Charging control circuit and electronic equipment

Abstract

This invention discloses a charging control circuit and electronic device. The charging control circuit includes: a power input terminal for connecting to an input power source; a power output terminal for connecting to a battery module; a constant current charging circuit and a constant voltage charging circuit, wherein the constant current charging circuit and the constant voltage charging circuit are connected in parallel between the power input terminal and the power output terminal, and the control terminal of the constant current charging circuit is also connected to the controlled terminal of the constant voltage charging circuit. The constant current charging circuit provides a constant charging current to the battery module and stops operating when the battery module voltage exceeds a preset voltage, and outputs a constant voltage charging trigger signal to the constant voltage charging circuit to control the constant voltage charging circuit to provide a constant charging voltage to the battery module. This invention solves the problem that existing charging circuits easily damage batteries.

Description

Technical Field

[0001] This invention relates to the field of charging management technology, and in particular to a charging control circuit and electronic device. Background Technology

[0002] There are many charging methods for existing batteries, including constant current charging, constant voltage charging, and constant voltage current limiting. Most existing technologies use either constant voltage charging or constant current charging. However, either constant voltage charging or constant current charging does not conform to the charging logic of lithium batteries and can easily damage the battery, thus affecting its lifespan. Summary of the Invention

[0003] The main objective of this invention is to propose a charging control circuit that aims to solve the problem that existing charging circuits are prone to damaging batteries.

[0004] To achieve the above objectives, the present invention provides a charging control circuit comprising:

[0005] Power input terminal, used to connect to the input power supply;

[0006] The power output terminal is used to connect the battery module;

[0007] A constant current charging circuit and a constant voltage charging circuit are provided, wherein the constant current charging circuit and the constant voltage charging circuit are connected in parallel between the power input terminal and the power output terminal, and the control terminal of the constant current charging circuit is also connected to the controlled terminal of the constant voltage charging circuit; wherein...

[0008] The constant current charging circuit is used to provide a constant charging current to the battery module, and stops working when the voltage of the battery module is greater than a preset voltage. It also outputs a constant voltage charging trigger signal to the constant voltage charging circuit to control the constant voltage charging circuit to provide a constant charging voltage to the battery module.

[0009] Optionally, the constant current charging circuit includes:

[0010] A constant current circuit, wherein the input terminal of the constant current circuit is connected to the power input terminal and the output terminal of the constant current circuit is connected to the power output terminal, and the constant current circuit is used to provide a constant charging current for the battery module;

[0011] A feedback indicator circuit is provided, wherein the detection terminal of the feedback indicator circuit is connected to the power output terminal, the feedback indicator circuit is used to detect the voltage of the power output terminal, and outputs a constant voltage charging trigger signal when the voltage of the power output terminal is greater than a preset voltage.

[0012] A switch control circuit is provided, wherein the controlled terminal of the switch control circuit is connected to the output terminal of the feedback indicator circuit, and the control terminal of the switch control circuit is connected to the controlled terminals of the constant current circuit and the constant voltage charging circuit respectively. The switch control circuit is used to control the constant current circuit to stop working when a constant voltage charging trigger signal is received, and to control the constant voltage charging circuit to provide a constant charging voltage to the battery module.

[0013] Optionally, the feedback indication circuit is further configured to output charging indication information when the voltage at the power output terminal is less than a preset voltage.

[0014] Optionally, the constant current circuit includes:

[0015] A constant current source circuit, wherein the input terminal of the constant current source circuit is connected to the power input terminal, the output terminal of the constant current source circuit is connected to the power output terminal, and the controlled terminal of the constant current source circuit is connected to the control terminal of the switch control circuit, and the constant current source circuit is used to provide a constant charging current for the battery module.

[0016] A current regulating circuit is electrically connected to the constant current source circuit. The current regulating circuit is used to regulate the charging current output by the constant current source circuit when triggered by the user.

