A battery reverse output prevention control circuit and an electronic product

Abstract

The present application discloses a battery reverse output prevention control circuit and an electronic product, relating to the technical field of battery control. The circuit includes a detection and judgment module, a driving module, a charging switch transistor Q1, and a switch transistor Q2. The charging switch transistor Q1 and the switch transistor Q2 are connected in series in the battery charging circuit. The charging switch transistor Q1 is used to keep conducting when the battery is charging. The detection and judgment module obtains the battery charging current and judges the magnitude of the charging current and a preset current threshold. If the charging current is higher than the preset current threshold, the detection and judgment module drives the switch transistor Q2 to conduct through the driving module, so that the charging current flows through the switch transistor Q2. Otherwise, the detection and judgment module drives the switch transistor Q2 to turn off through the driving module, so that the charging current flows through the body diode of the switch transistor Q2. The above circuit and the electronic product including the same can prevent reverse voltage output at the battery charging port and will not have a great impact on the battery heat and charging efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of battery control, and particularly to a battery reverse output prevention control circuit and an electronic product. Background Art

[0002] In order to improve the safety of batteries, many foreign battery certifications require that there should be no voltage output at the charging port of the battery. Currently, the common practice is to connect a diode for preventing the reverse output of the battery in series in the battery charging circuit. By using the unidirectional conductivity of the diode, it is possible to avoid voltage output at the battery charging port. However, this method of connecting a diode in series in the battery charging circuit has the following defects: First, due to the large power consumption of the diode, it will increase the generation of heat in the battery pack during battery charging; second, due to the voltage drop of the diode, it will have a certain impact on the battery charging efficiency during battery charging.

[0003] Therefore, there is an urgent need to design a circuit that can both prevent reverse voltage output at the battery charging port and will not have a great impact on the battery heat and charging efficiency. Summary of the Invention

[0004] In order to prevent reverse voltage output at the battery charging port and will not have a great impact on the battery heat and charging efficiency, the present application provides a battery reverse output prevention control circuit and an electronic product.

[0005] In a first aspect, the present application provides a battery reverse output prevention control circuit, adopting the following technical solution: The circuit includes a detection and judgment module, a driving module, a charging switch tube Q1, and a switch tube Q2; the detection and judgment module is respectively connected to the negative electrode of the battery charging port and the driving module; the charging switch tube Q1 and the switch tube Q2 are connected in series in the battery charging circuit, and the control end of the switch tube Q2 is connected to the driving module; the end of the charging switch tube Q1 not connected to the switch tube Q2 is grounded; the end of the switch tube Q2 not connected to the charging switch tube Q1 is connected to the negative electrode of the battery charging port; the charging switch tube Q1 is used to remain conductive when the battery is charging;

[0006] The detection and judgment module is used to obtain the battery charging current I c , and judge the magnitude of the charging current I c and a preset current threshold I c(th) ;

[0007] If the charging current I c is higher than the preset current threshold I c(th) , then the detection and judgment module drives the switch tube Q2 to conduct through the driving module, so that the charging current I c flows through the switch tube Q2 to charge the battery;

[0008] If the charging current I c is lower than the preset current threshold I c(th) , then the detection and judgment module drives the switching transistor Q2 to turn off through the driving module, so that the charging current I c flows through the body diode of the switching transistor Q2 to charge the battery.

[0009] By adopting the above technical solution, when the battery charging current I c is relatively large, the switching transistor Q2 connected in series in the battery charging circuit is turned on, and then the charging current flows through the switching transistor Q2, ensuring normal charging of the battery. Compared with the traditional method using a diode, the switching transistor Q2 has less influence on the heat of the battery and the charging efficiency; when the battery charging current I c is relatively small or even there is no charging current, the switching transistor Q2 connected in series in the battery charging circuit is turned off, and then the charging current can only flow through the body diode of the switching transistor Q2. At this time, because the body diode of the switching transistor Q2 has a one-way conduction function, it can prevent the battery charging port from having a reverse voltage output, effectively avoiding the situation of battery discharging and ensuring the safety of the battery.

