Power supply control circuit of microcontroller and microcontroller

Abstract

The invention discloses a power supply control circuit of a microcontroller and the microcontroller, and the power supply control circuit comprises a low-dropout linear regulator, the first end of the low-dropout linear regulator is connected with a first power supply, and the second end of the low-dropout linear regulator is connected with a second power supply; the microcontroller supports multiple power supply modes, and in each power supply mode, the first power supply and the second power supply are configured with corresponding enabling states and power supply voltages; the clamping circuit is used for outputting a clamped voltage based on the voltage of the first power supply; the diode is in a conduction or cut-off state under different power supply modes; the reference circuit is used for outputting a reference voltage based on the voltage of the second power supply when the diode is switched on; when the diode is turned off, the reference voltage is output based on the clamped voltage. According to the reference circuit, the power supply source and the power supply path of the reference circuit are controlled through the working states of the diodes in the different power supply modes, so that the problem that the power supply path of the reference circuit is coupled and conflicted when the different power supply modes are switched is solved.

Description

Technical Field

[0001] This invention belongs to the field of electronic power technology, specifically relating to a power control circuit for a microcontroller and a microcontroller. Background Technology

[0002] In existing technologies, MCU (Microcontroller Unit) chips are widely used in various consumer electronics products due to their advantages such as small size, high performance, and low power consumption. With advancements in manufacturing processes and increasing application demands, the integration and complexity of modern MCU chips are constantly increasing, while the requirements for power consumption control are becoming increasingly stringent. To adapt to the performance and energy efficiency requirements of different operating scenarios, MCU chips are typically designed to support multiple power domains and operate in different external power supply modes, such as single-supply high-voltage mode, single-supply low-voltage mode, and dual-supply mode, to achieve flexible power management and system optimization. However, the voltage ranges differ significantly between different power supply modes, and when the MCU chip switches between different power supply modes, coupling and conflict issues arise in the power supply path of the reference circuit. Summary of the Invention

[0003] In view of the above problems, embodiments of the present invention are proposed to provide a power control circuit and a microcontroller that overcome or at least partially solve the above problems.

[0004] In a first aspect, embodiments of the present invention provide a power control circuit for a microcontroller, the power control circuit comprising: a low dropout linear regulator, a first terminal connected to a first power supply, and a second terminal connected to a second power supply; the microcontroller supports multiple power modes, and in each power mode, the first power supply and the second power supply are configured with corresponding enable states and supply voltages; Clamping circuit for outputting clamped voltage based on the voltage of the first power supply; A diode is disposed at one end between the second terminal of the low dropout linear regulator and the second power supply; the diode is in the on or off state under different power supply modes. The reference circuit has its input terminals connected to the clamping circuit and the diode, respectively, and is used to output a reference voltage based on the voltage of the second power supply when the diode is turned on, and to output a reference voltage based on the clamped voltage when the diode is turned off.

[0005] Optionally, in the first power supply mode, the first power supply is enabled and the supply voltage is high voltage, while the second power supply is disabled. The output terminal of the reference circuit is connected to the low dropout linear regulator to receive the clamped first power supply and output a reference voltage according to the clamped first power supply. The low-dropout linear regulator receives the first power supply voltage and outputs the voltage after stepping down the first power supply voltage according to the reference voltage.

[0006] Optionally, in the second power supply mode, the first power supply is enabled and the supply voltage is low, and the second power supply is enabled and the supply voltage is low. The low-dropout linear regulator is in an enabled state, the diode is in a conducting state, and the reference circuit outputs a reference voltage based on the second power supply voltage.

[0007] Optionally, in the third power supply mode, the first power supply is enabled and the supply voltage is high, and the second power supply is enabled and the supply voltage is low. The low-dropout linear regulator is in an enabled state, the diode is in a cutoff state, and the reference circuit outputs a reference voltage based on the clamped first power supply voltage.

[0008] Optionally, the clamping circuit includes a first Zener diode, a MOSFET, and a second Zener diode; One end of the first Zener diode is connected to the first power supply and the gate of the MOS transistor, respectively, and the other end is grounded, which is used to clamp the voltage of the first power supply and output it to the gate of the MOS transistor. The drain of the MOS transistor is connected to the first power supply, and the source of the MOS transistor is connected to the second Zener diode. The second Zener diode is used to clamp the source voltage of the MOSFET before outputting it; One end of the reference circuit is located between the source of the MOS transistor and the second Zener diode, and is used to receive the voltage clamped by the second Zener diode.

[0009] Optionally, the clamping circuit further includes a resistor, one end of which is connected to the first power supply, and the other end is connected to the gate of the first Zener diode and the MOS transistor, respectively.