[0017] Optionally, the constant current circuit includes a first capacitor, a third transistor, a fourth transistor, a second field-effect transistor, and a potentiometer. The collector of the third transistor is connected to the power input terminal, and the emitter of the third transistor is connected to the power output terminal. The collector of the fourth transistor is connected to the power input terminal, and the emitter of the fourth transistor is connected to both the base of the third transistor and the base of the fourth transistor. The base of the fourth transistor is also connected to the first terminal of the potentiometer, and the second terminal of the potentiometer is grounded. The input terminal of the second field-effect transistor is connected to the power input terminal, and the output terminal of the second field-effect transistor is connected to the third terminal of the potentiometer. The controlled terminal of the second field-effect transistor is connected to the control terminal of the switch control circuit. The first terminal of the first capacitor is connected to the collector of the fourth transistor, and the second terminal of the first capacitor is connected to both the first and third terminals of the potentiometer.

[0018] Optionally, the feedback indicator circuit includes a first resistor, a second resistor, a light-emitting diode (LED), a first transistor, and a second transistor. The first end of the first resistor is connected to the power input terminal, the second end of the first resistor is connected to the collector of the first transistor, and the emitter of the first transistor is connected to the power output terminal. The first end of the second resistor is connected to the power input terminal, and the second end of the second resistor is connected to the anode of the LED. The cathode of the LED is connected to the collector of the second transistor, and the emitter of the second transistor is connected to the power output terminal. The second end of the first resistor is also connected to the base of the first transistor, and the base of the first transistor is also connected to the base of the second transistor. The common terminal of the LED and the second transistor is connected to the controlled terminal of the switch control circuit.

[0019] Optionally, the switch control circuit includes a third resistor, a fourth resistor, and a first field-effect transistor. The first end of the third resistor is connected to the power input terminal, the second end of the third resistor is connected to the input terminal of the first field-effect transistor, the output terminal of the first field-effect transistor is connected to the first end of the fourth resistor, the second end of the fourth resistor is grounded, the controlled terminal of the first field-effect transistor is also connected to the output terminal of the feedback indicator circuit, and the second end of the third resistor is also connected to the controlled terminals of the constant current circuit and the constant voltage charging circuit, respectively.

[0020] Optionally, the charging control circuit further includes:

[0021] A voltage conversion circuit is provided, wherein the input terminal of the voltage conversion circuit is connected to the power input terminal, and the output terminal of the voltage conversion circuit is connected to the input terminal of the constant current charging circuit. The voltage conversion circuit is used to convert the power supply into a charging power supply and then output it.

[0022] Optionally, the constant voltage charging circuit is an LDO voltage regulator circuit.

[0023] The present invention also proposes an electronic device, including a battery module and the above-mentioned charging control circuit.

[0024] In this invention, by setting up a constant current charging circuit and a constant voltage charging circuit, constant current charging and constant voltage charging of the battery module are achieved. Furthermore, the charging mode of the battery module can be intelligently switched according to the voltage of the battery module, thereby ensuring that the charging of the battery module conforms to the charging logic, reducing the damage caused by charging the battery, and extending the battery's service life. This solves the problem that existing charging circuits are prone to damaging the battery. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a functional module diagram of an embodiment of the charging control circuit of the present invention;

[0027] Figure 2 This is a functional module schematic diagram of another embodiment of the charging control circuit of the present invention;

[0028] Figure 3 This is a schematic diagram of the circuit structure of an embodiment of the charging control circuit of the present invention;

[0029] Figure 4 This is a functional module schematic diagram of another embodiment of the charging control circuit of the present invention.

[0030] Explanation of icon numbers:

[0031] label name label name 10 Constant current charging circuit led LED 20 Constant voltage charging circuit RF potentiometer 30 Voltage conversion circuit C1 First capacitor 11 constant current circuit Q1~Q4 Transistor 1 to Transistor 4 12 Feedback indicator circuit M1, M2 First field-effect transistor, second field-effect transistor 13 Switch control circuit

[0032] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0035] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0036] This invention proposes a charging control circuit.

