Power management circuit

Abstract

The invention provides a power management circuit. According to the power supply management circuit provided by the invention, on one hand, the power supply inlet protection circuit is arranged between the external voltage source and the power equipment, so that the equipment can be protected from being damaged by overvoltage and overcurrent in the circuit; secondly, a buck-boost circuit and a step-down circuit are arranged between the power supply inlet protection circuit and the controller, so that the controller can be ensured to obtain stable power supply under various external voltage source conditions; and on the third aspect, by arranging the bus voltage sensing circuit, the controller can control the control circuit based on the bus voltage sensed by the bus voltage sensing circuit, on one hand, the power equipment can be protected from being influenced by voltage fluctuation of an external voltage source; the equipment fault or damage risk caused by unstable voltage of the external voltage source is avoided, and the reliability and stability of the whole system can be improved; and on the other hand, the external voltage source can be protected from being influenced by the power equipment.

Description

Technical Field

[0001] The present application relates to the field of electronic and electrical technology, and in particular to a power management circuit. Background Art

[0002] In modern electronic devices and power systems, power management is a crucial link. As the functions of electronic devices become more diverse and complex, the requirements for power supply are getting higher and higher. These devices not only require stable voltage and current supply, but also require the power management system to be able to cope with various abnormal situations (such as overvoltage, overcurrent and voltage fluctuations).

[0003] Traditional power management technologies are unable to cope with complex power quality requirements and diverse working environments, and are no longer able to meet the needs of modern applications. Therefore, in order to adapt to the growing demand, new power management solutions must be proposed to provide higher stability and reliability. Summary of the invention

[0004] In view of this, the present application provides a power management circuit to achieve multi-level protection and stable power supply for power management, thereby improving reliability and stability.

[0005] Specifically, the present application is implemented through the following technical solutions: The present application provides a power management circuit, which includes a power inlet protection circuit, a bus voltage sensing circuit, a control circuit, a buck-boost circuit, a buck circuit and a controller; wherein: The input end of the power inlet protection circuit is connected to an external voltage source, and the output end of the power inlet protection circuit is respectively connected to the input end of the bus voltage sensing circuit, the input end of the control circuit, and the input end of the buck-boost circuit; The output end of the bus voltage sensing circuit is connected to the controller; the bus voltage sensing circuit is used to sense the bus voltage of the power inlet protection circuit and feed back the sensed bus voltage to the controller; The control end of the control circuit is connected to the controller, and the output end of the control circuit is connected to the power device; the control circuit is used to be turned on or off under the control of the controller, so as to supply power to the power device when turned on; The output end of the buck-boost circuit is connected to the input end of the buck circuit; wherein the buck-boost circuit is used to convert the first voltage signal output by the power inlet protection circuit into a stable second voltage signal output; The output end of the step-down circuit is connected to the power supply end of the controller; the step-down circuit is used to convert the second voltage signal into a third voltage signal suitable for the operation of the controller; The controller is used to initially set the internal state machine to an idle state, and to switch the state machine to a working state when the bus voltage is within a preset range, and to switch the state machine to a protection state when the bus voltage is not within the preset range; wherein the controller controls the control circuit to be disconnected when the state machine is in the idle state and the protection state, and controls the control circuit to be turned on when the state machine is in the working state.

[0006] The power management circuit provided in this embodiment can realize multi-level protection and stable power supply of power management, and improve reliability and stability. Specifically, on the one hand, by setting a power input protection circuit between the external voltage source and the power device, it is possible to protect the circuit from damage to the device by overvoltage and overcurrent, and improve the reliability and stability of the device; on the second hand, by setting a buck-boost circuit and a buck circuit between the power input protection circuit and the controller, it is possible to ensure that the controller can obtain stable power supply under various external voltage source conditions; on the third hand, by setting a bus voltage sensing circuit, the controller can control the control circuit based on the bus voltage sensed by the bus voltage sensing circuit. On the one hand, it can protect the power device from the influence of voltage fluctuations of the external voltage source, avoid the risk of equipment failure or damage caused by the unstable voltage of the external voltage source, and improve the reliability and stability of the entire system; on the other hand, it can also protect the external voltage source from the influence of the power device.

