Power supply system for aerosol-generating device

Abstract

A power supply system (101) is adapted as part of an aerosol-generating device (100). In the power supply system, a power supply terminal (VDD) of a microcontroller (1) is connected to a rechargeable power source (2) such that a voltage of the power supply terminal of the microcontroller varies according to a charge level of the rechargeable power source. No DC-DC converter is used between the rechargeable power source and the microcontroller so that the microcontroller can monitor the level of charge of the rechargeable power source.

Description

[0001] The present invention relates to a power supply system, in particular such a system suitable for being part of an aerosol-generating device. The invention also relates to an aerosol-generating device when the aerosol-generating device comprises the power supply system of the invention. Background Art

[0002] Each aerosol-generating device incorporates a microcontroller, which performs several functions, notably activating and controlling a heater dedicated to heating the amount of aerosol precursor used to generate the aerosol. The microcontroller is typically powered by a battery via a low-dropout (LDO) regulator. The LDO regulator ensures a nearly constant voltage is supplied to the microcontroller at its supply terminal, usually designated VDD. This allows for stable and constant operation of the microcontroller. In practice, many microcontrollers are supplied with a DC voltage of approximately 3.2 V (volts), while the battery's output voltage can vary from less than 2.5 V to more than 4.2 V, depending on the battery type and its current charge level. If the DC voltage fed to the microcontroller is too high relative to the nominal value specified for the microcontroller (e.g., 4.0 V instead of 3.2 V), the microcontroller's internal clock will run too fast, significantly increasing its energy consumption unnecessarily, and certain peripherals within the microcontroller may be affected. Consequently, the duration of use of the aerosol-generating device between refills is shortened.

[0003] The function of a battery monitoring integrated circuit (BMIC) is to prevent the battery's output voltage from dropping excessively, reaching a deep depletion state. Before reaching a deep depletion state, the BMIC triggers the microcontroller to isolate the battery, thereby limiting further energy consumption. The BMIC also prevents further charging of the battery after a deep depletion condition has occurred. This is typically implemented in conjunction with a charging integrated circuit (CIC), which stops charging the battery upon reaching a full charge. This ensures the safety of the aerosol-generating device.

[0004] However, the use of an LDO regulator and a battery monitoring integrated circuit increases the unit cost price and energy consumption of the aerosol generating device and complicates the device structure.

[0005] Starting from this situation, one object of the present invention is to alleviate the above-mentioned disadvantages.

[0006] In particular, the present invention allows for the suppression of redundant components within a power supply system intended for an aerosol-generating device.In this way, the present invention enables the number of components within an aerosol-generating device to be minimised. Summary of the Invention

[0007] To meet at least one of these or other objects, a first aspect of the present invention provides a power supply system suitable for use as part of an aerosol-generating device, the power supply system comprising:

[0008] - a microcontroller configured to control power supplied to the load; and

[0009] - A rechargeable power source having an output voltage that varies according to a charge level of the rechargeable power source.

[0010] The microcontroller is connected to be fed with further power from the rechargeable power source.

[0011] According to the invention, a power supply terminal of a microcontroller dedicated to receiving power to allow operation of the microcontroller is connected to the rechargeable power source so that the voltage of the power supply terminal of the microcontroller varies according to the charge level of the rechargeable power source.

[0012] In other words, the present invention proposes connecting the microcontroller's VDD terminal to a rechargeable power source, allowing the microcontroller to receive the rechargeable power source's output voltage, which varies according to its current charge level. Specifically, no DC-DC converter or linear regulator (such as an LDO) is placed between the rechargeable power source's output and the microcontroller's VDD terminal. This power connection allows the microcontroller to sense and monitor the rechargeable power source's current output voltage, thereby controlling its management. Specifically, the microcontroller can prevent further power from the rechargeable power source from being supplied to the load, preventing the rechargeable power source from entering a deep depletion state. Furthermore, if the rechargeable power source is already in a deep depletion state for any reason, the microcontroller can prevent charging for safety reasons. Furthermore, because the microcontroller can sense the rechargeable power source's output voltage, it can detect when a full charge has been achieved and then cease charging. Because these functions can be performed by the microcontroller, a battery monitoring integrated circuit is not required. Consequently, the power supply system of the present invention can be simpler, reducing its unit cost.

[0013] Generally for the present invention, the rechargeable power source may be a battery (eg, a lithium-ion secondary battery) or a capacitor, or any other rechargeable power source type.

[0014] This power connection also improves the power consumption of the aerosol generating device because the power loss of the LDO regulator due to power regulation is no longer required. It also eliminates the power consumption of the battery monitoring integrated circuit.

