Control circuit and control method for SIMO converter of wireless sensor

Abstract

The invention discloses a controller and a control method for an SIMO converter of a wireless sensor, light load and heavy load modes of each output branch are judged by detecting load currents corresponding to identified output branches in the SIMO converter, and different inductive currents are provided in the light load and heavy load modes by changing parameters of the SIMO converter, so that the SIMO converter of the wireless sensor is controlled. Therefore, the SIMO converter is ensured to be in a relatively wide load dynamic range; and the output voltages of the output branches are utilized to carry out priority ranking on the output branches, so that the inductor in the SIMO converter only outputs power to a single output branch each time, and the problem of cross adjustment among multiple output branches is avoided. Furthermore, when the single branch is in a heavy load state, and the single branch has an output demand, the inductive current does not need to be charged from zero, so that better transient response is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of DC-DC converters, and particularly relates to a controller and a control method for a SIMO converter used in wireless sensors. Background Art

[0002] In the past few decades, the rapid development of ultra-low power (ULP) circuits and high data rate (HDR) radio frequency communication systems has enabled wireless sensor nodes (WSNs) to successfully play a key role in the Internet of Things (IoT). Currently, wireless sensor networks have been widely used to improve energy efficiency by controlling building, office, and home environments. A large number of sensor nodes are distributed everywhere to monitor environmental parameters such as temperature, humidity, and light intensity.

[0003] Each wireless sensor node consists of a microcomputer (MCU) operated by a control node, a sensor (SENSOR), and a radio frequency module (Rx / Tx) for sending measurement data. To save area, the converter usually adopts a single-inductor multi-output (SIMO) topology. However, for wireless sensor nodes, they are in the ultra-low power mode for a large part of the time, with a power consumption of about dozens of microwatts, and only activate the radio frequency module with a higher power consumption of about dozens of milliwatts in a very short time when a system command arrives. The converter needs to simultaneously meet fast transient response and a wide dynamic load current range.

[0004] The energy distribution methods of single-inductor multi-output converters are divided into time-division multiplexing and sequential function. Time-division multiplexing means that only a single output branch is powered during one charge and discharge cycle of the inductor, and multiple cycles are required to complete the power supply to multiple branches. This method usually operates in the DCM mode, and the inductor current needs to drop to zero each time. The inductor current discharges discontinuously to each branch. Its advantage is that there is no cross-regulation problem between outputs, but it can only be applied to the light load mode. Sequential power supply means that the inductor is charged once in a cycle and then supplies power to multiple output branches in sequence, and it can operate in the DCM and CCM modes. Its advantage is that it can work in a wide dynamic load current range, but the inductor current discharges continuously to each branch, resulting in a serious cross-regulation problem. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a controller and a control method for a SIMO converter used in wireless sensors. The technical problems to be solved by the present invention are realized through the following technical solutions:

[0006] In the first aspect, the present invention provides a control method for a SIMO converter used in wireless sensors, and the control method includes:

[0007] Judge the output voltages of each output branch in the SIMO converter, and identify the output branches that meet the preset voltage conditions;

[0008] Compare the load current corresponding to the identified output branch with the preset light / heavy load demarcation threshold, set the output branch corresponding to the load current less than the preset light / heavy load demarcation threshold to the light load mode, and set the output branch corresponding to the load current greater than the preset light / heavy load demarcation threshold to the heavy load mode;

[0009] If there are multiple identified output branches, perform priority sorting according to the output voltages of the output branches to obtain the priority order;

[0010] If all output branches are in the light load mode, set the SIMO converter to work in the DCM mode, so that the inductor in the SIMO converter is fully discharged after being charged in each switching cycle, and control the output branches corresponding to the light load mode to supply power in turn according to the priority order;

[0011] If only one output branch is in the heavy load mode, set the SIMO converter to work in the PCCM mode and control the output branch corresponding to the heavy load mode to supply power;

[0012] If multiple output branches are in the heavy load mode, set the SIMO converter to work in the DCCM mode and control the output branches corresponding to the heavy load mode to supply power in turn according to the priority order.

