A boost input schmitt trigger circuit and a method of operation thereof

Abstract

This invention discloses a boost input Schmitt trigger circuit and its operating method, relating to the field of backup power wake-up for low-power electronic devices. It includes a backup power module, a button wake-up switch module, a boost control chip, a boost power conversion module, and an output voltage divider feedback module. It also includes an enable voltage divider module and a self-locking feedback module. The enable voltage divider module includes a first voltage divider resistor R1 and a second voltage divider resistor R2. One end of the first voltage divider resistor R1 is connected to the system input bus, and the other end of the first voltage divider resistor R1 is electrically connected to the enable pin EN of the boost control chip, one end of the second voltage divider resistor R2, and the first end of the self-locking feedback module. The other end of the second voltage divider resistor R2 is connected to reference ground. The second end of the self-locking feedback module is connected to the system output bus. This design ensures a continuous and stable power supply to the system after the boost circuit starts operating, while also maximizing the utilization of battery or supercapacitor energy, thus improving efficiency.

Description

Technical Field

[0001] This invention relates to the field of backup power wake-up for low-power electronic devices, specifically a boost input Schmitt trigger circuit and its operating method. Background Technology

[0002] In existing wake-up systems, a button press triggers the boost converter chip to operate. The enable pin of the DC-DC boost converter chip is connected to the input voltage via a voltage divider resistor to detect whether the enable voltage of the DC-DC boost converter chip is higher than the activation threshold. Wake-up systems, including Linux systems, often use a single minimal system in a low-power mode. When a wake-up button signal is detected, the microcontroller controls the enable pin of the boost converter chip, enabling the DC-DC boost converter chip to operate and supply power to the core system. When the backup power supply is detected to be lower than the threshold, the microcontroller controls the enable pin of the DC-DC boost converter chip to stop supplying power to the system.

[0003] The aforementioned wake-up system has the following drawbacks: First, it increases circuit complexity, requiring a low-power minimum system to always be running to detect the button wake-up signal, which not only increases costs but is also unfeasible for products with limited space. Second, because the enable pin of the boost chip is connected to the input voltage through a voltage divider resistor, the enable threshold is fixed. When the backup power supply voltage is at the threshold, the boost chip boosts and starts to supply power to the system. If the enable voltage divider is lower than the threshold during system startup, the boost chip will shut down, and the system will fail to start. This may lead to loss of system parameters, register corruption, and other issues, resulting in product damage or abnormalities. Summary of the Invention

[0004] This invention provides a boost input Schmitt trigger circuit and its working method. By cooperating with the enable voltage divider module and the self-locking feedback module, an adjustable Schmitt trigger hysteresis threshold is formed at the enable terminal of the boost control chip, while simultaneously achieving output voltage self-locking maintenance. This solves the problems of unadjustable input trigger threshold, unstable start-stop, and high standby power consumption in the prior art.

[0005] The present invention provides the following technical solution: a boost input Schmitt trigger circuit, including a backup power module, a key wake-up switch module, a boost control chip, a boost power conversion module, an output voltage divider feedback module, and also includes an enable voltage divider module and a self-locking feedback module;

[0006] The output terminal of the backup power module is connected to the input terminal of the button wake-up switch module, and the output terminal of the button wake-up switch module is connected to the system input bus; the system input bus is electrically connected to the input terminal of the boost power conversion module and the power pin VS of the boost control chip, respectively.

[0007] The switching terminal of the boost power conversion module is electrically connected to the switching pin SW of the boost control chip, and the output terminal of the boost power conversion module is connected to the system output bus.

[0008] The output voltage divider feedback module is connected in series between the system output bus and the reference ground, and the voltage divider node of the output voltage divider feedback module is electrically connected to the feedback pin FB of the boost control chip.

[0009] The enable voltage divider module includes a first voltage divider resistor R1 and a second voltage divider resistor R2; one end of the first voltage divider resistor R1 is connected to the system input bus, and the other end of the first voltage divider resistor R1 is electrically connected to the enable pin EN of the boost control chip, one end of the second voltage divider resistor R2, and the first end of the self-locking feedback module; the other end of the second voltage divider resistor R2 is connected to reference ground; and the second end of the self-locking feedback module is connected to the system output bus.