[0015] Therefore, in a preferred embodiment of the invention, the microcontroller may be configured to monitor the voltage at its supply terminals and prevent charging of the rechargeable power source if this voltage is less than a low-level threshold.

[0016] According to an improvement of the present invention, the microcontroller can be adapted to operate in either a standard mode or a low-consumption mode, wherein the power consumption of the microcontroller in the low-consumption mode is lower than that in the standard mode. The microcontroller can then be further configured to activate the low-consumption mode for operation when the voltage at its power supply terminal is above a voltage threshold, and to switch to the standard mode when the voltage at the power supply terminal becomes less than the voltage threshold. This can thereby avoid unnecessary excessive power consumption of the microcontroller due to its VDD voltage being above the nominal value. Consequently, the duration of use of the aerosol generating device can be saved before the rechargeable power source is next charged. Depending on the type of microcontroller, several low-consumption modes can be implemented for the microcontroller. For example, some modules within the microcontroller can be switched to an idle mode.

[0017] Typically, a microcontroller's clock frequency is proportional to its VDD voltage. This excessive internal clock frequency can be one reason why a microcontroller consumes too much power due to a high VDD voltage.

[0018] Alternatively, when the microcontroller is internally clocked, the microcontroller can be configured so that, for the same voltage value at the microcontroller's power supply terminals, the clock frequency value effective in low-power mode is lower than another clock frequency value effective in the standard mode. This operation allows the microcontroller to operate more stably. Generally speaking, a microcontroller's variable clock frequency can lead to unstable operation. By activating low-power mode when the voltage at the power supply terminals is less than a voltage threshold, this variation in clock frequency can be suppressed.

[0019] According to another refinement of the invention, in particular when intended for use in an aerosol-generating device, the power supply system may further comprise:

[0020] - a DC-DC converter connected so that the load is fed with power from the rechargeable power source through the DC-DC converter; and

[0021] a MOSFET switch connected in series with the load between the output of the DC-DC converter and a ground terminal of the power supply system, the MOSFET switch having a gate connected to a first control output terminal of the microcontroller for the microcontroller to allow or prevent power supply to the load.

[0022] According to an optional but preferred additional feature of the present invention, the MOSFET switch can be a p-type switch and connected between the output of the DC-DC converter and the load. This configuration allows the microcontroller to control the power supply to the load even when the rechargeable power source is in a low-level charging state. In fact, to perform this control, the microcontroller does not need to provide a control voltage to the MOSFET switch that may be higher than its VDD voltage, as this is impossible. Specifically, the source of the p-type MOSFET switch is connected to the output of the DC-DC converter, the gate of the p-type MOSFET switch is connected to the microcontroller, and the drain of the p-type MOSFET switch is connected to the load. Generally speaking, a p-type MOSFET turns on when the potential of its source electrode is higher than the potential of its gate electrode by a predetermined threshold or more. Since the DC-DC converter supplies a boosted voltage to the source terminal of the p-type MOSFET, the microcontroller only needs to supply a low-level voltage to the gate terminal of the p-type MOSFET (enabling power even when the rechargeable power source is in a low-level charging state) to turn on the p-type MOSFET.

[0023] According to another improvement of the present invention, the microcontroller may include a second control output terminal and be configured to supply a pulse width modulation type control signal to the second control output terminal. Then, the power supply system may further include:

[0024] - a light emitting diode connected to the second control output terminal of the microcontroller, so that the microcontroller controls the light emission of the light emitting diode; and

[0025] a capacitor connected in parallel with the light-emitting diode in order to convert the pulse-width modulation type control signal into a direct current, which is conducted through the light-emitting diode and whose value varies as the pulse-width modulation type control signal varies.

[0026] Typically, the light intensity of an LED is proportional to the voltage applied to the LED. A microcontroller outputs a voltage that is only as high as its VDD voltage, either in a continuous waveform or a pulsed waveform (e.g., pulse-width modulation). This means that the light intensity of the LED can vary based on the charge level of the rechargeable power source. This capacitor allows the light intensity of the LED to remain approximately constant even if the charge level of the rechargeable power source changes. Since this capacitor can function as a bypass capacitor or a smoothing capacitor, controlling the pulse-width modulation control signal based on the charge level of the rechargeable power source maintains the voltage applied to the LED at approximately the same level.