[0007] Furthermore, the voltage management circuit provided in the present application, on the first hand, when entering the protection state to protect functional equipment, limits or stops normal operation, and by setting a reset signal, can automatically restore the state machine to the idle state after the fault or abnormal situation is resolved, so that the device can quickly resume normal operation; on the second hand, after switching to the protection state, it will only switch back to the idle state after the reset signal is manually triggered, which can ensure that it switches back to the idle state after the fault is eliminated, avoiding switching back to the idle state before the fault is eliminated, and avoiding the state machine entering an infinite loop.

[0008] Furthermore, the power management circuit provided in the present application can stably supply power to multiple control devices by setting multiple target step-down circuits, thereby ensuring stable operation of each control device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of a first embodiment of a power management circuit provided in the present application; Figure 2 A schematic diagram of a power management circuit shown as an exemplary embodiment of the present application; Figure 3 A circuit diagram of a buck-boost circuit according to an exemplary embodiment of the present application; Figure 4 A schematic diagram of a power input circuit shown as an exemplary embodiment of the present application; Figure 5 A schematic diagram of a power management circuit is shown in another exemplary embodiment of the present application.

[0010] Description of reference numerals: 1: Power inlet protection circuit; 2: Bus voltage sensing circuit; 3: Control circuit; 4: Buck-boost circuit; 5: Buck circuit; 6: Controller; 7: Target step-down circuit; 11: Overcurrent protection circuit; 12: Surge protection circuit; 13: Anti-reverse connection circuit; 14: Filter circuit; 41: control chip; 42: Switching tube circuit; 43: Feedback circuit; L1: first inductor; T1: first transient suppression diode; T2: second transient suppression diode; T3: The third transient suppression diode; M1: transistor; D1: voltage zener diode; R3: the third resistor; R4: the fourth resistor; C1: first capacitor; C2: second capacitor; C3: the third capacitor; C4: fourth capacitor; L2: common mode inductor; R1: first resistor; R2: Second resistor M2: MOS tube; C5: The fifth capacitor. DETAILED DESCRIPTION

[0011] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0012] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0013] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0014] Specific embodiments are given below to introduce the technical solution of the present application in detail.

[0015] Figure 1 This is a schematic diagram of the first embodiment of the power management circuit provided by this application. Please refer to Figure 1 The power management circuit provided in this embodiment includes a power inlet protection circuit 1, a bus voltage sensing circuit 2, a control circuit 3, a step-up / step-down circuit 4, a step-down circuit 5 and a controller 6; wherein, The input end of the power inlet protection circuit 1 is connected to an external voltage source, and the output end of the power inlet protection circuit 1 is respectively connected to the input end of the bus voltage sensing circuit 2, the input end of the control circuit 3, and the input end of the buck-boost circuit 4; The output end of the bus voltage sensing circuit 2 is connected to the controller 6; the bus voltage sensing circuit 2 is used to sense the bus voltage of the power inlet protection circuit 1 and feed back the sensed bus voltage to the controller 6; The control end of the control circuit 3 is connected to the controller 6, and the output end of the control circuit 3 is connected to the power device; the control circuit 3 is used to be turned on or off under the control of the controller 6, so as to supply power to the power device when turned on; The output end of the buck-boost circuit 4 is connected to the input end of the buck circuit 5; wherein the buck-boost circuit 4 is used to convert the first voltage signal output by the power inlet protection circuit 1 into a stable second voltage signal output; The output end of the step-down circuit 5 is connected to the power supply end of the controller 6; the step-down circuit 5 is used to convert the second voltage signal into a third voltage signal suitable for the operation of the controller 6; The controller 6 is used to initially set the internal state machine to an idle state, and to switch the state machine to a working state when the bus voltage is within a preset range, and to switch the state machine to a protection state when the bus voltage is not within the preset range; wherein the controller 6 controls the control circuit 3 to be disconnected when the state machine is in the idle state and the protection state, and controls the control circuit 3 to be turned on when the state machine is in the working state.

[0016] Specifically, the power inlet protection circuit 1 is used to protect the subsequent circuit from power surges, voltage polarity reversal, and power noise interference, ensuring the safe and stable operation of the circuit. It should be noted that the subsequent circuit refers to the bus voltage sensing circuit 2, the control circuit 3, the buck-boost circuit 4, and the buck circuit 5.