[0010] As a further improvement of the present invention, the boost power conversion module includes a power inductor L and a diode D1. One end of the power inductor L serves as the input terminal of the boost power conversion module and is connected to the system input bus. The other end of the power inductor L serves as the switching terminal of the boost power conversion module and is electrically connected to the switching pin SW of the boost control chip and the anode of the diode D1. The cathode of the diode D1 serves as the output terminal of the boost power conversion module and is connected to the system output bus.

[0011] As a further improvement of the present invention, the output voltage divider feedback module includes a fourth voltage divider resistor R4 and a fifth voltage divider resistor R5. One end of the fourth voltage divider resistor R4 is connected to the system output bus, and the other end of the fourth voltage divider resistor R4 serves as the voltage divider node of the output voltage divider feedback module. It is also electrically connected to the feedback pin FB of the boost control chip and one end of the fifth voltage divider resistor R5. The other end of the fifth voltage divider resistor R5 is connected to the reference ground.

[0012] As a further improvement of the present invention, the self-locking feedback module is a self-locking feedback resistor R3. One end of the self-locking feedback resistor R3 is connected to the enable pin EN of the boost control chip as the first end of the self-locking feedback module, and the other end of the self-locking feedback resistor R3 is connected to the system output bus as the second end of the self-locking feedback module.

[0013] As a further improvement of the present invention, the button wake-up switch module is any one of a mechanical button switch, a MOSFET electronic switch, or a transistor electronic switch.

[0014] As a further improvement of the present invention, the input power module is one or both of a lithium battery pack and a supercapacitor module.

[0015] A method for operating a boost input Schmitt trigger circuit, applicable to the aforementioned boost input Schmitt trigger circuit, includes the following steps:

[0016] The trigger button wakes up the switch module and turns it on, allowing the backup power module's input voltage to be connected to the system input bus.

[0017] The input voltage is divided by the first voltage divider resistor R1 and the second voltage divider resistor R2 of the enable voltage divider module and then output to the enable pin EN of the boost control chip.

[0018] When the voltage of the system input bus rises to the circuit's turn-on threshold voltage, the voltage of the enable pin EN reaches the enable threshold of the boost control chip, and the boost control chip starts working.

[0019] After the boost control chip is started, it outputs a high-frequency switching signal through the switch pin SW to control the boost power conversion module to complete the energy storage and release of electrical energy, boost the input low-voltage DC to high-voltage DC, and establish a stable output voltage at the system output bus.

[0020] The output voltage of the system output bus is divided by the output voltage divider feedback module and fed back to the feedback pin FB of the boost control chip. The boost control chip adjusts the duty cycle of the switching signal in real time according to the voltage of the feedback pin FB to realize closed-loop voltage regulation control of the output voltage.

[0021] After the output voltage of the system output bus is stabilized, the voltage of the output voltage divider feedback module is fed back to the enable pin EN of the boost control chip through the self-locking feedback module, pulling the potential of the enable pin EN high.

[0022] When the voltage of the system input bus drops to the circuit's turn-off threshold voltage, the voltage of the enable pin EN is lower than the enable threshold of the boost control chip, the chip turns off, the output voltage is disconnected, and the Schmitt trigger turn-off control is completed.

[0023] As a further improvement of the present invention, a standby sleep step is also included:

[0024] Disconnecting the button wakes up the switch in the switch module, completely disconnecting the backup power module from the subsequent circuit, resulting in no voltage input to the system input bus, no operation of the boost control chip, and the circuit entering a zero-power standby state.

[0025] As a further improvement of the present invention, it also includes an output voltage configuration step: by adjusting the resistance ratio of the fourth voltage divider resistor R4 and the fifth voltage divider resistor R5 of the output voltage divider feedback module, the output voltage value of the system output bus is configured, and the output voltage V OUT The calculation formula is:

[0026] V OUT = VFB ×(1+ R4 / R5);

[0027] Among them, V FB This is the reference voltage for the feedback pin of the boost control chip.

[0028] As a further improvement of the present invention, it also includes a hysteresis voltage configuration step: adjusting the resistance values ​​of the first voltage divider resistor R1, the second voltage divider resistor R2 of the enable voltage divider module and the self-locking feedback resistor R3 of the self-locking feedback module to adjust the magnitude of the Schmitt trigger hysteresis voltage.

[0029] The present invention has the following beneficial effects:

[0030] The main function of the circuit in this application is to boost the voltage when the voltage of the battery or supercapacitor is higher than the threshold at the EN pin. Then, through the voltage divider capability of R3, the voltage at the EN pin is further raised. Therefore, even if the voltage of the front-end battery or supercapacitor falls below the set value for the boost control chip, the boost circuit will still operate because the voltage at the EN pin is still above the threshold. This ensures a continuous and stable power supply to the system after the boost circuit starts operating, while also maximizing the utilization of battery or supercapacitor energy, thus improving efficiency. Attached Figure Description

[0031] Figure 1 This is a system block diagram of the present invention.

