WO2019124141A1 - Power conversion device and power supply device - Google Patents

Abstract

A power conversion circuit 7A comprises a frequency modulation unit 12A that generates a voltage CLK in which pulse waves are superimposed on a voltage (VH-VL), and a booster unit 13A that receives the voltage CLK from the frequency modulation unit 12A and generates a voltage Vout that is higher than the voltage CLK using a charge pump operation. The booster unit 13A has capacitors C2, C3 that are charged by the voltage CLK, and, on the basis of the pulse waves included in the voltage CLK, switches between a first operation in which a charge is stored in the capacitors C2, C3 and a second operation in which a voltage based on the charge and the voltage CLK are superimposed for output.

Description

Power converter and power supply

The present disclosure describes a power converter and a power supply.

Patent Document 1 discloses a semiconductor integrated circuit device having a high voltage generation circuit. This circuit device adopts a charge pump system as a high voltage generation circuit. And, the circuit device has an oscillator and a charge pump.

Non-Patent Document 1 discloses an AC-DC conversion circuit. The conversion circuit converts an input voltage into a DC voltage. Also, the conversion circuit boosts the DC voltage to a predetermined voltage. The conversion circuit receives, for example, an input voltage having a frequency of several hundred megahertz or more and several gigahertz or less. Such a frequency band is applied to, for example, an RFID (Radio Frequency IDentifier).

WO 2004/030191

As a power converter, what utilizes a switching converter circuit, and what utilizes a booster circuit are mentioned. The switching converter circuit uses an inductor. However, it is difficult to mount the inductor in an integrated circuit in an appropriate size. On the other hand, the booster circuit can be implemented in an integrated circuit with an appropriate size.

As in the circuit disclosed in Non-Patent Document 1, when power of a high frequency AC voltage is input to the booster circuit, the conversion efficiency of the power is good. However, when low frequency AC power is input to the booster circuit, the power conversion efficiency is reduced due to the operation principle of the booster circuit.

Thus, the present disclosure describes a power conversion device and a power supply device that can improve power conversion efficiency.

A power conversion device according to an embodiment of the present disclosure receives a first voltage having a first frequency, and generates a second voltage on which a pulse wave having a second frequency higher than the first frequency with respect to the first voltage is superimposed. And a boosting unit that receives the second voltage from the frequency modulation unit and generates an output voltage higher than the second voltage by charge pump operation, and the boosting unit is charged by the second voltage. According to the pulse wave included in the second voltage, the first operation having the capacitor and storing the charge in the capacitor and the second operation that the voltage based on the charge and the second voltage are superimposed and output are output .

The boosting unit includes a first operation of charging the capacitor with the first voltage to accumulate charge in the capacitor, and a second operation of overlapping the voltage based on the accumulated charge and the first voltage and outputting the superimposed voltage. Here, the output power output from the booster is defined by the output voltage and the output current. First, the maximum value of the output voltage is determined by the peak voltage value of the first voltage and the number of capacitors connected in series with each other. Next, the magnitude of the output current is proportional to the number of repetitions of the charging operation and the output operation. That is, as the number of repeating the charging operation and the output operation increases, more charge transfer is performed. As a result, the output current increases. The power conversion device generates a second voltage by superimposing a pulse wave having a second frequency higher than the first frequency on a first voltage having a first frequency in the frequency modulation unit. Then, the booster switches between the charging operation and the output operation based on the pulse wave. Therefore, the number of repetitions of the charging operation and the output operation is larger than that in the configuration in which the first voltage is directly input to the booster. That is, much charge transfer is performed. As a result, the output current output from the booster is increased according to the frequency of the pulse wave. Therefore, the average output power output from the booster is increased. As a result, the power converter can improve the power conversion efficiency.

The above power converter further includes a rectifying unit that receives an input voltage having a first frequency from the power source, rectifies the input voltage to generate a first voltage, and provides the first voltage to a frequency modulation unit. Good. According to this configuration, the number of times of charge transfer in the booster increases. As a result, the output current is further increased. Therefore, the power converter can further enhance the power conversion efficiency.

The above power converter receives an input voltage from a power source, generates an input control signal based on a magnitude relation between an absolute value of the input voltage and an input threshold value, and provides an input voltage detection unit for providing the input control signal to a rectifying unit. You may provide further. The rectifying unit may rectify the input voltage based on the input control signal to generate a first voltage. According to this configuration, the input voltage can be reliably rectified.

The above power converter may further include an internal voltage generation unit that receives an input voltage from the power source, generates a drive voltage for driving the input voltage detection unit, and provides the input voltage detection unit with the drive voltage. . According to this configuration, the drive voltage required to drive the input voltage detection unit is generated from the input voltage. That is, the power conversion device does not have to include a battery for supplying a voltage for driving the input voltage detection unit. Furthermore, the power converter does not need to replace the battery. Therefore, the power converter is easy to maintain.

The power conversion device described above receives an input control signal from an input voltage detection unit, generates an oscillation control signal for controlling start and stop of an oscillation operation for generating a pulse wave in a frequency modulation unit based on the input control signal. The apparatus may further include an oscillation control unit that provides the control signal to the frequency modulation unit. According to this configuration, it is possible to control the start and stop of the oscillation operation based on the absolute value of the input voltage. As a result, when the absolute value of the input voltage is smaller than the threshold value, the oscillation operation can be stopped. Therefore, the magnitude of the input voltage provided for power conversion is limited to the threshold or more. As a result, the power converter can output an output voltage of a desired magnitude.

The above power conversion device receives an output voltage from the booster, generates an output control signal based on a magnitude relation between an absolute value of the output voltage and an output threshold, and provides an output control signal to the oscillation control unit. The oscillation control unit may generate an oscillation control signal based on the input control signal and the output control signal, and the frequency modulation unit may control the start and stop of the oscillation operation based on the oscillation control signal. . According to this configuration, it is possible to stop the oscillation operation when the output voltage becomes larger than the threshold. Therefore, the power converter can place a limit on the magnitude of the output voltage.

The above power converter may further include a limiter unit that receives the output voltage from the booster and defines the maximum value of the output voltage. According to this configuration, an upper limit can be provided to the voltage output from the power conversion device.

In the power converter, the first rectifier as the rectifier, the first frequency modulator as the frequency modulator, and the first booster as the booster generate the first output voltage as the output voltage. The power conversion unit is configured, and a second rectification unit different from the first rectification unit, a second frequency modulation unit different from the first frequency modulation unit, and a second booster unit different from the first booster unit , And the second power conversion unit connected in parallel to the first power conversion unit, and the second rectification unit receives the input voltage and generates the third voltage from which the input voltage is rectified. Starting based on the input voltage, the second frequency modulation unit receives the third voltage, and superimposes a pulse wave having a fourth frequency higher than the third frequency of the third voltage with respect to the third voltage. The operation of generating four voltages is started based on the third voltage, and the second booster performs the second frequency modulation. Receiving a fourth voltage from may generate high second output voltage than the fourth voltage by a charge pump operation. According to this configuration, the stability of the operation at the time of startup of the power conversion device can be enhanced.

A power supply device according to another aspect of the present disclosure includes: a power source generating power of an input voltage having a first frequency; and the power source connected to the power source to convert power of the input voltage into power of a DC voltage. And a power converter. This power supply device has the above-described power conversion circuit. Therefore, good power conversion efficiency can be obtained. As a result, the power supply device can supply desired power.

According to the power conversion device and the power supply device of the present disclosure, the conversion efficiency can be improved.