[0010] Optionally, the cathode of the first Zener diode is connected to both the resistor and the first power supply, and the anode of the first Zener diode is grounded.

[0011] Optionally, the cathode of the second Zener diode is connected to the source of the MOS transistor, and the anode of the second Zener diode is grounded.

[0012] Optionally, the anode of the diode is located between the second terminal of the low-dropout linear regulator and the second power supply, and the cathode of the diode is located between the clamping circuit and the reference circuit.

[0013] Secondly, embodiments of the present invention provide a microcontroller including the power control circuit described above.

[0014] In an embodiment of the present invention, the power control circuit includes: a low-dropout linear regulator, with a first terminal connected to a first power supply and a second terminal connected to a second power supply; a microcontroller supporting multiple power modes, wherein in each power mode, the first and second power supplies are configured with corresponding enable states and supply voltages; a clamping circuit for outputting a clamped voltage based on the voltage of the first power supply; a diode, one end of which is located between the second terminal of the low-dropout linear regulator and the second power supply; the diode being in a conducting or cut-off state in different power modes; and a reference circuit, with its input terminals connected to the clamping circuit and the diode respectively, for outputting a reference voltage based on the voltage of the second power supply when the diode is conducting, and outputting a reference voltage based on the clamped voltage when the diode is cut off. The present invention solves the problem of coupling and conflict in the power supply path of the reference circuit when the MCU chip switches between different power modes by controlling the power supply source and power supply path of the reference circuit according to the working state of the diode in different power modes.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the power control circuit of a microcontroller according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the power control circuit of another microcontroller according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a clamping circuit according to an embodiment of the present invention.

[0017] Figure reference numerals: Low dropout linear regulator 10, first power supply 11, second power supply 12, clamping circuit 13, first Zener diode 131, MOSFET 132, second Zener diode 133, resistor 134, clamping output voltage 135, diode 14, reference circuit 15. Detailed Implementation

[0018] Embodiments of the present invention will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] In existing technologies, MCU chips are widely used in various consumer electronics products due to their advantages such as small size, high performance, and low power consumption. With advancements in manufacturing processes and increasing application demands, the integration and complexity of modern MCU chips are constantly increasing, while the requirements for power consumption control are becoming increasingly stringent. To adapt to the performance and energy efficiency requirements of different operating scenarios, MCU chips are typically designed to support multiple power domains and operate in different external power supply modes, such as single-supply high-voltage mode, single-supply low-voltage mode, and dual-supply mode, to achieve flexible power management and system optimization.

[0020] However, the voltage range varies significantly under different power supply modes. When the MCU chip switches between different power supply modes, there are coupling and conflict issues in the power supply path of the reference circuit. For example, in the single-supply high-voltage mode, the low-dropout linear regulator requires a reference voltage. Since the reference circuit that provides the reference voltage is powered by a low-voltage supply, an additional low-voltage power supply is needed to power the reference circuit. In the single-supply low-voltage mode, the low-voltage power supply needs to be used to power the reference circuit through the output of the low-dropout linear regulator. In the single-supply high-voltage mode or dual-supply mode, the path from the output of the low-dropout linear regulator to the reference circuit needs to be shielded.

[0021] One of the core concepts of this invention is that by controlling the power supply source and power supply path of the reference circuit through the working state of the diode in different power supply modes, the problem of coupling and conflict in the power supply path of the reference circuit when the MCU chip switches between different power supply modes is solved.

[0022] Reference Figure 1 The diagram shows a schematic of the power control circuit of a microcontroller according to an embodiment of the present invention. The power control circuit may specifically include the following structure: The low dropout linear regulator 10 has its first terminal connected to the first power supply 11 and its second terminal connected to the second power supply 12. The microcontroller supports multiple power supply modes, and in each power supply mode, the first power supply 11 and the second power supply 12 are configured with corresponding enable states and supply voltages.

[0023] The low-dropout linear regulator 10 is a widely used power management integrated circuit used to stably convert higher input voltages (such as battery voltage or system mains power) to lower output voltages. Its key feature is its ability to operate normally even with a very small input-output voltage difference (i.e., "dropout"). The analog circuitry inside a microcontroller is highly sensitive to power supply noise. For example, noise can cause a decrease in the sampling accuracy of the microcontroller's internal ADC (Analog-to-Digital Converter) and an increase in clock jitter, affecting system stability. The low-dropout linear regulator 10 has a high power supply rejection ratio (PSRR), effectively filtering out noise from the upstream power supply and providing a stable, low-noise voltage to the microcontroller. Furthermore, the low-dropout linear regulator 10 can stably convert higher input voltages to lower output voltages, powering the low-voltage circuitry within the microcontroller.