[0032] Figure 2 This is a circuit diagram of the present invention.

[0033] Figure 3 This is a flowchart of the circuit operation method in this invention. Detailed Implementation

[0034] The technical solutions of the embodiments of this specification will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of this specification and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of this specification.

[0035] The terms "first," "second," "third," etc., in the description, claims, and accompanying drawings are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0036] In the following description, terms such as “inner,” “outer,” “upper,” “lower,” “left,” and “right” are used only to facilitate the description of the embodiments and to simplify 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, and therefore should not be construed as a limitation of this specification.

[0037] All data involved in this application are information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0038] Example 1

[0039] Please see Figure 1 , 2 As shown, a boost input Schmitt trigger circuit includes a backup power module, a key-button wake-up switch module, a boost control chip, a boost power conversion module, and an output voltage divider feedback module. It also includes an enable voltage divider module and a self-locking feedback module. The output terminal of the backup power module is connected to the input terminal of the key-button wake-up switch module, and the output terminal of the key-button wake-up switch module is connected to the system input bus. The system input bus is electrically connected to the input terminal of the boost power conversion module and the power supply pin VS of the boost control chip. The switch terminal of the boost power conversion module is electrically connected to the switch pin SW of the boost control chip, and the output terminal of the boost power conversion module is connected to the system output bus. The output voltage divider feedback module is connected in series between the system output bus and the reference ground. The voltage divider node of the output voltage divider feedback module is electrically connected to the feedback pin FB of the boost control chip. The enable voltage divider module includes a first voltage divider resistor R1 and a second voltage divider resistor R2. One end of the first voltage divider resistor R1 is connected to the system input bus, and the other end of the first voltage divider resistor R1 is electrically connected to the enable pin EN of the boost control chip, one end of the second voltage divider resistor R2, and the first end of the self-locking feedback module. The other end of the second voltage divider resistor R2 is connected to the reference ground. The second end of the self-locking feedback module is connected to the system output bus.

[0040] In the above scheme, the input power module uses a battery or supercapacitor to provide low-voltage DC input to the circuit.

[0041] The button wake-up switch module uses a mechanical tactile button combined with a P-channel MOSFET to form an electronic switch. When the button is pressed, the MOSFET is turned on, and the input power is connected to the subsequent circuit. When the button is released, the circuit is kept on by output self-locking, and the power-off control can be achieved through an external MCU. In the off state, the input power module is completely disconnected from the subsequent circuit, and the static standby power consumption of the circuit is zero, making it suitable for low-power portable devices.

[0042] The power supply pin VS of the boost control chip is the chip's power supply terminal, the enable pin EN is the chip's start / stop control terminal (active high), the switch pin SW is the lead-out terminal of the internal power switch transistor, used to drive the external power inductor, and the feedback pin FB is the voltage regulation feedback terminal. When the chip is working, it will stabilize the voltage of the FB pin through closed-loop control.

[0043] The boost power conversion module includes a power inductor L and a diode D1. One end of the power inductor L serves as the input terminal of the boost power conversion module and is connected to the system input bus. The other end of the power inductor L serves as the switching terminal of the boost power conversion module and is electrically connected to the switching pin SW of the boost control chip and the anode of the diode D1. The cathode of the diode D1 serves as the output terminal of the boost power conversion module and is connected to the system output bus.

[0044] The output voltage divider feedback module includes a fourth voltage divider resistor R4 and a fifth voltage divider resistor R5. One end of the fourth voltage divider resistor R4 is connected to the system output bus, and the other end of the fourth voltage divider resistor R4 serves as the voltage divider node of the output voltage divider feedback module. It is also electrically connected to the feedback pin FB of the boost control chip and one end of the fifth voltage divider resistor R5. The other end of the fifth voltage divider resistor R5 is connected to the reference ground.

[0045] The self-locking feedback module is a self-locking feedback resistor R3. One end of the self-locking feedback resistor R3 serves as the first end of the self-locking feedback module and is connected to the enable pin EN of the boost control chip. The other end of the self-locking feedback resistor R3 serves as the second end of the self-locking feedback module and is connected to the system output bus.