[0017] For details, please continue to refer to Figure 1 The control circuit 3 is arranged between the power inlet protection circuit 1 and the power device, and the control end of the control circuit 3 is connected to the controller 6, which is controlled by the controller 6, that is, the controller 6 controls the on and off of the control circuit 3. Further, when the control circuit 3 is turned on, the power device is powered.

[0018] For further information, please refer to Figure 1 , the controller 6 is connected to the output end of the bus voltage sensing circuit 2 and the control end of the control circuit 3 respectively. The control logic inside the controller 6 is briefly introduced as follows: For details, please continue to refer to Figure 1 The bus voltage sensing circuit 2 is arranged between the power inlet protection circuit 1 and the controller 6, and is used to sense the bus voltage of the power inlet protection circuit 1, and feed back the sensed bus voltage to the controller 6. The controller 6 controls the on and off of the control circuit 3 according to the sensed bus voltage.

[0019] The specific principle of the controller 6 controlling the control circuit 3 is briefly introduced below: Specifically, a state machine is provided inside the controller 6, and the state machine has three states, namely, an idle state, a working state and a protection state. Furthermore, the control of the control circuit 3 by the controller 6 is different depending on the state of the state machine. Specifically, when the state machine is in the idle state and the protection state, the controller 6 controls the control circuit 3 to be disconnected. At this time, the control circuit 3 is disconnected, and the connection between the external voltage source and the power device is cut off; further, when the state machine is in the working state, the controller 6 controls the control circuit 3 to be turned on. At this time, the control circuit 3 is turned on, and the external voltage source supplies power to the power device through the power input protection circuit 1.

[0020] Furthermore, the state of the state machine is controlled by the bus voltage sensed by the bus voltage sensing circuit 2. Specifically, initially, the controller 6 sets the state of the state machine to an idle state. Furthermore, the controller 6 monitors the bus voltage in real time, and switches the state machine to a working state when the bus voltage is within a preset range, and switches the state machine to a protection state when the bus voltage is not within a preset range.

[0021] It should be noted that the preset range is set according to the operating voltage range of the power device, which is equal to the operating voltage range of the power device. For example, in one embodiment, the preset range is 24V to 26V.

[0022] In this embodiment, by providing a power inlet protection circuit 1 between an external voltage source and a power device, it is possible to protect the device from damage caused by overvoltage and overcurrent in the circuit, improve the reliability and stability of the device, and extend the service life of the device.

[0023] Furthermore, by setting up a bus voltage sensing circuit 2, the controller 6 can control the control circuit 3 based on the bus voltage sensed by the bus voltage sensing circuit 2. On the one hand, it can protect the power equipment from the influence of voltage fluctuations of the external voltage source, avoid the risk of equipment failure or damage caused by the unstable voltage of the external voltage source, and improve the reliability and stability of the entire system; on the other hand, it can also protect the external voltage source from the influence of the power equipment.

[0024] For further information, please refer to Figure 1 The power management circuit provided in this embodiment also includes a step-up / step-down circuit 4 and a step-down circuit 5.

[0025] Specifically, the buck-boost circuit 4 is disposed between the power inlet protection circuit 1 and the buck circuit 5 , and is used to convert a first voltage signal output by the power inlet protection circuit 1 into a stable second voltage signal.

[0026] Specifically, the buck-boost circuit 4 (Buck-Boost Converter) is a DC-DC converter, which can convert an input first voltage signal into a stable second voltage signal.

[0027] Specifically, when the external voltage source is unstable, fluctuates, or is abnormal, the buck-boost circuit 4 can convert the first voltage signal output by the power inlet protection circuit 1 into a stable second voltage signal output.

[0028] It should be noted that the specific voltage value of the second voltage signal is set according to actual needs and is not limited in this embodiment. For example, in a possible implementation, the voltage value of the second voltage signal is 24V.

[0029] Specifically, the buck-boost circuit 4 dynamically adjusts the output second voltage signal according to the input first voltage signal and the output requirement. If the voltage of the input first voltage signal is lower than the required voltage, the boost circuit 4 increases it; if the voltage of the input first voltage signal is higher than the required voltage, the buck-boost circuit 4 decreases it. In specific implementation, the buck-boost circuit 4 can achieve voltage conversion by adjusting the duty cycle of the switch.