FIG. 1 is a view showing the configuration of a sensor device provided with a power supply device according to the first embodiment. FIG. 2 is a block diagram showing the configuration of the power supply device according to the first embodiment. Part (a) of FIG. 3 is an example of the circuit configuration in the rectifying unit. Part (b) of FIG. 3 is an example of a circuit configuration in the frequency modulation unit. Part (c) of FIG. 3 is an example of the circuit configuration in the booster. Part (a) of FIG. 4 is an example of the circuit configuration in the input voltage detection unit. The part (b) of FIG. 4 is an example of the circuit structure in an output voltage detection part. Part (a) of FIG. 5 is an example of a circuit configuration in the oscillation control unit. Part (b) of FIG. 5 is an example of a circuit configuration in the internal voltage generation unit. Part (a) of FIG. 6 is an illustration of the input voltage. Part (b) of FIG. 6 is an example of the control signal input to the frequency modulation unit. Part (c) of FIG. 6 is an example of the voltage output from the rectifying unit. Part (d) of FIG. 6 is an example of the clock voltage. Part (e) of FIG. 6 is an example of the current output from the booster. Part (a) of FIG. 7 is a diagram conceptually showing the energy balance in the power supply apparatus according to the comparative example. Part (b) of FIG. 7 is a diagram conceptually showing the energy balance in the power supply device according to the embodiment. FIG. 8 is a graph showing experimental results by a computer. FIG. 9 is a block diagram showing the configuration of the power supply device according to the second embodiment. Part (a) of FIG. 10 is an example of the circuit configuration of the frequency modulation unit provided in the power supply device according to the second embodiment. Part (b) of FIG. 10 is an example of the circuit configuration of the limiter provided in the power supply device according to the second embodiment. Part (c) of FIG. 10 is a graph showing the characteristics of the limiter. FIG. 11 is a block diagram showing the configuration of the power supply device according to the third embodiment. Part (a) of FIG. 12 is an example of the circuit configuration of the rectifying unit provided in the power supply device according to the third embodiment. Part (b) of FIG. 12 and part (c) of FIG. 12 are circuit diagrams for explaining the operation of the rectifying unit. FIG. 13 is a block diagram showing the configuration of the power supply device according to the fourth embodiment. FIG. 14 is a block diagram showing the configuration of the power supply apparatus according to the first modification. Part (a) of FIG. 15 is an example of the circuit configuration of the frequency modulation unit provided in the power supply device according to the first modification. Part (b) of FIG. 15 is an example of the circuit configuration of the booster provided in the power supply apparatus according to the first modification. FIG. 16 is a block diagram showing the configuration of the power supply device according to the second modification. FIG. 17 is a block diagram showing a configuration of a power supply device according to the third modification. FIG. 18 is an example of a circuit configuration of a booster provided in a power supply device according to the fourth modification. FIG. 19 is a block diagram showing a configuration of a power supply device according to a comparative example.

Hereinafter, the power conversion device and the power supply device of the present disclosure will be described in detail with reference to the attached drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

First Embodiment
Attention is focused on the Internet of Things (IoT) to cope with social changes such as further efficiency of agriculture, industry, and commerce, aging, and population decline. IoT is a technology that autonomously collects information by mounting a sensor and an information communication circuit in every device. The IoT autonomously acquires measurement data, which is an environmental variable such as temperature, pressure, vibration, chemical substance, and traffic, indoors and outdoors, using a sensor. And IoT transfers those measurement data to the cloud server via the Internet. The transferred data is analyzed as big data. As a result of analysis, when an abnormality is detected or a state in which a response is necessary is made, feedback is returned to the device to be monitored. Thus, in the IoT, devices basically perform information collection, information transmission, and feedback without human intervention. The measuring terminal measures environmental variables and sends the information to the Internet. Integrated circuit system for IoT is an important element in this terminal. The measurement terminal autonomously exerts the function as an IoT terminal even in a place where power is not supplied. Therefore, a so-called energy harvesting technology is being considered that uses environmental energy as power for integrated circuit systems. In particular, in energy harvesting technology, research on individual circuit systems for extracting electric power from sunlight, heat, vibration, radio waves, etc. is active.

As shown in FIG. 1, the power supply device 1A is used for the sensor device 2. The sensor device 2 is a terminal device configuring an IoT.

The sensor device 2 is connected to the Internet 100 via the antenna 3. The sensor device 2 transmits the collected data to another system such as the cloud server 101 via the Internet 100. The sensor device 2 also receives various data such as a measurement program via the Internet 100.

The sensor device 2 includes a power supply device 1A and a measurement device 4. The measuring device 4 collects various data such as the temperature, humidity or vibration frequency of the object 102. The measuring device 4 transmits the data. The measuring device 4 also receives data from the outside. For example, the measuring device 4 includes a sensor 4a, a digital circuit 4b, a memory circuit 4c, and a communication circuit 4d.

The power supply device 1A supplies power for driving the measuring device 4. That is, the power supply device 1A supplies the power required for the operation of the sensor 4a, the digital circuit 4b, the memory circuit 4c, and the communication circuit 4d that constitute the measuring device 4. Here, the power supply device 1A converts energy (for example, vibration energy) supplied from the outside to obtain power. That is, the power supply device 1A does not require the provision of power from a device such as a so-called battery that has stored power in advance. Therefore, when vibration energy is received from the object 102, the power supply device 1A continues the power supply to the measuring device 4. The vibration used as the energy source may be sine wave vibration or random vibration. That is, the type of vibration used as the energy source is not limited. Therefore, after being installed on the object 102, the sensor device 2 continues to drive using the vibration energy of the object 102. That is, the sensor device 2 does not have to perform battery replacement. The object 102 includes an object 102a and an object 102b independent of the object 102a. The object 102 a may supply energy to the vibration power generation element 6. The object 102b may be measured from the sensor 4a.

The power supply device 1A includes a vibration power generation element 6 (power source) and a power conversion circuit 7A (power conversion device). The vibration power generation element 6 converts vibration energy of the object 102 into electric power. This power is alternating current. Then, the power conversion circuit 7A converts the alternating current into a direct current usable for driving the measuring device 4.

The vibration power generation element 6 receives the vibration of the object 102 and generates AC power. For example, the vibration power generation element 6 utilizes a piezoelectric phenomenon. The vibration power generation element 6 has a vibrator such as a cantilever. The resonance frequency of the vibrator is adjusted to the vibration frequency of the object 102. Then, the vibration power generation element 6 generates AC power according to the frequency at which the vibrator actually vibrates. Therefore, the AC power output from the vibration power generation element 6 corresponds to the frequency of the vibrating vibrator. Further, the frequency of the AC power output from the vibration power generation element 6 corresponds to the vibration frequency of the object 102. For example, the frequency of AC power is several hundred hertz or more and several megahertz or less.

Power conversion circuit 7A is electrically connected to vibration generating element 6. Further, the power conversion circuit 7A is electrically connected to the measuring device 4. As described above, the power conversion circuit 7A converts the AC power output from the vibration power generation element 6 into DC power according to the specification of the measuring device 4. That is, the power conversion circuit 7A outputs a DC voltage.

The power conversion circuit 7A will be described in detail below.

The power conversion circuit 7A functionally includes an input voltage detection unit 11, a frequency modulation unit 12A, and a boosting unit 13A. The input voltage detection unit 11 detects the magnitude of the input voltage. The frequency modulation unit 12A converts the frequency of the alternating current from a low value to a high value. The booster 13A provides DC power to the measuring device 4 which is an integrated circuit. The power conversion circuit 7A drives a booster circuit using a signal obtained by frequency-modulating input AC power. According to this configuration, charge transfer is performed a plurality of times in one cycle of AC power output from the vibration power generation element. Thus, the average output power is increased. Furthermore, reactive power is reduced.

As shown in FIG. 2, the power conversion circuit 7A has inputs 7a and 7b and an output 7c. The input 7 a is connected to the vibration power generation element 6. The input 7a receives a voltage Vdd (input voltage, see part (a) of FIG. 6). The input 7 b is connected to the vibration power generation element 6. The input 7b receives the voltage Vss. The output 7 c is connected to the measuring device 4. The output 7c provides a voltage Vout (first output voltage).