[0024] The microcontroller supports multiple power modes, which means that the microcontroller can dynamically adjust the power supply strategy of the internal circuit according to different working requirements. In each mode, the system will configure a specific enable state (on or off) and corresponding output voltage value for the first power supply 11 and the second power supply 12, thereby realizing flexible reconfiguration of the power supply architecture.

[0025] Clamping circuit 13 is used to output the clamped voltage based on the voltage of the first power supply 11.

[0026] The input terminal of the clamping circuit 13 is located between the first terminal of the low dropout linear regulator 10 and the first power supply 11. The clamping circuit 13 receives the voltage of the first power supply 11, clamps the voltage to the clamping voltage (VCLAMP) based on the voltage of the first power supply 11, and then outputs the clamping voltage. The clamping voltage refers to the maximum or target voltage level at which the clamping circuit 13 limits the voltage. That is, when the clamping circuit is working normally, when the input voltage exceeds a certain threshold, the circuit starts to "clamp" the voltage so that it no longer rises.

[0027] Diode 14 is located between the second terminal of the low-dropout linear regulator 10 and the second power supply 12; in different power supply modes, diode 14 is in the on or off state.

[0028] One end of diode 14 is located between the second terminal of low-dropout linear regulator 10 and the second power supply 12. When the second power supply 12 is enabled, the voltage at the end of diode 14 located between the second terminal of low-dropout linear regulator 10 and the second power supply 12 is the voltage of the second power supply 12. Diode 14 has unidirectional conductivity, and current can only flow from the anode to the cathode and cannot flow in the reverse direction. In different power supply modes, diode 14 is in the on or off state.

[0029] The reference circuit 15 has its input terminals connected to the clamping circuit 13 and the diode 14, respectively. When the diode 14 is turned on, it outputs a reference voltage based on the voltage of the second power supply 12; when the diode 14 is turned off, it outputs a reference voltage based on the clamped voltage.

[0030] Reference circuit 15 is a circuit capable of providing a high-precision, high-stability DC voltage output. Its output voltage is virtually unaffected by changes in power supply voltage, load current, temperature, and time, providing a stable, accurate, and repeatable reference voltage for the system. The input terminals of reference circuit 15 are connected to clamping circuit 13 and diode 14, respectively. Reference circuit 15 can be powered by the voltage output from clamping circuit 13 or based on the voltage flowing through diode 14 to output a reference voltage.

[0031] When diode 14 is on, reference circuit 15 is powered by the voltage from the second power supply 12 flowing through diode 14 and outputs a reference voltage. When diode 14 is off, reference circuit 15 is powered by the clamping voltage output from clamping circuit 13 and outputs a reference voltage. In different power modes, diode 14 is either on or off. When the microcontroller switches between different power modes, the power source and power path of reference circuit 15 are different depending on the power mode, thus resolving the problem of conflicting power sources and power paths for reference circuit 15.

[0032] In an embodiment of the present invention, the power control circuit includes: a low-dropout linear regulator, with a first terminal connected to a first power supply and a second terminal connected to a second power supply; a microcontroller supporting multiple power modes, wherein in each power mode, the first and second power supplies are configured with corresponding enable states and supply voltages; a clamping circuit for outputting a clamped voltage based on the voltage of the first power supply; a diode, one end of which is located between the second terminal of the low-dropout linear regulator and the second power supply; the diode being in a conducting or cut-off state in different power modes; and a reference circuit, with its input terminals connected to the clamping circuit and the diode respectively, for outputting a reference voltage based on the voltage of the second power supply when the diode is conducting, and outputting a reference voltage based on the clamped voltage when the diode is cut off. The present invention solves the problem of coupling and conflict in the power supply path of the reference circuit when the MCU chip switches between different power modes by controlling the power supply source and power supply path of the reference circuit according to the working state of the diode in different power modes.

[0033] Reference Figure 2 The diagram shows a schematic of the power control circuit of another microcontroller according to an embodiment of the present invention. In the first power mode, the first power supply 11 is enabled and the supply voltage is high voltage, while the second power supply 12 is disabled. The output of the reference circuit 15 is connected to the low dropout linear regulator 10 to receive the voltage of the clamped first power supply 11 and output a reference voltage according to the voltage of the clamped first power supply 11. The low-dropout linear regulator 10 receives the voltage from the first power supply 11 and outputs the voltage after stepping down the voltage of the first power supply 11 according to the reference voltage.