[0027] Generally for the present invention, the power supply system may further include:

[0028] - a charger module arranged for charging the rechargeable power source with energy originating from an external power source;

[0029] - a first sensing circuit arranged for sensing, during use of the power supply system, whether the external power source is currently available with respect to the charger module;

[0030] - a second sensing circuit arranged for sensing whether the load is connected to the power supply system such that the load conducts an output current supplied by the power supply system; and

[0031] a power supply switch arranged in series between the rechargeable power source and the power supply terminals of the microcontroller and connected to the first sensing circuit and the second sensing circuit so as to allow the further power to be passed from the rechargeable power source to the microcontroller only when at least one of the following two conditions is sensed:

[0032] ● The external power source is currently active with respect to the charger module, and

[0033] ● The load is connected to the power supply system.

[0034] Due to this power connection scheme, power is only supplied to the microcontroller when it is expected that the rechargeable power source will be charged or discharged. This can further improve the energy consumption of the aerosol generating device.

[0035] In a possible simple embodiment, the first sensing circuit may include:

[0036] - a first sensing resistor connected in parallel between the external power supply terminal and ground; and

[0037] - a first operational amplifier having a non-inverting input terminal and an inverting input terminal connected to both ends of the first sensing resistor and an output terminal connected to the control terminal of the power supply switch.

[0038] Due to this power supply connection, power is automatically supplied to the microcontroller in response to the external power supply being available.

[0039] The power supply system may further include a pull-up resistor connected in series between the external power source and the first sensing resistor. The enable terminal of the charger module may then be configured to input a divided voltage generated by the pull-up resistor and the first sensing resistor. Due to this power supply connection, the charger module is automatically enabled in response to the availability of external power, simultaneously providing power to the microcontroller.

[0040] The second sensing circuit may include:

[0041] - a second sensing resistor connected in series with the load;

[0042] - a second operational amplifier having a non-inverting input terminal and an inverting input terminal connected to both ends of the second sense resistor and an output terminal connected to the control terminal of the power supply switch; and

[0043] - a bypass circuit connected between the rechargeable power source and the load, the bypass circuit bypassing the DC-DC converter and the MOSFET switch.

[0044] Thanks to this supply connection, the microcontroller can distinguish whether a load is available without enabling the DC-DC converter.

[0045] The bypass circuit may include a backflow prevention diode having an anode connected to the rechargeable power source and a cathode connected to the load. The DC-DC converter may then be a boost converter. Due to this power supply connection, backflow current that may cause unstable operation of the aerosol-generating device through the bypass circuit can be prevented primarily by the backflow prevention diode.

[0046] The bypass circuit may further comprise a current limiting resistor connected in series between the rechargeable power source and the load. Due to this power supply connection, the microcontroller can distinguish whether the load is available at a very low current.

[0047] In a possible first embodiment of the invention, the power supply system may then further comprise:

[0048] - a first NOT gate, an input terminal of the first NOT gate being connected to the output terminal of the first operational amplifier;

[0049] - a second NOT gate, an input terminal of the second NOT gate being connected to the output terminal of the second operational amplifier; and

[0050] - an AND gate having an input terminal connected to the respective output terminals of the first NOT gate and the second NOT gate, and an output terminal connected to the control terminal of the power supply switch.

[0051] In such a first embodiment, the power supply switch may be a p-type MOSFET. Due to this power supply connection, power is automatically supplied to the microcontroller in response to an external power source or load being available.

[0052] Alternatively, in other possible embodiments of the present invention, the power supply system may further include:

[0053] - a NOR gate having an input terminal connected to the respective output terminals of the first operational amplifier and the second operational amplifier and an output terminal connected to the control terminal of the power supply switch.

[0054] In such other embodiments, the power supply switch may also be a p-type MOSFET. Due to this power supply connection, power is automatically supplied to the microcontroller in response to an external power source or load being available.

[0055] Typically for the present invention, the microcontroller is further connected to receive a detection signal, the detection signal being indicative of the current supplied to the load. Thus, the microcontroller can perform feedback control on the power currently supplied to the load.

[0056] A second aspect of the present invention provides an aerosol generating device, comprising:

[0057] - the power supply system according to the first invention; and

[0058] - a heater connected to the power supply system so as to be supplied with power by the power supply system, and forming a load.

[0059] These and other features of the present invention will now be described with reference to the accompanying drawings, which relate to preferred but non-limiting embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is a block diagram of an aerosol generating device according to the present invention.

[0061] Figure 2 It shows the possible use Figure 1 Diagram of the mode management of the microcontroller used in the aerosol generating device.

[0062] Figure 3 It is possible to use Figure 1 Detailed view of a first embodiment of an aerosol-generating device.