The power conversion circuit 7A includes a power conversion unit 14A and a control unit 16A. Power conversion unit 14 </ b> A receives AC power from vibration power generation element 6. The power conversion unit 14A converts alternating current power into direct current power. The power conversion unit 14A outputs DC power to the measuring device 4. Control unit 16A controls the operation of power conversion unit 14A using AC power received by power conversion unit 14A and DC power output from power conversion unit 14A.

The power converter 14A has inputs 14a and 14b and an output 14c. The input 14a is connected to the input 7a of the power conversion circuit 7A. The input 14a receives a voltage Vdd. The input 14b is connected to the input 7b of the power conversion circuit 7A. The input 14b receives the voltage Vss. The output 14c is connected to the output 7c of the power conversion circuit 7A. The output 14c provides a voltage Vout.

The power converter 14A has inputs 14d and 14e. The inputs 14d and 14e receive an input control signal φ1 generated by the control unit 16A, an input control signal φ2 and an oscillation control signal EN. Although the details will be described later, the input 14d receives an input control signal φ1 and an input control signal φ2. The input 14e receives an oscillation control signal EN.

The power conversion unit 14A includes a rectification unit 17A (first rectification unit), a frequency modulation unit 12A (first frequency modulation unit), and a boosting unit 13A (first boosting unit). The rectifying unit 17A rectifies the voltage Vdd. The frequency modulation unit 12A generates a voltage CLK on which the clock signal is superimposed, based on the voltages VH and VL output from the rectification unit 17A. The boosting unit 13A boosts the voltage CLK on which the clock signal is superimposed.

The rectifying unit 17A has inputs 17a, 17b and 17c, and outputs 17d and 17e. The input 17a is connected to the input 14a of the power conversion unit 14A. The input 17a receives the voltage Vdd. The input 17b is connected to the input 14b of the power conversion unit 14A. The input 17b receives the voltage Vss. The input 17c is connected to the input 14d of the power conversion unit 14A. The input 17c receives input control signals φ1 and φ2. The output 17d is connected to the frequency modulation unit 12A. The output 17 d outputs a voltage VH. The output 17e is connected to the frequency modulation unit 12A. The output 17e outputs a voltage VL.

Part (a) of FIG. 3 shows a circuit configuration of the rectifying unit 17A. The rectifying unit 17A includes switches S1, S2, S3, and S4, and a capacitor C1. The switches S1, S2, S3 and S4 are, for example, MOSFETs (metal-oxide-semiconductor field-effect transistors). The input 17a is connected to the switches S1 and S2, respectively. The input 17b is connected to the switches S3 and S4, respectively. The switch S1 is connected in series to the switch S3. The switch S2 is connected in series to the switch S4. And one end of the capacitor C1 is connected between the switches S1 and S3. The other end of the capacitor C1 is connected between the switches S2 and S4.

For example, when the voltage Vdd is positive, the input control signal φ1 is ON (1). Further, the input control signal φ2 is OFF (0). In this case, the rectifying unit 17A connects the input 17a to the output 17d. The rectifying unit 17A connects the input 17b to the output 17e. As shown in part (c) of FIG. 6, a voltage Vdd is provided at the output 17d (Vdd = VH). The voltage Vss is provided to the output 17e (Vss = VL).

Conversely, when the voltage Vdd is negative, the input control signal φ1 is OFF (0). The input control signal φ2 is ON (1). In this case, the rectifying unit 17A connects the input 17b to the output 17d. The rectifying unit 17A connects the input 17a to the output 17e. As shown in part (c) of FIG. 6, the voltage Vss is provided to the output 17d (Vss = VH). The output Vdd is provided at the output 17e (Vdd = VL).

As shown in FIG. 2, the frequency modulation unit 12A has inputs 12a, 12b, 12c and an output 12d. The input 12a is connected to the output 17d of the rectifying unit 17A. Input 12a receives voltage VH. The input 12b is connected to the output 17e of the rectifying unit 17A. Input 12 b receives voltage VL. The input 12c is connected to the input 14e of the power conversion unit 14A. The input 12c receives an oscillation control signal EN. The output 12d is connected to the booster 13A. The output 12 d outputs a voltage CLK. The voltage CLK has a waveform in which a clock waveform is superimposed (see part (d) of FIG. 6). The clock waveform repeats ON-OFF with the voltage VH as an envelope.

Part (b) of FIG. 3 shows a circuit configuration of the frequency modulation unit 12A. That is, the frequency modulation unit 12A has a circuit configuration called a so-called ring oscillator. The frequency modulation unit 12A includes one NAND circuit G1 and an even number of inverter circuits G2 and G3. The inverter circuit G2 is connected in series to the inverter circuit G3. The NAND circuit G1 is connected to the inverter circuit G2 of the first stage. The NAND circuit G1 controls the start of the oscillation operation and the stop of the oscillation operation based on the oscillation control signal EN. For example, when the oscillation control signal EN is ON (1), the frequency modulation unit 12A starts the oscillation operation. Conversely, when the oscillation control signal EN is OFF (0), the frequency modulation unit 12A stops the oscillation operation. The number of inverter circuits G2 and G3 is determined based on the desired clock frequency (second frequency). The clock frequency may be, for example, several megahertz or more. The clock frequency may be greater than several gigahertz. In other words, the clock frequency may be larger than the frequency of the voltage Vdd output from the vibration generating element 6. The voltage VH received by the input 12a and the voltage VL received by the input 12b are input to the respective inverter circuits G2 and G3 as drive voltages.

Here, the first voltage in the present embodiment means a voltage received by the frequency modulation unit 12A. The first voltage is a voltage used to generate the voltage CLK. For example, the frequency modulation unit 12A shown in part (b) of FIG. 3 receives the voltages VH and VL. The frequency modulation unit 12A inputs the voltages VH and VL to the inverter circuits G2 and G3. The voltages VH and VL are drive voltages of the inverter circuits G2 and G3. The clock voltage is superimposed on the drive voltage. Therefore, in the present embodiment, the first voltage is a voltage (VH−VL).

Note that the aspect of the first voltage is not limited to the voltage (VH-VL). The aspect of the first voltage can take various aspects depending on the voltage input to the inverter circuits G2 and G3. For example, the voltage VH may be input to the input 12a, and the voltage Vss (GND) may be input to the input 12b. In this case, the first voltage is the voltage VH. Also, the voltage VL may be input to the input 12a, and the voltage Vss (GND) may be input to the input 12b. In this case, the first voltage is the voltage VL. Furthermore, when the power conversion unit 14A does not include the rectifying unit 17A, the voltage Vdd may be input to the input 12a and the voltage Vss may be input to the input 12b. In this case, the first voltage is a voltage (Vdd-Vss).

The first frequency and the third frequency in the present embodiment may be defined as the frequency of the voltage Vdd output from the vibration power generation element 6. Further, as described above, the frequency of the voltage Vdd is the frequency of the vibrating vibrator, and the frequency of the vibrator is the frequency of the vibration generated by the object 102. Therefore, the first frequency may be the frequency of the vibration provided from the object 102. For example, the frequency of mechanical vibration is approximately several hertz or more and several kilohertz or less. As a result, the range of the first frequency is also approximately several hertz or more and several kilohertz or less.

The second frequency and the fourth frequency in the present embodiment are the frequency of the clock signal generated by the ring oscillator circuit. The second frequency may be greater than the first frequency. For example, if the range of the first frequency is approximately several hertz or more and several kilohertz or less, the second frequency may be greater than several megahertz. Also, the second frequency may be greater than several gigahertz.

