Battery low-voltage protection circuit

Abstract

The utility model relates to the technical field of battery protection, and discloses a battery low-voltage protection circuit which is high in safety and stable, and comprises a main control module (10c) which is configured in a voltage protection circuit and is used for outputting a control signal and an enable signal; the power supply input end of the protection loop module (10b) is connected with one end of the battery module, the protection loop module (10b) is used for acquiring a voltage signal, and the output end of the protection loop module (10b) is connected with the power supply end of the main control module (10c); the protection loop module (10b) compares an input voltage signal with a preset value, when the voltage value of the voltage signal is lower than the preset value, the protection loop module (10b) outputs a low level according to a comparison result, and the low level is used for controlling the master control module (10c) to be converted into a stop state from a standby state.

Description

Technical Field

[0001] The utility model relates to the technical field of battery protection, and more specifically, to a battery low-voltage protection circuit. Background Art

[0002] At present, most of the batteries used in flashlights are lithium batteries. In most application scenarios, when the voltage of the lithium battery is lower than 3V or 2.7V, the flashlight cannot continue to work.

[0003] At present, the control circuit basically controls the LED action through a single-chip microcomputer. However, when in standby, the single-chip microcomputer and its peripheral circuits will still continue to consume the lithium battery. The lithium battery discharges electricity to a relatively low voltage (such as 2.2V) for a long time and multiple times, resulting in damage or shortened life of the lithium battery due to over-discharge.

[0004] Therefore, how to completely disconnect the voltage circuit after the lithium battery enters the low-voltage state to improve the service life of the lithium battery has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a battery low-voltage protection circuit with high safety and stability in view of the above-mentioned defect that when in standby, the single-chip microcomputer and its peripheral circuits will still continue to consume the lithium battery, and the lithium battery discharges electricity to a relatively low voltage (such as 2.2V) for a long time and multiple times, resulting in damage or shortened life of the lithium battery due to over-discharge in the prior art.

[0006] The technical solution adopted by the utility model to solve its technical problems is to construct a battery low-voltage protection circuit, which includes:

[0007] A main control module, which is configured in the voltage protection circuit and is used for outputting a control signal and an enable signal;

[0008] A protection loop module, whose power input end is connected to one end of the battery module and is used for obtaining a voltage signal,

[0009] The output end of the protection loop module is connected to the power supply end of the main control module;

[0010] The protection loop module compares the input voltage signal with a preset value. When the voltage value of the voltage signal is lower than the preset value, the protection loop module outputs a low level according to the comparison result, and the low level is used to control the main control module to change from the standby state to the stop state;

[0011] The protection loop module includes a protection controller, a first MOS transistor and a second MOS transistor,

[0012] The power input terminal of the protection controller is connected to one end of the battery module for obtaining the voltage signal.

[0013] The source electrode of the first MOS transistor is connected to one end of the battery module for obtaining the voltage signal.

[0014] The drain electrode of the first MOS transistor is connected to the power supply terminal of the main control module.

[0015] The source electrode of the second MOS transistor is connected to the other end of the battery module.

[0016] The gate electrode of the second MOS transistor is connected to the gate control terminal of the protection controller.

[0017] The gate electrode of the first MOS transistor is connected to the drain electrode of the second MOS transistor.

[0018] When the voltage value of the voltage signal is lower than the preset value, the gate control terminal of the protection controller outputs a low level, and the first MOS transistor is controlled to turn off, so that no current signal exists at the power supply terminal of the main control module.

[0019] The protection circuit module further includes a voltage regulator.

[0020] The input terminal of the voltage regulator is connected to the drain electrode of the first MOS transistor.

[0021] The output terminal of the voltage regulator is connected to the power supply terminal of the main control module; it further includes a control module, whose power input terminal is connected to one end of the battery module for receiving the voltage signal input by the battery module.

[0022] The signal input terminal of the control module is connected to the control signal output terminal of the main control module for receiving the control signal.

[0023] The pulse input terminal of the control module is connected to the pulse signal output terminal of the main control module for receiving the pulse signal.

[0024] When the control signal output by the main control module is at a high level, the control module is controlled to conduct, and the voltage signal is used to trigger the LED assembly to work.