[0010] In a specific implementable embodiment, the detection and judgment module includes a comparator U1, a first voltage input sub-module and a second voltage input sub-module;

[0011] The non-inverting input terminal of the comparator U1 is connected to the first voltage input sub-module, and the inverting input terminal is connected to the second voltage input sub-module; the output terminal of the comparator U1 is connected to the driving module; the second voltage input sub-module is also connected to the negative electrode of the battery charging port;

[0012] The comparator U1 is configured to output a high-level signal to the driving module to drive the switching transistor Q2 to turn on when the voltage value at the non-inverting input terminal is higher than the voltage value at the inverting input terminal;

[0013] The comparator U1 is also configured to output a low-level signal to the driving module to drive the switching transistor Q2 to turn off when the voltage value at the non-inverting input terminal is lower than the voltage value at the inverting input terminal.

[0014] By adopting the above technical solution, the comparator U1 is used in the detection and judgment module, and the inverting input terminal of the comparator U1 is connected to the negative electrode of the battery charging port through the second voltage input sub-module, that is, the voltage at the inverting input terminal of the comparator U1 is determined by the voltage value of the battery charging port. By configuring a reference voltage at the non-inverting input terminal of the comparator U1, it can be realized that when the battery charging current I c is higher than the preset current threshold I c(th) , the comparator U1 outputs a low level; otherwise, it outputs a high level.

[0015] In a specific feasible implementation, the first voltage input sub-module includes resistor R3, resistor R4, and resistor R5;

[0016] The first end of resistor R3 is respectively connected to the first end of resistor R4, the first end of resistor R5, and the non-inverting input terminal of comparator U1; the second end of resistor R3 is connected to the supply voltage; the second end of resistor R4 is grounded; the second end of resistor R5 is connected to the output terminal of comparator U1.

[0017] By adopting the above technical solution, through the specific circuit design of the first voltage input sub-module, the configuration of the voltage at the non-inverting input terminal of comparator U1 is achieved.

[0018] In a specific feasible implementation, the second voltage input sub-module includes resistor R1, resistor R2, and switching transistor Q3;

[0019] The first end of resistor R1 is respectively connected to the first end of switching transistor Q3 and the inverting input terminal of comparator U1; the second end of switching transistor Q3 is connected to the first end of resistor R2; the second end of resistor R2 is connected to the negative pole of the battery charging port; the control terminal of switching transistor Q3 and the second end of resistor R1 are both connected to the supply voltage.

[0020] By adopting the above technical solution, through the specific circuit design of the second voltage input sub-module, a corresponding voltage value can be output to the inverting input terminal of comparator U1 based on the voltage value of the battery charging port, facilitating comparator U1 to perform comparison and judgment.

[0021] In a specific feasible implementation, the driving module includes switching transistor Q4, switching transistor Q5, and diode D1; the control terminal of switching transistor Q5 is connected to the detection and judgment module, the first end of switching transistor Q5 is connected to the control terminal of switching transistor Q4, and the second end of switching transistor Q5 is grounded;

[0022] The first end of switching transistor Q4 is connected to the supply voltage, the second end of switching transistor Q4 is connected to the positive pole of diode D1; the negative pole of diode D1 is connected to the control terminal of switching transistor Q2.

[0023] By adopting the above technical solution, through the specific circuit design of the driving module, the conduction and cutoff of switching transistor Q2 can be driven, and diode D1 is used to prevent current backflow, improving the system safety.

[0024] In a specific feasible implementation, the detection and judgment module further includes an LDO voltage regulation sub-module; the LDO voltage regulation sub-module is respectively connected to the supply voltage, the first voltage input sub-module, and the second voltage input sub-module;

[0025] The LDO voltage regulator sub-module is used to convert the supply voltage into a stable voltage U VCC , and output the voltage U VCC to the first voltage input sub-module and the second voltage input sub-module.

[0026] By adopting the above technical solution, the supply voltage is converted into a stable voltage U through the LDO voltage regulator sub-module VCC , providing a stable voltage source for the circuit.