[0034] The first power supply mode is the single-power-voltage high-voltage mode. In this mode, the first power supply 11 is enabled and its supply voltage is high voltage, while the second power supply 12 is disabled. The clamping circuit 13 receives the voltage from the first power supply 11, performs voltage reduction clamping on the high voltage of the first power supply 11, and outputs a clamping voltage. The reference circuit 15 is powered by the clamping voltage output by the clamping circuit 13 and outputs a reference voltage. The output terminal of the reference circuit 15 is connected to the low-dropout linear regulator 10. The reference circuit 15 outputs a reference voltage to the low-dropout linear regulator 10. The low-dropout linear regulator 10 receives the reference voltage sent by the reference circuit 15 and also receives the high voltage of the first power supply 11. Based on the reference voltage sent by the reference circuit 15, the low-dropout linear regulator 10 reduces and stabilizes the high voltage of the first power supply 11, and then outputs the reduced and stabilized voltage through its second terminal to power the low-voltage circuit inside the microprocessor.

[0035] In single-supply high-voltage mode, clamping circuit 13 clamps the high voltage of first power supply 11 to clamping voltage, and the clamping voltage supplies power to reference circuit 15. In this way, there is no need to add a low-voltage power supply to power the reference circuit, thus solving the power supply problem of the reference circuit in single-supply high-voltage mode.

[0036] In this embodiment of the invention, under the second power supply mode, the first power supply 11 is enabled and the supply voltage is low, and the second power supply 12 is enabled and the supply voltage is low. The low-dropout linear regulator 10 is in an disabled state, the diode 14 is in a conducting state, and the reference circuit 15 outputs a reference voltage based on the voltage of the second power supply 12.

[0037] The second power supply mode is the single-supply low-voltage mode. In this mode, the first power supply 11 and the second power supply 12 are both low-voltage power supplies, and they are at the same potential. The microcontroller controls the low-dropout linear regulator 10 to be in an disabled state via an enable signal, meaning the low-dropout linear regulator 10 is not in operation. Since the first power supply 11 is a low-voltage power supply, the voltage drop after being stepped down by the clamping circuit 13 does not meet the operating power supply voltage requirements of the reference circuit 15. The diode 14 is in a forward conducting state, providing a path for the voltage of the second power supply 12 to the reference circuit 15. The reference circuit 15 is then powered by the second power supply 12, thus solving the power supply problem of the reference circuit 15 in the single-supply low-voltage mode.

[0038] In single-supply low-voltage mode, the low-dropout linear regulator 10 is in a non-operating state, and the diode 14 is in a forward-conducting state, providing a path for the voltage of the second power supply 12 to the reference circuit 15. The reference circuit 15 is powered by the second power supply 12, generates a reference voltage, and provides a reference voltage for other circuits inside the microcontroller, such as the ADC circuit.

[0039] In this embodiment of the invention, under the third power supply mode, the first power supply 11 is enabled and the supply voltage is high voltage, and the second power supply 12 is enabled and the supply voltage is low voltage. The low-dropout linear regulator 10 is in an enabled state, the diode 14 is in a cutoff state, and the reference circuit 15 outputs a reference voltage based on the voltage of the clamped first power supply 11.

[0040] The third power supply mode is the dual power supply mode. In the dual power supply mode, the first power supply 11 is a high-voltage power supply and the second power supply 12 is a low-voltage power supply. The microcontroller controls the low-dropout linear regulator 10 to be in an disabled state through the enable signal, that is, the low-dropout linear regulator 10 is in a non-working state, the diode 14 is in a cut-off state, and the reference circuit 15 is powered by the clamping voltage output after the high voltage of the first power supply 11 is stepped down by the clamping circuit 13. This solves the power supply problem of the reference circuit 15 in the dual power supply mode. In addition, the diode 14 in the cut-off state can shield the path of the low voltage of the second power supply 12 to the reference circuit 15, and prevent the low voltage of the second power supply 12 from affecting the reference circuit 15.

[0041] In dual power supply mode, the low dropout linear regulator 10 is in a non-operating state. The reference circuit 15 is powered by the clamping voltage output by the clamping circuit 13 after the high voltage of the first power supply 11 is stepped down, generating a reference voltage and providing a reference voltage for other circuits inside the microcontroller, such as the ADC circuit.

[0042] In this embodiment of the invention, the anode of diode 14 is located between the second terminal of low dropout linear regulator 10 and the second power supply 12, and the cathode of diode 14 is located between clamping circuit 13 and reference circuit 15.

[0043] Diode 14 has unidirectional conductivity; current can only flow from the anode to the cathode and cannot flow in the reverse direction. When the anode voltage is greater than the cathode voltage and the difference is greater than or equal to the forward voltage, diode 14 conducts and current flows through it. When the anode voltage is less than the cathode voltage, diode 14 is cut off and the current is extremely small, almost zero.