[0030] For example, in one possible implementation, the external voltage source is a 48V voltage signal, the first voltage signal output by the power inlet protection circuit 1 is also 48V, and the buck-boost circuit 4 converts the 48V first voltage signal into a stable 24V second voltage signal output by stepping down the voltage; for another example, in a possible implementation, the external voltage source is a 12V voltage signal, the first voltage signal output by the power inlet protection circuit 1 is also 12V, and the buck-boost circuit 4 converts the 12V first voltage signal into a stable 24V second voltage signal output by stepping up the voltage.

[0031] For details, please continue to refer to Figure 1 The step-down circuit 5 is arranged between the step-up / step-down circuit 4 and the controller 6, and is used to convert the second voltage signal output by the step-up / step-down circuit 4 into a third voltage signal suitable for the operation of the controller 6 to power the controller 6.

[0032] The working voltage of the controller 6 is generally weak, and the second voltage signal output by the step-up / step-down circuit 4 needs to be stepped down to obtain a third voltage signal that can adapt to the controller 6. For example, in one embodiment, the working voltage of the controller 6 is 3.3V.

[0033] For example, in a possible implementation, the second voltage signal output by the buck-boost circuit 4 is greater than the voltage signal required for the operation of the controller 6, and the buck circuit 5 can reduce the second voltage signal to a third voltage signal suitable for the operation of the controller 6. In combination with the above example, at this time, the buck circuit 5 can convert the 24V second voltage signal into a 3.3V third voltage signal to power the controller 6.

[0034] The power management circuit provided in this embodiment can ensure that the controller 6 can obtain stable power supply under various external voltage source conditions by setting a buck-boost circuit 4 and a buck circuit 5 between the power inlet protection circuit 1 and the controller 6, thereby ensuring the stable operation and reliability of the system.

[0035] Specifically, when the external voltage source fluctuates violently or is unstable, the combination of the boost / boost circuit 4 and the step-down circuit 5 can effectively alleviate the impact of voltage changes, ensuring that no matter how the external voltage changes, the controller 6 can always obtain a stable voltage and can work stably.

[0036] Further, referring to the previous description, when the controller 6 is working stably, the controller 6 can detect the bus voltage signal in real time to determine whether it is within the preset range. When the bus voltage is within the preset range, the state machine of the controller 6 switches to the working state; when the bus voltage is not within the preset range, the state machine of the controller 6 switches to the protection state, and controls the switch in the control circuit 3 to disconnect, thereby ensuring the safety of the circuit operation.

[0037] The power management circuit provided in this embodiment can realize multi-level protection and stable power supply of power management, and improve reliability and stability. Specifically, on the one hand, by setting a power input protection circuit between the external voltage source and the power device, it is possible to protect the circuit from damage to the device by overvoltage and overcurrent, and improve the reliability and stability of the device; on the second hand, by setting a buck-boost circuit and a buck circuit between the power input protection circuit and the controller, it is possible to ensure that the controller can obtain stable power supply under various external voltage source conditions; on the third hand, by setting a bus voltage sensing circuit, the controller can control the control circuit based on the bus voltage sensed by the bus voltage sensing circuit. On the one hand, it can protect the power device from the influence of voltage fluctuations of the external voltage source, avoid the risk of equipment failure or damage caused by the unstable voltage of the external voltage source, and improve the reliability and stability of the entire system; on the other hand, it can also protect the external voltage source from the influence of the power device.

[0038] Optionally, the controller 6 is further configured to switch the state machine to an idle state when a reset signal is detected after the state machine is switched to the protection state.

[0039] Specifically, when the state machine switches to the protection state, it indicates that there is an abnormality in the power management circuit, and the abnormality in the circuit needs to be manually eliminated. Further, after the abnormality in the circuit is manually eliminated, the reset button is manually pressed to trigger the reset signal; further, after detecting the reset signal, the controller 6 switches the state machine to the idle state so that the subsequent state machine can be switched to the working state to maintain the normal operation of the circuit.