[0025] The pulse signal is used to control the brightness of the LED assembly.

[0026] In some embodiments, the first MOS transistor and the second MOS transistor are selected as N-channel MOS transistors.

[0027] In some embodiments, the control module includes a third MOS transistor and a fourth MOS transistor.

[0028] The source of the third MOS transistor is connected to one end of the battery module for receiving the voltage signal input by the battery module.

[0029] The drain of the third MOS transistor is connected to the positive electrode of the LED assembly.

[0030] The drain of the fourth MOS transistor is connected to the gate of the third MOS transistor.

[0031] The gate of the fourth MOS transistor is connected to the control signal output end of the main control module for receiving the control signal.

[0032] The source of the fourth MOS transistor is connected to the common terminal.

[0033] In some embodiments, the control module further includes a boost controller.

[0034] The power input end of the boost controller is connected to the drain of the third MOS transistor.

[0035] The pulse input end of the boost controller is connected to the pulse signal output end of the main control module for receiving the pulse signal.

[0036] The signal output end of the boost controller is connected to the positive electrode of the LED assembly.

[0037] In some embodiments, the third MOS transistor is selected as a P-channel MOS transistor.

[0038] The fourth MOS transistor is selected as an N-channel MOS transistor.

[0039] In some embodiments, a voltage detection module is further included. Its first end is connected to one end of the battery module for acquiring the voltage signal.

[0040] The second end of the voltage detection module is coupled to the external trigger signal end of the main control module.

[0041] The third end of the voltage detection module is connected to the enable end of the main control module.

[0042] In some embodiments, the voltage detection module includes a fifth MOS transistor.

[0043] The drain of the fifth MOS transistor is connected to one end of the battery module.

[0044] The source of the fifth MOS transistor is connected to the external trigger signal end of the main control module.

[0045] The gate of the fifth MOS transistor is connected to the enable end of the main control module.

[0046] In the battery low-voltage protection circuit of the present utility model, it includes a main control module and a protection circuit module for outputting control signals and enable signals. Among them, the protection circuit module compares the input voltage signal with a preset value. When the voltage value of the voltage signal is lower than the preset value, the protection circuit module outputs a low level according to the comparison result, and the low level is used to control the main control module to change from the standby state to the stop state. Compared with the prior art, by comparing the voltage signal with the preset value through the protection circuit module, when the voltage value of the voltage signal is lower than the preset value, the protection circuit module outputs a low level to stop the main control module and the peripheral circuit from standby according to the result. When the lithium battery voltage is lower than the set voltage, the protection circuit module is completely disconnected, causing the main control module and the peripheral circuit to stop operating, and not consuming the low-power battery. It can effectively solve the problem that when in standby, the single-chip microcomputer and the peripheral circuit will still continue to consume the lithium battery, and the lithium battery will be discharged to a relatively low voltage (such as 2.2V) for a long time and multiple times, resulting in damage or shortening of the life of the lithium battery due to over-discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present utility model will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0048] Figure 1a is the circuit schematic diagram of an embodiment of the control module provided by the present utility model;

[0049] Figure 1b is the circuit schematic diagram of an embodiment of the protection circuit module provided by the present utility model;

[0050] Figure 1c is the circuit schematic diagram of an embodiment of the main control module provided by the present utility model.

[0051] Figure 1d is the circuit schematic diagram of an embodiment of the voltage detection module and the switch module provided by the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific embodiments of the present utility model will now be described in detail with reference to the drawings.

[0053] As Figure 1a - Figure 1d shown, in the first embodiment of the battery low-voltage protection circuit of the present utility model, the battery low-voltage protection circuit includes a control module 10a, a protection circuit module 10b, a main control module 10c, and a switch and voltage detection module 10d.

[0054] Among them, the control module 10a functions as a switch, a filter for voltage regulation and dimming. It is used to receive the voltage signal input by the battery module (corresponding to VBAT). When the voltage signal is greater than 2.6V, the internal switching element (such as a MOS transistor) of the control module 10a is controlled to conduct, and the voltage signal is output to the positive electrode of the LED assembly to control the working state of the LED assembly.