As shown in FIG. 2, the booster 13A has an input 13a and an output 13b. The input 13a is connected to the output 12d of the frequency modulation unit 12A. Input 13a receives voltage CLK. The output 13 b is connected to the measuring device 4. The output 13 b outputs a voltage Vout.

Part (c) of FIG. 3 shows the circuit configuration of the booster 13A. The booster 13A includes a plurality of diodes D1, D2, and D3 and a plurality of capacitors C2, C3, and C4. The boosting unit 13A performs an operation of charging the capacitors C2 and C3, an operation of superimposing a voltage derived from the charged charge on the voltage CLK to be input, and an operation of outputting the superimposed voltage CLK. repeat. This repetition is controlled based on the clock frequency included in voltage CLK. That is, the higher the frequency of the voltage CLK, the more the operation of charging, the operation of overlapping, and the operation of outputting are repeated. As a result, a large amount of charge is transferred. In other words, the booster 13A generates power proportional to the clock frequency. Specifically, the current value increases according to the number of times of charge transfer. As a result, power is increased. Then, the voltage (second voltage, see part (d) in FIG. 6) output from the diode D3 is stabilized by the capacitor C4. As a result, the voltage Vout is output as a substantial DC voltage.

Here, the second voltage in the present embodiment is a voltage output from the diode D3 as described above. The second voltage may be substantially an alternating voltage. The second voltage is a voltage stabilized by the capacitor C4. The second voltage may be a substantially direct voltage.

As described above, the on / off control of the switches S1, S2, S3 and S4 in the rectifying unit 17A is based on the input control signals φ1 and φ2. Further, on / off control of the oscillation operation in the frequency modulation unit 12A is based on the oscillation control signal EN.

As shown in FIG. 2, the control unit 16A has inputs 16a, 16b and 16c, and outputs 16d and 16e. The input 16a is connected to the input 7a of the power conversion circuit 7A. Input 16a receives voltage Vdd. The input 16b is connected to the output 14c of the power conversion unit 14A. The input 16b receives the voltage Vout. The input 16c is connected to the internal voltage generation unit 22 (described later). The input 16c receives the voltages + Vp and -Vp. The output 16d is connected to the input 14d of the power conversion unit 14A. The output 16d outputs input control signals φ1 and φ2. The output 16e is connected to the input 14e of the power conversion unit 14A. The output 16e outputs an oscillation control signal EN.

The control unit 16A includes a reference voltage generation unit 18, an input voltage detection unit 11, an output voltage detection unit 19, and an oscillation control unit 21.

The reference voltage generator 18 provides a reference voltage to the input voltage detector 11 and the output voltage detector 19. Specifically, the reference voltage generation unit 18 provides the input voltage detection unit 11 with the reference voltages + Vref and -Vref via the output 18a. Further, the reference voltage generation unit 18 provides the output voltage detection unit 19 with the reference voltage + Vmax via the output 18 b.

The input voltage detection unit 11 controls the on / off operation of the switches S1, S2, S3, and S4 of the rectification unit 17A based on the voltage Vdd. The input voltage detection unit 11 starts the oscillation operation of the frequency modulation unit 12A when the voltage Vdd becomes larger than the threshold (the reference voltage (+ Vref) and the reference voltage (−Vref)). The reference voltage (+ Vref) and the reference voltage (-Vref) are input threshold values in the present embodiment. The input threshold may be set based on, for example, the voltage Vout (or power) required of the power conversion circuit 7A. That is, when the amplitude of the voltage Vdd is small, the converted voltage Vout (or power) may not satisfy the required value. Therefore, the minimum value of the voltage Vdd in which the converted voltage Vout (or power) satisfies the required value may be used as the input threshold.

The input voltage detection unit 11 has inputs 11a, 11b and 11c, and outputs 11d and 11e. The input 11a is connected to the input 16a of the control unit 16A. The input 11a receives the voltage Vdd. The input 11b is connected to the ground GND. The input 11 c is connected to the output 18 a of the reference voltage generator 18. Input 11 c receives reference voltages + Vref and −Vref. The output 11d is connected to the output 16d of the control unit 16A. The output 11 d outputs input control signals φ1 and φ2. The output 11 e is connected to the oscillation control unit 21. The output 11e outputs input control signals φ1 and φ2.

Part (a) of FIG. 4 shows a circuit configuration of the input voltage detection unit 11. The input voltage detection unit 11 has two operational amplifiers G4 and G5. The reference voltage + Vref is provided to the inverting input of the operational amplifier G4. The voltage Vdd is provided to the non-inverting input of the operational amplifier G4. The voltage Vdd is provided to the inverting input of the operational amplifier G5. A reference voltage -Vref is provided to the non-inverting input of the operational amplifier G5.

The input voltage detection unit 11 generates input control signals φ1 and φ2 according to the magnitude of the voltage Vdd. Specifically, the input voltage detection unit 11 operates as follows (see (a) of FIG. 6 and (b) of FIG. 6).
When voltage Vdd ≧ reference voltage (+ Vref), input control signal φ1 = 1.
When voltage Vdd <reference voltage (+ Vref), input control signal φ1 = 0.
When voltage Vdd ≧ reference voltage (−Vref), input control signal φ2 = 0.
When voltage Vdd <reference voltage (−Vref), input control signal φ2 = 1.

The output voltage detection unit 19 stops the oscillating operation of the frequency modulation unit 12A when the voltage value of the voltage Vout becomes larger than the threshold value (reference voltage (+ Vmax)). As shown in FIG. 2, the output voltage detector 19 has inputs 19a, 19b, 19c and an output 19d. The input 19c is connected to the input 16b of the control unit 16A. The input 19c receives the voltage Vout. The input 19b is connected to the ground GND. The input 19 a is connected to the output 18 b of the reference voltage generator 18. The input 19a receives a reference voltage (+ Vmax). The output 19 d is connected to the oscillation control unit 21. The output 19d outputs an output control signal φ3. The reference voltage (+ Vmax) is an output threshold in the embodiment. The output threshold is set based on the maximum value of the voltage Vout required of the power conversion circuit 7A.

Part (b) of FIG. 4 shows a circuit configuration of the output voltage detection unit 19. The output voltage detection unit 19 has one operational amplifier G6. The reference voltage + Vmax is provided to the non-inverting input of the operational amplifier G6. The voltage Vout is provided to the inverting input of the operational amplifier G6.

The output voltage detection unit 19 generates an output control signal φ3 according to the magnitude of the voltage Vout. Specifically, the output voltage detection unit 19 operates as follows.
When voltage Vout ≧ reference voltage (+ Vmax), output control signal φ3 = 0.
When voltage Vout <reference voltage (+ Vmax), output control signal φ3 = 1.

As shown in FIG. 2, the oscillation control unit 21 has inputs 21 a and 21 b and an output 21 c. The input 21 a is connected to the output 11 e of the input voltage detection unit 11. The input 21a receives input control signals φ1 and φ2. The input 21 b is connected to the output 19 d of the output voltage detection unit 19. The input 21b receives an output control signal φ3. The output 21c is connected to the output 16e of the control unit 16A. The output 21 c outputs an oscillation control signal EN.

Part (a) of FIG. 5 shows a circuit configuration of the oscillation control unit 21. The oscillation control unit 21 includes an OR circuit G7 and an AND circuit G8. OR circuit G7 receives input control signals φ1 and φ2. OR circuit G7 outputs control signal φ4. AND circuit G8 receives output control signal φ3 and control signal φ4. The AND circuit G8 outputs an oscillation control signal EN. Specifically, the oscillation control unit 21 operates as follows.