[0040] The voltage management circuit provided in this embodiment, on the one hand, when entering the protection state to protect the functional equipment, limits or stops the normal operation, and by setting the reset signal, can automatically restore the state machine to the idle state after the fault or abnormal situation is resolved, so that the device can quickly resume normal operation; on the second hand, after switching to the protection state, it will switch back to the idle state only after the reset signal is manually triggered, which can ensure that it switches back to the idle state after the fault is eliminated, avoiding switching back to the idle state before the fault is eliminated, and avoiding the state machine entering an infinite loop.

[0041] Optional, Figure 2This is a schematic diagram of a power management circuit according to an exemplary embodiment of the present application. Figure 2 In a possible implementation, the power management circuit further includes a plurality of target voltage reduction circuits 7; wherein, The input ends of the multiple target buck circuits 7 are all connected to the output ends of the buck-boost circuit 4, and the output end of each target buck circuit 7 is connected to a different control device; wherein each target buck circuit is used to convert the second voltage signal into an operating voltage signal required by the control device connected thereto, so as to provide a stable power supply for the control device.

[0042] Specifically, the number of the target voltage reduction circuits 7 is set according to actual needs, and is not limited in this embodiment. Further, one target voltage reduction circuit is connected to one control device to supply power to the control device.

[0043] It should be noted that the voltage value of the operating voltage signal output by each target buck circuit 7 is equal to the operating voltage required by the control device connected to the target buck circuit 7. The operating voltage of each control device is a low voltage signal. The required operating voltages of the various control devices may be the same or different, and are not limited in this embodiment.

[0044] For example, in one possible implementation, there are two target step-down circuits, one of which outputs a 5V operating voltage signal for powering a single-chip microcomputer, and the other outputs a 3.3V operating voltage signal for powering a DSP chip.

[0045] The power management circuit provided in this embodiment can stably supply power to multiple control devices by setting multiple target step-down circuits, thereby ensuring stable operation of each control device.

[0046] Figure 3 This is a circuit diagram of a buck-boost circuit according to an exemplary embodiment of the present application. Figure 3 Based on the above embodiment, the buck-boost circuit 4 includes a control chip 41, a switch circuit 42 and a feedback circuit 43; wherein, The feedback circuit 43 is used to sense the second voltage signal output by the switch tube circuit 42 and provide the sensed feedback signal to the controller 6; The control chip 41 is used to control the switching frequency and duty cycle of the switch tube circuit 42 according to the first voltage signal and the feedback signal, so as to adjust the stability of the output voltage output by the switch tube circuit 42; The switch tube circuit 42 is used to adjust the voltage up and down conversion under the control of the control chip 41.

[0047] Specifically, a buck-boost circuit, also known as a Buck-Boost circuit, is a circuit used to regulate the output voltage regardless of whether the input voltage is higher or lower than the desired output voltage.

[0048] Specifically, the switch tube circuit 42 is composed of a plurality of switch tubes. Figure 4 In the example shown, the switch tube circuit 42 is an H-type switch tube circuit composed of 4 switch tubes.

[0049] The working principle of the step-up / step-down circuit 4 is briefly introduced below: Specifically, the feedback circuit 43 monitors the second voltage signal output by the switch tube circuit 42 in real time. Further, the feedback circuit 43 converts the monitored voltage signal into a feedback signal and transmits it to the control chip 41. After receiving the feedback signal, the control chip 41 compares and processes the feedback signal and the first voltage signal, calculates the switching frequency and duty cycle required for each switch tube in the switch tube circuit 42, and then generates a switching signal for controlling each switch tube based on the calculation result, and controls each switch tube according to the switching signal. Further, after controlling each switch tube, the purpose of raising or lowering the voltage is achieved through the coordinated action of each switch tube.

[0050] The power management circuit provided in this embodiment provides a specific circuit structure of a buck-boost circuit, through which the controller can be stably powered.

[0051] Figure 4 This is a schematic diagram of a power input circuit shown in an exemplary embodiment of the present application, please refer to Figure 4 In the power management circuit provided in this embodiment, the power inlet protection circuit 1 includes an overcurrent protection circuit 11, a surge protection circuit 12, an anti-reverse connection circuit 13 and a filter circuit 14 connected in sequence; wherein, The overcurrent protection circuit 11 is used to protect the power management circuit from overcurrent damage; The surge protection circuit 12 is used to protect the subsequent circuit from voltage surge or overvoltage damage; The anti-reverse connection circuit 13 is used to prevent the subsequent circuit from being damaged when the external voltage source input polarity is incorrectly connected.