[0055] For example: The voltage signal input by the battery module (corresponding to VBAT) has a wide range of 2.8V - 30V. It can support the application of 1 - 6 series-connected lithium batteries, output and drive an LED string up to 30V. The operating frequency is a fixed frequency of 1MHz, which minimizes external components. In addition, a wide dimming frequency range of 20kHz - 1MHz can be output through the pins of the control module 10a (corresponding to EN / PWM), and the internal soft start limits the inrush current. The protection functions include overvoltage protection for an open LED assembly.

[0056] The protection circuit module 10b sets a lowest preset value (such as 2.2V) for the voltage value of the battery module (corresponding to VBAT). It functions to detect signals, compare signals, and output a level signal according to the comparison result.

[0057] For example, when the voltage value of the battery module (corresponding to VBAT) is lower than the preset value (such as 2.2V), the protection circuit module 10b outputs a low-level signal according to the comparison result of the two, thereby controlling the internal switching element (such as a MOS transistor) to turn off, and then cutting off the current signal of the circuit to avoid the main control module 10c and the peripheral circuit from continuing to consume power from the battery module (corresponding to VBAT) when the battery module is at a low voltage value.

[0058] The main control module 10c functions to monitor the power of the battery module (corresponding to VBAT), switch to the power-saving mode, receive signals, enable signals, control signals, and output PWM pulse signals.

[0059] The switch module 10d is used to input a touch signal to the main control module 10c, and the main control module 10c adjusts the working mode or state of the control module 10a according to the input touch signal.

[0060] For example: When the voltage of the battery module (corresponding to VBAT) is greater than 2.6V, when the push-button switch S1 of the switch module is pressed, there will be voltage on V-LED, the control module 10a is controlled to conduct, and at the same time the main control module 10c also outputs a PWM signal to control the LED1 - LED5 of the control module 10a to be turned on and adjust their brightness.

[0061] The voltage detection module 10d is used to detect the voltage signal of the battery module (corresponding to VBAT). The main control module 10c controls the voltage detection module 10d to conduct, and then feeds back the detected voltage signal to the main control module 10c. When the fed-back voltage signal is lower than 2.6V, the main control module 10c stops outputting the control signal of low level, and the control module 10a is in the off state; otherwise, it outputs the control signal of high level.

[0062] Specifically, the main control module 10c is configured in the voltage protection circuit and is used to output control signals (high level or low level) and enable signals;

[0063] Further, the protection loop module 10b is provided with a preset value (such as 2.2V);

[0064] The power input terminal of the protection loop module 10b is connected to one end of the battery module (corresponding to VBAT) for obtaining the voltage signal.

[0065] The output terminal of the protection loop module 10b is connected to the power supply terminal of the main control module 10c;

[0066] The protection loop module 10b compares the input voltage signal with the preset value (such as 2.2V). When the voltage value of the voltage signal is lower than the preset value (such as 2.2V), the protection loop module 10b outputs a low level according to the comparison result of the two. The low level is used to control the switch tube inside it to turn off, so as to turn off the loop current loop, so that the main control module 10c changes from the standby state to the stop state, so as to avoid the main control module 10c and the peripheral circuit from continuing to consume the battery module (corresponding to VBAT) when the voltage value of the battery module (corresponding to VBAT) is at a low value.

[0067] Using this technical solution, the protection loop module 10b compares the voltage signal with the preset value. When the voltage value of the voltage signal is lower than the preset value, the protection loop module 10b outputs a low level according to the result to stop the standby of the main control module 10c and the peripheral circuit. When the voltage of the lithium battery is lower than the set voltage, the protection loop module 10b is completely disconnected, so that the main control module 10c and the peripheral circuit stop operating, and will not consume the low-power battery, which can effectively solve the problem that when in standby, the single-chip microcomputer and the peripheral circuit will still continue to consume the lithium battery, and the lithium battery discharges to a lower voltage (such as 2.2V) for a long time and multiple times, resulting in damage or shortening of the life of the lithium battery due to over-discharge.

[0068] In some embodiments, in order to ensure the reliability of the shutdown of the current loop of the main control module 10c, as Figure 1b shown, a protection controller U6, a first MOS transistor Q1 and a second MOS transistor Q2 can be arranged in the protection loop module 10b.

