On-line modulation and ultra-low leakage current boost circuit

Abstract

The utility model discloses an on-line modulation and ultra-low leakage current booster circuit, which comprises an LM5022 booster circuit, an on-line modulation voltage circuit and an electric leakage optimization circuit, the on-line voltage modulation circuit adopts a controllable voltage follower U11000, overcomes the problem of fixed output voltage of a traditional booster circuit, and realizes on-line voltage modulation of the booster circuit. The electric leakage optimization circuit adopts an external switch design based on a three-stage switch control circuit, overcomes the problem of large leakage current of a traditional booster circuit, and realizes ultra-low leakage current of the booster circuit. According to the circuit, the requirements of different oil injectors can be met by modulating different VBOOST voltages, so that the same ECU can be matched with different engines; and meanwhile, the requirement of ultralow leakage current is met when the key switch is switched off and the booster circuit does not work under normal power supply of the ECU.

Description

Technical Field

[0001] This invention belongs to the field of internal combustion engine electronic control system - ECU hardware controller, and particularly relates to a boost circuit with online modulation and ultra-low leakage current. Background Technology

[0002] Internal combustion engine electronic control systems are typically available in 12V and 24V types. Fuel injectors require a stable high-voltage supply to ensure rapid activation and thus provide stable power output. Due to the wide variety of fuel injectors on the market, their VBOOST voltage requirements differ.

[0003] Currently, most boost controllers on the market use fixed voltage or hardware resistor voltage division to regulate the output voltage, which does not support online adjustment of the output voltage. With increasing market demands for adjustments to ECU control strategies, the ECU needs to maintain power supply even when the engine is off. This presents a new challenge: ensuring the vehicle can still start smoothly after long periods of inactivity. To address this, engine manufacturers have imposed stringent requirements on ECUs, specifying leakage current of less than 1mA. However, early boost controllers mostly lacked enable control functions, making it impossible to maintain a non-operating mode under constant power conditions. Although some recent products have introduced enable designs, they still cannot meet the ultra-low leakage current requirement. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this application is to provide a boost circuit with online modulation and ultra-low leakage current, so as to achieve online modulation voltage compatibility with various injectors.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] An online modulation and ultra-low leakage current boost circuit includes an LM5022 boost circuit, an online modulation voltage circuit, and a leakage current optimization circuit.

[0007] The online modulation voltage circuit includes an operational amplifier U11000 and a filter network. U11000 acts as a voltage follower, and its input is connected to the control output of an external controller through the filter network. Its output is connected to the voltage loop pin of the LM5022 boost circuit.

[0008] The leakage current optimization circuit is controlled by a three-stage switch, including a first-stage switch control circuit, a second-stage switch control circuit, and a third-stage switch control circuit. The first-stage switch control circuit includes resistors R13141, R13140, and Q12034. The base of Q12034 is connected to an external control signal through R13141 and R13140, its emitter is connected to the internal power supply, and its collector is connected to the second-stage switch control circuit. The second-stage switch control circuit includes resistors R8026, R8031, and Q8005. The base of the circuit is connected to the output of the first-stage switching control circuit via R8026 and R8031, the emitter is connected to the system power input, and the collector is connected to the third-stage switching control circuit. The third-stage switching control circuit includes C8017, R8024, R8019, R8021, and Q8004. The gate of Q8004 is connected to the output of the second-stage switching control circuit via R8024, R8019, and R8021, the source is connected to the system power input, and the drain is connected to the power supply terminal of the LM5022 controller.

[0009] Furthermore, the filter network includes a resistor R13128 and a capacitor C13198. R13128 and C13198 form an RC low-pass filter with a time constant τ = R13128 × C13198.

[0010] Furthermore, in the leakage current optimization circuit, a 12V voltage is output through the on-board PMIC module as the internal power supply for the system, providing power for the control of the Q12033 small signal MOS. The gate of Q12033 is connected to 12V through resistor R13128. When the computer is stopped, the PMIC has no output, which is used to disconnect the circuit when the computer is stopped to reduce the leakage current generated by the ECU.

