35 (inductor current), and switch SW2 operates autonomously with control based on the voltage of the charging elements 22-24 (capacitor voltage (Cap voltage)). In other words, the charge management circuit block 20 and the voltage conversion circuit block 30 perform local control independently within their respective analog circuit blocks, with the voltage conversion circuit block 30 performing control similar to the internal rhythm of a biological control system, and the charge management circuit block 20 performing control similar to a reflex in a biological control system. Therefore, in the power supply circuit 120, the charging management circuit block 20 and the voltage conversion circuit block 30 do not directly exchange signals between each other, and each block operates autonomously to charge the charging elements 22 to 24 with the currents of the inductors 33 to 35.

[0042] 5, in the power supply circuit 120, the charge management circuit block 20 and the voltage conversion circuit block 30 each operate autonomously, thereby independently controlling the charge management circuit block 20 and the voltage conversion circuit block 30. The voltage conversion circuit block 30 operates autonomously according to its own internal rhythm, enabling it to operate independently without exchanging signals with other analog circuit blocks.

[0043] In this way, the power supply circuit 120 is made up of multiple analog circuit blocks, and is configured so that one analog circuit block and another analog circuit block are controlled to different thresholds based on a common index (control like a reflex in the control system of a living organism), or one analog circuit block and another analog circuit block are configured to operate autonomously according to their own internal rhythms (control like the internal rhythms in the control system of a living organism). By replacing each of the multiple analog circuit blocks that make up the power supply circuit 120 in this way with a configuration that controls them autonomously without directly exchanging signals with each other, it is possible to achieve distributed control of the power supply circuit 120 with no dependency between the analog circuit blocks.

[0044] 5(a), a power generation element 110 may be provided on each of three wires provided with inductors 33-35. The charge management circuit block 20 includes a plurality of charging elements 22-24 and a switch SW2 (charge management switch) provided on each of the plurality of charging elements 22-24. Therefore, any of the charging elements 22-24 can be selected and charged with power simultaneously extracted from the plurality of power generation elements 110.

[0045] The multiple power generating elements 110 may be the same type of power generating elements 110 or different types of power generating elements 110. Therefore, the configuration of a power supply circuit in which multiple power generating elements 110 of different types are connected will be described below as a modified example.

[0046] (Variation) 7 is a circuit diagram of a power supply module 100A according to a modified example. The power supply module 100A includes a photoelectric power generation element 111, a thermoelectric power generation element 112, an electrostatic vibration power generation element 113, an electromagnetic vibration power generation element 114, and a power supply circuit 120A. The power supply module 100A extracts power generated by each of the photoelectric power generation element 111, the thermoelectric power generation element 112, the electrostatic vibration power generation element 113, and the electromagnetic vibration power generation element 114 using the power supply circuit 120A, and supplies the power to a load circuit (not shown), such as a sensor.

[0047] Here, photoelectric power generation element 111 is a power generation element that converts light energy into electric power using, for example, a phenomenon known as the photoelectric effect. Electrostatic vibration power generation element 113 is a power generation element that converts vibration energy into electric power using, for example, an electret. Thermoelectric power generation element 112 and electromagnetic vibration power generation element 114 have already been described, so their description will not be repeated.

[0048] The power supply circuit 120A is composed of multiple analog circuit blocks, and includes power supply management circuit blocks 10A to 10D, a charge management circuit block 20, and voltage conversion circuit blocks 30A to 30D. The power supply management circuit block 10A is an analog circuit block (first analog circuit block) that starts up a part of the power supply circuit 120A connected to the photovoltaic power generation element 111, and includes a start-up switch circuit 11a and a start-up circuit 12. The start-up switch circuit 11a starts up the power supply circuit 120A using the power stored in the charging elements 22 to 24. In the power supply management circuit block 10A, the start-up switch circuit 11a is a circuit provided for the photovoltaic power generation element 111, but the start-up circuit 12 is a circuit shared with the other power generation elements.

[0049] The power management circuit block 10B is an analog circuit block (first analog circuit block) that starts up a part of the power supply circuit 120A connected to the thermoelectric generating element 112, and includes a start-up switch circuit 11b and a start-up circuit 12. The start-up switch circuit 11b starts up the power supply circuit 120A using the power stored in the charging elements 22 to 24 via the start-up circuit 12. In the power management circuit block 10B, the start-up switch circuit 11b is a circuit provided for the thermoelectric generating element 112, but the start-up circuit 12 is a circuit shared with the other generating elements.

[0050] The power management circuit block 10C is an analog circuit block (first analog circuit block) that starts up a part of the power supply circuit 120A connected to the electrostatic vibration power generation element 113, and includes a start-up switch circuit 11c and a start-up circuit 12. The start-up switch circuit 11c starts up the power supply circuit 120A using the power charged in the charging elements 22 to 24 via the start-up circuit 12. In the power management circuit block 10C, the start-up switch circuit 11c is a circuit provided for the electrostatic vibration power generation element 113, but the start-up circuit 12 is a circuit shared with the other power generation elements.