[0037] Currently, there are many charging methods for existing batteries, including constant current charging, constant voltage charging, and constant voltage current limiting. Most existing technologies use either constant voltage charging or constant current charging. However, either constant voltage charging or constant current charging does not conform to the charging logic of lithium batteries and can easily damage the battery, thus affecting its lifespan.

[0038] To solve the above problems, refer to Figures 1 to 3 In one embodiment, the charging control circuit includes:

[0039] Power input terminal, used to connect to the input power supply;

[0040] The power output terminal is used to connect the battery module;

[0041] A constant current charging circuit 10 and a constant voltage charging circuit 20 are provided, wherein the constant current charging circuit 10 and the constant voltage charging circuit 20 are connected in parallel between the power input terminal and the power output terminal, and the control terminal of the constant current charging circuit 10 is also connected to the controlled terminal of the constant voltage charging circuit 20; wherein,

[0042] The constant current charging circuit 10 is used to provide a constant charging current to the battery module, and stops working when the voltage of the battery module is greater than a preset voltage. It also outputs a constant voltage charging trigger signal to the constant voltage charging circuit 20 to control the constant voltage charging circuit 20 to provide a constant charging voltage to the battery module.

[0043] In this embodiment, the constant current charging circuit 10 can be implemented using a mirror constant current circuit 11, a constant current source, or other constant current circuits 11, to provide a constant charging current for the battery module, enabling constant current charging of the battery module. The constant current charging circuit 10 can also include a voltage detection circuit and a switch control circuit 13, which can be implemented using discrete components such as switching transistors, capacitors, and resistors to control the operating state of the constant voltage charging circuit 20. The constant voltage charging circuit 20 can be implemented using an LDO voltage regulator circuit, a constant voltage source, or other constant voltage circuits, to provide a constant charging voltage for the battery module, enabling constant voltage charging of the battery module.

[0044] It is understood that battery charging typically involves a constant current charging phase and a constant voltage charging phase. The battery first undergoes constant current charging, and when the battery voltage rises to a certain value, the constant current charging phase ends and the battery enters the constant voltage charging phase until charging is stopped. Therefore, in this embodiment, the constant current charging circuit 10 can also stop operating when the battery module voltage exceeds a preset voltage, while simultaneously outputting a constant voltage charging trigger signal to the constant current charging circuit 10 to control the constant voltage charging circuit 20 to operate. This allows the battery module to transition from the constant current charging phase to the constant voltage charging phase, thus conforming to the charging logic of the battery module, reducing damage caused by battery charging, and extending the battery's lifespan. The constant current charging circuit 10 can include a voltage detection circuit, or use discrete components such as switching transistors and resistors to implement voltage detection and signal output. This allows the constant current charging circuit 10 to output a signal to the constant voltage charging circuit 20 when the battery module transitions from the constant current charging phase to the constant voltage charging phase, thereby switching the charging mode of the battery module.