[0063] Figure 4 and Figure 3 Correspondingly, it is possible to use Figure 1 A second embodiment of the aerosol-generating device.

[0064] For the sake of clarity, the same reference numerals indicated in different figures of the drawings denote the same elements or elements having the same function. DETAILED DESCRIPTION

[0065] refer to Figure 1, the aerosol generating device 100 comprises a microcontroller 1, a battery 2, a heater 3 and a DC-DC converter 4. To make the drawings clear, the following labels are added:

[0066] "MCU" is used for microcontroller 1, which stands for microcontroller unit,

[0067] "Boost DC-DC" is used for DC-DC converter 4,

[0068] "Overvoltage protection" for charging input port 5, and

[0069] The "charger" is used to charge the circuit 6.

[0070] Heater 3 is designed to heat a quantity of aerosol precursor originating from pod 102 under the control of microcontroller 1, in order to generate an aerosol for inhalation by a user of aerosol-generating device 100. Heater 3 is powered by battery 2 via DC-DC converter 4, which adjusts the voltage supplied to heater 3 according to the current output voltage value of battery 2. Generally speaking, DC-DC converter 4 generates a voltage boost. Therefore, the converter may be a boost converter, a type of converter well known in the art. The operation of DC-DC converter 4 is controlled by microcontroller 1 based on the current output voltage value of battery 2. DC-DC converter 4 may be a buck-boost converter.

[0071] To allow for charging of the battery 2, the aerosol-generating device 100 may further include a charging input port 5 and a charger module 6. The charging input port 5 may include an input protection chip that connects directly to a USB-C socket or a wireless receiving coil. Reference numeral 200 denotes an external power source, which is physically or wirelessly connected to the charging input port 5 to charge the battery 2. The charging input port 5 preferably incorporates input protection and input cutoff. Specifically, the charging input port 5 may be integrated with a protection IC. The input cutoff can be accessed by the microcontroller 1, specifically for preventing the battery 2 from being recharged if the output voltage of the battery 2 sensed by the microcontroller 1 indicates deep depletion. The microcontroller 1 can detect the deep depletion state of the battery 2 when the monitored VDD value falls below a predetermined low-level threshold. The charger module 6 may have the function of adjusting the voltage charge value and the current charge value according to the actual charge level of the battery 2. Specifically, the charger module 6 may be or include a charging IC.

[0072] According to the present invention, battery 2 (e.g., a lithium-ion secondary battery) is connected to the VDD terminal of microcontroller 1 without an intermediate voltage converter. This allows microcontroller 1 to measure the current output voltage of battery 2 and control the operation of DC-DC converter 4 based on the measurement result. With this power supply connection configuration, microcontroller 1 is compatible with a wide range of VDD voltage values. For example, it can operate within a VDD range of 1.7 V to 5.5 V.

[0073] As is well known, if the actual VDD value at which the microcontroller 1 is operated differs from the nominal value specified for that microcontroller, this may result in increased power consumption of the microcontroller. However, this increased power consumption of the microcontroller 1 is unnecessary for the aerosol-generating device 100 to deliver aerosol. Therefore, when the current VDD value results in excessive power consumption, the operation of the microcontroller 1 can be switched from a standard mode to a low-power mode. This situation may occur when the VDD value is above a threshold (e.g., 2.55 V), particularly because the clock frequency within the microcontroller 1 may be too high at this time. Therefore, it is advantageous for the microcontroller 1 to be configured to operate in the low-power mode when the VDD voltage is above the threshold, and to switch back to the standard mode when the VDD voltage falls below the threshold. Figure 2 The possible variations of the clock frequency of the microcontroller 1 as a function of the VDD voltage are shown. The horizontal axis shows the value of the VDD voltage expressed in Volts (V) and the vertical axis shows the value of the clock frequency expressed in Megahertz (MHz) and is labeled CLK. The normal mode for operating the microcontroller 1 may correspond to the following: Figure 2 The clock frequency value directly results from the VDD value in the diagram. However, in a possible refinement of the present invention, normal mode can be implemented only when the current VDD value is less than 2.55 V (corresponding to a frequency value less than 9 MHz). When the current VDD value is higher than 2.55 V, a low-power mode can be implemented, reducing the effective clock frequency to less than or equal to 9 MHz. This also allows for stable operation of the microcontroller 1, as variations in the VDD value can be suppressed.