[0011] Furthermore, the leakage current optimization logic of the leakage current optimization circuit is as follows: The leakage current optimization circuit receives an external control signal and controls the power supply state of the LM5022 controller through a three-level switch control circuit. That is, a low-level signal turns on Q12034, which in turn turns on Q8005 and Q8004 in sequence, and the LM5022 controller works normally; a high-level signal turns off Q12034, which in turn turns off Q8005 and Q8004 in sequence, and the LM5022-VIN is not powered, thus realizing leakage current control.

[0012] Furthermore, the LM5022 boost circuit may include:

[0013] (1) Power input section

[0014] Filter capacitors C10004, C10005, C10006, C10007, and C10009 are connected in parallel at the power input terminal, with one end connected to the input power supply and the other end grounded.

[0015] Energy storage inductors L10001 and L10000 are connected in parallel, with one end connected to the power input and the anode of diode D1000, and the other end connected to the output of the boost circuit.

[0016] The forward diode D1000 is a dual-channel parallel power diode, with its anode connected to one end of the energy storage inductor L10001 / L10000 and its cathode connected to the BOOST output terminal.

[0017] (2) Output section

[0018] Energy storage electrolytic capacitors C13192, C10015, and C10010 are connected in parallel at the BOOST output terminal, with one end connected to the output terminal of the boost circuit and the other end grounded.

[0019] Ceramic capacitors C10011, C10016, C10017, C10021, C10018, C10019, C10022, and C10020 are distributed around the BOOST output terminal. Together with the energy storage electrolytic capacitor, they improve EMC performance and eliminate noise.

[0020] (3) Switch control section

[0021] The switching MOS Q10000 and Q12025 are two NMOS connected in parallel. The drain is connected to one end of the energy storage inductor L10001 / L10000 and the cathode of the diode D1000. The source is connected to the power input. The gate is connected to the output of the LM5022 controller through resistors R13115 and R7005. The switching action of the boost circuit is controlled by the LM5022.

[0022] Pull-down resistors R10012 and R13138 are connected in parallel, with one end connected to the gate of Q10000 and Q12025, and the other end grounded;

[0023] Noise cancellation components R13132 and C13199 are connected in series, and R10006 and C10026 are connected in series, respectively, between the gate and source of the MOS.

[0024] The sampling resistor R10021 is connected in series in the source circuit of the MOS, with one end connected to the source of the MOS and the other end grounded. It collects the loop current when the MOS is closed and feeds it back to the LM5022 controller, which internally performs current upper limit control to ensure the stable operation of the DC-DC converter.

[0025] (4) Controller and feedback compensation section

[0026] DCDC Controller: U12010 is an LM5022 controller. Its input is connected to the power supply and its output is connected to the gate of the MOSFET. It drives the MOSFET to realize the boost circuit function through fixed frequency control.

[0027] Current feedback compensation circuit: including R13043, R13046 and C13162, connected to the relevant pins of the LM5022 controller, used to stabilize the circuit operation;

[0028] The VCC bypass capacitor C13164 is connected between the VCC pin of the LM5022 controller and ground;

[0029] Slope compensation circuit: including R7021, C7010 and C13165, connected to the relevant pins of the LM5022 controller to improve circuit stability;

[0030] The frequency setting resistor R13044 is connected to the frequency setting pin of the LM5022 controller. The operating frequency of the boost circuit is determined by setting the resistor value.

[0031] The undervoltage detection feedback resistors R13045 and R7019 are connected in series between the power input terminal and the undervoltage detection pin of the LM5022 controller to detect whether the input voltage is undervoltage.

[0032] The soft-start setting capacitor C7009 is connected between the soft-start pin of the LM5022 controller and ground to control the soft-start process of the boost circuit and reduce the starting stress.

[0033] The output voltage feedback voltage divider resistors R13041, R13136 and R7020 are connected in series between the BOOST output terminal and ground. After voltage division, they are connected to the feedback pin of the LM5022 controller to provide feedback on the output voltage of the boost circuit and realize voltage regulation.

[0034] The voltage feedback filter capacitor C13184 is connected between the output terminal of the feedback voltage divider resistor and ground to filter out glitches in the feedback loop.