[0045] Reference Figure 3 , Figure 3This is a schematic diagram of the circuit structure of an embodiment of the charging control circuit. The constant current charging circuit 10 consists of a feedback indicator circuit 12, a constant current circuit 11, and a switch control circuit 13. The constant current circuit 11 is composed of a first capacitor C1, a third transistor Q3, a fourth transistor Q4, a second field-effect transistor M2, and a potentiometer RF. The feedback indicator circuit 12 is composed of a first resistor R1, a second resistor R2, a light-emitting diode LED, a first transistor Q1, and a second transistor Q2. The constant voltage charging circuit 20 is an LDO voltage regulator circuit. The switch control circuit 13 is composed of a third resistor R3, a fourth resistor R4, and a first field-effect transistor M1. When charging of the battery begins, the positive terminal voltage of the battery module is very low. The VBE voltage of the first transistor Q1 and the second transistor Q2 is greater than the turn-on voltage. At this time, the first transistor Q1 and the second transistor Q2 are turned on, and the constant current circuit 11 generates a constant current output to the battery module. Since the second transistor Q2 is turned on at this time, the gate of the first field-effect transistor M1 is at a low level, the first field-effect transistor M1 is turned off, and the power supply outputs a high level to the LDO voltage regulator circuit and the second field-effect transistor M2 through the third resistor R3. Here, the LDO voltage regulator circuit can be set to low level enable, so the LDO voltage regulator circuit does not work at this time, and the VGS of the second field-effect transistor M2 is >0, so it is in the off state, which enables the constant current charging circuit 10 to work normally and generate a constant current to charge the battery module. As charging proceeds normally, the voltage at the positive terminal of the battery module gradually increases. When the voltage at the positive terminal reaches the preset voltage, the VBE voltage of the first transistor Q1 and the second transistor Q2 is less than the turn-on voltage, causing them to turn off. The gate of the first field-effect transistor M1 becomes high, triggering a constant-voltage charging signal. This turns on the first field-effect transistor M1, causing the gates of the LDO voltage regulator circuit and the second field-effect transistor M2 to become low, enabling the LDO voltage regulator circuit to perform constant-voltage charging of the battery module. The preset voltage can be the voltage at which the battery module receives constant-current charging. Simultaneously, the second field-effect transistor M2 turns on, preventing the constant-current circuit 11 from operating normally, thus causing the charging control circuit to switch to constant-voltage charging mode to charge the battery module.

[0046] In this invention, by setting up a constant current charging circuit 10 and a constant voltage charging circuit 20, constant current charging and constant voltage charging of the battery module are achieved. Furthermore, the charging mode of the battery module can be intelligently switched according to its voltage, ensuring that the charging of the battery module conforms to the charging logic, thereby reducing damage caused by charging and extending the battery's lifespan. This invention utilizes pure hardware circuitry to achieve voltage detection and charging mode control switching, eliminating the need for integrated chips. This improves the accuracy of the mode switching trigger point, the stability of mode switching, and the response speed of mode switching. Moreover, the hardware circuit structure used is simple and easy to implement, effectively reducing the cost of the charging control circuit and facilitating its use and promotion.

[0047] Reference Figures 1 to 3 In one embodiment, the constant current charging circuit 10 includes:

[0048] A constant current circuit 11 is provided, wherein the input terminal of the constant current circuit 11 is connected to the power input terminal, and the output terminal of the constant current circuit 11 is connected to the power output terminal. The constant current circuit 11 is used to provide a constant charging current for the battery module.

[0049] Feedback indicator circuit 12, the detection terminal of the feedback indicator circuit 12 is connected to the power output terminal, the feedback indicator circuit 12 is used to detect the voltage of the power output terminal, and output a constant voltage charging trigger signal when the voltage of the power output terminal is greater than a preset voltage;

[0050] A switch control circuit 13 is provided, the controlled terminal of which is connected to the output terminal of the feedback indication circuit 12, and the control terminal of which is connected to the controlled terminals of the constant current circuit 11 and the constant voltage charging circuit 20 respectively. The switch control circuit 13 is used to control the constant current circuit 11 to stop working when a constant voltage charging trigger signal is received, and to control the constant voltage charging circuit 20 to provide a constant charging voltage to the battery module.

[0051] In this embodiment, the feedback indicator circuit 12 can use discrete components such as switching transistors, resistors, and capacitors to detect the voltage at the power output terminal. When the voltage at the power output terminal is greater than a preset voltage, it can output a constant voltage charging trigger signal to control the constant voltage charging circuit 20 to switch the battery charging mode. The constant current circuit 11 can be implemented using a mirror constant current circuit 11, a constant current source, or other constant current circuits to provide a constant charging current for the battery module, enabling the battery module to perform constant current charging. The switch control circuit 13 can use discrete components such as switching transistors, resistors, and capacitors to control the constant current circuit 11 and the constant voltage charging circuit 20.