[0013] In an embodiment of the present invention, judging the output voltages of each output branch in the SIMO converter and identifying the output branches that meet the preset voltage conditions includes:

[0014] Compare the output voltages of each output branch in the SIMO converter with the preset lower threshold reference voltage, and identify the output branches with output voltages less than the preset lower threshold reference voltage.

[0015] In an embodiment of the present invention, the preset light / heavy load demarcation threshold is 1 mA.

[0016] In an embodiment of the present invention, setting the SIMO converter to work in the DCM mode includes:

[0017] Set the system clock of the SIMO converter to a preset low frequency value, the peak value of the inductor current to a preset value lpeak, and the valley value of the inductor current to 0.

[0018] In an embodiment of the present invention, setting the SIMO converter to work in the PCCM mode includes:

[0019] Set the system clock of the SIMO converter to a low level, with the peak inductor current being the preset value lpeak and the valley inductor current being the preset value lvalley.

[0020] In an embodiment of the present invention, a priority order is obtained by performing priority sorting according to the output voltages of the output branches, including:

[0021] Sort the output voltages of the output branches from smallest to largest, and use them as the priority order from the most preferred to the least preferred in sequence.

[0022] In a second aspect, the present invention provides a SIMO converter for a wireless sensor, including:

[0023] A request arbitration unit, a mode selection unit, and an inductor current detection unit; wherein,

[0024] The request arbitration unit is configured to identify the output branches among the output voltages of the respective output branches of the SIMO converter that meet the preset voltage condition; when there are multiple identified output branches, perform priority sorting on the respective output branches according to the output voltages of the respective output branches;

[0025] The mode selection unit is configured to compare the load current corresponding to the identified output branch with a preset light / heavy load demarcation threshold, and configure the parameters of the SIMO converter according to the comparison result, so that the SIMO converter operates in the corresponding operating mode and supplies power in sequence according to the priority order; the operating modes include: DCM mode, PCCM mode, and DCCM mode;

[0026] The inductor current detection unit is configured to detect the parameters of the SIMO converter and determine whether the parameters of the SIMO converter reach the preset values.

[0027] In an embodiment of the present invention, the parameters of the SIMO converter include:

[0028] System clock, peak inductor current, and valley inductor current.

[0029] In an embodiment of the present invention, the mode selection unit compares the load current corresponding to the identified output branch with a preset light / heavy load demarcation threshold, and configures the parameters of the SIMO converter according to the comparison result, so that the SIMO converter operates in the corresponding operating mode, including:

[0030] The mode selection unit compares the load current corresponding to the identified output branch with a preset light / heavy load demarcation threshold, sets the output branch corresponding to the load current less than the preset light / heavy load demarcation threshold to the light load mode, and sets the output branch corresponding to the load current greater than the preset light / heavy load demarcation threshold to the heavy load mode;

[0031] If all output branches are in the light load mode, set the system clock of the SIMO converter to a preset low frequency value, the peak inductor current to a preset value lpeak, and the valley inductor current to 0, so that the SIMO converter operates in the DCM mode;

[0032] If only one output branch is in the heavy load mode, set the system clock of the SIMO converter to a low level, the peak inductor current to a preset value lpeak, and the valley inductor current to a preset value lvalley, so that the SIMO converter operates in the PCCM mode;

[0033] If multiple output branches are in the heavy load mode, set the system clock of the SIMO converter to a low level, the peak inductor current to a preset value lpeak, and the valley inductor current to a preset value lvalley, so that the SIMO converter operates in the DCCM mode.