[0035] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0036] As can be seen from the above embodiments, this application employs a controllable voltage follower U11000, overcoming the problem of fixed output voltage in traditional boost circuits and achieving online voltage modulation of the boost circuit; it also employs an external switch design based on a three-stage switch control circuit, overcoming the problem of large leakage current in traditional boost circuits and achieving ultra-low leakage current in the boost circuit. This circuit can meet the needs of different injectors by modulating different VBOOST voltages, thereby enabling the same ECU to be matched with different engines; at the same time, it meets the requirement of ultra-low leakage current by ensuring that the BOOST circuit does not work when the key switch is off under constant power supply to the ECU.

[0037] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0039] Figure 1 This is a schematic diagram illustrating a typical application topology of the LM5022 boost circuit according to an exemplary embodiment.

[0040] Figure 2 This is a schematic diagram illustrating the practical application of the LM5022 boost circuit - input / output / switching control section according to an exemplary embodiment.

[0041] Figure 3 This is a schematic diagram illustrating an actual application of the LM5022 boost circuit - controller and feedback compensation section according to an exemplary embodiment.

[0042] Figure 4 This is a schematic diagram illustrating a practical application of the LM5022 boost circuit—a line-modulated voltage circuit—according to an exemplary embodiment.

[0043] Figure 5 This is a schematic diagram illustrating a practical application of the LM5022 boost circuit - leakage current optimization circuit according to an exemplary embodiment. Detailed Implementation

[0044] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0045] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0046] Terminology Explanation:

[0047] MCU: Micro Controller Unit;

[0048] ECU: Electronic Control Unit;

[0049] VBOOST: Boost Voltage;

[0050] PMIC: Power Management IC;

[0051] MOS: MOSFET, Field-Effect Transistor;

[0052] DCDC: Direct Current to Direct Current Converter;

[0053] EMC: Electromagnetic Compatibility;

[0054] Online voltage modulation: Different voltages can be set in real time via software control;

[0055] Leakage current: The current consumed by the ECU when the controller is constantly powered and the key switch is off.

[0056] This application provides a practical application scheme based on the LM5022 boost circuit, including a basic boost topology circuit, to achieve a fixed 57.6V BOOST voltage output within the input voltage range of 6V to 60V.

[0057] This application provides an online modulation and ultra-low leakage current boost circuit, including an LM5022 boost circuit, an online modulation voltage circuit, and a leakage current optimization circuit, to achieve an online modulation output BOOST voltage with an output range of 33.7V-81.4V within the input voltage range of 6V to 60V.

[0058] The online modulation voltage circuit includes an operational amplifier U11000 and a filter network. U11000 acts as a voltage follower, and its input is connected to the control output of an external controller (such as an MCU) through the filter network. Its output is connected to the voltage loop (FB) pin of the LM5022 boost circuit, feeding back the 0-5V variable voltage source output by the external controller to the FB loop of the LM5022, thus realizing the feedback loop of the FB signal and achieving VBOOST online modulation output voltage.

[0059] The filtering network includes R13128 and C13198, which work together to filter the PWM signal output by the external controller to generate a smooth DC voltage, thereby achieving precise control of the feedback pin (FB) of the LM5022 boost controller and achieving the purpose of online modulation of the BOOST output voltage.

[0060] R13041 / R7020 / R13136 are VBOOST voltage feedback divider resistors. These three resistors set a fixed VBOOST voltage. R13134 outputs the U11000 voltage follower to the voltage feedback circuit. The resistance values ​​of R13041 / R7020 / R13136 / R13134 directly affect the VBOOST output range. Vfb is the input comparison threshold of the FB pin of the LM5022, defined as 1.25V.

[0061] After introducing a bias voltage into the FB of the LM5022 for voltage division, different bias voltages result in different VBOOST output voltages. The calculation formula is as follows:

[0062]

[0063] Where Duty is the duty cycle of the control signal;

[0064] When R13041 / R7020 / R13136 / R13134 are set to 60400Ω / 1370Ω / 1370Ω / 6340Ω respectively, the VBOOST output voltage corresponding to the 0-100% duty cycle of the PWM signal output by the external controller can be calculated from the above formula to be 33.7V-81.4V.