[0052] The filter circuit 14 is used to filter out high-frequency noise and interference in the external voltage source.

[0053] Specifically, in a possible implementation, the surge protection circuit 12 includes a first inductor L1, a first transient suppression diode T1, a second transient suppression diode T2, and a third transient suppression diode T3; wherein, The first end of the first inductor L1 constitutes the input end of the surge protection circuit 12; The second end of the first inductor L1 is connected to the second end of the first transient suppression diode T1 to form the output end of the surge protection circuit 12; The second end of the first transient suppression diode T1 constitutes the grounding end of the surge protection circuit 12; wherein the grounding end is grounded; The first end of the second transient suppression diode T2 is grounded; the first end of the third transient suppression diode T3 is connected to the second end of the first inductor L1; The second end of the second transient suppression diode T2 and the second end of the third transient suppression diode T3 are connected to the earth.

[0054] Furthermore, in a possible implementation, the anti-reverse connection circuit 13 includes a transistor M1, a voltage stabilizing diode D1, a third resistor R3 and a fourth resistor R4; wherein, The drain of the transistor M1 constitutes the input end of the anti-reverse connection circuit 13; the source of the transistor M1 is connected to the cathode of the voltage stabilizing diode D1 and the second end of the fourth resistor R4 to constitute the output end of the anti-reverse connection circuit 13; The gate of the transistor M1 is connected to the anode of the voltage stabilizing diode D1 and the first end of the fourth resistor R4 and then connected to the second end of the third resistor R3; A first end of the third resistor R3 is grounded.

[0055] Optionally, in a possible implementation, the filter circuit 14 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a common mode inductor L2; wherein, The first capacitor C1 and the second capacitor C2 are connected in series to form a capacitor branch; one end of the capacitor branch forms the input end of the filter circuit 14; the other end of the capacitor branch is grounded; The third capacitor C3 and the fourth capacitor C4 are respectively connected in parallel with the capacitor branch; The common mode inductor L2 is arranged between the third capacitor C3 and the fourth capacitor C4; one end of the fourth capacitor C4 constitutes the output end of the power inlet protection circuit 1.

[0056] Furthermore, in a possible implementation, a light-emitting diode LED1 can be set between the overcurrent protection circuit 11 and the surge protection circuit 12, and a light-emitting diode LED2 can be set between the surge protection circuit 12 and the anti-reverse connection circuit 13. When the circuit works normally, LED 1 is on and LED 2 is off; when the circuit is reversely connected, LED 1 is off and LED 2 is on, and the working status of the circuit is indicated by these two light-emitting diodes.

[0057] The following briefly introduces the working principle of the power inlet protection circuit 1: Specifically, when the circuit voltage suddenly rises above the normal operating voltage, the first transient suppression diode T1, the second transient suppression diode T2 and the third transient suppression diode T3 in the surge protection circuit 12 will be quickly turned on to absorb the surge voltage and limit the voltage amplitude. Through two-stage surge suppression, the subsequent circuit is protected from damage by the transient voltage spike.

[0058] Furthermore, the anti-reverse connection circuit 13 is provided with a transistor M1, a voltage stabilizing diode D1, a third resistor R3 and a fourth resistor R4, and the third resistor R3 and the fourth resistor R4 realize the purpose of voltage division to prevent the transistor M1 from being burned during normal operation. Furthermore, when the circuit is reversely connected, the voltage stabilizing diode D1 is reversed, the PN junction in the tube is increased by the reverse voltage, the holes and electrons are difficult to move, the voltage stabilizing diode D1 is in a cut-off state and cannot be turned on, and the current cannot pass at this time, thereby preventing the circuit from being damaged when the circuit is reversely connected.

[0059] Furthermore, the filter circuit 14 is provided with a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a common mode inductor L2. Since the common mode inductor L2 has a higher impedance to high frequency signals, and the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 have a lower impedance to high frequency signals, a filtering effect is formed. In addition, the first capacitor C1, the first capacitor C2 and the common mode inductor L2 play a role in suppressing common mode noise, and the third capacitor C3 and the fourth capacitor C4 play a role in suppressing differential mode noise, thereby filtering out high frequency noise and interference in the external voltage source.