[0044] The anode of diode 14 is located between the second terminal of the low-dropout linear regulator 10 and the second power supply 12, and the cathode of diode 14 is located between the clamping circuit 13 and the reference circuit 15. In the single-supply high-voltage mode, the first power supply 11 is a high-voltage power supply and the second power supply 12 is not enabled. The cathode voltage of diode 14 is the clamping voltage output by the clamping circuit 13. The cathode voltage of diode 14 is greater than the anode voltage of diode 14, so diode 14 is cut off, thereby shielding the path of the output voltage output from the second terminal of the low-dropout linear regulator 10 to the reference circuit 15, and preventing the output voltage of the low-dropout linear regulator 10 from affecting the reference circuit 15.

[0045] Utilizing the unidirectional conductivity of diode 14, in single-supply high-voltage mode, diode 14 is cut off, thereby shielding the path from the output voltage of low-dropout linear regulator 10 to reference circuit 15, preventing the output voltage of low-dropout linear regulator 10 from affecting reference circuit 15; in single-supply low-voltage mode, diode 14 is turned on, thereby providing a path from the voltage of second power supply 12 to reference circuit 15, solving the power supply problem of reference circuit 15 in single-supply low-voltage mode; in dual-supply mode, diode 14 is cut off, and the high voltage of first power supply 11 is stepped down by clamping circuit 13 to power reference circuit 15, while shielding the path from the low voltage of second power supply 12 to reference circuit 15, preventing the low voltage of second power supply 12 from affecting reference circuit.

[0046] Reference Figure 3 The diagram shows a structural schematic of a clamping circuit according to an embodiment of the present invention. The clamping circuit 13 includes a first Zener diode 131, a MOSFET 132, and a second Zener diode 133. One end of the first Zener diode 131 is connected to the gate of the first power supply 11 and the MOSFET 132 respectively, and the other end is grounded, which is used to clamp the voltage of the first power supply 11 and output it to the gate of the MOSFET 132. The drain of MOSFET 132 is connected to the first power supply 11, and the source of MOSFET 132 is connected to the second Zener diode 133. The second Zener diode 133 is used to clamp the source voltage of the MOSFET 132 before outputting it; One end of the reference circuit 15 is located between the source of the MOSFET 132 and the second Zener diode 133, and is used to receive the voltage after the second Zener diode 133 clamps.

[0047] A Zener diode is a specially designed diode that primarily operates in the reverse breakdown region. Unlike ordinary diodes, it allows for controlled reverse breakdown when the reverse voltage reaches a specific value (i.e., the Zener voltage). The reverse voltage is the voltage applied to the diode that lowers the anode potential than the cathode potential. In the reverse breakdown region, even if the reverse current varies over a wide range, the voltage across its terminals remains almost constant, thus achieving a stable voltage output. Zener diodes are suitable for power supply regulation, overvoltage protection, and voltage clamping circuits.

[0048] One end of the first Zener diode 131 is connected to both the first power supply 11 and the gate of the MOSFET 132, while the other end is grounded. This diode clamps the voltage from the first power supply 11 and outputs it to the gate of the MOSFET 132, meaning the gate voltage of the MOSFET 132 is the clamping voltage of the first Zener diode 131. For example, the first Zener diode 131 clamps the voltage of the first power supply 11 to approximately 5.8V, preventing the gate voltage of the MOSFET 132 from exceeding its breakdown voltage and thus damaging the MOSFET 132.

[0049] The drain of MOSFET 132 is connected to the first power supply 11, and the source of MOSFET 132 is connected to the second Zener diode 133. The second Zener diode 133 is used to clamp the source voltage of MOSFET 132 and output it. The output voltage of the clamping circuit 13 is the clamping output voltage 135, which is the voltage output through the node between the source of MOSFET 132 and the second Zener diode 133. When the clamping output voltage 135 is higher than the clamping voltage of the first Zener diode 131 minus the gate-source voltage of MOSFET 132, MOSFET 132 is turned off. The clamping circuit 13 is not working; when the clamping output voltage 135 is lower than the clamping voltage of the first Zener diode 131 minus the gate-source voltage of the MOSFET 132, the MOSFET 132 is turned on and generates the clamping output voltage 135. At this time, the clamping output voltage 135 is equal to the clamping voltage of the first Zener diode 131 minus the gate-source voltage of the MOSFET 132. At the same time, the second Zener diode 133 also limits the maximum voltage of the clamping output voltage 135, so as to prevent the clamping output voltage 135 supplying power to the reference circuit 15 from exceeding the power supply limit that the reference circuit 15 can withstand.