When 11 (0), 22 (0), 33 (0), EN = 0.
When 11 (1), 22 (0) and 33 (0), EN = 0.
When 11 (0), 22 (1), 33 (0), EN = 0.
When 11 (0), 22 (0), 33 (1), EN = 0.
When φ1 (1), φ2 (0) and φ3 (1), EN = 1.
When φ1 (0), φ2 (1) and φ3 (1), EN = 1.

The oscillation control unit 21 outputs the oscillation control signal EN = 1 when the voltage Vdd is equal to or higher than the reference voltage + Vref and the voltage Vout is equal to or lower than the reference voltage Vmax. Further, when the voltage Vdd is lower than the reference voltage -Vref and the voltage Vout is lower than the reference voltage Vmax, the oscillation control signal EN = 1 is output. When the oscillation control signal EN = 1 is input to the frequency modulation unit 12A, the frequency modulation unit 12A starts the oscillation operation. Conversely, the oscillation control unit 21 outputs the oscillation control signal EN = 0 when the voltage Vdd is less than or equal to the reference voltage + Vref. The oscillation control unit 21 outputs the oscillation control signal EN = 0 when the voltage Vdd is equal to or higher than the reference voltage -Vref. Furthermore, the oscillation control unit 21 outputs the oscillation control signal EN = 0 when the voltage Vout is equal to or higher than the reference voltage Vmax. When the oscillation control signal EN = 0 is input to the frequency modulation unit 12A, the frequency modulation unit 12A stops the oscillation operation.

The reference voltage generation unit 18, the input voltage detection unit 11, the output voltage detection unit 19, and the oscillation control unit 21 that constitute the control unit 16A require power for driving the respective circuits. The power supply device 1A has an internal voltage generation unit 22 (see FIG. 2), and the internal voltage generation unit 22 supplies necessary power to the control unit 16A.

As shown in FIG. 2, the internal voltage generation unit 22 generates a voltage used for the operation of the control unit 16A. That is, the internal voltage generation unit 22 receives the voltage Vdd and outputs the voltages + Vp and -Vp. The internal voltage generator 22 has an input 22a and an output 22b. The input 22a is connected to the input 7a of the power conversion circuit 7A. The input 22a receives the voltage Vdd. The output 22b is connected to the input 16c of the control unit 16A. The output 22b outputs voltages + Vp and -Vp. For example, as shown in part (b) of FIG. 5, the internal voltage generation unit 22 includes a gate G9 which is a pMOSFET and a gate G10 which is an nMOSFET. Then, the internal voltage generation unit 22 provides the voltage Vdd to each of the gates G9 and G10. Then, gate G9 outputs voltage + Vp. On the other hand, gate G10 outputs voltage -Vp. The reference voltage generation unit 18, the input voltage detection unit 11, the output voltage detection unit 19, and the oscillation control unit 21 operate using these voltages + Vp and -Vp.

The power conversion circuit 7A includes a frequency modulation unit 12A and a boosting unit 13A. Frequency modulation unit 12A receives voltage VH having a first frequency f1. The frequency modulation unit 12A generates a voltage CLK. The voltage CLK is obtained by superimposing a pulse wave having a second frequency f2 higher than the first frequency f1 with respect to the voltage VH. Booster 13A receives voltage CLK from frequency modulator 12A. The frequency modulation unit 12A generates a voltage Vout higher than the voltage CLK by charge pump operation. The booster 13A has capacitors C2 and C3. Capacitors C2 and C3 are charged by voltage CLK. The boosting unit 13A performs a first operation of accumulating charges in the capacitors C2 and C3 and a second operation of superposing and outputting a voltage based on the charges and the voltage CLK. The switching between the first operation and the second operation is based on a pulse wave included in the voltage CLK.

The boosting unit 13A charges the capacitors C2 and C3 with the voltage VH and stores the charges in the capacitors C2 and C3 and an operation of superposing the voltage Vc based on the stored charges and the voltage VH and outputting the result. Including. Here, the output power output from the booster 13A is defined by the voltage Vout and the output current. First, the maximum value of the voltage Vout is determined by the peak voltage value of the voltage VH and the number of capacitors C2 and C3 connected in series. Next, the magnitude of the output current is proportional to the number of repetitions of the charging operation and the output operation. That is, as the number of repeating the charging operation and the output operation increases, more charge transfer is performed. As a result, the magnitude of the output current is increased. The power conversion circuit 7A superimposes a pulse wave having a second frequency f2 higher than the first frequency f1 on the voltage VH having the first frequency f1 in the frequency modulation unit 12A. As a result, voltage CLK is generated. Then, the booster 13A switches between the charging operation and the output operation based on the pulse wave. Therefore, the number of repetitions of the charging operation and the output operation is larger than in the configuration in which the voltage VH is directly input to the booster 13A. That is, much charge transfer is performed. As a result, when the frequency of the pulse wave increases, the output current output from the booster 13A increases. Therefore, the average output power output from the booster 13A is increased. As a result, the power conversion efficiency can be enhanced.

The power conversion circuit 7A further includes a rectifying unit 17A. The rectifying unit 17A receives the voltage Vdd having the first frequency f1 from the vibration power generation element 6, generates a voltage VH in which the voltage Vdd is full-wave rectified, and outputs the voltage VH to the frequency modulation unit 12A. According to this configuration, the number of times of charge transfer in the booster 13A increases. As a result, the output current is further increased. Therefore, the power conversion efficiency can be further enhanced.

The power conversion circuit 7A further includes an input voltage detection unit 11. Input voltage detection unit 11 receives voltage Vdd from vibration generating element 6, generates input control signals φ1 and φ2 based on the magnitude relation between the absolute value of voltage Vdd and the input threshold, and rectifies input control signals φ1 and φ2 Output to 17A. The rectifying unit 17A rectifies the voltage Vdd into voltages VH and VL based on the input control signals φ1 and φ2. According to this configuration, the voltage Vdd can be reliably full-wave rectified.

The power conversion circuit 7A further includes an oscillation control unit 21. The oscillation control unit 21 receives the input control signals φ1 and φ2 from the input voltage detection unit 11, and controls the start and stop of the oscillation operation for generating a pulse wave in the frequency modulation unit 12A based on the input control signals φ1 and φ2. The control signal EN is generated, and the oscillation control signal EN is output to the frequency modulation unit 12A. According to this configuration, it is possible to control the start and stop of the oscillation operation based on the absolute value of voltage Vdd. As a result, when the absolute value of the voltage Vdd is smaller than the threshold value, the oscillation operation can be stopped. Therefore, since it is possible to limit the magnitude of the voltage Vdd provided for power conversion to a value larger than the threshold value, the power conversion circuit 7A can output the voltage Vout of a desired magnitude.

The power conversion circuit 7A further includes an output voltage detection unit 19. Output voltage detection unit 19 receives voltage Vout from boosting unit 13A, generates output control signal φ3 based on the magnitude relationship between the absolute value of voltage Vout and the output threshold, and outputs output control signal φ3 to oscillation control unit 21. . The oscillation control unit 21 generates an oscillation control signal EN that controls the start and stop of the oscillation operation based on the input control signals φ1 and φ2 and the output control signal φ3. According to this configuration, it is possible to stop the oscillation operation when the voltage Vout becomes larger than the threshold. Therefore, a limitation can be placed on the magnitude of the voltage Vout.

Power conversion circuit 7A further includes an internal voltage generation unit 22. Internal voltage generation unit 22 receives voltage Vdd from vibration power generation element 6. The internal voltage generation unit 22 generates power for driving the input voltage detection unit 11, the output voltage detection unit 19, and the oscillation control unit 21. The internal voltage generation unit 22 outputs power to the input voltage detection unit 11, the output voltage detection unit 19, and the oscillation control unit 21. According to this configuration, the voltage required for the operation of each part is generated from the voltage Vdd. Therefore, the power conversion circuit 7A does not have to prepare a battery for supplying a voltage for operating each part. Furthermore, there is no need to replace the battery. Therefore, the power conversion circuit 7A is easy to maintain and manage.