[0065] The leakage current optimization circuit is controlled by a three-stage switch, including a first-stage switch control circuit, a second-stage switch control circuit, and a third-stage switch control circuit. The first-stage switch control circuit includes R13141, R13140, and Q12034. The base of Q12034 is connected to an external control signal through R13141 and R13140, the emitter is connected to the internal power supply of the system, and the collector is connected to the second-stage switch control circuit. The second-stage switch control circuit includes R8026, R8031, and Q8005. The base of Q8005 is connected to... R8026 and R8031 are connected to the output of the first-level switch control circuit, the emitter is connected to the system power input (which can be the battery input voltage), and the collector is connected to the third-level switch control circuit. The third-level switch control circuit includes C8017, R8024, R8019, R8021, and Q8004. The gate of Q8004 is connected to the output of the second-level switch control circuit through R8024, R8019, and R8021, the source is connected to the system power input, and the drain is connected to the power supply terminal of the LM5022 controller.

[0066] In practical implementation, the on-board PMIC module can output 12V voltage as the internal power supply of the system, providing power for the control of the Q12033 small signal MOS. The gate of Q12033 is connected to 12V through resistor R13128. When the computer is stopped, the PMIC has no output, which is used to disconnect the circuit when the computer is stopped to reduce the leakage current generated by the ECU.

[0067] The leakage current optimization logic is as follows: The leakage current optimization circuit receives external control signals (such as the Vboost_PWM_Enable control signal output by the MCU) and controls the power supply status of the LM5022 controller through a three-stage switch control circuit. A low-level signal turns on Q12034, which in turn turns on Q8005 and Q8004 sequentially, allowing the LM5022 to operate normally. A high-level signal turns off Q12034, which in turn turns off Q8005 and Q8004 sequentially, resulting in no power supply to the LM5022-VIN, thus achieving leakage current control. When the car is parked, the key switch is off, the PMIC is disabled, VDD5 has no output, Q12034 is off, all stages of the switches are off, the LM5022 has no power supply, and no leakage current is generated.

[0068] Specifically, the LM5022 boost circuit may include:

[0069] (1) Power input section

[0070] Filter capacitors: C10004, C10005, C10006, C10007, and C10009 are connected in parallel at the power input terminal. One end is connected to the input power supply (VBATT_2), and the other end is grounded to provide a stable power input for the circuit and reduce power ripple and noise.

[0071] Energy storage inductors: L10001 and L10000 are connected in parallel. One end is connected to the power input (VBATT_2) and the anode of diode D1000, and the other end is connected to the BOOST output terminal. They are used to store and release energy, enhance the BOOST output power, and reduce the inductor size to achieve vibration resistance.

[0072] Conducting diode: D1000 is a dual-channel parallel power diode. The anode is connected to one end of the energy storage inductor (L10001 / L10000), and the cathode is connected to the BOOST output terminal to prevent the BOOST output voltage from flowing back to the power input terminal, while enhancing the BOOST output power.

[0073] (2) Output section

[0074] Energy storage electrolytic capacitors: C13192, C10015, and C10010 are connected in parallel at the BOOST output terminal, with one end connected to the BOOST output terminal and the other end grounded to ensure the stability of the BOOST voltage; in one embodiment, three 620uF electrolytic capacitors are selected to minimize the drop in BOOST voltage with each injection, thus meeting the requirement for rapid opening of the injector when continuously injecting fuel.

[0075] Ceramic capacitors: C10011, C10016, C10017, C10021, C10018, C10019, C10022, and C10020 are distributed around the BOOST output terminal. Together with the energy storage electrolytic capacitor, they improve EMC performance and eliminate noise.

[0076] (3) Switch control section

[0077] Switching MOS: Q10000 and Q12025 are two NMOS transistors connected in parallel. The drain is connected to one end of the energy storage inductor (L10001 / L10000) and the cathode of diode D1000 (BOOST output terminal). The source is connected to the power input (VBATT_2). The gate is connected to the output terminal of the LM5022 controller through resistors R13115 and R7005. The switching action of the BOOST circuit is controlled by the LM5022 to enhance the BOOST output power.