[0027] In a specific feasible implementation, when the switching transistor Q3 is turned on, the voltage value U at the inverting input terminal of the comparator U1 - satisfies:

[0028] U - <(U VCC -U GS(th)Q3 ) (1);

[0029] where, U GS(th)Q3 represents the turn-on voltage of the switching transistor Q3;

[0030] When the comparator U1 outputs a high level, the voltage value at the non-inverting input terminal of the comparator U1 is denoted as U + ; when the comparator U1 outputs a low level, the voltage value at the non-inverting input terminal of the comparator U1 is denoted as U′ + ; then the voltage value U - , voltage value U + and voltage value U′ + respectively satisfy:

[0031]

[0032]

[0033]

[0034] where, U C- represents the voltage value of the negative electrode of the battery charging port, Rx represents the resistance value after the parallel connection of resistor R4 and resistor R5, Ry represents the resistance value after the parallel connection of resistor R3 and resistor R5,

[0035] In a specific feasible implementation, the voltage value U C- of the negative electrode of the battery charging port satisfies: U C- =I C *(R DS(ON)Q1 +R DS(ON)Q2 ) (5);

[0036] where, RDS(ON)Q1 Represents the on-resistance of the charging switch transistor Q1, R DS(ON)Q2 Represents the on-resistance of the switch transistor Q2, I C Represents the battery charging current;

[0037] At the critical value when the output level of the comparator U1 changes, there is a voltage value U' + = voltage value U - ; The voltage value U' + Satisfies:

[0038]

[0039] Where, I C(th) Represents the preset current threshold;

[0040] When I C > I C(th) Then, U - < U' + (7);

[0041] When I C < I C(th) Then, U - > U' + (8);

[0042] U' + > U + (9);

[0043] According to Formulas 1 to 9, and setting the value of the current threshold I C(th) , by adjusting the resistance values of the resistor R1, resistor R2, resistor R3, resistor R4 and resistor R5, it is achieved that when the battery charging current I C > I C(th) , the comparator U1 outputs a high level; when the battery charging current I C < I C(th) , the comparator U1 outputs a low level.

[0044] By adopting the above technical solution, those skilled in the art can, after setting the value of the current threshold I C(th) , by selecting appropriate resistance values of the resistor R1, resistor R2, resistor R3, resistor R4 and resistor R5, achieve the protection of battery charging, and avoid the output voltage at the battery charging port when the battery charging current is small, causing potential safety hazards.

[0045] In a second aspect, the present application provides an electronic product, and the electronic product includes a battery reverse output prevention control circuit as in any one of the first aspect or the implementable embodiments of the first aspect.

[0046] In summary, the technical solution of the present application at least includes the following beneficial technical effects:

[0047] When the battery charging current I c is relatively large, the switching transistor Q2 connected in series in the battery charging circuit is turned on, and the charging current flows through the switching transistor Q2, ensuring the normal charging of the battery. Compared with the traditional method using a diode, the switching transistor Q2 has less influence on the heat of the battery and the charging efficiency; when the battery charging current I c is relatively small or even there is no charging current, the switching transistor Q2 connected in series in the battery charging circuit is turned off, and the charging current can only flow through the body diode of the switching transistor Q2. At this time, because the body diode of the switching transistor Q2 has a one-way conduction function, it can prevent the battery charging port from having a reverse voltage output, effectively avoiding the situation of battery discharging and ensuring the safety of the battery. Description of the Drawings

[0048] Figure 1 is a schematic diagram of the battery reverse output prevention control circuit in an embodiment of the present application;

[0049] Figure 2 is the current waveform of the charging current I C and the output end of the driving module 2.

[0050] Description of the Reference Numerals:

[0051] 1. Detection and judgment module; 11. First voltage input sub-module; 12. Second voltage input sub-module; 13. LDO voltage regulation sub-module; 2. Driving module. Detailed Embodiment

[0052] To make the purpose, technical solution and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the drawings.

[0053] The embodiment of the present application provides a battery reverse output prevention control circuit. Referring to Figure 1 , the circuit includes a detection and judgment module 1, a driving module 2, a charging switching transistor Q1 and a switching transistor Q2; the detection and judgment module 1 is respectively connected to the negative electrode of the battery charging port and the driving module 2; the charging switching transistor Q1 and the switching transistor Q2 are connected in series in the battery charging circuit, and the control end of the switching transistor Q2 is connected to the driving module 2; the end of the charging switching transistor Q1 not connected to the switching transistor Q2 is grounded; the end of the switching transistor Q2 not connected to the charging switching transistor Q1 is connected to the negative electrode of the battery charging port; the charging switching transistor Q1 is used to remain on when the battery is charging, that is, the charging switching transistor Q1 is used to remain on when the battery is connected to the charger;