[0060] The power management circuit provided in this embodiment provides a specific structure of a power entry circuit. Through the power entry protection circuit, the subsequent circuit can be protected from power surges, reverse voltage polarity and power noise interference, ensuring the safe and stable operation of the circuit.

[0061] Figure 5 Another exemplary embodiment of the present invention shows a schematic diagram of a power management circuit. Please refer to Figure 5 , based on the above embodiment, the bus voltage sensing circuit 2 includes a first resistor R1 and a second resistor R2; the resistance value of the first resistor R1 is greater than the resistance value of the second resistor R2; wherein, The first end of the first resistor R1 constitutes the input end of the bus voltage sensing circuit 2; The second end of the first resistor R1 and the first end of the second resistor R2 are connected to form the output end of the bus voltage sensing circuit 2; A second end of the second resistor R2 is grounded.

[0062] Specifically, the bus voltage sensing circuit 2 senses the bus voltage through the voltage division effect of the first resistor R1 and the second resistor R2. In specific implementation, the resistance values ​​of the first resistor R1 and the second resistor R2 can be adjusted to determine whether the sensed bus voltage is within a safe range.

[0063] It should be noted that the resistance values ​​of the first resistor R1 and the second resistor R2 are set according to actual needs, and the resistance value of the first resistor R1 is much greater than the resistance value of the second resistor R2.

[0064] For further information, please refer to Figure 5 On the basis of the above embodiment, the control circuit 3 includes a MOS tube M2 and a fifth capacitor C5; wherein, The gate of the MOS tube M2 and the first end of the fifth capacitor C5 are connected to form the control end of the control circuit 3; The base of the MOS tube M2 constitutes the input end of the control circuit 3; The drain of the MOS tube M2 and the second end of the fifth capacitor C5 are connected to form the output end of the control circuit 3 .

[0065] Specifically, the control circuit 3 is turned on and off through the MOS tube M2. When the gate voltage reaches the on-threshold, the MOS tube is turned on and the control circuit 3 is turned on; when the gate voltage is lower than the on-threshold, the MOS tube is turned off and the control circuit 3 is disconnected.

[0066] Therefore, the controller 6 controls the control circuit 3 by controlling the control signal input to the MOS tube M2. When the controller 6 inputs a high-level control signal, the gate voltage of the MOS tube M2 is higher than the conduction threshold, and M2 is turned on; when the controller 6 inputs a low-level control signal, the gate voltage of the MOS tube M2 is lower than the conduction threshold, and M2 is turned off.

[0067] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A power management circuit, characterized in that: The power management circuit includes a power inlet protection circuit, a bus voltage sensing circuit, a control circuit, a buck-boost circuit, a buck circuit and a controller; wherein, The input end of the power inlet protection circuit is connected to an external voltage source, and the output end of the power inlet protection circuit is respectively connected to the input end of the bus voltage sensing circuit, the input end of the control circuit, and the input end of the buck-boost circuit; The output end of the bus voltage sensing circuit is connected to the controller; the bus voltage sensing circuit is used to sense the bus voltage of the power inlet protection circuit and feed back the sensed bus voltage to the controller; The control end of the control circuit is connected to the controller, and the output end of the control circuit is connected to the power device; the control circuit is used to be turned on or off under the control of the controller, so as to supply power to the power device when turned on; The output end of the buck-boost circuit is connected to the input end of the buck circuit; wherein the buck-boost circuit is used to convert the first voltage signal output by the power inlet protection circuit into a stable second voltage signal output; The output end of the step-down circuit is connected to the power supply end of the controller; the step-down circuit is used to convert the second voltage signal into a third voltage signal suitable for the operation of the controller; The controller is used to initially set the internal state machine to an idle state, and to switch the state machine to a working state when the bus voltage is within a preset range, and to switch the state machine to a protection state when the bus voltage is not within the preset range; wherein the controller controls the control circuit to be disconnected when the state machine is in the idle state and the protection state, and controls the control circuit to be turned on when the state machine is in the working state.