The power supply device 1A includes a vibration power generation element 6 and a power conversion circuit 7A. The vibration power generation element 6 generates the power of the voltage Vdd having the first frequency f1. The power conversion circuit 7A is connected to the vibration power generation element 6, and converts the power of the voltage Vdd into the power of the DC voltage. The power supply device 1A includes the power conversion circuit 7A described above. Therefore, good power conversion efficiency can be obtained. As a result, the power supply device 1A can supply desired power.

The power conversion circuit 7A converts alternating current power into direct current power. The power conversion circuit 7A is a booster circuit. The power conversion circuit 7A converts the AC voltage into a DC voltage having a high voltage value by increasing the voltage amplitude of the AC. The power conversion circuit 7A inputs the AC power input to the modulation circuit that modulates the frequency. Next, the power conversion circuit 7A inputs the frequency-increased signal from the modulation circuit to the booster circuit. This configuration can be referred to as a frequency modulation type AC-DC boost system. According to this method, for example, it is assumed that AC power having a frequency of 1 kilohertz generated by vibrational power generation is converted to power of 10 megahertz by a frequency modulation circuit. In this conversion, the output voltage of the power conversion circuit 7A is approximately 3000 times the output voltage of the power conversion circuit of the comparative example described later. This output power corresponds to the output power of the booster circuit used in the RFID. RFID is a system that uses radio waves to read and write data of an RF tag contactlessly. As a result, the power conversion circuit 7A has a practical size. Therefore, the power conversion circuit 7A can be integrated in the IoT integrated circuit for vibration power generation. As a result, the power conversion circuit 7A contributes to the miniaturization of the IoT terminal.

By the way, there is a switching converter using a switching inductor in the power conversion circuit. Another circuit is a booster circuit having a capacitor and a switch. Switching converter inductors can not be implemented in realistic sizes on integrated circuits. Thus, the switching converter inductor is externally attached.

On the other hand, the booster circuit can reduce the size (capacitance) of the capacitor to such an extent that integration is possible by increasing the frequency. Therefore, it is possible to miniaturize the IoT terminal. In RFID, input AC power is high frequency. Thus, an integrated boost circuit can be easily applied. As shown in FIG. 19, the power conversion circuit according to the comparative example directly inputs alternating current power (AC) from direct current power (DC) by directly inputting alternating current power (AC) from vibration generating element 206 to boosting unit 203. Convert to). Then, the power conversion circuit according to the comparative example provides direct current power (DC) to the measuring device 204. For example, the power supply device 200 applied to the RFID directly inputs the output of the vibration power generation element 206 to the booster 203. The booster 203 generates power proportional to the frequency of the input signal. This is because the output charge is transferred only once in one cycle. The output voltage is smoothed by the stabilization capacitor.

On the other hand, conventionally, the alternating current output from the vibration power generation element has a low frequency. Therefore, it was necessary to use the required switching converter of the external inductor. The output voltage of the vibration power generating element is, for example, about several hundred micro W / cm ³ . Then, assume that the integrated circuit requires a voltage of around 1 volt. When trying to generate a voltage of 1 volt using a voltage of several hundreds of micro W / cm ^3, if the power frequency of vibration power generation is 1 kilohertz, the output power of the booster circuit is several nanowatts . That is, most of the power is reactive power. On the other hand, the IoT terminal includes the vibration power generation element 6 that generates low frequency AC power. The power conversion circuit 7A is a booster circuit control means that can be integrated. Therefore, the IoT terminal provided with the power conversion circuit 7A can be miniaturized.

Part (a) of FIG. 7 conceptually shows the energy balance of the power supply device 200 according to the comparative example. Part (b) of FIG. 7 conceptually shows the energy balance of the power supply device 1A according to the embodiment. The powers P1 and P2 generated by the vibration power generation elements 6 and 206 are divided into powers P1a and P2a, power consumptions P1b and P2b, and reactive powers P1c and P2c. The powers P1a and P2a are powers to be effectively converted. The power consumptions P1b and P2b are powers consumed by the power conversion circuit. The reactive powers P1c and P2c are power that only reciprocates between the vibration generating elements 6, 206 and the conversion circuit and is not consumed.

As shown in part (a) of FIG. 7, in the power supply device 200 according to the comparative example, most of the power P1 generated by the vibration power generation element 206 is reactive power P1c. In power supply apparatus 200, power P1a to be effectively converted is small. This is because, as described above, when the output of the vibration power generation element 206 is directly provided to the booster 203, charge transfer is performed according to the output frequency of the vibration power generation element 206 in the booster 203. That is, since the number of times of charge transfer is small, only a small amount of current can be extracted.

On the other hand, as shown in part (b) of FIG. 7, the power supply device 1A reduces reactive power P2c. Then, the power supply device 1A increases the power P2a to be effectively converted. Here, in the power supply device 1A, even if the power consumption P2b in the control unit 16A or the like is present, the power P2a to be effectively converted increases. As a result, the power supply device 1A can increase the conversion efficiency.

<Example of experiment by computer>
FIG. 8 compares the output power when the booster circuit performs the conventional AC-DC operation with the output power when the booster circuit performs the AC-DC operation according to the embodiment. The horizontal axis of FIG. 8 indicates the frequency of the AC power input to the booster circuit. The vertical axis represents DC power output from the booster circuit. The output voltage of the booster circuit was 1 volt. According to the AC-DC operation according to the comparative example, the input AC power is 1 kilohertz. The output power is a few nanowatts (see symbol A1). That is, it was found that in the AC-DC operation according to the comparative example, most of the power becomes reactive power. On the other hand, according to the AC-DC operation according to the embodiment, for example, the frequency is increased to 10 MHz. In that case, the output power was found to be several tens of microwatts (see symbol A2). That is, the size of the power conversion circuit 7A can be made equal to that of the booster circuit required for high frequency input such as RFID. Therefore, it has been confirmed that the power conversion circuit 7A can realize the integration of the AC-DC booster circuit system for vibration power generation.

Second Embodiment
As shown in FIG. 9, a power supply device 1B according to the second embodiment includes a vibration power generation element 6 and a power conversion circuit 7B. The power conversion circuit 7B includes a power conversion unit 14B, a control unit 16B, and an internal voltage generation unit 22. The power conversion unit 14B includes a rectification unit 17A, a frequency modulation unit 12B (second frequency modulation unit), and a boosting unit 13A. Here, the frequency modulation unit 12B is different from the frequency modulation unit 12A in that the oscillation control signal EN from the control unit 16B is not required. Furthermore, the control unit 16B is different from the control unit 16A in that the control unit 16B does not have the oscillation control unit 21 and the output voltage detection unit 19 for generating the oscillation control signal EN. The control unit 16B is different from the control unit 16A in that the control unit 16B includes a limiter 31 (a limiter unit).

As shown in part (a) of FIG. 10, the frequency modulation unit 12B is an LC oscillation circuit. The frequency modulation unit 12B is not a ring oscillator. The frequency modulation unit 12B includes coils L1 and L2, capacitors C5 and C6, and field effect transistors M1 and M2 (FETs). The coil L1, the capacitor C5 and the transistor M1 generate a voltage CLK at the output 12d. The coil L2, the capacitor C6 and the transistor M2 generate the voltage CLKb at the output 12e. According to this configuration, the LC oscillation circuit performs the oscillation operation autonomously. Therefore, the oscillation control signal EN can be omitted. That is, when the voltage Vdd increases to some extent, the frequency modulation unit 12B automatically starts oscillation. For example, the frequency modulation unit 12B starts oscillation when the transconductance of the transistors M1 and M2 becomes higher than the loss of the LC resonator.