[0046] The button wake-up switch module can be any one of a mechanical button switch, a MOSFET electronic switch, or a transistor electronic switch.

[0047] The input power module is one or both of lithium battery packs and supercapacitor modules.

[0048] In this application, the boost control chip is model SGM6623 from Sanbang Microelectronics. The main function of the circuit in this application is to boost the voltage when the voltage of the battery or supercapacitor is higher than the threshold at the EN pin. Then, through the voltage division capability of R3, the voltage at the EN pin is raised again. Thus, even if the voltage of the front-end battery or supercapacitor is lower than the set value for the boost control chip, the boost circuit will still work because the voltage at the EN pin is still higher than the threshold. This ensures that the boost circuit can continuously and stably power the system after it starts working, and also makes the most of the energy from the battery or supercapacitor, improving the utilization rate.

[0049] Example 2

[0050] R1=36kΩ, R2=5.1kΩ, R3=100kΩ, the enable voltage threshold V of the boost control chip. EN =0.8V,

[0051] When the button is pressed to wake up, V OUT =V IN -V D1 -V L =V IN -0.3 (V D1 ≈0.3V, inductance V L (Voltage drop is negligible)

[0052] The equation is as follows: I R3 =(V OUT -V EN ) / R3=(V IN -0.3-V EN ) / R3=(V IN -0.3-0.8) / 100k,

[0053] I R2 = V EN / R2=0.8 / 5.1k,

[0054] I R1 =(V IN -V EN ) / R1=(V IN -V EN ) / R1=(V IN -0.8) / 36k,

[0055] I R2 = I R1 + I R3 ,

[0056] From the above four equations, we get: VIN≈5.03V.

[0057] Therefore, when the button is pressed, the battery or supercapacitor voltage needs to be greater than 5.03V for the boost circuit to work.

[0058] When the boost circuit is working, V OUT =12V,

[0059] The equation is as follows: I R3 =(V OUT -V EN ) / R3=(12-V EN R3 = (12 - 0.8) / 100k

[0060] I R2 = V EN / R2=0.8 / 5.1k,

[0061] I R1 =(V IN -V EN ) / R1 = (V IN -0.8) / 36k,

[0062] I R2 = I R1 + I R3 ,

[0063] From the above four equations, we get: V IN ≈2.42V,

[0064] From the above calculations, it can be seen that when the boost circuit is working, V IN The boost circuit will only stop working when the voltage drops below 2.42V.

[0065] Example 3

[0066] R1=36kΩ, R2=5.1kΩ, R3=120kΩ, the enable voltage threshold V of the boost control chip. EN It is 0.8V.

[0067] When the button is pressed to wake up, V OUT =V IN -V D1 -V L =V IN -0.3 (V D1 (≈0.3V, inductor voltage drop VL is negligible)

[0068] The equation is as follows: I R3 =(V OUT -V EN ) / R3=(V IN -0.3-V EN ) / R3=(V IN -0.3-0.8) / 120k,

[0069] I R2 = V EN / R2=0.8 / 5.1k,

[0070] I R1 =(V IN -V EN ) / R1=(V IN -V EN ) / R1=(V IN -0.8) / 36k,

[0071] I R2 = I R1 + I R3 ,

[0072] From the above four equations, we get: V IN ≈5.21V.

[0073] Therefore, when the button is pressed, the battery or supercapacitor voltage needs to be greater than 5.21V for the boost circuit to work.

[0074] When the boost circuit is working, V OUT =12V,

[0075] The equation is as follows: I R3 =(V OUT -V EN ) / R3=(12-V EN R3 = (12 - 0.8) / 120k

[0076] I R2 = V EN / R2=0.8 / 5.1k,

[0077] I R1 =(V IN -V EN ) / R1 = (V IN -0.8) / 36k,

[0078] I R2 = I R1 + I R3 ,

[0079] From the above four equations, we get: V IN ≈3.09V.

[0080] From the above calculations, it can be seen that when the boost circuit is working, V IN The boost circuit will only stop working when the voltage drops below 3.09V.

[0081] As can be seen from Examples 2 and 3, the turn-on threshold and turn-off threshold of the boost circuit can be adjusted by adjusting the resistance values ​​of R1, R2, and R3. That is, the turn-on threshold voltage of the circuit increases as the resistance value of R3 increases.