[0051] The power management circuit block 10D is an analog circuit block (first analog circuit block) that starts up part of the power supply circuit 120A connected to the electromagnetic vibration power generation element 114, and includes a start-up switch circuit 11d and a start-up circuit 12. The start-up switch circuit 11d starts up the power supply circuit 120A using the power stored in the charging elements 22 to 24. In the power management circuit block 10D, the start-up switch circuit 11d is a circuit provided for the electromagnetic vibration power generation element 114, but the start-up circuit 12 is a circuit shared with the other power generation elements.

[0052] The charge management circuit block 20 is an analog circuit block (second analog circuit block) that includes charging elements 22 to 24 and manages the power to be charged to the charging elements 22 to 24, and includes a selector circuit 21. The selector circuit 21 switches between charging and not charging the charging elements 22 to 24 based on the voltages of the charging elements 22 to 24. Note that the charging elements 22 to 24 are not limited to being included in the charge management circuit block 20, and may be provided separately from the charge management circuit block 20 and connected to the charge management circuit block 20.

[0053] The voltage conversion circuit block 30A is an analog circuit block (third analog circuit block) that includes an inductor and the like and converts the voltage input from the photoelectric power generation element 111 and outputs it to the charging elements 22-24. The voltage conversion circuit block 30B is an analog circuit block (third analog circuit block) that includes an inductor and the like and converts the voltage input from the thermoelectric power generation element 112 and outputs it to the charging elements 22-24. The voltage conversion circuit block 30C is an analog circuit block (third analog circuit block) that includes an inductor and the like and converts the voltage input from the electrostatic vibration power generation element 113 and outputs it to the charging elements 22-24. The voltage conversion circuit block 30D is an analog circuit block (third analog circuit block) that includes an inductor and the like and converts the voltage input from the electromagnetic vibration power generation element 114 and outputs it to the charging elements 22-24.

[0054] In the power supply circuit 120A, the power management circuit blocks 10A to 10D and the charge management circuit block 20 operate independently of each other using the internal power supply voltage as a common index, and the voltage conversion circuit blocks 30A to 30D operate autonomously at an internal rhythm different from that of the charge management circuit block 20. In other words, the power supply circuit 120A performs distributed control in which the power management circuit blocks 10A to 10D, the charge management circuit block 20, and the voltage conversion circuit blocks 30A to 30D operate independently without directly exchanging signals with each other.

[0055] The power supply circuit 120A extracts power from four power generation elements: the photoelectric power generation element 111, the thermoelectric power generation element 112, the electrostatic vibration power generation element 113, and the electromagnetic vibration power generation element 114. It combines multiple analog circuit blocks for distributed control. Therefore, the power supply circuit 120A is scalable, allowing it to be designed simply by rearranging the analog circuit blocks depending on the type of power generation element to be connected. Furthermore, the scalability of the power supply circuit 120A is achieved without any degradation in performance. For example, when a dedicated power supply circuit was provided for each of the photoelectric power generation element 111, the thermoelectric power generation element 112, the electrostatic vibration power generation element 113, and the electromagnetic vibration power generation element 114, and the power supply capacity was simulated, a total of approximately 106 μW of power could be supplied. On the other hand, when a single power supply circuit 120A was provided to combine the four power generation elements, a power supply capacity of approximately 102 μW could be supplied. Therefore, even when a single power supply circuit 120A was provided to combine the four power generation elements, there was almost no degradation in performance.

[0056] Because each block that performs distributed control of the power supply circuit 120A is composed of general analog circuits, appropriate design can sufficiently reduce standby power (control power when the power generation amount of the power generation element is small). Figure 8 is a diagram showing an example (simulation results) of the standby power of the power supply circuit 120A when power is supplied from both a thermoelectric power generation element and an electromagnetic vibration power generation element in a modified example. As shown in Figure 8, the standby power of the power supply circuit 120A is low, totaling 984 pW (= 0.984 nW), less than 1 nW. The standby power of commercially available power supply circuits for energy harvesting elements is approximately 1 μW, which is approximately 1,000 times the standby power of the power supply circuit 120A.

[0057] Furthermore, the power supply circuit 120A may be configured with multiple analog circuit blocks each configured as a different semiconductor chip. Because the power supply circuit 120A performs distributed control that does not directly exchange signals between analog circuit blocks, there is no need for coordination between the analog circuit blocks. This allows each company to develop a semiconductor chip for each analog circuit block, enabling differentiation of performance for each analog circuit block. Meanwhile, the design of the power supply circuit 120A can utilize a design platform that can be realized by combining semiconductor chips developed for each analog circuit block.

[0058] The analog circuit blocks included in the power supply circuit 120 or the power supply circuit 120A are not limited to the power management circuit blocks 10, 10A to 10D, the charge management circuit block 20, and the voltage conversion circuit blocks 30, 30A to 30D. The analog circuit blocks included in the power supply circuit 120 or the power supply circuit 120A may be other analog circuit blocks including other functions such as a calibration circuit.