[0050] In this embodiment of the invention, the clamping circuit 13 further includes a resistor 134, one end of which is connected to the first power supply 11, and the other end is connected to the gate of the first Zener diode 131 and the gate of the MOS transistor 132, respectively.

[0051] Resistor 134 is connected in series with the first Zener diode 131. One end of resistor 134 is connected to the first power supply 11, and the other end is connected to the gate of the first Zener diode 131 and the gate of the MOSFET 132. Resistor 134 is a current-limiting resistor, whose main function is to limit the current flowing through the first Zener diode 131 and prevent the first Zener diode 131 from burning out due to overheating. Since the first Zener diode 131 is working in the reverse breakdown region, the voltage across it is basically stable at the nominal Zener voltage, but the current flowing through it can vary greatly. If there is no external limit, when the input voltage is higher than the Zener voltage, the first Zener diode 131 will conduct. Due to the semiconductor characteristics, once it breaks down, the internal resistance becomes very small. If there is no resistor to limit the current, the current will rise sharply, the power consumption will increase rapidly, and the diode will overheat and burn out.

[0052] By using resistor 134 connected in series with the first Zener diode 131, excess voltage can be absorbed and the current can be limited, ensuring that the first Zener diode 131 operates within a safe range and avoiding damage due to overcurrent.

[0053] In this embodiment of the invention, the cathode of the first Zener diode 131 is connected to the resistor 134 and the first power supply 11, respectively, and the anode of the first Zener diode 131 is grounded.

[0054] The cathode of the first Zener diode 131 is connected to both the resistor 134 and the first power supply 11, while the anode of the first Zener diode 131 is grounded. In single-supply high-voltage mode, the first power supply 11 is a high-voltage power supply, and the cathode potential of the first Zener diode 131 is lower than the anode potential. The first Zener diode 131 operates in the reverse breakdown region, clamping the first power supply 11 and outputting it to the gate of the MOSFET 132. That is, the gate voltage of the MOSFET 132 is the clamping voltage of the first Zener diode 131, causing the MOSFET 132 to conduct. The first Zener diode 131 operates in the reverse breakdown region, thus clamping the first power supply 11 and outputting it to the gate of the MOSFET 132, preventing the gate voltage of the MOSFET 132 from exceeding the limit. To address the issue of breakdown voltage damaging the MOSFET 132, the second Zener diode 133 clamps the source voltage of the MOSFET 132. The clamped output voltage 135, i.e., the voltage output by the clamping circuit 13, is generated through the node between the source of the MOSFET 132 and the second Zener diode 133, and powers the reference circuit 15. In this way, it is not necessary to add an additional low-voltage power supply to power the reference circuit, thus solving the power supply problem of the reference circuit in the single-supply high-voltage mode. Furthermore, the diode 14 is in the off state, shielding the path from the output voltage of the low-dropout linear regulator 10 to the reference circuit 15, thereby avoiding the influence of the output voltage of the low-dropout linear regulator 10 on the reference circuit 15.

[0055] In single-supply low-voltage mode, both the first power supply 11 and the second power supply 12 are low-voltage power supplies. The clamping circuit 13 requires a voltage drop, which is the gate-source voltage of the MOSFET 132. The gate-source voltage of the MOSFET 132 needs to be greater than the threshold voltage to conduct. The low voltage from the first power supply 11, after being stepped down by the clamping circuit 13, does not meet the operating power supply voltage requirements of the reference circuit 15. Since the clamping output voltage 135 is lower than the voltage of the second power supply 12 minus the voltage drop of the diode 14, for example, the MOSFET... The gate-source voltage of transistor 132 needs to be greater than the threshold voltage to conduct. In other words, the clamping circuit 13 needs to consume a voltage drop. If the gate-source voltage drop of MOSFET 132 is 1.2V, then 5V minus 1.2V equals 3.8V. 3.8V is less than the voltage of the second power supply 12 (5V) minus the voltage drop of diode 14 (0.7V). At this time, diode 14 is forward conducting, providing a path for the voltage of the second power supply 12 to the reference circuit 15, thereby solving the power supply problem of the reference circuit 15 in the single power supply low voltage mode.

[0056] In dual-power supply mode, the first power supply 11 is a high-voltage power supply and the second power supply 12 is a low-voltage power supply. The clamping output voltage 135 is higher than the voltage of the second power supply 12 minus the voltage drop of the diode 14. At this time, the diode 14 is cut off. The clamping circuit 13 clamps the high voltage of the first power supply 11 and outputs the clamping output voltage 135. The clamping output voltage 135 supplies power to the reference circuit 15. At the same time, since the diode 14 is cut off, the path from the voltage of the second power supply 12 to the reference circuit 15 is blocked, thereby avoiding the voltage of the second power supply 12 from affecting the reference circuit 15.