[0082] Example 4

[0083] Please see Figure 3 As shown, a method for operating a boost input Schmitt trigger circuit, applicable to the aforementioned boost input Schmitt trigger circuit, includes the following steps:

[0084] The trigger button wakes up the switch module and turns it on, allowing the backup power module's input voltage to be connected to the system input bus.

[0085] The input voltage is divided by the first voltage divider resistor R1 and the second voltage divider resistor R2 of the enable voltage divider module and then output to the enable pin EN of the boost control chip.

[0086] When the voltage of the system input bus rises to the circuit's turn-on threshold voltage, the voltage of the enable pin EN reaches the enable threshold of the boost control chip, and the boost control chip starts working.

[0087] After the boost control chip is started, it outputs a high-frequency switching signal through the switch pin SW to control the boost power conversion module to complete the energy storage and release of electrical energy, boost the input low-voltage DC to high-voltage DC, and establish a stable output voltage at the system output bus.

[0088] The output voltage of the system output bus is divided by the output voltage divider feedback module and fed back to the feedback pin FB of the boost control chip. The boost control chip adjusts the duty cycle of the switching signal in real time according to the voltage of the feedback pin FB to realize closed-loop voltage regulation control of the output voltage.

[0089] After the output voltage of the system output bus is stabilized, the voltage of the output voltage divider feedback module is fed back to the enable pin EN of the boost control chip through the self-locking feedback module, pulling the potential of the enable pin EN high.

[0090] When the voltage of the system input bus drops to the circuit's turn-off threshold voltage, the voltage of the enable pin EN is lower than the enable threshold of the boost control chip, the chip turns off, the output voltage is disconnected, and the Schmitt trigger turn-off control is completed.

[0091] The standby sleep mode steps of the above circuit are as follows:

[0092] Disconnecting the button wakes up the switch in the switch module, completely disconnecting the backup power module from the subsequent circuit, resulting in no voltage input to the system input bus, no operation of the boost control chip, and the circuit entering a zero-power standby state.

[0093] The output voltage configuration steps for the above circuit are as follows: By adjusting the resistance ratio of the fourth voltage divider resistor R4 and the fifth voltage divider resistor R5 in the output voltage divider feedback module, the output voltage value of the system output bus is configured, and the output voltage V... OUT The calculation formula is:

[0094] V OUT = V FB ×(1+ R4 / R5);

[0095] Among them, V FB This is the reference voltage for the feedback pin of the boost control chip.

[0096] The steps for configuring the hysteresis voltage of the above circuit are as follows: by adjusting the resistance values ​​of the first voltage divider resistor R1, the second voltage divider resistor R2 of the enable voltage divider module, and the self-locking feedback resistor R3 of the self-locking feedback module, the magnitude of the Schmitt trigger hysteresis voltage is adjusted.

[0097] In the above, the shutdown of the boost control chip is controlled by a microcontroller.

[0098] The embodiments described above are merely preferred embodiments of this specification and are not intended to limit the scope of this specification. Any modifications and improvements made by those skilled in the art to the technical solutions of this specification without departing from the spirit of this specification should fall within the protection scope defined by the claims of this specification.

Claims

1. A boost input Schmitt trigger circuit, comprising a backup power module, a key-activated wake-up switch module, a boost control chip, a boost power conversion module, and an output voltage divider feedback module, characterized in that, It also includes an enable voltage divider module and a self-locking feedback module; The output terminal of the backup power module is connected to the input terminal of the button wake-up switch module, and the output terminal of the button wake-up switch module is connected to the system input bus; the system input bus is electrically connected to the input terminal of the boost power conversion module and the power pin VS of the boost control chip, respectively. The switching terminal of the boost power conversion module is electrically connected to the switching pin SW of the boost control chip, and the output terminal of the boost power conversion module is connected to the system output bus. The output voltage divider feedback module is connected in series between the system output bus and the reference ground, and the voltage divider node of the output voltage divider feedback module is electrically connected to the feedback pin FB of the boost control chip. The enable voltage divider module includes a first voltage divider resistor R1 and a second voltage divider resistor R2; one end of the first voltage divider resistor R1 is connected to the system input bus, and the other end of the first voltage divider resistor R1 is electrically connected to the enable pin EN of the boost control chip, one end of the second voltage divider resistor R2, and the first end of the self-locking feedback module; the other end of the second voltage divider resistor R2 is connected to reference ground; and the second end of the self-locking feedback module is connected to the system output bus.