[0074] Back to Figure 1A p-type MOSFET switch 7 can be inserted in series between the DC-DC converter 4 and the heater 3. The drain of the p-MOSFET switch 7 can be connected to a power supply terminal of the heater 3, and its source is connected to the output terminal (VOUT) of the DC-DC converter 4. The other power supply terminal of the heater 3 is connected to the ground of the aerosol-generating device 100. The gate of the p-MOSFET switch 7 is connected to a first control output terminal of the microcontroller 1, so that the first control output terminal can drive the switch 7 into a blocking state or a conducting state to activate, adjust, or prevent operation of the heater 3. Because a p-MOSFET type switch 7 is used, the microcontroller 1 can control it even when the current VDD value is low. Since the boosted voltage of the DC-DC converter 4 is supplied to the source of the p-MOSFET switch 7, the microcontroller 1 can drive the switch 7 into a conducting state by simply applying a low-level voltage (e.g., 0V, corresponding to ground potential) to the gate of the p-MOSFET switch 7.

[0075] Within the aerosol-generating device 100, the microcontroller 1 and battery 2, connected to each other as described above, together form the minimum configuration of a power supply system according to the present invention. This power supply system is designated 101 in the accompanying drawings. Advantageously, the power supply system 101 may further include a charging input port combined with an overvoltage protection IC 5 and a charger module 6. The addition of a DC-DC converter 4 and a p-type MOSFET switch 7 to the power supply system 101 is particularly suitable for the aerosol-generating device 100. The heater 3 constitutes the electrical load for the power supply system 101.

[0076] The power supply system 101 may further include a sensing circuit 30 adapted to detect whether the heater 3 is actually connected to the power supply system 101. Preferably, the sensing circuit 30 may further be adapted to measure the output current currently supplied by the power supply system 101 to the heater 3. The microcontroller 1 may advantageously use the result of this measurement to adjust the aerosol generation by using a loop configuration with feedback control.

[0077] Possibly, the microcontroller 1 can further be adapted to control a user interface 9, such as a light-emitting diode (LED). To this end, the microcontroller 1 can be provided with a second control output terminal 12 adapted to deliver a pulse-width-modulated signal. This second control output terminal of the microcontroller 1 can then be provided with a capacitor 10, such that the capacitor is connected in parallel with the LED 9 between the microcontroller output terminal and the ground of the aerosol-generating device 100. In this way, the light intensity emitted by the LED 9 can be adjusted by the microcontroller 1. The capacitor 10 smoothes the current supplied to the LED 9 during such operation. In other words, the capacitor 10 can function as a bypass capacitor or a smoothing capacitor. Specifically, when such a pulse-width-modulated control signal is controlled based on the charge level of the battery 2, the applied voltage of the LED 9 (which corresponds to the light intensity emitted by the LED 9) can be maintained at approximately the same level.

[0078] Now refer to Figure 3 The description of the first embodiment of the aerosol generating device 100 continues. Only the elements other than those already described will now be explained. BUS Indicates that the external power supply 200 ( Figure 3 The charging DC voltage V supplied to the charging input port combined with the overvoltage protection IC 5 is not shown in FIG. BAT represents the output voltage of battery 2, and V HTR Indicates the voltage supplied from the output terminal of the DC-DC converter 4 to the heater 3. The acronyms of the terminals indicated on the integrated circuit have the following common meanings: IN for DC voltage input, OVLO for overvoltage lockout comparator, GND for ground terminal, OUT for DC voltage output, SW for switch terminal, CE for enable of the charger module 6, SYS for power path function, BAT for the terminal of the charger module 6 to be connected to the battery 2, VIN for the DC voltage input terminal of the DC-DC converter 4, EN for the enable terminal, VOUT for the output terminal of the DC-DC converter 4, FB for the feedback terminal, VDD for the power supply terminal of the microcontroller 1, and I / O for the input or output control terminal of the microcontroller. The combination of the charging input port and the overvoltage protection IC 5 can be disconnected from the external power supply based on the input voltage of the OVLO terminal. If the voltage of the OVLO terminal is lower than the divided voltage V BUSIf the corresponding input voltage exceeds a threshold, the combination of the charging input port and the overvoltage protection IC 5 can determine the occurrence of an overvoltage input to the power supply system 101. Reference numeral 11 denotes a first control output terminal of the microcontroller 1, which is connected to the gate of the p-MOSFET switch 7, allowing the microcontroller 1 to allow or prevent power from the DC-DC converter 4 to the heater 3. Reference numeral 12 denotes a second control output terminal of the microcontroller 1, which is connected to the LED 9 and the capacitor 10, allowing the microcontroller 1 to control the light intensity emitted by the LED 9.