[0054] The detection and judgment module 1 is used to obtain the battery charging current I c , and judge the magnitude of the charging current I c and the preset current threshold I c(th) ;

[0055] If the charging current I c is higher than the preset current threshold I c(th) , then the detection and judgment module 1 drives the switch tube Q2 to conduct through the driving module 2, so that the charging current I c flows through the switch tube Q2 to charge the battery;

[0056] If the charging current I c is lower than the preset current threshold I c(th) , then the detection and judgment module 1 drives the switch tube Q2 to turn off through the driving module 2, so that the charging current I c flows through the body diode of the switch tube Q2 to charge the battery. Specifically, the positive electrode of the body diode of the switch tube Q2 is connected to the ground terminal through the charging switch tube Q1, and the negative electrode of the body diode of the switch tube Q2 is connected to the negative electrode of the battery charging port.

[0057] Further, the negative electrode of the above battery charging port is the negative electrode of the battery charger.

[0058] Therefore, when the battery charging current I c is relatively large, the switch tube Q2 connected in series in the battery charging circuit is made to conduct, then the charging current flows through the switch tube Q2, ensuring normal charging of the battery. Compared with the traditional method using a diode, the switch tube Q2 has less influence on the heat of the battery and the charging efficiency; when the battery charging current I c is relatively small or even there is no charging current, the switch tube Q2 connected in series in the battery charging circuit is made to turn off, then the charging current can only flow through the body diode of the switch tube Q2. Since the body diode of the switch tube Q2 has a one-way conduction function, it can prevent reverse voltage output at the battery charging port, effectively avoiding the situation of battery discharge and ensuring the safety of the battery.

[0059] In a possible implementation manner, continue to refer to Figure 1 , the detection and judgment module 1 includes a comparator U1, a first voltage input sub-module 11 and a second voltage input sub-module 12;

[0060] The non-inverting input terminal of the comparator U1 is connected to the first voltage input sub-module 11, and the inverting input terminal is connected to the second voltage input sub-module 12; the output terminal of the comparator U1 is connected to the driving module 2; the second voltage input sub-module 12 is also connected to the negative electrode of the battery charging port;

[0061] The comparator U1 is configured to output a high-level signal to the driving module 2 when the voltage value at the non-inverting input terminal is higher than the voltage value at the inverting input terminal, causing the driving module 2 to drive the switching transistor Q2 to conduct.

[0062] The comparator U1 is further configured to output a low-level signal to the driving module 2 when the voltage value at the non-inverting input terminal is lower than the voltage value at the inverting input terminal, causing the driving module 2 to drive the switching transistor Q2 to turn off.

[0063] Therefore, the comparator U1 is adopted in the detection and judgment module 1, and the inverting input terminal of the comparator U1 is connected to the negative electrode of the battery charging port through the second voltage input sub-module 12. That is, the voltage at the inverting input terminal of the comparator U1 is determined by the voltage value of the battery charging port. By configuring a reference voltage at the non-inverting input terminal of the comparator U1, it is possible to achieve that when the battery charging current I c is higher than the preset current threshold I c(th) the comparator U1 outputs a low level; otherwise, it outputs a high level.

[0064] In a possible implementation manner, referring to Figure 1 the first voltage input sub-module 11 includes a resistor R3, a resistor R4, and a resistor R5;

[0065] The first end of the resistor R3 is respectively connected to the first end of the resistor R4, the first end of the resistor R5, and the non-inverting input terminal of the comparator U1; the second end of the resistor R3 is connected to the supply voltage; the second end of the resistor R4 is grounded; the second end of the resistor R5 is connected to the output terminal of the comparator U1.

[0066] Through the specific circuit design of the first voltage input sub-module 11, the voltage at the non-inverting input terminal of the comparator U1 is configured.

[0067] In a possible implementation manner, referring to Figure 1 the second voltage input sub-module 12 includes a resistor R1, a resistor R2, and a switching transistor Q3;

[0068] The first end of the resistor R1 is respectively connected to the first end of the switching transistor Q3 and the inverting input terminal of the comparator U1; the second end of the switching transistor Q3 is connected to the first end of the resistor R2; the second end of the resistor R2 is connected to the negative electrode of the battery charging port; the control terminal of the switching transistor Q3 and the second end of the resistor R1 are both connected to the supply voltage.