[0069] Among them, the protection controller U6 is provided with a preset value (such as 2.2V), and has the functions of signal reception, comparison, and output control level.

[0070] The first MOS transistor Q1 and the second MOS transistor Q2 act as switches, and both are selected as N-channel MOS transistors.

[0071] Specifically, the power input terminal (corresponding to pin 6) of the protection controller U6 is connected to one end of the battery module (corresponding to VBAT) through the thirty-second resistor R32 for obtaining a voltage signal.

[0072] The source electrode of the first MOS transistor Q1 is connected to one end of the battery module (corresponding to VBAT) for obtaining a voltage signal.

[0073] The drain electrode of the first MOS transistor Q1 is connected to the power supply terminal (corresponding to VDD-MUC) of the main control module 10c through the second diode D2.

[0074] The source electrode of the second MOS transistor Q2 is connected to the other end of the battery module (corresponding to VBAT).

[0075] The gate electrode of the second MOS transistor Q2 is connected to the gate control terminal (corresponding to pin 1) of the protection controller U6.

[0076] The gate electrode of the first MOS transistor Q1 is connected to the drain electrode of the second MOS transistor Q2 through the sixth resistor R6.

[0077] The gate electrode of the first MOS transistor Q1 is also connected to one end of the battery module (corresponding to VBAT) through the fifth resistor R5.

[0078] When the voltage value of the fed-back voltage signal is lower than the preset value (such as 2.2V), the gate control terminal of the protection controller U6 outputs a low level. At this time, the second MOS transistor Q2 is controlled to turn off, and no level signal is output at its drain electrode, thereby controlling the first MOS transistor Q1 to turn off, and the output circuit of the battery module (corresponding to VBAT) is turned off, so that no current signal exists at the power supply terminal of the main control module 10c.

[0079] In some embodiments, as Figure 1b shown, the protection loop module 10b further includes a voltage regulator U3 and an eighth MOS transistor Q8.

[0080] Among them, the input terminal (corresponding to the VIN terminal) of the voltage regulator U3 is connected to the cathode of the second diode D2, and the anode of the second diode D2 is connected to the drain electrode of the first MOS transistor Q1.

[0081] The output terminal of the voltage regulator U3 is connected to the power supply terminal (corresponding to VDD-MUC) of the main control module 10c.

[0082] An eighteenth capacitor C18 and a seventh capacitor C7 are also connected in parallel between the input terminal (corresponding to the VIN terminal) of the voltage regulator U3 and the cathode of the second diode D2.

[0083] An eighth capacitor C8 and a ninth capacitor C9 are connected in parallel to the power supply terminal (corresponding to VDD-MUC) of the main control module 10c.

[0084] That is, when both the second MOS transistor Q2 and the first MOS transistor Q1 are turned on, a current signal in the output loop of the battery module (corresponding to VBAT) flows through the second diode D2 and the voltage regulator U3, and then is input to the power supply terminal (corresponding to VDD-MUC) of the main control module 10c.

[0085] Furthermore, the gate of the eighth MOS transistor Q8 is connected to the charging control gate terminal (corresponding to pin 3) of the protection controller U6, the source of the eighth MOS transistor Q8 is connected to the other ends (which are the common terminals) of the eighth capacitor C8 and the ninth capacitor C9, and the drain of the eighth MOS transistor Q8 is connected to the other end (corresponding to the negative electrode) of the battery module (corresponding to VBAT).

[0086] When the charging control gate terminal (corresponding to pin 3) of the protection controller U6 outputs a high level, the eighth MOS transistor Q8 is controlled to be turned on, and a current loop is formed in the battery module (corresponding to VBAT).

[0087] When the charging control gate terminal (corresponding to pin 3) of the protection controller U6 outputs a low level, the eighth MOS transistor Q8 is controlled to be turned off, and the current loop of the battery module (corresponding to VBAT) is controlled to be turned off, which can also effectively prevent the voltage of the battery module (corresponding to VBAT) from being continuously consumed when it is in a low voltage state.

[0088] In some embodiments, in order to improve the performance of controlling the working state of the LED assembly, as Figure 1a shown, a control module 10a can be provided in the protection circuit for receiving the voltage signal input by the battery module (corresponding to VBAT), the input control signal of the main control module 10c, and the PWM pulse signal.