[0078] Pull-down resistors: R10012 and R13138 are connected in parallel, with one end connected to the gate of Q10000 and Q12025 and the other end grounded, to ensure that the MOS is in a stable off state when the controller is not working.

[0079] Noise cancellation components: R13132 and C13199 are connected in series, and R10006 and C10026 are connected in series, respectively between the gate and source of the MOS, to eliminate the noise generated during MOS switching and reduce EMC interference.

[0080] Sampling resistor: R10021 is connected in series in the source circuit of MOS, with one end connected to the source of MOS and the other end grounded. It collects the loop current when MOS is closed and feeds it back to the LM5022 controller. The controller internally performs current upper limit control to ensure the stable operation of DC-DC and avoid damage to peripheral devices by transient large current.

[0081] (4) Controller and feedback compensation section

[0082] DCDC Controller: U12010 is an LM5022 controller. Its input is connected to the power supply (VDD5), and its output is connected to the gate of the MOS. It drives the MOS to achieve the BOOST function through fixed frequency control.

[0083] Current feedback compensation circuit: R13043, R13046 and C13162 form a current feedback compensation circuit, which is connected to the relevant pins of the LM5022 controller to stabilize the circuit operation.

[0084] VCC bypass capacitor: C13164 is connected between the VCC pin of the LM5022 controller and ground to provide a stable power supply to the controller.

[0085] Slope compensation circuit: R7021, C7010 and C13165 form a slope compensation circuit, which is connected to the relevant pins of the LM5022 controller to improve the stability of the circuit.

[0086] Frequency setting resistor: R13044 is connected to the frequency setting pin of the LM5022 controller. The operating frequency of the BOOST circuit is determined by setting the resistor value.

[0087] Undervoltage detection feedback resistors: R13045 and R7019 are connected in series between the power input terminal and the undervoltage detection pin of the LM5022 controller to detect whether the input voltage is undervoltage.

[0088] Soft start setting capacitor: C7009 is connected between the soft start pin of the LM5022 controller and ground to control the soft start process of the BOOST circuit and reduce startup stress.

[0089] The soft-start time corresponding to 220nF is 3.846-7.143us.

[0090] Output voltage feedback divider resistors: R13041, R13136 and R7020 are connected in series between the BOOST output terminal and ground. After voltage division, they are connected to the feedback pin of the LM5022 controller to provide feedback on the BOOST output voltage and realize voltage regulation.

[0091] Voltage feedback filter capacitor: C13184 is connected between the output terminal of the feedback voltage divider resistor and ground to filter out glitches in the feedback loop, making the circuit more stable.

[0092] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0093] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An on-line modulated and ultra-low leakage current boost circuit, characterized by, The LM5022 voltage boosting circuit, the online modulation voltage circuit, and the leakage optimization circuit are included. The online modulation voltage circuit includes an operational amplifier U11000 and a filter network. The U11000 serves as a voltage follower, the input end of which is connected to the control output end of an external controller through the filter network, and the output end is connected to the voltage ring pin of the LM5022 voltage boosting circuit. The leakage optimization circuit is controlled by a three-stage switch and includes a first-stage switch control circuit, a second-stage switch control circuit, and a third-stage switch control circuit. The first-stage switch control circuit includes R13141, R13140, and Q12034. The base of Q12034 is connected to an external control signal through R13141 and R13140, the emitter is connected to the internal power supply of the system, and the collector is connected to the second-stage switch control circuit. The second-stage switch control circuit includes R8026, R8031, and Q8005. The base of Q8005 is connected to the output end of the first-stage switch control circuit through R8026 and R8031, the emitter is connected to the system power supply input, and the collector is connected to the third-stage switch control circuit. The third-stage switch control circuit includes C8017, R8024, R8019, R8021, and Q8004. The gate of Q8004 is connected to the output end of the second-stage switch control circuit through R8024, R8019, and R8021, the source is connected to the system power supply input, and the drain is connected to the power supply end of the LM5022 controller.

2. The circuit of claim 1, wherein, The filter network includes a resistor R13128 and a capacitor C13198, which form an RC low-pass filter with a time constant τ = R13128 × C13198.