The resonant frequency of this LC resonant circuit is set sufficiently higher than the frequency of the voltage Vdd. For example, it is assumed that the frequency of the voltage Vdd is f_AC and the oscillation frequency is f_clk. The oscillation frequency is f_clk = 1 / 2π√ (LC). Then, the coils L1 and L2 and the capacitors C5 and C6 are set to satisfy f_AC << f_clk.

The booster 13A does not use the voltage CLKb. Therefore, the output 12d of the frequency modulation unit 12B shown in part (a) of FIG. 10 is connected to the input 13a of the booster 13A. Further, the output 12e may not be connected to the input 13c.

The control unit 16B includes an input voltage detection unit 11, a reference voltage generation unit 18, and a limiter 31. The frequency modulation unit 12B autonomously starts oscillation. Therefore, the oscillation control signal EN is unnecessary. Therefore, the control unit 16B does not include the oscillation control unit 21.

The limiter 31 suppresses the voltage Vout from becoming excessively large when the amplitude of the voltage Vdd exceeds a predetermined value. Therefore, the voltage Vout is controlled to a predetermined voltage value. As shown in part (b) of FIG. 10, the limiter 31 is a limiter circuit utilizing the rectifying action of the diode D4. The limiter 31 is connected to the diode D4 so that the voltage Vout is a reverse voltage. According to this connection configuration, the diode D4 is turned on at the target voltage Vpp (see part (c) of FIG. 10). Therefore, the voltage Vout can be suppressed from becoming excessively large.

Third Embodiment
As shown in FIG. 11, the power supply device 1C according to the third embodiment includes a vibration power generation element 6 and a power conversion circuit 7C. The power conversion circuit 7C has a power conversion unit 14C and a control unit 16C. The power conversion unit 14C includes a rectification unit 17B (second rectification unit), a frequency modulation unit 12B, and a boosting unit 13A. Here, the rectifying unit 17B does not require the input control signals φ1 and φ2. The rectifying unit 17B does not require the input control signals φ1 and φ2. Therefore, the control unit 16C does not have a configuration for generating the input control signals φ1 and φ2. The input 16b of the control unit 16C is connected to the output 14c of the power conversion unit 14C. The control unit 16C has a limiter 31. The limiter 31 receives the voltage Vout from the input 16 b.

As shown in part (a) of FIG. 12, the rectifying unit 17B is an autonomous switch circuit. The rectifying unit 17B automatically switches the voltage to be output based on the magnitude relationship between the voltage Vdd and the voltage Vss. The rectifying unit 17B includes a pair of switch circuits S5 and S6. The switch circuit S5 includes a pair of p-type transistors QP1 and QP2. The switch circuit S6 includes a pair of n-type transistors QN1 and QN2. The capacitor C7 is provided between the output 17d and the output 17e.

The voltage Vdd and the voltage Vss are input to the switch circuit S5. The voltage Vss and the voltage Vss are also input to the switch circuit S6. The switch circuit S5 is connected to the output 17d. The switch circuit S5 provides one of the voltage Vdd and the voltage Vss as the voltage VH to the output 17d. The switch circuit S6 is connected to the output 17e. The switch circuit S6 provides one of the voltage Vdd and the voltage Vss as the voltage VL to the output 17d. The provided voltage is determined based on the magnitude relationship between the voltage Vdd and the voltage Vss.

For example, as shown in part (b) of FIG. 12, when the voltage Vdd is larger than the voltage Vss (Vdd> Vss), the switch circuit S5 provides the voltage Vdd (VH = Vdd) at the output 17d. Further, the switch circuit S6 provides the voltage Vss to the output 17e (VL = Vss). On the other hand, as shown in part (c) of FIG. 12, when the voltage Vdd is smaller than the voltage Vss (Vdd <Vss), the switch circuit S5 provides the voltage Vss at the output 17d (VH = Vss). The switch circuit S6 also provides the voltage Vdd at the output 17e (VL = Vdd).

According to this configuration, the rectifying unit 17B switches the voltage to be provided to the outputs 17d and 17e based on the magnitude relationship between the voltage Vdd and the voltage Vss. Then, the frequency modulation unit 12B autonomously starts the oscillation operation when the voltage amplitudes of the voltages VH and VL supplied from the outputs 17d and 17e become equal to or higher than the voltage that can be oscillated. Then, the boosting unit 13A receives the voltage CLK provided from the frequency modulation unit 12B and performs a boosting operation. Thus, the power conversion unit 14C of the power supply device 1C according to the third embodiment does not require the input control signals φ1 and φ2 and the oscillation control signal EN. That is, the power conversion unit 14C can start the operation autonomously based on the voltages Vdd and Vss. Therefore, the configuration of the power conversion circuit 7C can be simplified.

Fourth Embodiment
As shown in FIG. 13, a power supply device 1D according to the fourth embodiment includes a vibration power generation element 6 and a power conversion circuit 7D. The power conversion circuit 7D includes a power conversion unit 14A (first power conversion unit), a power conversion unit 14C (second power conversion unit), a control unit 16A, and an internal voltage generation unit 22. The power conversion circuit 7D includes a power conversion circuit 7A and a power conversion unit 14C. The power conversion unit 14C is connected in parallel to the power conversion unit 14A. The input 14a of the power conversion unit 14C is connected to the input 7a of the power conversion circuit 7A. The input 14b of the power conversion unit 14C is connected to the input 7b of the power conversion circuit 7A. The output 14c of the power conversion unit 14C is connected to the output 7c of the power conversion unit 14C.

According to this configuration, when the supply of the voltage Vdd from the vibration power generation element 6 is started, first, the power conversion unit 14C autonomously starts the power conversion operation based on the voltage Vdd and the voltage Vss. Specifically, the rectifying unit 17B (second rectifying unit) receives the voltages Vdd and Vss. The rectifying unit 17B outputs the voltages VH2 and VL2. The frequency modulation unit 12B (second frequency modulation unit) receives the voltages VH2 and VL2, and then the frequency modulation unit 12B generates a voltage CLK2 (fourth voltage) using the voltage (VH2-VL2) as a third voltage. Then, the booster 13B (second booster) receives the voltage CLK2. Then, the booster 13B provides the voltage Vout2 (second output voltage) to the output 14c. Then, when the voltage Vout2 reaches a predetermined voltage value, the operation is switched from the power conversion unit 14C to the operation of the power conversion unit 14A. That is, the input control signals φ1 and φ2 and the oscillation control signal EN are provided from the control unit 16A to the power conversion unit 14A. Then, after the conditions for stable operation of the control unit 16A are satisfied, the control unit 16A and the power conversion unit 14A can be operated. Therefore, the stability immediately after the start of the operation in the power supply device 1D can be improved.

The power conversion circuit and the power supply device of the present disclosure have been described. However, the power conversion circuit and the power supply device of the present disclosure are not limited to the above aspect.

<Modification 1>
For example, as illustrated in FIG. 14, the power supply device 1E according to the modification 1 may include the power conversion circuit 7E. The power conversion circuit 7E includes a power conversion unit 14D, a control unit 16A, and an internal voltage generation unit 22. The power conversion unit 14D includes a rectification unit 17A, a frequency modulation unit 12C, and a boosting unit 13B. As shown in part (a) of FIG. 15, the frequency modulation unit 12C has a configuration for extracting the voltage CLKb. The frequency modulation unit 12A does not have a configuration for extracting the voltage CLKb. That is, the frequency modulation unit 12C includes an output line connected between the inverter circuit G2 and the inverter circuit G3. The output line is connected to the output 12e of the frequency modulation unit 12C. As shown in part (b) of FIG. 15, the booster 13B has a first circuit CR1 and a second circuit CR2. The first circuit CR1 and the second circuit CR2 are connected in parallel with each other. Then, the voltage CLK is input to the first circuit CR1. The voltage CLKb is input to the second circuit CR2. According to this configuration, the output power can be further increased. The frequency modulation unit 12C and the boosting unit 13B according to the first modification may be applied to the power conversion circuits 7A, 7B, 7C, 7D according to the first, second, third and fourth embodiments.