2. The boost input Schmitt trigger circuit according to claim 1, characterized in that, The boost power conversion module includes a power inductor L and a diode D1. One end of the power inductor L serves as the input terminal of the boost power conversion module and is connected to the system input bus. The other end of the power inductor L serves as the switching terminal of the boost power conversion module and is electrically connected to the switching pin SW of the boost control chip and the anode of the diode D1. The cathode of the diode D1 serves as the output terminal of the boost power conversion module and is connected to the system output bus.

3. The boost input Schmitt trigger circuit according to claim 1, characterized in that, The output voltage divider feedback module includes a fourth voltage divider resistor R4 and a fifth voltage divider resistor R5. One end of the fourth voltage divider resistor R4 is connected to the system output bus, and the other end of the fourth voltage divider resistor R4 serves as the voltage divider node of the output voltage divider feedback module. It is also electrically connected to the feedback pin FB of the boost control chip and one end of the fifth voltage divider resistor R5. The other end of the fifth voltage divider resistor R5 is connected to the reference ground.

4. The boost input Schmitt trigger circuit according to claim 1, characterized in that, The self-locking feedback module is a self-locking feedback resistor R3. One end of the self-locking feedback resistor R3 serves as the first end of the self-locking feedback module and is connected to the enable pin EN of the boost control chip. The other end of the self-locking feedback resistor R3 serves as the second end of the self-locking feedback module and is connected to the system output bus.

5. The boost input Schmitt trigger circuit according to claim 1, characterized in that, The button wake-up switch module can be any one of a mechanical button switch, a MOSFET electronic switch, or a transistor electronic switch.

6. The boost input Schmitt trigger circuit according to claim 1, characterized in that, The input power module is one or both of lithium battery packs and supercapacitor modules.

7. A method for operating a boost input Schmitt trigger circuit, the method being applicable to the boost input Schmitt trigger circuit according to any one of claims 1-6, characterized in that, Includes the following steps: The trigger button wakes up the switch module and turns it on, allowing the backup power module's input voltage to be connected to the system input bus; The input voltage is divided by the first voltage divider resistor R1 and the second voltage divider resistor R2 of the enable voltage divider module and then output to the enable pin EN of the boost control chip. When the voltage of the system input bus rises to the circuit's turn-on threshold voltage, the voltage of the enable pin EN reaches the enable threshold of the boost control chip, and the boost control chip starts working. After the boost control chip is started, it outputs a high-frequency switching signal through the switch pin SW to control the boost power conversion module to complete the energy storage and release of electrical energy, boost the input low-voltage DC to high-voltage DC, and establish a stable output voltage at the system output bus. The output voltage of the system output bus is divided by the output voltage divider feedback module and fed back to the feedback pin FB of the boost control chip. The boost control chip adjusts the duty cycle of the switching signal in real time according to the voltage of the feedback pin FB to realize closed-loop voltage regulation control of the output voltage. After the output voltage of the system output bus is stabilized, the voltage of the output voltage divider feedback module is fed back to the enable pin EN of the boost control chip through the self-locking feedback module, pulling the potential of the enable pin EN high. When the voltage of the system input bus drops to the circuit's turn-off threshold voltage, the voltage of the enable pin EN is lower than the enable threshold of the boost control chip, the chip turns off, the output voltage is disconnected, and the Schmitt trigger turn-off control is completed.

8. The operating method of the boost input Schmitt trigger circuit according to claim 7, characterized in that, It also includes standby and hibernation steps: Disconnecting the button wakes up the switch in the switch module, completely disconnecting the backup power module from the subsequent circuit, resulting in no voltage input to the system input bus, no operation of the boost control chip, and the circuit entering a zero-power standby state.

9. The operating method of the boost input Schmitt trigger circuit according to claim 7, characterized in that, It also includes an output voltage configuration step: by adjusting the resistance ratio of the fourth voltage divider resistor R4 and the fifth voltage divider resistor R5 in the output voltage divider feedback module, the output voltage value of the system output bus is configured, and the output voltage V... OUT The calculation formula is: V OUT = V FB ×(1+ R4 / R5); Among them, V FB This is the reference voltage for the feedback pin of the boost control chip.

10. The operating method of the boost input Schmitt trigger circuit according to claim 7, characterized in that, It also includes a hysteresis voltage configuration step: by adjusting the resistance values ​​of the first voltage divider resistor R1 and the second voltage divider resistor R2 of the enable voltage divider module and the self-locking feedback resistor R3 of the self-locking feedback module, the magnitude of the Schmitt trigger hysteresis voltage is adjusted.

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