[0079] exist Figure 3 The first embodiment and Figure 4 In an alternative embodiment (described later), the CE terminal of the charger module 6 and the EN terminal of the DC / DC converter 4 operate according to positive logic. This means that once a high-level voltage is input to the corresponding enable terminal, the charger module 6 and the DC / DC converter 4 are enabled. Alternatively, the CE terminal of the charger module 6 and / or the EN terminal of the DC / DC converter 4 may operate according to negative logic.

[0080] The first sensing circuit 60 is dedicated to sensing whether the external power source 200 is currently effective relative to the charger module 6. Figure 3 As shown, the first sensing circuit 60 may include a voltage-dividing resistor bridge connected between the VBUS terminal of the charger module 6 and the ground GND of the power supply system 101. The first sensing circuit includes a first sensing resistor 61 and a pull-up resistor 63 connected in series to form a voltage-dividing resistor bridge. When the external power source 200 is active, a high-level voltage is input to the CE terminal of the charger module 6 through the pull-up resistor 63. As described above, since the CE terminal of the charger module 6 operates according to positive logic, the charger module 6 is automatically enabled once the external power source 200 is available. The sensing resistor 61 is connected between the CE terminal of the charger module 6 and the ground GND, and the pull-up resistor 63 is connected between the VBUS terminal and the CE terminal of the charger module 6. The first sensing circuit 60 also includes a first operational amplifier 62, whose non-inverting input terminal is connected to the node between the sensing resistor 61 and the pull-up resistor 63, and whose inverting input terminal is connected to the ground GND of the power supply system 101. In this manner, once the external power source 200 is connected to the charging input port 5 , the output terminal of the operational amplifier 62 is at a high level, and the charging input port transmits power to the charger module 6 .

[0081] Sensing circuit 30 is primarily dedicated to sensing whether current can flow through the load formed by heater 3. In the general portion of this specification, this circuit 30 is referred to as second sensing circuit 30. For this purpose, this second sensing circuit includes a second sensing resistor 31 connected in series with heater 3, for example, between the heater and the ground GND of power supply system 101. Furthermore, second sensing circuit 30 includes a second operational amplifier 32 and a bypass circuit that supplies a test current from battery 2 directly to heater 3 without passing through DC-DC converter 4. The input terminals of operational amplifier 32 are connected to both ends of sensing resistor 31, so that once heater 3 is connected to power supply system 101, its output terminal is at a high level, regardless of whether microcontroller 1 activates heating operation. This is because once heater 3 is connected to power supply system 101, the test current from battery 2 automatically flows through second sensing circuit 30. The test current flowing through sensing resistor 31 is preferably small, which is why the bypass circuit includes a current-limiting resistor 34. For example, the resistance value of current-limiting resistor 34 can be greater than 1 kΩ, and this value can also be greater than the resistance values ​​of other resistors in power supply system 101 (e.g., heater 3). The bypass circuit also includes a backflow prevention diode 33, which is oriented so as to prevent current from flowing back from the output terminal of DC-DC converter 4 to battery 2 when DC-DC converter 4 generates a voltage boost (e.g., when it is a step-up type). Specifically, the anode of backflow prevention diode 33 is connected to battery 2, and the cathode of backflow prevention diode 33 is connected to current-limiting resistor 34.

[0082] The VDD terminal of the microcontroller 1 can be connected to the battery 2 via a dedicated power supply switch 40, which is controlled by the sensing circuits 60 and 30. In this way, if the heater 3 is disconnected and the external power supply 200 cannot be connected to the power supply system 101, the microcontroller 1 can be prevented from being powered. The power supply switch 40 can be a p-type MOSFET, whose source S is connected to the battery 2 and whose drain D is connected to the VDD terminal of the microcontroller 1. The gate G of the switch 40 is controlled by the sensing circuits 60 and 30, for example using two NOT gates 64 and 35 and an AND gate 41. The output terminal of the first operational amplifier 62 is connected to the input terminal of the NOT gate 64, and the output terminal of the NOT gate 64 is connected to the first input terminal of the AND gate 41 (at Figure 3 (denoted by A in the figure). Meanwhile, the output terminal of second operational amplifier 32 is connected to the input terminal of inverter 35, and its output terminal is connected to the second input terminal (denoted by B) of AND gate 41. The output terminal of AND gate 41 is connected to gate G of p-MOSFET switch 40. Therefore, the truth table for the power supply of microcontroller 1 is as follows:

[0083]

[0084] Therefore, the microcontroller 1 is powered by the battery 2 or the charger module 6 unless both the heater 3 and the external power source 200 are simultaneously unavailable or disconnected. In other words, the microcontroller 1 is powered as soon as at least one of the external power source 200 and the heater 3 is available or connected to the power supply system 101. This prevents the microcontroller 1 from being operated by the battery 2 when the aerosol-generating device 100 is unable to generate aerosol, thereby conserving battery power.