[0069] Further, the second end of the resistor R3 is also connected to the control terminal of the switching transistor Q3 and the second end of the resistor R1.

[0070] Through the specific circuit design of the second voltage input sub-module 12, a corresponding voltage value can be output to the inverting input terminal of the comparator U1 based on the voltage value of the negative electrode of the battery charging port, facilitating the comparator U1 to perform comparison and judgment.

[0071] In a possible implementation manner, referring to Figure 1 , the driving module 2 includes a switching transistor Q4, a switching transistor Q5, and a diode D1;

[0072] The control terminal of the switching transistor Q5 is connected to the detection and judgment module 1, the first terminal of the switching transistor Q5 is connected to the control terminal of the switching transistor Q4, and the second terminal of the switching transistor Q5 is grounded;

[0073] The first terminal of the switching transistor Q4 is connected to the supply voltage, and the second terminal of the switching transistor Q4 is connected to the positive electrode of the diode D1; the negative electrode of the diode D1 is connected to the control terminal of the switching transistor Q2.

[0074] In this embodiment, when the detection and judgment module 1 outputs a high level, that is, when the comparator U1 outputs a high level, the switching transistors Q5 and Q4 are turned on, and then the current output from the supply voltage terminal passes through the switching transistor Q4 and the diode D1 to drive the switching transistor Q2 to turn on; when the detection and judgment module 1 outputs a low level, that is, when the comparator U1 outputs a low level, the switching transistors Q5 and Q4 are turned off, and the switching transistor Q2 is not turned on.

[0075] Therefore, through the specific circuit design of the driving module 2, the on and off of the switching transistor Q2 can be driven, and the diode D1 is used to prevent current backflow, improving the system safety.

[0076] In a possible implementation manner, referring to Figure 1 , the detection and judgment module 1 further includes an LDO voltage regulator sub-module 13; the LDO voltage regulator sub-module 13 is respectively connected to the supply voltage, the first voltage input sub-module 11, and the second voltage input sub-module 12; specifically, the LDO voltage regulator sub-module 13 is respectively connected to the control terminal of the switching transistor Q3, the second terminal of the resistor R1, and the second terminal of the resistor R3;

[0077] The LDO voltage regulator sub-module 13 is used to convert the supply voltage into a stable voltage U VCC , and output the voltage U VCC to the first voltage input sub-module 11 and the second voltage input sub-module 12.

[0078] By converting the supply voltage into a stable voltage U VCC through the LDO voltage regulator sub-module 13, a stable voltage source is provided for the circuit.

[0079] In a possible implementation, according to Figure 1 , when the switching transistor Q3 is turned on, the voltage value U at the inverting input terminal of the comparator U1 - satisfies:

[0080] U - < (U VCC - U GS(th)Q3 ) (1);

[0081] Where, U GS(th)Q3 represents the turn-on voltage of the switching transistor Q3.

[0082] When the comparator U1 outputs a high level, the voltage value at the non-inverting input terminal of the comparator U1 is denoted as U + ; when the comparator U1 outputs a low level, the voltage value at the non-inverting input terminal of the comparator U1 is denoted as U' + ; then the voltage values U - , voltage value U + and voltage value U' + respectively satisfy:

[0083]

[0084]

[0085]

[0086] Where, U C- represents the voltage value of the negative electrode of the battery charging port, Rx represents the resistance value after the parallel connection of resistor R4 and resistor R5, Ry represents the resistance value after the parallel connection of resistor R3 and resistor R5, In the formula, R1 represents the resistance value of resistor R1, R2 represents the resistance value of resistor R2, R3 represents the resistance value of resistor R3, and R4 represents the resistance value of resistor R4.

[0087] Referring to Figure 1 , and since the charging switching transistor Q1 and the switching transistor Q2 are connected in series in the battery charging circuit, and the end of the charging switching transistor Q1 not connected to the switching transistor Q2 is grounded; the end of the switching transistor Q2 not connected to the charging switching transistor Q1 is connected to the negative electrode of the battery charging port; when there is a charging current I C at the negative electrode of the battery charging port, then the voltage value U C- of the negative electrode of the battery charging port satisfies:

[0088] U C- = I C * (R DS(ON)Q1 + R DS(ON)Q2 ) (5);

[0089] Among them, R DS(ON)Q1 represents the on-resistance of the charging switch transistor Q1, and R DS(ON)Q2 represents the on-resistance of the switch transistor Q2, and I C represents the battery charging current.