<Modification 2>
For example, as shown in FIG. 16, the power supply device 1F according to the second modification may include the auxiliary power supply 32. The auxiliary power supply 32 assists the function of the internal voltage generation unit 22. That is, the auxiliary power supply 32, which is a battery, provides a part of the voltage necessary to drive the control unit 16A. According to this configuration, the power supply device 1F can reliably provide the necessary voltage to the control unit 16A by the auxiliary power supply 32 and the internal voltage generation unit 22. In addition, since the voltage provided by the auxiliary power supply 32 is small, the replacement cycle of the auxiliary power supply 32 can be made extremely long. The auxiliary power supply 32 according to the second modification may be applied to the power conversion circuits 7A, 7B, 7C, 7D according to the first, second, third and fourth embodiments.

<Modification 3>
For example, as shown in FIG. 17, a power supply device 1G according to the third modification is a modification of the power supply device 1D according to the fourth embodiment. The power supply device 1G omits the internal voltage generation unit 22 of the power supply device 1D. That is, the power supply device 1G may not have the internal voltage generation unit 22. The power supply device 1G uses the voltage Vdd_int output from the power conversion unit 14C to drive the control unit 16A. Specifically, the output 14c of the power conversion unit 14C is connected to the input 16c of the control unit 16A. With this connection configuration, the power conversion unit 14C can provide the voltage Vdd_int required to drive the control unit 16A. Furthermore, the limiter 33 is connected to the output 14c of the power conversion unit 14C. The limiter 33 has a configuration similar to that of the limiter 31. According to this limiter 33, it is possible to set a limit on the voltage Vdd_int provided to the control unit 16A. Therefore, input of an excessive voltage to the control unit 16A can be suppressed. Furthermore, according to this configuration, the operation stability at the time of startup of the power supply device 1G is enhanced. Moreover, according to this configuration, the circuit configuration of the power supply device 1G can be simplified.

<Modification 4>
For example, the booster is not limited to the circuit configuration shown in the embodiment. FIG. 18 shows a circuit configuration of the booster 13H. The booster 13H has diodes D1, D2, D3 and capacitors C2, C3, C4. The connection configuration of these is the same as that of the booster 13A. On the other hand, the booster 13H uses the voltage CLKb to control charge transfer in the capacitors C2 and C3. Then, inverter circuits G11, G12, and G13 are connected to the capacitors C2 and C3 in order to mutually invert the phase of the voltage CLKb input to the capacitor C2 and the phase of the voltage CLKb input to the capacitor C3. Specifically, the inverter circuit G11 is connected to the capacitor C2. Inverter circuits G12 and G13 are connected to the capacitor C3.

<Modification 5>
For example, in the above embodiment, the vibration power generation element is illustrated as the power source of the AC power of the power supply device 1A. However, the power source of alternating current power is not limited to the vibration power generation element. As a power source of alternating current power, any element capable of generating alternating current power having a frequency lower than the frequency of the frequency modulation unit 12A may be applied. For example, the power supply device 1A can be effectively applied to a low frequency also as a wireless power reception circuit.

DESCRIPTION OF SYMBOLS 1A, 1B, 1C, 1D, 1E, 1G, 200 ... Power supply device, 2 ... Sensor apparatus, 3 ... Antenna, 4 ... Measurement apparatus, 6, 206 ... Vibration generator element, 7A, 7B, 7C, 7D, 7E ... Power conversion circuit, 11 ... Input voltage detection unit, 12A, 12B, 12C ... Frequency modulation unit, 13A, 13B, 13H, 203 ... Boosting unit, 14A, 14B, 14C ... Power conversion unit, 16A, 16B, 16C ... Control Unit 17A, 17B: Rectification unit, 18: Reference voltage generation unit, 19: Output voltage detection unit, 22: Internal voltage generation unit, 21: Oscillation control unit, 31, 33: Limiter, 32: Auxiliary power supply, 100: Internet Reference numeral 101: Cloud server, 102: target object, Vdd: voltage (input voltage), CLK: voltage, Vout: output voltage, φ1, φ2: input control signal, φ3: output control signal, φ ... control signal, EN ... oscillation control signal.

Claims (9)

1. A frequency modulation unit receiving a first voltage having a first frequency and generating a second voltage on which a pulse wave having a second frequency higher than the first frequency with respect to the first voltage is superimposed;
   And a booster configured to receive the second voltage from the frequency modulation unit and generate an output voltage higher than the second voltage by charge pump operation.
   The boosting unit includes a capacitor charged by the second voltage, and a first operation of accumulating charge in the capacitor, and a second operation of overlapping a voltage based on the charge and the second voltage. The power converter according to any one of the above, wherein the pulse wave is included in the second voltage.
2. The power supply device may further include a rectifying unit receiving an input voltage having the first frequency from a power source, rectifying the input voltage to generate the first voltage, and providing the first voltage to the frequency modulation unit. Power converter according to claim 1.
3. It further comprises an input voltage detection unit that receives the input voltage from the power source, generates an input control signal based on a magnitude relationship between an absolute value of the input voltage and an input threshold, and provides the input control signal to the rectification unit. ,
   The power conversion device according to claim 2, wherein the rectifying unit rectifies the input voltage based on the input control signal to generate the first voltage.
4. 4. The system according to claim 3, further comprising an internal voltage generation unit that receives the input voltage from the power source, generates a drive voltage for driving the input voltage detection unit, and provides the drive voltage to the input voltage detection unit. Power converter as described.
5. Receiving an input control signal from the input voltage detection unit; generating an oscillation control signal for controlling start and stop of an oscillation operation for generating the pulse wave in the frequency modulation unit based on the input control signal; The power conversion device according to claim 3, further comprising an oscillation control unit that provides a signal to the frequency modulation unit.
6. The output voltage detection unit further receives an output voltage from the boosting unit, generates an output control signal based on a magnitude relation between an absolute value of the output voltage and an output threshold, and provides the output control signal to the oscillation control unit. Equipped
   The oscillation control unit generates the oscillation control signal based on the input control signal and the output control signal.
   The power conversion device according to claim 5, wherein the frequency modulation unit controls start and stop of the oscillation operation based on the oscillation control signal.
7. The power conversion device according to any one of claims 1 to 5, further comprising a limiter unit which receives the output voltage from the booster and defines a maximum value of the output voltage.
8. A first power converter configured to generate a first output voltage as the output voltage, a first rectifier as the rectifier, a first frequency modulator as the frequency modulator, and a first booster as the booster. Configure
   It includes the second rectifier different from the first rectifier, the second frequency modulator different from the first frequency modulator, and the second booster different from the first booster. And a second power converter connected in parallel to the first power converter,
   The second rectifying unit starts an operation of receiving the input voltage and generating a third voltage obtained by rectifying the input voltage based on the input voltage.
   The second frequency modulation unit receives the third voltage and generates a fourth voltage on which a pulse wave having a fourth frequency higher than the third frequency of the third voltage is superimposed on the third voltage. Starting operation based on the third voltage,
   The second booster according to any one of claims 2 to 6, wherein the second booster receives the fourth voltage from the second frequency modulation unit and generates a second output voltage higher than the fourth voltage by charge pump operation. Power converter according to claim 1.
9. A power source generating power of an input voltage having a first frequency;
   9. A power supply device comprising: the power conversion device according to any one of claims 1 to 8, which is connected to the power source and converts power of the input voltage into power of a direct current voltage.

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