[0057] In this embodiment of the invention, the cathode of the second Zener diode 133 is connected to the source of the MOS transistor 132, and the anode of the second Zener diode 133 is grounded.

[0058] The cathode of the second Zener diode 133 is connected to the source of the MOSFET 132, and the anode of the second Zener diode 133 is grounded. When the second Zener diode 133 operates in the reverse breakdown region, it clamps the source voltage of the MOSFET 132, limiting the maximum voltage of the clamped output voltage 135 and preventing the clamped output voltage 135 supplying power to the reference circuit 15 from exceeding the power supply limit that the reference circuit 15 can withstand.

[0059] In single-supply high-voltage mode, the first power supply 11 is a high-voltage power supply. The cathode potential of the first Zener diode 131 is lower than the anode potential. The first Zener diode 131 operates in the reverse breakdown region, clamping the first power supply 11 and outputting it to the gate of the MOSFET 132. That is, the gate voltage of the MOSFET 132 is the clamping voltage of the first Zener diode 131. The MOSFET 132 is turned on, and the first Zener diode 131 operates in the reverse breakdown region. This clamps the first power supply 11 and outputs it to the gate of the MOSFET 132, preventing the gate voltage of the MOSFET 132 from exceeding the breakdown voltage and causing damage to the MOSFET 132. Zener diode 133 can clamp the source voltage of MOSFET 132. The clamp output voltage 135, which is the voltage output by clamping circuit 13, is output through the node between the source of MOSFET 132 and the second Zener diode 133. This clamp output voltage is used to power reference circuit 15. In this way, there is no need to add a separate low-voltage power supply to power the reference circuit, which solves the power supply problem of the reference circuit in single-supply high-voltage mode. In addition, diode 14 is in the cut-off state, which shields the path from the output voltage of low-dropout linear regulator 10 to reference circuit 15, thereby avoiding the influence of the output voltage of low-dropout linear regulator 10 on reference circuit 15.

[0060] In the single-supply low-voltage mode, the first power supply 11 is a low-voltage power supply, the second power supply 12 is a low-voltage power supply, and the clamping circuit 13 requires a voltage drop, which is the gate-source voltage of the MOSFET 132. The gate-source voltage of the MOSFET 132 needs to be greater than the threshold voltage to conduct. The low voltage of the first power supply 11, after being stepped down by the clamping circuit 13, does not meet the operating power supply voltage requirements of the reference circuit 15. Since the clamping output voltage 135 is lower than the voltage of the second power supply 12 minus the voltage drop of the diode 14, the diode 14 is forward-biased and provides a path for the voltage of the second power supply 12 to the reference circuit 15, thereby solving the power supply problem of the reference circuit 15 in the single-supply low-voltage mode.

[0061] In dual-power supply mode, the first power supply 11 is a high-voltage power supply and the second power supply 12 is a low-voltage power supply. The clamping output voltage 135 is higher than the voltage of the second power supply 12 minus the voltage drop of the diode 14. At this time, the diode 14 is cut off. The clamping circuit 13 clamps the high voltage of the first power supply 11 and outputs the clamping output voltage 135. The clamping output voltage 135 supplies power to the reference circuit 15. At the same time, since the diode 14 is cut off, the path from the voltage of the second power supply 12 to the reference circuit 15 is blocked, thereby avoiding the voltage of the second power supply 12 from affecting the reference circuit 15.

[0062] The embodiments of the present invention utilize the unidirectional conductivity of diode 14 and the clamping characteristics of MOSFET 132, first Zener diode 131, and second Zener diode 133 to avoid problems arising when switching between three power modes and meet the needs of different application scenarios.

[0063] In an embodiment of the present invention, the power control circuit includes: a low-dropout linear regulator, with a first terminal connected to a first power supply and a second terminal connected to a second power supply; a microcontroller supporting multiple power modes, wherein in each power mode, the first and second power supplies are configured with corresponding enable states and supply voltages; a clamping circuit for outputting a clamped voltage based on the voltage of the first power supply; a diode, one end of which is located between the second terminal of the low-dropout linear regulator and the second power supply; the diode being in a conducting or cut-off state in different power modes; and a reference circuit, with its input terminals connected to the clamping circuit and the diode respectively, for outputting a reference voltage based on the voltage of the second power supply when the diode is conducting, and outputting a reference voltage based on the clamped voltage when the diode is cut off. The present invention solves the problem of coupling and conflict in the power supply path of the reference circuit when the MCU chip switches between different power modes by controlling the power supply source and power supply path of the reference circuit according to the working state of the diode in different power modes.