[0090] Furthermore, when the output level of the comparator U1 undergoes a conversion at the critical value, there is a voltage value U' + = the voltage value U - ; the voltage value U' + satisfies:

[0091]

[0092] Among them, I C(th) represents the preset current threshold;

[0093] When I C > I C(th) , U - < U' + (7);

[0094] When I C < I C(th) , U - > U' + (8);

[0095] U' + > U + (9);

[0096] According to Formulas 1 to 9, set the value of the current threshold I C(th) , and by adjusting the resistance values of the resistor R1, resistor R2, resistor R3, resistor R4, and resistor R5, it can be achieved that when the battery charging current I C > I C(th) , the comparator U1 outputs a high level; when the battery charging current I C < I C(th) , the comparator U1 outputs a low level.

[0097] Therefore, according to the above formulas, those skilled in the art can, after setting the value of the current threshold I C(th) , achieve the protection of battery charging by selecting appropriate resistance values of the resistor R1, resistor R2, resistor R3, resistor R4, and resistor R5, and avoid the output voltage at the battery charging port when the battery charging current is small, thus causing potential safety hazards.

[0098] Exemplarily, referring to Figure 2 , for the control circuit adopting the embodiment of the present application, and after setting the current threshold I C(th) , the charging current I CThe waveform at the output terminal of the waveform and drive module 2 and the current waveform at the output terminal of the drive module 2;

[0099] As can be seen from the figure: The charging current I C starts to decrease from 1 A, and each step decreases by 100 mA. When the charging current I C drops to 300 mA, the drive module 2 starts to control the switch Q2 to turn off; until the current and voltage at the negative electrode of the battery charging port both return to 0, that is, when the charger output current and voltage both return to 0, the switch Q2 is completely turned off, thereby preventing the output voltage of the battery charging port from discharging through the charging circuit and improving the battery safety.

[0100] The embodiment of the present application provides an electronic product, and the electronic product includes the above battery anti-reverse output control circuit.

[0101] The above are all the preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A battery anti-reverse output control circuit, characterized in that: The invention comprises a detection and judgment module (1), a driving module (2), a charging switch tube Q1 and a switch tube Q2; the detection and judgment module (1) is connected to the negative pole of the battery charging port and the driving module (2) respectively; the charging switch tube Q1 and the switch tube Q2 are connected in series in the battery charging circuit, and the control end of the switch tube Q2 is connected to the driving module (2); the end of the charging switch tube Q1 not connected to the switch tube Q2 is grounded; the end of the switch tube Q2 not connected to the charging switch tube Q1 is connected to the negative pole of the battery charging port; the positive pole of the body diode of the switch tube Q2 is grounded through the charging switch tube Q1, and the negative pole of the body diode of the switch tube Q2 is connected to the negative pole of the battery charging port; the charging switch tube Q1 is used to remain conductive when the battery is charging; The detection and judgment module (1) is used to obtain the battery charging current I c , and judge the charging current I c With the preset current threshold I c(th) size; If the charging current I c Higher than the preset current threshold I c(th) , the detection and judgment module (1) drives the switch tube Q2 to conduct through the driving module (2), so that the charging current I c The current flows through the switch tube Q2 to charge the battery; If the charging current I c Lower than the preset current threshold I c(th) , the detection and judgment module (1) drives the switch tube Q2 to turn off through the driving module (2), so that the charging current I c The current flowing through the body diode of the switch tube Q2 charges the battery; The detection and judgment module (1) includes a comparator U1, a first voltage input submodule (11) connected to one input end of the detection and judgment module (1), and a second voltage input submodule (12) connected to another input end of the detection and judgment module (1); the output end of the comparator U1 is connected to the driving module (2); the second voltage input submodule (12) is also connected to the negative pole of the battery charging port; The first voltage input submodule (11) comprises a resistor R3, a resistor R4 and a resistor R5; The first end of the resistor R3 is connected to the first end of the resistor R4, the first end of the resistor R5 and the non-inverting input terminal of the comparator U1 respectively; the second end of the resistor R3 is connected to the power supply voltage; the second end of the resistor R4 is grounded; and the second end of the resistor R5 is connected to the output terminal of the comparator U1; The second voltage input submodule (12) comprises a resistor R1, a resistor R2 and a switch tube Q3; The first end of the resistor R1 is connected to the first end of the switch tube Q3 and the inverting input end of the comparator U1 respectively; the second end of the switch tube Q3 is connected to the first end of the resistor R2; the second end of the resistor R2 is connected to the negative electrode of the battery charging port; the control end of the switch tube Q3 and the second end of the resistor R1 are both connected to the power supply voltage.