[0034] Advantages of the present invention:

[0035] In the solution provided by the present invention, by detecting the load current corresponding to the identified output branch in the SIMO converter, the judgment of the light load and heavy load modes of each output branch is realized. By changing the parameters of the SIMO converter, different inductor current magnitudes are provided in the light load and heavy load modes, so as to ensure that the SIMO converter is in a relatively wide load dynamic range; and the output voltages of the output branches are used to sort the priorities of each output branch, so that the inductor in the SIMO converter outputs power to only a single output branch each time, avoiding the cross-regulation problem between multiple output branches. Further, when a single branch is in the heavy load, when there is an output demand for this single branch, the inductor current does not need to be charged from zero, so as to have a better transient response. Description of the drawings

[0036] Figure 1 It is a step schematic diagram of a control method for a SIMO converter for wireless sensors provided by an embodiment of the present invention;

[0037] Figure 2 It is a flow schematic diagram of a control method for a SIMO converter for wireless sensors provided by an embodiment of the present invention;

[0038] Figure 3 It is a topology diagram of a SIMO converter provided by an embodiment of the present invention;

[0039] Figures 4a - 4c It is a schematic diagram of different working states of a SIMO converter provided by an embodiment of the present invention;

[0040] Figure 5A waveform diagram of the light load mode in a SIMO converter provided by an embodiment of the present invention;

[0041] Figure 6 A waveform diagram of the single-channel heavy load mode in a SIMO converter provided by an embodiment of the present invention;

[0042] Figure 7 A waveform diagram of the multi-channel heavy load mode in a SIMO converter provided by an embodiment of the present invention;

[0043] Figure 8 A schematic structural diagram of a control circuit of a SIMO converter for a wireless sensor provided by an embodiment of the present invention. Detailed implementation manners

[0044] The following further describes the present invention in detail with reference to specific embodiments, but the implementation manners of the present invention are not limited thereto.

[0045] An embodiment of the present invention provides a controller and a control method for a SIMO converter for a wireless sensor.

[0046] Figure 1 A schematic diagram of the steps of a control method for a SIMO converter for a wireless sensor provided by an embodiment of the present invention, Figure 2 A schematic flow diagram of a control method for a SIMO converter for a wireless sensor provided by an embodiment of the present invention. Next, first in combination with Figure 1 and Figure 2 The control method for a SIMO converter for a wireless sensor provided by an embodiment of the present invention is introduced.

[0047] The control method for a SIMO converter for a wireless sensor provided by an embodiment of the present invention, as Figure 1 shown, may include:

[0048] S1, judging the output voltages of each output branch in the SIMO converter, and marking the output branches that meet the preset voltage conditions.

[0049] For S1, it may include:

[0050] Comparing the output voltages of each output branch in the SIMO converter with a preset lower threshold reference voltage, and marking the output branches with voltages less than the preset lower threshold reference voltage.

[0051] Specifically, a topology diagram of a SIMO converter provided by an embodiment of the present invention, as Figure 3As shown, it may include: 1 power supply, 1 inductor, 3 loads, and multiple switches. Among them, the power supply can be a battery with a rated voltage of 3V, and the 3 loads can be a sensor, an MCU, and a radio frequency transceiver respectively. For the 3 loads, they exhibit different output power requirements during operation. The output power requirement of the sensor is generally about 10uW, the output power requirement of the MCU is generally 40uW, and the output power requirement of the radio frequency transceiver in the sleep mode is generally 10uW, while in the active mode it is about 40mW.

[0052] It can be understood that Figure 3 In the SIMO converter shown, the positive terminal VBAT of the power supply is arranged in series at the source terminal of the first power transistor PMOS1. The drain terminal of the first power transistor PMOS1 is connected to the VL terminal of the inductor, and this VL terminal is simultaneously connected to the drain terminal of the second power transistor NMOS1. The source terminal of the second power transistor NMOS1 is grounded. The VR terminal of the inductor is simultaneously connected to the drain terminals of the third power transistor NMOS2, the fourth power transistor PMOS2, the fifth power transistor PMOS3, and the sixth power transistor PMOS4. The source terminal of the third power transistor NMOS2 is grounded, and the source terminals of the fourth power transistor PMOS2, the fifth power transistor PMOS3, and the sixth power transistor PMOS4 are respectively connected to the corresponding output capacitors.

[0053] By sampling the output voltages of each output branch in the SIMO converter, comparing the sampled output voltages with their corresponding preset lower threshold reference voltages respectively, it is judged whether there is an output voltage of an output branch less than its corresponding preset lower threshold reference voltage. If not, the inductor does not charge or discharge and does not supply power to the load. If so, the output branch with an output voltage less than the preset lower threshold reference voltage is marked.