[0089] Specifically, the power input terminal of the control module 10a is connected to one end of the battery module (corresponding to VBAT) for receiving the voltage signal input by the battery module (corresponding to VBAT).

[0090] The signal input terminal of the control module 10a is connected to the control signal output terminal (corresponding to ON / OFF-P-LED) of the main control module 10c for receiving the control signal input by the main control module 10c.

[0091] The pulse input terminal (corresponding to the EN / PWM terminal) of the control module 10a is connected to the pulse signal output terminal (corresponding to pin 5) of the main control module 10c for receiving the pulse signal input by the main control module 10c.

[0092] When the control signal output by the main control module 10c is at a high level, the control module 10a is controlled to conduct, and the voltage signal is used to trigger the LED component to work.

[0093] Combined with the input pulse signal, the brightness of the LED component is controlled by this pulse signal.

[0094] In some embodiments, such as Figure 1a As shown, the control module 10a includes a switch branch 101. Among them, the switch branch 101 includes a third MOS transistor Q3 and a fourth MOS transistor Q4.

[0095] Among them, the above MOS transistor has a switching function.

[0096] The third MOS transistor Q3 is selected as a P-channel MOS transistor.

[0097] The fourth MOS transistor Q4 is selected as an N-channel MOS transistor.

[0098] Specifically, the source electrode of the third MOS transistor Q3 is connected to one end of the battery module (corresponding to VBAT) for receiving the voltage signal input by the battery module (corresponding to VBAT).

[0099] The drain electrode of the third MOS transistor Q3 is connected to the positive electrode of the LED component through the first inductor L1 and the first diode D1 connected in series.

[0100] The drain electrode of the fourth MOS transistor Q4 is connected to the gate electrode of the third MOS transistor Q3 through the twenty-first resistor R21.

[0101] The gate electrode of the third MOS transistor Q3 is connected to one end of the battery module (corresponding to VBAT) through the twentieth resistor R2.

[0102] The gate electrode of the fourth MOS transistor Q4 is connected to the control signal output terminal (corresponding to pin 12) of the main control module 10c for receiving the control signal.

[0103] The source electrode of the fourth MOS transistor Q4 is connected to the common terminal.

[0104] That is, when the control signal output by the main control module 10c is at a high level, the fourth MOS transistor Q4 is controlled to conduct, the level of the gate electrode of the third MOS transistor Q3 is pulled low, and it is controlled to conduct. The voltage signal (corresponding to 2.6V) output by the battery module (corresponding to VBAT) is input to the anode of the LED component (corresponding to LED1-LED5) through the third MOS transistor Q3, the first inductor L1 and the first diode D1, thereby controlling the LED component (corresponding to LED1-LED5) to conduct.

[0105] In some embodiments, such as Figure 1aAs shown, the control module 10a further includes a boost controller U2. Among them, the power input terminal (corresponding to pin 7) of the boost controller U2 is connected to the drain of the third MOS transistor Q3.

[0106] The pulse input terminal (corresponding to pin 9) of the boost controller U2 is connected to the pulse signal output terminal (corresponding to pin 5) of the main control module 10c for receiving pulse signals.

[0107] The signal output terminals (corresponding to pins 4 and 5) of the boost controller U2 are connected to the positive pole of the LED assembly.

[0108] When the third MOS transistor Q3 and the fourth MOS transistor Q4 are controlled to conduct, the LED assembly (corresponding to LED1-LED5) is lit. After the pulse signal input by the main control module 10c is boosted or adjusted by the boost controller U2, the LED assembly (corresponding to LED1-LED5) is dimmed.

[0109] In some embodiments, as Figure 1d shown, the voltage protection circuit includes a switch module 10d and a voltage detection module 10d.

[0110] Among them, the switch module 10d is used to input a touch signal to the main control module 10c, and the main control module 10c adjusts the working mode or state of the control module 10a according to the input touch signal.

[0111] The voltage detection module 10d is used to detect the voltage signal of the battery module (corresponding to VBAT) and feed back the obtained voltage signal to the main control module 10c.

[0112] Specifically, the first end of the voltage detection module 10d is connected to one end of the battery module (corresponding to VBAT) to obtain a voltage signal.