[0059] (Aspect) (1) The power supply circuit according to the present disclosure comprises: A power supply circuit including a plurality of analog circuit blocks, a first analog circuit block; a second analog circuit block that operates independently of the first analog circuit block based on a common index with the first analog circuit block; a third analog circuit block that operates independently of the first analog circuit block and the second analog circuit block; The first analog circuit block, the second analog circuit block, and the third analog circuit block operate independently without directly transferring signals to each other.

[0060] (2) In the power supply circuit according to (1), the first analog circuit block is a power management circuit block that starts up the power supply circuit, the second analog circuit block is a charge management circuit block that includes a charging element and manages power to be charged to the charging element; The first analog circuit block and the second analog circuit block use the internal power supply voltage as a common index and operate independently based on different thresholds.

[0061] (3) In the power supply circuit according to (2), the third analog circuit block is a voltage conversion circuit block that converts an input voltage and outputs the converted voltage; The third analog circuit block operates autonomously with an internal rhythm based on the inductor current, without directly exchanging signals with the second analog circuit block.

[0062] (4) In the power supply circuit according to (2) or (3), the first analog circuit block includes a first voltage monitor circuit that monitors an internal power supply voltage of the power management circuit block; The second analog circuit block includes a second voltage monitor circuit that is different from the first voltage monitor circuit and monitors the internal power supply voltage of the charge management circuit block.

[0063] (5) In the power supply circuit described in any one of (1) to (4), the second analog circuit block is a charge management circuit block including a plurality of charging elements and a charge management switch provided for each of the plurality of charging elements, and can select any one of the plurality of charging elements to charge with power extracted from the plurality of power generating elements.

[0064] (6) In the power supply circuit according to (5), each of the plurality of power generating elements is an energy harvesting element.

[0065] (7) In the power supply circuit according to any one of (1) to (5), the first analog circuit block, the second analog circuit block, and the third analog circuit block can be configured as different semiconductor chips.

[0066] (8) A power supply module according to the present disclosure includes a plurality of power generating elements and the power supply circuit according to any one of (1) to (7).

[0067] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0068] 10, 10A to 10D power management circuit block, 11, 11a to 11d start switch circuit, 12 start circuit, 20, 240 charge management circuit block, 21, 221 selector circuit, 22 to 24, 222 to 224 charging element, 30, 30A to 30D, 230 voltage conversion circuit block, 31, 231 rectifier circuit, 32, 232 DC-DC conversion circuit, 33 to 35, 233 to 235 inductor, 36 to 38 diode, 100, 100A, 200 power module, 110, 210 power generation element, 111 photoelectric power generation element, 112 thermoelectric power generation element, 113 electrostatic vibration power generation element, 114 electromagnetic vibration power generation element, 120, 120A, 220 power supply circuit.

Claims

1. A power supply circuit including a plurality of analog circuit blocks, a first analog circuit block; a second analog circuit block that operates independently of the first analog circuit block based on a common index with the first analog circuit block; a third analog circuit block that operates independently of the first analog circuit block and the second analog circuit block; The power supply circuit, wherein the first analog circuit block, the second analog circuit block, and the third analog circuit block operate independently without directly transferring signals to each other.

2. the first analog circuit block is a power management circuit block that starts up the power supply circuit; the second analog circuit block is a charge management circuit block that includes a charging element and manages power to be charged to the charging element; 2. The power supply circuit according to claim 1, wherein the first analog circuit block and the second analog circuit block operate independently based on different thresholds, using an internal power supply voltage as the common index.

3. the third analog circuit block is a voltage conversion circuit block that converts an input voltage and outputs the converted voltage; 3. The power supply circuit according to claim 2, wherein said third analog circuit block operates autonomously with an internal rhythm based on a current in an inductor without directly exchanging signals with said second analog circuit block.

4. the first analog circuit block includes a first voltage monitor circuit that monitors an internal power supply voltage of the power management circuit block; 3. The power supply circuit according to claim 2, wherein said second analog circuit block includes a second voltage monitor circuit that is different from said first voltage monitor circuit and monitors an internal power supply voltage of a charge management circuit block.

5. The power supply circuit according to any one of claims 1 to 4, wherein the second analog circuit block is a charge management circuit block including a plurality of charging elements and a charge management switch provided in each of the plurality of charging elements, and is capable of selecting and charging any one of the plurality of charging elements with power extracted from a plurality of power generation elements.

6. The power supply circuit according to claim 5 , wherein each of the plurality of power generating elements is an energy harvesting element.

7. 5. The power supply circuit according to claim 1, wherein the first analog circuit block, the second analog circuit block, and the third analog circuit block can be configured as different semiconductor chips.

8. A plurality of power generating elements; A power supply module comprising: the power supply circuit according to any one of claims 1 to 4.

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