[0054] S2. Compare the load current corresponding to the marked output branch with the preset light / heavy load demarcation threshold. Set the output branch with a load current less than the preset light / heavy load demarcation threshold to the light load mode, and set the output branch with a load current greater than the preset light / heavy load demarcation threshold to the heavy load mode.

[0055] Optionally, the preset light / heavy load demarcation threshold can be 1mA.

[0056] From Figure 2 it can be seen that for the marked output branches, sample the load currents of the marked output branches respectively, compare the sampled load currents with the set preset light / heavy load demarcation threshold respectively, and judge whether there is a load current of any output branch greater than the preset light / heavy load demarcation threshold. If not, it indicates that all the marked output branches are in the light load mode. If so, it indicates that the marked output branches with a load current greater than the preset light / heavy load demarcation threshold are in the heavy load mode.

[0057] Specifically, the following is a schematic diagram of different working states of a SIMO converter provided by an embodiment of the present invention. As Figures 4a - 4c shown, it can be seen that the SIMO converter proposed by the embodiment of the present invention has three working states. Among them, Figure 4a this is the working state in which the SIMO converter proposed by the embodiment of the present invention charges the inductor. The specific working process includes: closing the first power transistor PMOS1, and at the same time closing one of the fourth power transistor PMOS2, the fifth power transistor PMOS3, and the sixth power transistor PMOS4. The voltage difference across the inductor (ΔV = VL - VR) is positive, and the inductor current rises. Figure 4b this is the working state in which the SIMO converter proposed by the embodiment of the present invention discharges the inductor. The specific working process includes: closing the second power transistor NMOS1, and at the same time closing one of the fourth power transistor PMOS2, the fifth power transistor PMOS3, and the sixth power transistor PMOS4. The voltage difference across the inductor (ΔV = VL - VR) is negative, and the inductor current drops. Figure 4c this is the working state in which the SIMO converter proposed by the embodiment of the present invention temporarily stores the inductor current. The specific working process includes: closing the second power transistor NMOS1 and the third power transistor NMOS2. The VL terminal and the VR terminal of the inductor are grounded at the same time. The voltage difference across the inductor (ΔV = VL - VR) is almost 0, and the inductor current almost remains unchanged. It should be emphasized that when the SIMO converter proposed by the embodiment of the present invention switches between the three working states, there is always a specific dead time. At this time, no power transistor is closed, and cross-conduction will not occur.

[0058] S3. If there are multiple marked output branches, perform a priority sorting according to the output voltages of the output branches to obtain a priority order.

[0059] Performing a priority sorting according to the output voltages of the output branches to obtain a priority order may include:

[0060] Sort the output voltages of the output branches from small to large, and use them as the priority order from the most preferred to the least preferred in turn.

[0061] If there are multiple marked output branches, it is necessary to sort the output branches of each mark so that the output branches of each mark can be powered on as needed in turn, and only one output branch is powered on each time. While determining the power output requirement, it is necessary to judge whether there is only a single branch with a power supply requirement. If there are more than one output branch with a power output requirement, sort these output branches with a power output requirement from small to large, from the most preferred to the least preferred in turn, so as to set the output branch with the highest priority in the power supply request as the power supply branch each time.

[0062] S4. If all output branches are in the light load mode, set the SIMO converter to operate in the DCM mode, so that the inductor in the SIMO converter is fully discharged after being charged in each switching cycle, and control the output branches corresponding to the light load mode to supply power in sequence according to the priority order.

[0063] Specifically, if all output branches are in the light load mode, set the SIMO converter to operate in the DCM mode; setting the SIMO converter to operate in the DCM mode may include:

[0064] Set the system clock of the SIMO converter to a preset low frequency value, the peak inductor current to a preset value lpeak, and the valley inductor current to 0.

[0065] Optionally, a waveform diagram of the light load mode in a SIMO converter provided by an embodiment of the present invention is as Figure 5 shown. The preset low frequency value can be set to 50 kHz, and the peak inductor current to the preset value lpeak can be set to 100 mA.