[0113] The second end of the voltage detection module 10d is coupled to the external trigger signal terminal (corresponding to pin 15) of the main control module 10c.

[0114] The third end of the voltage detection module 10d is connected to the enable terminal (corresponding to pin 16) of the main control module 10c.

[0115] Furthermore, the voltage detection module 10d includes a fifth MOS transistor Q5, which has a switching function.

[0116] Specifically, the drain of the fifth MOS transistor Q5 is connected to one end of the battery module (corresponding to VBAT) through the forty-third resistor R43.

[0117] The source of the fifth MOS transistor Q5 is connected to the external trigger signal terminal (corresponding to pin 15) of the main control module 10c through the sixty-first resistor R61.

[0118] The gate of the fifth MOS transistor Q5 is connected to the enable terminal (corresponding to pin 16) of the main control module 10c through the forty-ninth resistor R49.

[0119] Furthermore, the switch module 10d includes a push-button switch S1. One end of the push-button switch S1 is connected to the switch signal terminal (corresponding to pin 3) of the main control module 10c through the thirty-fourth resistor R34, and the other end of the push-button switch S1 is connected to the common terminal.

[0120] Its working principle is as follows: When the voltage of the battery module (corresponding to VBAT) is greater than 2.6V, it is regulated by the voltage regulator U3, and the output is 2.5V, providing a stable operating voltage for the MCU of the main control module 10c. The forty-third resistor R43 and the fifty-third resistor R53 are a voltage-dividing circuit for the voltage control of the battery module (corresponding to VBAT);

[0121] When the MCU of the main control module 10c needs to obtain the voltage value of the battery module (corresponding to VBAT), a high level is output from pin 16 of the main control module 10c to the gate of the fifth MOS transistor Q5, thereby controlling the fifth MOS transistor Q5 to conduct. The operation of the fifth MOS transistor Q5 is equivalent to connecting the forty-third resistor R43 and the fifty-third resistor R53, and after voltage division, it is supplied to pin 15 of the main control module 10c. If the battery voltage is too low, the output of pin 12 of the MCU is a low-level signal, and the fourth MOS transistor Q4 and the third MOS transistor Q3 will not conduct, and there will be no voltage at V-LED. When the push-button switch S1 is pressed in real time, the LED assembly (corresponding to LED1-LED5) will also have no response;

[0122] When the voltage of the battery module (corresponding to VBAT) is greater than 2.6V, when the push-button switch S1 is pressed, there is voltage at the V-LED terminal, indicating that the fourth MOS transistor Q4 and the third MOS transistor Q3 are operating. At the same time, pin 5 of the main control module 10c also outputs a PWM pulse signal to control the LED assembly (corresponding to LED1-LED5) to be lit. In addition, when the MCU of the main control module 10c needs to measure the voltage of the detected battery module (corresponding to VBAT), the enable terminal (corresponding to pin 16) of the main control module 10c outputs a high-level signal to make the fifth MOS transistor Q5 operate, and the actual voltage of the battery module (corresponding to VBAT) is obtained by voltage division using the forty-third resistor R43 and the fifty-third resistor R53.

[0123] When the voltage of the battery module (corresponding to VBAT) is lower than 2.6V, the main control module 10c outputs ON / OFF-P-LED to stop operating, thereby controlling the fourth MOS transistor Q4 and the third MOS transistor Q3 to cut off, and there is no power at V-LED. Therefore, the control module 10a will not operate;

[0124] At this time, the MCU and its peripherals of the main control module 10c are still powered on. When the voltage of the battery module (corresponding to VBAT) itself is greater than 2.6V, the LED component (corresponding to LED1-LED5) will continue to operate. After a period of time, the voltage of the battery module (corresponding to VBAT) will be lower than 2.6V again.

[0125] The main control module 10c outputs N / OFF-P-LED to stop operating. The main control module 10c and its peripherals still maintain voltage, and there is basically a loss of 2 mA. Therefore, the battery voltage will decrease after standby for a period of time. At this time, when the voltage of the battery module (corresponding to VBAT) is lower than 2.3V, the DO terminal of the protection controller U6 outputs a low level, thereby controlling the second MOS transistor Q2 and the first MOS transistor Q1 to cut off. There is no input voltage at the voltage input terminal of the voltage regulator U3, and the MCU of the main control module 10c stops operating. At this time, there is no 2 mA consumption, and only 0.1 uA of consumption remains. Therefore, the voltage of the battery module (corresponding to VBAT) will hardly decrease any further.