2. The battery reverse output prevention control circuit according to claim 1, characterized in that: The comparator U1 has a non-inverting input terminal connected to the first voltage input submodule (11), and an inverting input terminal connected to the second voltage input submodule (12); the comparator U1 is configured to output a high-level signal to the driving module (2) when the voltage value at the non-inverting input terminal is higher than the voltage value at the inverting input terminal, so that the driving module (2) drives the switch tube Q2 to conduct; The comparator U1 is further configured to output a low-level signal to the driving module (2) when the voltage value of the non-inverting input terminal is lower than the voltage value of the inverting input terminal, so that the driving module (2) drives the switch tube Q2 to turn off.

3. The battery reverse output prevention control circuit according to claim 1, characterized in that: The driving module (2) comprises a switch tube Q4, a switch tube Q5 and a diode D1; The control end of the switch tube Q5 is connected to the detection and judgment module (1), the first end of the switch tube Q5 is connected to the control end of the switch tube Q4, and the second end of the switch tube Q5 is grounded; The first end of the switch tube Q4 is connected to the power supply voltage, the second end of the switch tube Q4 is connected to the anode of the diode D1 ; the cathode of the diode D1 is connected to the control end of the switch tube Q2 .

4. The battery reverse output prevention control circuit according to claim 1, characterized in that: The detection and judgment module (1) further includes an LDO voltage stabilizing submodule (13); the LDO voltage stabilizing submodule (13) is respectively connected to the power supply voltage, the first voltage input submodule (11) and the second voltage input submodule (12); The LDO voltage stabilizing submodule (13) is used to convert the supply voltage into a stable voltage U VCC and the voltage U VCC The output is to a first voltage input submodule (11) and a second voltage input submodule (12).

5. The battery reverse output prevention control circuit according to claim 4, characterized in that: When the switch tube Q3 is turned on, the voltage value U - satisfy: IN - <(U VCC -IN GS(th)Q3 ) (1); Among them, U GS(th)Q3 Indicates the turn-on voltage of the switch tube Q3; When the comparator U1 outputs a high level, the voltage value of the non-inverting input terminal of the comparator U1 is recorded as U + When the comparator U1 outputs a low level, the voltage value of the comparator U1 non-inverting input terminal is recorded as U' + ; Then the voltage value U - , voltage value U + and voltage value U' + Satisfy respectively: Among them, U C- Indicates the voltage value of the negative electrode of the battery charging port, Rx indicates the resistance value of the resistor R4 and the resistor R5 in parallel, Ry represents the resistance value of resistor R3 and resistor R5 connected in parallel.

6. The battery reverse output prevention control circuit according to claim 5, characterized in that: The voltage value U of the negative electrode of the battery charging port C- satisfy: U C- =I C *(R DS(ON)Q1 +R DS(ON)Q2 ) (5); Among them, R DS(ON)Q1 Indicates the on-state internal resistance of the charging switch tube Q1, R DS(ON)Q2 Indicates the on-state internal resistance of the switch tube Q2, I C Indicates the battery charging current; When the comparator U1 outputs a critical value of the level conversion, there is a voltage value U' + = voltage value U - The voltage value U' + satisfy: Among them, I C(th) Indicates the preset current threshold; This I C >I C(th) time, U - <U' + (7) This I C <I C(th) time, U - >U' + (8) IN' + >In + (9); According to formula 1 to formula 9, the current threshold I is set C(th) By adjusting the resistance values of the resistors R1, R2, R3, R4 and R5, the battery charging current I C >I C(th) When the battery charging current I C <I C(th) When , the comparator U1 outputs a low level.

7. An electronic product, characterized in that: The invention comprises the battery reverse output prevention control circuit according to any one of claims 1 to 6.

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