[0052] Optionally, the feedback indication circuit 12 is also used to output charging indication information when the voltage at the power output terminal is less than a preset voltage.

[0053] In one embodiment, the feedback indicator circuit 12 may also be equipped with indicator devices such as light-emitting diodes, digital tubes, and displays to realize the function of indicating charging information. (See also...) Figure 3 , Figure 3 This is a schematic diagram of a circuit structure for an embodiment of a charging control circuit. In this circuit, a first resistor R1, a second resistor R2, a light-emitting diode (LED), a first transistor Q1, and a second transistor Q2 form a feedback indicator circuit 12. When charging of the battery begins, the positive terminal voltage of the battery module is very low. The VBE voltage of the first transistor Q1 and the second transistor Q2 is greater than the turn-on voltage. At this time, the first transistor Q1 and the second transistor Q2 are turned on, and the LED emits light, thus outputting charging indicator information so that the user can know that the battery module is in the constant current charging stage through the LED.

[0054] Optionally, the constant current circuit 11 includes:

[0055] A constant current source circuit is provided, wherein the input terminal of the constant current source circuit is connected to the power input terminal, the output terminal of the constant current source circuit is connected to the power output terminal, the controlled terminal of the constant current circuit 11 is connected to the control terminal of the switch control circuit 13, and the constant current source circuit is used to provide a constant charging current for the battery module.

[0056] A current regulating circuit is electrically connected to the constant current source circuit. The current regulating circuit is used to regulate the charging current output by the constant current source circuit when triggered by the user.

[0057] In this embodiment, the constant current source circuit can be implemented using a mirror constant current circuit 11, a constant current source, or other constant current circuits 11, to provide a constant charging current for the battery module, enabling the battery module to perform constant current charging. The current adjustment circuit can be implemented using an adjustable potentiometer. It is understood that, according to the formula U=IR, when the voltage is constant, the user can use the adjustable potentiometer to change the resistance, thereby changing the magnitude of the charging current. This allows the charging control circuit of the present invention to be used to charge different battery modules, improving the practicality of the charging control circuit.

[0058] In this invention, by setting up a constant current circuit 11, a feedback indicator circuit 12, and a switch control circuit 13, intelligent charging switching of the battery module is achieved. It can intelligently switch the charging mode of the battery module according to its voltage, ensuring that the charging of the battery module conforms to the charging logic, thereby reducing damage caused by charging and extending the battery's lifespan. It is worth noting that the feedback indicator circuit 12 and the switch control circuit 13 can utilize pure hardware circuits to achieve voltage detection and charging mode control switching, eliminating the need for integrated chips. This improves the accuracy of the mode switching trigger point, the stability of mode switching, and the response speed of mode switching. Furthermore, the hardware circuit structure used is simple and easy to implement, effectively reducing the cost of the charging control circuit and facilitating its use and promotion.

[0059] Reference Figure 3 In one embodiment, the constant current circuit 11 includes a first capacitor C1, a third transistor Q3, a fourth transistor Q4, a second field-effect transistor M2, and a potentiometer RF. The collector of the third transistor Q3 is connected to the power input terminal, and the emitter of the third transistor Q3 is connected to the power output terminal. The collector of the fourth transistor Q4 is connected to the power input terminal, and the emitter of the fourth transistor Q4 is connected to both the base of the third transistor Q3 and the base of the fourth transistor Q4. The base of the fourth transistor Q4 is also connected to the first terminal of the potentiometer RF, and the second terminal of the potentiometer RF is grounded. The input terminal of the second field-effect transistor M2 is connected to the power input terminal, and the output terminal of the second field-effect transistor M2 is connected to the third terminal of the potentiometer. The controlled terminal of the second field-effect transistor M2 is connected to the control terminal of the switch control circuit 13. The first terminal of the first capacitor C1 is connected to the collector of the fourth transistor Q4, and the second terminal of the first capacitor C1 is connected to both the first and third terminals of the potentiometer RF.