[0126] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. These all fall within the protection scope of the present invention.

Claims

1. A battery low voltage protection circuit, characterized in that: have: A main control module, which is configured in the voltage protection circuit and is used to output control signals and enable signals; The protection circuit module has a power input terminal connected to one end of the battery module to obtain a voltage signal. The output end of the protection circuit module is connected to the power supply end of the main control module; The protection circuit module compares the input voltage signal with a preset value. When the voltage value of the voltage signal is lower than the preset value, the protection circuit module outputs a low level according to the comparison result. The low level is used to control the main control module to switch from a standby state to a stop state. The protection circuit module includes a protection controller, a first MOS tube and a second MOS tube. The power input terminal of the protection controller is connected to one end of the battery module to obtain the voltage signal. The source of the first MOS tube is connected to one end of the battery module to obtain the voltage signal. The drain of the first MOS tube is connected to the power supply terminal of the main control module. The source of the second MOS tube is connected to the other end of the battery module. The gate of the second MOS tube is connected to the gate control terminal of the protection controller. The gate of the first MOS tube is connected to the drain of the second MOS tube, When the voltage value of the voltage signal is lower than the preset value, the gate control terminal of the protection controller outputs a low level, and the first MOS tube is controlled to be turned off, so that there is no current signal at the power supply terminal of the main control module; The protection circuit module also includes a voltage stabilizer. The input end of the voltage regulator is connected to the drain of the first MOS tube. The output end of the voltage regulator is connected to the power supply end of the main control module; and a control module is also included, whose power supply input end is connected to one end of the battery module and is used to receive the voltage signal input by the battery module. The signal input end of the control module is connected to the control signal output end of the main control module for receiving the control signal. The pulse input terminal of the control module is connected to the pulse signal output terminal of the main control module for receiving the pulse signal. When the control signal output by the main control module is at a high level, the control module is controlled to be turned on, and the voltage signal is used to trigger the LED component to work. The pulse signal is used to control the brightness of the LED component.

2. The battery low voltage protection circuit according to claim 1, characterized in that: The first MOS transistor and the second MOS transistor are selected as N-channel MOS transistors.

3. The battery low voltage protection circuit according to claim 1, characterized in that: The control module includes a third MOS tube and a fourth MOS tube, The source of the third MOS tube is connected to one end of the battery module and is used to receive the voltage signal input by the battery module. The drain of the third MOS tube is connected to the positive electrode of the LED component. The drain of the fourth MOS tube is connected to the gate of the third MOS tube, The gate of the fourth MOS tube is connected to the control signal output terminal of the main control module and is used to receive the control signal. The source of the fourth MOS tube is connected to the common end.

4. The battery low voltage protection circuit according to claim 3, characterized in that: The control module also includes a boost controller, The power input terminal of the boost controller is connected to the drain of the third MOS tube. The pulse input terminal of the boost controller is connected to the pulse signal output terminal of the main control module for receiving the pulse signal. The signal output terminal of the boost controller is connected to the positive electrode of the LED component.

5. The battery low voltage protection circuit according to claim 4, characterized in that: The third MOS tube is selected as a P-channel MOS tube, The fourth MOS tube is selected as an N-channel MOS tube.

6. The battery low voltage protection circuit according to claim 1, characterized in that: It also includes a voltage detection module, a first end of which is connected to one end of the battery module and is used to obtain the voltage signal. The second end of the voltage detection module is coupled to the external trigger signal end of the main control module. The third terminal of the voltage detection module is connected to the enable terminal of the main control module.

7. The battery low voltage protection circuit according to claim 6, characterized in that: The voltage detection module includes a fifth MOS tube, The drain of the fifth MOS tube is connected to one end of the battery module. The source of the fifth MOS tube is connected to the external trigger signal terminal of the main control module. The gate of the fifth MOS tube is connected to the enable terminal of the main control module.

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