[0085] To allow microcontroller 1 to check the actual power supply to heater 3, it is further possible to also connect the output of a second operational amplifier 32 to input terminal 13 of microcontroller 1. However, sensing resistor 31 and operational amplifier 32 can be dedicated exclusively to detecting the flow of a test current conducted by a bypass circuit comprising diode 33 and resistor 34, and a further sensing resistor (not shown) can be arranged in series with this sensing resistor 31, with a voltage measurement device suitable for providing a quantitative assessment of the current flowing through heater 3. The result of this heater current measurement can also be transmitted to a dedicated input terminal of microcontroller 1 for quantitative feedback control of heater operation.

[0086] Figure 4 An alternative embodiment is shown in which the AND gate 41, together with the NOT gates 64 and 35, is replaced by a NOR gate 42. The A input terminal of the NOR gate 42 is directly connected to the output terminal of the first operational amplifier 62, and the B input terminal of the same NOR gate 42 is directly connected to the output terminal of the second operational amplifier 32. The truth table for the power supply of the microcontroller 1 is then as follows:

[0087]

[0088] The truth table of the power supply of the microcontroller 1 is the same as Figure 3 The truth table of the embodiment is the same. Figure 4 Embodiments of the present invention also implement a p-MOSFET transistor for switch 40 .

[0089] Figure 4 The following variants shown also work with Figure 3 Compatible with the following examples:

[0090] - An additional output control terminal 14 of the microcontroller 1 may be dedicated to activating the DC-DC converter 4. Instead of connecting the enable terminal EN of the DC-DC converter 4 to its VIN terminal using a bias resistor, this output control terminal 14 is connected to the enable terminal EN of the DC-DC converter 4, as in Figure 3 shown; and

[0091] Another additional output control terminal 15 of the microcontroller 1 can be dedicated to activating the charger module 6. This output control terminal 15 can be connected to the enable terminal CE of the charger module 6, instead of connecting the enable terminal CE to the intermediate node between the pull-up resistor 63 and the sense resistor 61. This can be another way to prevent charging of the battery 2 if the microcontroller 1 senses a deep depletion of the battery 2 via its VDD terminal.

[0092] Anyone will appreciate that the detailed embodiments of the invention provided above may be varied and adjusted while maintaining at least some of the advantages mentioned. In addition, all numerical values ​​cited are for illustrative purposes only and may be changed according to each embodiment of the invention.

Claims

1. A power supply system (101), adapted to be part of an aerosol generating device (100), comprising: - a microcontroller (1) configured to control power supplied to a load; as well as - a rechargeable power source (2) having an output voltage that varies according to the charge level of the rechargeable power source, wherein the microcontroller (1) is connected so as to be fed with another electric power from the power supply (2), The invention is characterized in that a power supply terminal (VDD) of the microcontroller (1) dedicated to receiving power to allow the microcontroller to operate is connected to the rechargeable power supply (2), so that the voltage of the power supply terminal of the microcontroller varies according to the charge level of the rechargeable power supply.

2. The power supply system (101) according to claim 1, wherein: The microcontroller (1) is configured to monitor the voltage of a power supply terminal (VDD) of the microcontroller and to prevent charging of the rechargeable power source (2) if the voltage of the power supply terminal of the microcontroller is less than a low-level threshold.

3. The power supply system (101) according to claim 1 or 2, wherein: The microcontroller (1) is adapted to operate in a standard mode or a low-consumption mode, wherein the power consumption of the microcontroller in the low-consumption mode is lower than that in the standard mode, and the microcontroller is further configured to activate the low-consumption mode for operation when the voltage of the power supply terminal (VDD) is higher than a voltage threshold, and switch to the standard mode when the voltage of the power supply terminal becomes lower than the voltage threshold.

4. The power supply system (101) according to claim 3, wherein: The microcontroller (1) is clocked internally and configured such that, for the same value of the voltage at a power supply terminal (VDD) of the microcontroller, the clock frequency value of the microcontroller effective in the low-consumption mode is lower than another clock frequency value effective in the standard mode.