2. The power management circuit according to claim 1, characterized in that: The controller is further configured to switch the state machine to an idle state when a reset signal is detected after the state machine is switched to the protection state.

3. The power management circuit according to claim 1, characterized in that: The power management circuit also includes a plurality of target voltage reduction circuits; wherein, The input ends of the multiple target buck circuits are all connected to the output ends of the buck-boost circuit, and the output end of each target buck circuit is connected to a different control device; wherein each target buck circuit is used to convert the second voltage signal into an operating voltage signal required by the control device connected thereto, so as to provide a stable power supply for the control device.

4. The power management circuit according to claim 1, characterized in that: The buck-boost circuit includes a control chip, a switch circuit and a feedback circuit; wherein, The feedback circuit is used to sense the second voltage signal output by the switch tube circuit and provide the sensed feedback signal to the controller; The control chip is used to control the switching frequency and duty cycle of the switch tube circuit according to the first voltage signal and the feedback signal, so as to adjust the stability of the output voltage output by the switch tube circuit; The switch tube circuit is used to adjust the voltage up and down conversion under the control of the control chip.

5. The power management circuit according to claim 1, characterized in that: The power inlet protection circuit includes an overcurrent protection circuit, a surge protection circuit, an anti-reverse connection circuit and a filter circuit connected in sequence; wherein, The overcurrent protection circuit is used to protect the power management circuit from overcurrent damage; The surge protection circuit is used to protect the subsequent circuit from voltage surge or overvoltage damage; The anti-reverse connection circuit is used to prevent the subsequent circuit from being damaged when the external voltage source input polarity is incorrectly connected; The filter circuit is used to filter out high-frequency noise and interference in the external voltage source.

6. The power management circuit according to claim 1, characterized in that: The bus voltage sensing circuit includes a first resistor and a second resistor; the resistance value of the first resistor is greater than the resistance value of the second resistor; wherein, The first end of the first resistor constitutes the input end of the bus voltage sensing circuit; The second end of the first resistor and the first end of the second resistor are connected to form an output end of the bus voltage sensing circuit; A second terminal of the second resistor is grounded.

7. The power management circuit according to claim 1, characterized in that: The control circuit includes a MOS tube and a fifth capacitor; wherein, The gate of the MOS tube and the first end of the fifth capacitor are connected to form the control end of the control circuit; The base of the MOS tube constitutes the input end of the control circuit; The drain of the MOS tube and the second end of the fifth capacitor are connected to form the output end of the control circuit.

8. The power management circuit according to claim 5, characterized in that: The surge protection circuit includes a first inductor, a first transient suppression diode, a second transient suppression diode and a third transient suppression diode; wherein, The first end of the first inductor constitutes the input end of the surge protection circuit; The second end of the first inductor is connected to the second end of the first transient suppression diode to form an output end of the surge protection circuit; The second end of the first transient suppression diode constitutes a ground terminal of the surge protection circuit; wherein the ground terminal is grounded; The first end of the second transient suppression diode is grounded; the first end of the third transient suppression diode is connected to the second end of the first inductor; The second end of the second transient suppression diode is connected to the second end of the third transient suppression diode and then connected to the earth.

9. The power management circuit according to claim 5 or 8, characterized in that: The anti-reverse connection circuit includes a transistor, a voltage stabilizing diode, a third resistor and a fourth resistor; wherein, The drain of the transistor constitutes the input end of the anti-reverse connection circuit; the source of the transistor is connected to the cathode of the voltage-stabilizing diode and the second end of the fourth resistor to constitute the output end of the anti-reverse connection circuit; The gate of the transistor is connected to the anode of the voltage stabilizing diode and the first end of the fourth resistor, and then connected to the second end of the third resistor; A first terminal of the third resistor is grounded.

10. The power management circuit according to claim 5, characterized in that: The filter circuit includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor and a common mode inductor; wherein, The first capacitor and the second capacitor are connected in series to form a capacitor branch; one end of the capacitor branch forms the input end of the filter circuit; the other end of the capacitor branch is grounded; The third capacitor and the fourth capacitor are respectively connected in parallel with the capacitor branch; The common mode inductor is arranged between the third capacitor and the fourth capacitor; one end of the fourth capacitor constitutes the output end of the power inlet protection circuit.

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