[0066] S5. If only one output branch is in the heavy load mode, set the SIMO converter to operate in the PCCM mode, and control the output branch corresponding to the heavy load mode to supply power.

[0067] Setting the SIMO converter to operate in the PCCM mode may include:

[0068] Set the system clock of the SIMO converter to a low level, the peak inductor current to a preset value lpeak, and the valley inductor current to a preset value lvalley.

[0069] A waveform diagram of the single-channel heavy load (PCCM) mode in a SIMO converter provided by an embodiment of the present invention is as Figure 6 shown. Judge each output branch. If any output branch is in the heavy load mode, set the system clock to a low level, that is, there is no fixed clock frequency. If there is only a single output branch with a power supply requirement and this output branch is in the heavy load mode, connect this output branch to the inductor to supply power to this output branch. When the output voltage reaches the upper threshold voltage of this output branch, at this time this output branch is still in the heavy load but has no power output requirement, disconnect the connection between this output branch and the inductor, and ground both ends of the inductor. Therefore, the inductor current does not directly drop to zero, but is temporarily stored in the inductor. When there is a power output request next time, the inductor does not start charging from 0, but starts charging from the inductor current value when the output branch was disconnected last time, thereby improving the transient response speed.

[0070] S6. If multiple output branches are in the overload mode, set the SIMO converter to operate in the DCCM mode, and control the output branches corresponding to the overload mode to supply power in sequence according to the priority order.

[0071] The waveform diagram of multiple overload modes in a SIMO converter provided by an embodiment of the present invention is as Figure 7 shown. When there is a power output requirement for more than one output branch, sort these output branches with power output requirements. According to the output voltage of the output branches, from the smallest to the largest, they are the most prioritized to the least prioritized. Thus, each time the output branch with the highest priority in the power supply request is set as the power supply branch, connect this power supply branch to the inductor, charge and discharge the inductor according to the determined peak inductor current and valley inductor current, supply power to the output branches with requests. When the output voltage of the output branch connected to the inductor reaches the preset upper threshold reference voltage of this output branch, discharge the inductor to zero and disconnect its connection with the inductor. It can be understood that in the DCCM mode, the parameter settings of the SIMO converter are the same as those in the PCCM mode.

[0072] Since the wireless sensor node needs to provide three different voltage rails and has a large load current range, the control method of the SIMO converter for wireless sensors proposed by the embodiment of the present invention changes the average inductor current value by switching different clock frequencies at low load and high load, providing a wide load dynamic range, and there is no cross-regulation between multiple output branches, having good transient response.

[0073] In a second aspect, corresponding to the above method embodiment, an embodiment of the present invention further provides a control circuit for a SIMO converter for wireless sensors, as Figure 8 shown, which may include:

[0074] A request arbitration unit, a mode selection unit, and an inductor current detection unit; wherein,

[0075] The request arbitration unit is used to identify the output branches among the output voltages of each output branch of the SIMO converter that meet the preset voltage conditions; when there are multiple identified output branches, perform priority sorting on each output branch according to the output voltage of each output branch;

[0076] The mode selection unit is used to compare the load current corresponding to the identified output branch with the preset heavy and light load demarcation threshold, configure the parameters of the SIMO converter according to the comparison result, and make the SIMO converter work in the corresponding working mode to supply power in sequence according to the priority order; the working modes include: DCM mode, PCCM mode, and DCCM mode;

[0077] The inductance current detection unit is used to detect the parameters of the SIMO converter and determine whether the parameters of the SIMO converter reach the preset values.

[0078] The parameters of the SIMO converter may include:

[0079] System clock, peak inductance current, and valley inductance current.