[0060] Reference Figure 3 , Figure 3This is a schematic diagram of the circuit structure of one embodiment of the charging control circuit. The constant current circuit 11 consists of a first capacitor C1, a third transistor Q3, a fourth transistor Q4, a second field-effect transistor M2, and a potentiometer RF. The second field-effect transistor M2 is a PMOS transistor, which conducts when its gate is at a low level. The third transistor Q3 and the fourth transistor Q4 are PNP transistors. When the second field-effect transistor M2 is turned off, the mirror constant current source circuit formed by the third transistor Q3 and the fourth transistor Q4 generates a constant charging current. The magnitude of the charging current can be changed by adjusting the potentiometer RF, thereby changing the battery charging current. When the gate of the second field-effect transistor M2 receives a low-level signal output from the switch control circuit 13, it conducts, thereby disrupting the mirror constant current source circuit formed by the third transistor Q3 and the fourth transistor Q4, and the charging current disappears. At this time, the battery enters the constant voltage charging stage.

[0061] Optionally, the feedback indication circuit 12 includes a first resistor R1, a second resistor R2, a light-emitting diode (LED), a first transistor Q1, and a second transistor Q2. The first end of the first resistor R1 is connected to the power input terminal, and the second end of the first resistor R1 is connected to the collector of the first transistor Q1. The emitter of the first transistor Q1 is connected to the power output terminal. The first end of the second resistor R2 is connected to the power input terminal, and the second end of the second resistor R2 is connected to the anode of the LED. The cathode of the LED is connected to the collector of the second transistor Q2, and the emitter of the second transistor Q2 is connected to the power output terminal. The second end of the first resistor R1 is also connected to the base of the first transistor Q1, and the base of the first transistor Q1 is also connected to the base of the second transistor Q2. The common terminal of the LED and the second transistor Q2 is connected to the controlled terminal of the switch control circuit 13.

[0062] Optionally, the switch control circuit 13 includes a third resistor R3, a fourth resistor R4, and a first field-effect transistor M1. The first end of the third resistor R3 is connected to the power input terminal, the second end of the third resistor R3 is connected to the input terminal of the first field-effect transistor M1, the output terminal of the first field-effect transistor M1 is connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is grounded, the controlled terminal of the first field-effect transistor M1 is also connected to the output terminal of the feedback indicator circuit 12, and the second end of the third resistor R3 is also connected to the controlled terminals of the constant current circuit 11 and the constant voltage charging circuit 20, respectively.

[0063] Reference Figure 3 , Figure 3This is a schematic diagram of the circuit structure of one embodiment of the charging control circuit. The feedback indicator circuit 12 consists of a first resistor R1, a second resistor R2, a light-emitting diode (LED), a first transistor Q1, and a second transistor Q2. The switch control circuit 13 consists of a third resistor R3, a fourth resistor R4, and a first field-effect transistor M1. The first transistor Q1 and the second transistor Q2 are NPN transistors, and the first field-effect transistor M1 is an NMOS transistor. When charging of the battery begins, the positive terminal voltage of the battery module is very low. The VBE voltage of the first transistor Q1 and the second transistor Q2 is greater than the turn-on voltage, so the first transistor Q1 and the second transistor Q2 are turned on, and the LED illuminates. With the second transistor Q2 turned on, the gate of the first field-effect transistor M1 is at a low level, and the first field-effect transistor M1 is turned off. The power supply outputs a high level to the LDO voltage regulator circuit and the second field-effect transistor M2 through the third resistor R3. Here, the LDO voltage regulator circuit can be set to low level enable. At this time, the LDO voltage regulator circuit does not work, and the VGS of the second field-effect transistor M2 is >0, so it is in the off state. This allows the constant current circuit 11 to work normally and generate a constant current to charge the battery module. As charging proceeds normally, the voltage at the positive terminal of the battery module gradually increases. When the voltage at the positive terminal of the battery module rises to the preset voltage, the VBE voltage of the first transistor Q1 and the second transistor Q2 is less than the turn-on voltage, so the first transistor Q1 and the second transistor Q2 turn off. The gate of the first field-effect transistor M1 becomes high, which means that a constant voltage charging trigger signal is output, the first field-effect transistor M1 turns on, and the gates of the LDO voltage regulator circuit and the second field-effect transistor M2 both become low, enabling the LDO voltage regulator circuit to work and perform constant voltage charging on the battery module. It can be understood that the first transistor Q1 and the second transistor Q2 in the feedback indicator circuit 12 can also form a mirror constant current circuit 11 to generate a constant current and output it to the battery module. The magnitude of this current is determined by the resistance value of the first resistor R1. Therefore, the feedback indicator circuit 12 can also be used as a constant current circuit 11 to perform constant current charging on the battery module. In practical applications, the corresponding resistor value can also be set according to the battery module so that the charging current can be adapted to the connected battery module.