3. The circuit of claim 1, wherein, In the leakage optimization circuit, a 12V voltage is output by the on-board PMIC module, which serves as the internal power supply of the system and provides power for the control of the small-signal MOS Q12033. The gate of Q12033 is connected to 12V through resistor R13128. When the PMIC has no output, it is used to disconnect to reduce the ECU leakage current when parking.

4. The circuit of claim 1, wherein, The leakage optimization logic of the leakage optimization circuit is as follows: the leakage optimization circuit receives an external control signal and controls the power supply state of the LM5022 controller through the three-stage switch control circuit. Specifically, a low-level signal turns on Q12034, which in turn turns on Q8005 and Q8004 in sequence, and the LM5022 controller works normally. A high-level signal turns off Q12034, which in turn turns off Q8005 and Q8004 in sequence, and the LM5022-VIN has no power supply, achieving leakage control.

5. The circuit of claim 1, wherein, The LM5022 voltage boosting circuit can include: (1) Power input part Filter capacitors C10004, C10005, C10006, C10007, and C10009 are connected in parallel at the power input end, one end connected to the input power supply, and the other end grounded. Energy storage inductors L10001 and L10000 are connected in parallel, one end connected to the power input and the anode of diode D1000, and the other end connected to the output end of the voltage boosting circuit. Conduction diode D1000 is a double-channel parallel power diode, anode connected to one end of the energy storage inductor L10001 / L10000, cathode connected to the BOOST output end; (2) Output part Energy storage electrolytic capacitor C13192, C10015, C10010 are connected in parallel at the BOOST output end, one end connected to the output end of the boost circuit, the other end grounded; Ceramic capacitor: C10011, C10016, C10017, C10021, C10018, C10019, C10022, C10020 are distributed around the BOOST output end, cooperating with the energy storage electrolytic capacitor to improve the EMC effect and eliminate noise; (3) Switching control part Switching MOS Q10000 and Q12025 are two parallel NMOS, drain connected to one end of the energy storage inductor L10001 / L10000 and the cathode of diode D1000, source connected to the power input, gate connected to the output end of the LM5022 controller through resistors R13115 and R7005, controlled by the LM5022 to realize the switching action of the boost circuit; Pull-down resistors R10012 and R13138 are connected in parallel, one end connected to the gate of Q10000 and Q12025, the other end grounded; Noise elimination elements R13132 and C13199 are connected in series, R10006 and C10026 are connected in series, connected between the gate and source of the MOS, respectively; Sampling resistor R10021 is connected in series in the source loop of the MOS, one end connected to the source of the MOS, the other end grounded, to collect the loop current when the MOS is closed and feedback to the LM5022 controller for current upper limit control to ensure stable DCDC operation; (4) Controller and feedback compensation part DCDC controller: U12010 is an LM5022 controller, its input end connected to the power supply, output end connected to the gate of the MOS, driven by the MOS to realize the function of the boost circuit through the constant frequency control mode; Current feedback compensation loop: including R13043, R13046 and C13162, connected to the related pins of the LM5022 controller, used to stabilize the circuit operation; VCC bypass capacitor C13164 connected between the VCC pin of the LM5022 controller and the ground; Slope compensation loop: including R7021, C7010 and C13165, connected to the related pins of the LM5022 controller, used to improve the stability of the circuit; Frequency setting resistor R13044 connected to the frequency setting pin of the LM5022 controller, the working frequency of the boost circuit is determined by setting the resistance value; Undervoltage detection feedback resistor R13045 and R7019 connected in series between the power input and the undervoltage detection pin of the LM5022 controller, used to detect whether the input voltage is undervoltage; Soft start setting capacitor C7009 connected between the soft start pin of the LM5022 controller and the ground, controls the soft start process of the boost circuit and reduces the starting stress; The output voltage feedback voltage dividing resistors R13041, R13136 and R7020 are connected in series between the BOOST output end and the ground, and are connected to the feedback pin of the LM5022 controller after voltage dividing, for feeding back the output voltage of the boost circuit, so as to realize voltage regulation. The voltage feedback filtering capacitor C13184 is connected between the output end of the feedback voltage dividing resistor and the ground, for filtering out glitch signals in the feedback loop.

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