[0080] The mode selection unit compares the load current corresponding to the identified output branch with the preset light / heavy load demarcation threshold, and configures the parameters of the SIMO converter according to the comparison result to make the SIMO converter work in the corresponding working mode, which may include:

[0081] The mode selection unit compares the load current corresponding to the identified output branch with the preset light / heavy load demarcation threshold, sets the output branch corresponding to the load current less than the preset light / heavy load demarcation threshold to the light load mode, and sets the output branch corresponding to the load current greater than the preset light / heavy load demarcation threshold to the heavy load mode;

[0082] If all output branches are in the light load mode, set the system clock of the SIMO converter to the preset low frequency value, the peak inductance current to the preset value lpeak, and the valley inductance current to 0, so that the SIMO converter works in the DCM mode;

[0083] If only one output branch is in the heavy load mode, set the system clock of the SIMO converter to the low level, the peak inductance current to the preset value lpeak, and the valley inductance current to the preset value lvalley, so that the SIMO converter works in the PCCM mode;

[0084] If multiple output branches are in the heavy load mode, set the system clock of the SIMO converter to the low level, the peak inductance current to the preset value lpeak, and the valley inductance current to the preset value lvalley, so that the SIMO converter works in the DCCM mode.

[0085] From Figure 8It can be seen that the request adjudication unit may include: an output request judgment circuit and an output priority sorting circuit; the mode selection unit may include: a load current sampling circuit, a mode switching circuit, and a pulse generation circuit; among them, the inductor current sampling circuit controls the peak value and valley value of the inductor current by sampling the magnitude of the inductor current; the load current sampling circuit samples the load current corresponding to the identified output branch, thereby judging whether each branch is in the heavy load or light load mode, and transmits the judgment result to the mode switching circuit, so that the mode switching circuit controls the SIMO converter to work in the corresponding working mode; the pulse generation circuit controls the coordinated work among the various modules in the control circuit of the SIMO converter through logical combination; the output request judgment circuit may include an output request number judgment sub-circuit and multiple comparators; the output request judgment circuit uses the comparator to compare and judge the output voltage of each output branch of the SIMO converter, and identifies the output branch that meets the preset voltage condition through the output request number judgment sub-circuit; if there are multiple identified output branches, the output priority sorting circuit sorts the priorities of the identified output branches to obtain the priority order. The inductor current detection unit may include: an inductor current sampling circuit, and the inductor current sampling circuit may include a peak current detection sub-circuit and a valley current detection sub-circuit, which are respectively used to detect the peak value and valley value of the inductor current. The control circuit of the SIMO converter may further include a peripheral circuit, and the peripheral circuit may include a bandgap reference circuit and a driving circuit; among them, the bandgap reference circuit may be used to generate the reference voltage and reference current required by the comparator, and the driving circuit may be used to enhance the gate signals of the various power transistors in the SIMO converter.

[0086] In the embodiment of the present invention, by detecting the load current corresponding to the identified output branch in the SIMO converter, the judgment of the light load and heavy load modes of each output branch is realized. By changing the parameters of the SIMO converter, different inductor current magnitudes are provided in the light load and heavy load modes, so as to ensure that the SIMO converter is in a relatively wide load dynamic range; and the output voltages of the output branches are used to sort the priorities of the output branches, so that the inductor in the SIMO converter outputs power to only a single output branch each time, avoiding the cross-regulation problem between multiple output branches. Further, when a single branch is in heavy load, when there is an output demand for this single branch, the inductor current does not need to be charged from zero, so it has a better transient response.

[0087] It should be noted that in the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0088] The above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A control method for a SIMO converter of a wireless sensor, characterized in that: include: Determine the output voltage of each output branch in the SIMO converter and identify the output branch that meets the preset voltage condition; Compare the load current corresponding to the identified output branch with the preset light-heavy load demarcation threshold, set the output branch corresponding to the load current less than the preset light-heavy load demarcation threshold to the light load mode, and set the output branch corresponding to the load current greater than the preset light-heavy load demarcation threshold to the heavy load mode; If there are multiple identified output branches, the priority order is obtained by sorting the output voltages of the output branches; If all output branches are in light load mode, the SIMO converter is set to work in DCM mode, so that the inductor in the SIMO converter is fully discharged after being charged in each switching cycle, and the output branches corresponding to the light load mode are controlled to supply power in sequence according to the priority order; If only one output branch is in heavy load mode, the SIMO converter is set to work in PCCM mode to control the output branch corresponding to the heavy load mode to supply power; If multiple output branches are in heavy load mode, the SIMO converter is set to work in DCCM mode, and the output branches corresponding to the heavy load mode are controlled to supply power in sequence according to the priority order.