[0064] Furthermore, in the technical solution of this invention, in the constant current circuit 11 and the feedback indicator circuit 12, the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4 are all used in the amplification region, thus forming two mirror constant current sources. Using switching transistors with identical characteristics, the temperature drift of the two symmetrical switching transistors cancels each other out, thereby suppressing the influence of temperature on the devices. In the switch control circuit 13, the operating mode is the saturation region of the MOSFET, so the influence of temperature drift can be disregarded. This invention, by setting up the mirror constant current circuit 11 to perform constant current charging of the battery module, can effectively suppress the influence of temperature on the devices, suppress current changes caused by device temperature drift, stabilize the charging current, thereby reducing damage to the battery module during charging and extending the battery module's service life.

[0065] Reference Figures 1 to 3 In one embodiment, the charging control circuit further includes:

[0066] A voltage conversion circuit 30 is provided, the input terminal of which is connected to the power input terminal, and the output terminal of which is connected to the input terminal of the constant current charging circuit 10. The voltage conversion circuit 30 is used to convert the power supply into a charging power supply and then output it.

[0067] In this embodiment, the voltage conversion circuit 30 can be implemented using a DC-DC voltage conversion circuit 30, an AC-DC voltage conversion circuit 30, etc., to convert the power supply into a charging power supply and output it to the constant current charging circuit 10, so that the constant current charging circuit 10 can provide a constant charging current to charge the battery module. It is understood that users can set a suitable voltage conversion circuit 30 according to actual usage needs to apply the charging control circuit of this invention to different devices, thereby enabling the charging of the battery module in different devices and improving the practicality of the charging control circuit.

[0068] Reference Figures 1 to 3 In one embodiment, the constant voltage charging circuit 20 is an LDO voltage regulator circuit.

[0069] In this embodiment, the constant voltage charging circuit 20 is an LDO voltage regulator circuit. The LDO voltage regulator circuit can be defined as active low, and its enable terminal is connected to the control terminal of the switch control circuit 13. Thus, when the switch control circuit 13 controls the constant current circuit 11 to stop working, the LDO voltage regulator circuit is enabled and starts working, outputting a constant voltage to charge the battery module. Similarly, the LDO voltage regulator circuit can also be configured with a suitable LDO voltage regulator circuit or other constant voltage circuits according to actual usage requirements, so that the charging control circuit of this invention can be applied to different devices, thereby enabling the charging of the battery module in different devices and improving the practicality of the charging control circuit.