5. The power supply system (101) according to any one of the preceding claims, further comprising: - a DC-DC converter (4) connected so that the load is fed with power from the rechargeable power source (2) via the DC-DC converter; as well as - a MOSFET switch (7) connected in series with the load between the output of the DC-DC converter (4) and a ground terminal (GND) of the power supply system (101), and having a gate connected to a first control output terminal (11) of the microcontroller (1) for the microcontroller to allow or prevent power supply to the load, The MOSFET switch (7) is a p-type switch and is connected between the output terminal of the DC-DC converter (4) and the load.

6. The power supply system (101) according to any one of the preceding claims, wherein The microcontroller (1) comprises a second control output terminal (12) and is configured to supply a control signal of the pulse width modulation type to the second control output terminal, And the power supply system (101) further comprises: - a light emitting diode (9), which is connected to a second control output terminal (12) of the microcontroller (1) so that the microcontroller controls the light emission of the light emitting diode; and - a capacitor (10) connected in parallel with the light-emitting diode (9) in order to convert the pulse-width modulation type control signal into a direct current, which is conducted through the light-emitting diode and whose value varies as the pulse-width modulation type control signal varies.

7. The power supply system (101) according to any one of the preceding claims, further comprising: - a charger module (6) arranged to charge the rechargeable power source (2) with energy originating from an external power source (200); - a first sensing circuit (60) arranged for sensing, during use of the power supply system (101), whether the external power source (200) is currently active relative to the charger module (6); - a second sensing circuit (30) arranged to sense whether the load is connected to the power supply system (101) such that the load conducts an output current supplied by the power supply system; as well as - a power supply switch (40) arranged in series between the rechargeable power source (2) and a power supply terminal (VDD) of the microcontroller (1) and connected to the first sensing circuit (60) and the second sensing circuit (30) so as to allow the further power to be passed from the rechargeable power source to the microcontroller only when at least one of the following two conditions is sensed: ● the external power source (200) is currently active with respect to the charger module (6), and ● The load is connected to the power supply system (101).

8. The power supply system (101) according to claim 7, wherein: The first sensing circuit (60) comprises: - a first sensing resistor (61) connected in parallel between the external power supply electrode (200) and ground (GND); and - a first operational amplifier (62) having a non-inverting input terminal and an inverting input terminal connected to both ends of the first sensing resistor (61), and an output terminal connected to the control terminal of the power supply switch (40).

9. The power supply system (101) according to claim 8, further comprising a pull-up resistor (63) connected in series between the external power source (200) and the first sensing resistor (61), in, The enable terminal (CE) of the charger module (6) is configured to input a divided voltage generated by the pull-up resistor (63) and the first sensing resistor (61).

10. The power supply system (101) according to claim 5 and any one of claims 7 to 9, wherein: The second sensing circuit (30) comprises: - a second sensing resistor (31) connected in series with the load; - a second operational amplifier (32) having a non-inverting input terminal and an inverting input terminal connected to both ends of the second sensing resistor (31), and an output terminal connected to the control terminal of the power supply switch (40); and - a bypass circuit (33) connected between the rechargeable power source (2) and the load, the bypass circuit bypassing the DC-DC converter (4) and the MOSFET switch (7).

11. The power supply system (101) according to claim 10, wherein: The bypass circuit includes a backflow prevention diode (33), an anode of the backflow prevention diode is connected to the rechargeable power source (2), and a cathode of the backflow prevention diode is connected to the load, and Wherein, the DC-DC converter (4) is a boost converter.

12. The power supply system (101) according to claim 10 or 11, wherein: The bypass circuit includes a current limiting resistor (34) connected in series between the rechargeable power source (2) and the load.

13. The power supply system (101) according to claim 8 or 9 and any one of claims 10 to 12, further comprising: - a first NOT gate (64), the input terminal of the first NOT gate being connected to the output terminal of the first operational amplifier (62); - a second NOT gate (35), the input terminal of the second NOT gate being connected to the output terminal of the second operational amplifier (32); and - an AND gate (41), the input terminal of which is connected to the respective output terminals of the first NOT gate (64) and the second NOT gate (35), and the output terminal of which is connected to the control terminal (G) of the power supply switch (40), Wherein, the power supply switch (40) is a p-type MOSFET.

14. The power supply system (101) according to claim 8 or 9 and any one of claims 10 to 12, further comprising: - a NOR gate (42), the input terminal of which is connected to the respective output terminals of the first operational amplifier (62) and the second operational amplifier (32), and the output terminal of which is connected to the control terminal (G) of the power supply switch (40), Wherein, the power supply switch (40) is a p-type MOSFET.

15. The power supply system (101) according to any one of the preceding claims, wherein The microcontroller (1) is further connected to receive a detection signal, the detection signal being indicative of the output current supplied to the load.

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