[0064] Embodiments of the present invention also provide a microcontroller including the power control circuit described above.

[0065] In an embodiment of the present invention, the power control circuit includes: a low-dropout linear regulator, with a first terminal connected to a first power supply and a second terminal connected to a second power supply; a microcontroller supporting multiple power modes, wherein in each power mode, the first and second power supplies are configured with corresponding enable states and supply voltages; a clamping circuit for outputting a clamped voltage based on the voltage of the first power supply; a diode, one end of which is located between the second terminal of the low-dropout linear regulator and the second power supply; the diode being in a conducting or cut-off state in different power modes; and a reference circuit, with its input terminals connected to the clamping circuit and the diode respectively, for outputting a reference voltage based on the voltage of the second power supply when the diode is conducting, and outputting a reference voltage based on the clamped voltage when the diode is cut off. The present invention solves the problem of coupling and conflict in the power supply path of the reference circuit when the MCU chip switches between different power modes by controlling the power supply source and power supply path of the reference circuit according to the working state of the diode in different power modes.

[0066] The terms "first" and "second" in the specification and claims of this invention may explicitly or implicitly include one or more of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0067] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0068] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A power control circuit for a microcontroller, characterized by The power supply control circuit comprises: a low dropout linear regulator, a first end of which is connected to a first power supply, and a second end of which is connected to a second power supply; the microcontroller supports multiple power supply modes, and in each power supply mode, the first power supply and the second power supply are configured with corresponding enable states and supply voltages; a clamping circuit, configured to output a clamped voltage based on a voltage of the first power supply; a diode, one end of which is arranged between the second end of the low dropout linear regulator and the second power supply; in different power supply modes, the diode is in a conducting state or a non-conducting state; a reference circuit, input ends of which are connected to the clamping circuit and the diode respectively, configured to output a reference voltage based on a voltage of the second power supply when the diode is in the conducting state, and output the reference voltage based on the clamped voltage when the diode is in the non-conducting state.

2. The power control circuit of claim 1, wherein, In a first power supply mode, the first power supply is in an enabled state and has a high supply voltage, and the second power supply is in a disabled state. An output end of the reference circuit is connected to the low dropout linear regulator, configured to receive the clamped voltage of the first power supply, and output the reference voltage according to the clamped voltage of the first power supply. The low dropout linear regulator receives the voltage of the first power supply, and outputs the voltage of the first power supply after being stepped down according to the reference voltage.

3. The power control circuit of claim 1, wherein In a second power supply mode, the first power supply is in the enabled state and has a low supply voltage, and the second power supply is in the enabled state and has a low supply voltage. The low dropout linear regulator is in the disabled state, the diode is in the conducting state, and the reference circuit outputs the reference voltage based on the voltage of the second power supply.

4. The power control circuit of claim 1, wherein In a third power supply mode, the first power supply is in the enabled state and has the high supply voltage, and the second power supply is in the enabled state and has the low supply voltage. The low dropout linear regulator is in the disabled state, the diode is in the non-conducting state, and the reference circuit outputs the reference voltage based on the clamped voltage of the first power supply.

5. The power control circuit of claims 1-4, wherein, The clamping circuit comprises a first Zener diode, a MOS tube and a second Zener diode. One end of the first Zener diode is connected to the first power supply and a gate of the MOS tube respectively, and the other end of the first Zener diode is grounded, configured to output the voltage of the first power supply after being clamped to the gate of the MOS tube. A drain of the MOS tube is connected to the first power supply, and a source of the MOS tube is connected to the second Zener diode. The second Zener diode is configured to output a voltage of the source of the MOS tube after being clamped. One end of the reference circuit is arranged between the source of the MOS tube and the second Zener diode, configured to receive the voltage of the second Zener diode after being clamped.

6. The power control circuit of claim 5, wherein, The clamping circuit further comprises a resistor, one end of the resistor is connected to the first power supply, and the other end of the resistor is connected to the first Zener diode and the gate of the MOS tube respectively.

7. The power control circuit of claim 6, wherein, A cathode of the first Zener diode is connected to the resistor and the first power supply respectively, and an anode of the first Zener diode is grounded.

8. The power control circuit of claim 5, wherein, A cathode of the second Zener diode is connected to the source of the MOS tube, and an anode of the second Zener diode is grounded.

9. The power control circuit of claim 1, wherein, An anode of the diode is arranged between a second end of the low-dropout linear regulator and the second power supply, and a cathode of the diode is arranged between the clamping circuit and the reference circuit.

10. A microcontroller, characterized by The power supply control circuit according to any one of claims 1 to 9.

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