2. The control method of a SIMO converter for a wireless sensor according to claim 1, characterized in that: The step of judging the output voltage of each output branch in the SIMO converter and identifying the output branch that meets the preset voltage condition includes: The output voltage of each output branch in the SIMO converter is compared with a preset lower threshold reference voltage, and the output branch whose output voltage is less than the preset lower threshold reference voltage is identified.

3. The control method of a SIMO converter for a wireless sensor according to claim 1, characterized in that: The preset light-load and heavy-load demarcation threshold is 1 mA.

4. The control method of a SIMO converter for a wireless sensor according to claim 1, characterized in that: The step of setting the SIMO converter to operate in the DCM mode includes: The system clock of the SIMO converter is set to a preset low frequency value, the peak value of the inductor current is set to a preset value lpeak, and the valley value of the inductor current is set to 0.

5. The control method of a SIMO converter for a wireless sensor according to claim 1, characterized in that: The step of setting the SIMO converter to operate in the PCCM mode includes: The system clock of the SIMO converter is set to a low level, the peak value of the inductor current is set to a preset value lpeak, and the valley value of the inductor current is set to a preset value lvalley.

6. The control method of a SIMO converter for a wireless sensor according to claim 1, characterized in that: The step of performing priority sorting according to the output voltages of the output branches to obtain a priority order includes: The output voltages of the output branches are sorted from smallest to largest in order of priority from most to least priority.

7. A control circuit for a SIMO converter of a wireless sensor, characterized in that: include: request decision unit, mode selection unit and inductor current detection unit; wherein, The request decision unit is used to identify the output branches of the SIMO converter that meet the preset voltage conditions among the output voltages of the output branches; when there are multiple identified output branches, prioritize the output branches according to the output voltages of the output branches; The mode selection unit is used to compare the load current corresponding to the identified output branch with the preset light-load and heavy-load boundary threshold, and configure the parameters of the SIMO converter according to the comparison result, so that the SIMO converter works in the corresponding working mode and supplies power in sequence according to the priority order; the working modes include: DCM mode, PCCM mode and DCCM mode; The inductor current detection unit is used to detect the parameters of the SIMO converter and determine whether the parameters of the SIMO converter reach preset values.

8. The control circuit of a SIMO converter for a wireless sensor according to claim 7, characterized in that: The parameters of the SIMO converter include: System clock, inductor current peak, and inductor current valley.

9. The control circuit of a SIMO converter for a wireless sensor according to claim 8, characterized in that: The mode selection unit compares the load current corresponding to the identified output branch with a preset light-load and heavy-load demarcation threshold, and configures the parameters of the SIMO converter according to the comparison result so that the SIMO converter operates in a corresponding working mode, including: The mode selection unit compares the load current corresponding to the identified output branch with a preset light-heavy load demarcation threshold, sets the output branch corresponding to the load current less than the preset light-heavy load demarcation threshold to the light load mode, and sets the output branch corresponding to the load current greater than the preset light-heavy load demarcation threshold to the heavy load mode; If all output branches are in light load mode, the system clock of the SIMO converter is set to a preset low frequency value, the peak value of the inductor current is set to a preset value lpeak, and the valley value of the inductor current is set to 0, so that the SIMO converter works in DCM mode; If only one output branch is in heavy load mode, the system clock of the SIMO converter is set to a low level, the peak value of the inductor current is set to a preset value lpeak, and the valley value of the inductor current is set to a preset value lvalley, so that the SIMO converter works in PCCM mode; If multiple output branches are in heavy load mode, the system clock of the SIMO converter is set to a low level, the peak value of the inductor current is set to a preset value lpeak, and the valley value of the inductor current is set to a preset value lvalley, so that the SIMO converter works in the DCCM mode.

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