[0070] The present invention also proposes an electronic device, which includes a battery module and the charging control circuit described above. The specific structure of the charging control circuit is as described in the above embodiments. Since the electronic device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0071] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A charging control circuit, characterized in that, include: Power input terminal, used to connect to the input power supply; The power output terminal is used to connect the battery module; A constant current charging circuit and a constant voltage charging circuit are provided, wherein the constant current charging circuit and the constant voltage charging circuit are connected in parallel between the power input terminal and the power output terminal, and the control terminal of the constant current charging circuit is also connected to the controlled terminal of the constant voltage charging circuit; wherein... The constant current charging circuit is used to provide a constant charging current to the battery module, and stops working when the voltage of the battery module is greater than a preset voltage. It also outputs a constant voltage charging trigger signal to the constant voltage charging circuit to control the constant voltage charging circuit to provide a constant charging voltage to the battery module. The constant current charging circuit includes: A constant current circuit, wherein the input terminal of the constant current circuit is connected to the power input terminal and the output terminal of the constant current circuit is connected to the power output terminal, and the constant current circuit is used to provide a constant charging current for the battery module; A feedback indicator circuit is provided, wherein the detection terminal of the feedback indicator circuit is connected to the power output terminal, the feedback indicator circuit is used to detect the voltage of the power output terminal, and outputs a constant voltage charging trigger signal when the voltage of the power output terminal is greater than a preset voltage. A switch control circuit is provided, wherein the controlled terminal of the switch control circuit is connected to the output terminal of the feedback indicator circuit, and the control terminal of the switch control circuit is connected to the controlled terminals of the constant current circuit and the constant voltage charging circuit respectively. The switch control circuit is used to control the constant current circuit to stop working when a constant voltage charging trigger signal is received, and to control the constant voltage charging circuit to provide a constant charging voltage to the battery module. The constant current circuit includes a third transistor, a fourth transistor, a second field-effect transistor, and a potentiometer. The collector of the third transistor is connected to the power input terminal, and the emitter of the third transistor is connected to the power output terminal. The collector of the fourth transistor is connected to the power input terminal, and the emitter of the fourth transistor is connected to the base of both the third and fourth transistors. The base of the fourth transistor is also connected to the first terminal of the potentiometer, and the second terminal of the potentiometer is grounded. The output terminal of the second field-effect transistor is connected to the third terminal of the potentiometer, and the input terminal of the second field-effect transistor is connected to the power input terminal. The controlled terminal of the second field-effect transistor is connected to the control terminal of the switch control circuit.

2. The charging control circuit as described in claim 1, characterized in that, The feedback indication circuit is also used to output charging indication information when the voltage at the power output terminal is less than a preset voltage.

3. The charging control circuit as described in claim 1, characterized in that, The constant current circuit includes: A constant current source circuit, wherein the input terminal of the constant current source circuit is connected to the power input terminal, the output terminal of the constant current source circuit is connected to the power output terminal, and the controlled terminal of the constant current source circuit is connected to the control terminal of the switch control circuit, and the constant current source circuit is used to provide a constant charging current for the battery module. A current regulating circuit is electrically connected to the constant current source circuit. The current regulating circuit is used to regulate the charging current output by the constant current source circuit when triggered by the user.

4. The charging control circuit as described in claim 1, characterized in that, The constant current circuit also includes a first capacitor, the first end of which is connected to the collector of the fourth transistor, and the second end of which is connected to the first and third ends of the potentiometer.

5. The charging control circuit as described in claim 1, characterized in that, The feedback indicator circuit includes a first resistor, a second resistor, a light-emitting diode (LED), a first transistor, and a second transistor. The first end of the first resistor is connected to the power input terminal, and the second end of the first resistor is connected to the collector of the first transistor. The emitter of the first transistor is connected to the power output terminal. The first end of the second resistor is connected to the power input terminal, and the second end of the second resistor is connected to the anode of the LED. The cathode of the LED is connected to the collector of the second transistor, and the emitter of the second transistor is connected to the power output terminal. The second end of the first resistor is also connected to the base of the first transistor, and the base of the first transistor is also connected to the base of the second transistor. The common terminal of the LED and the second transistor is connected to the controlled terminal of the switch control circuit.

6. The charging control circuit as described in claim 1, characterized in that, The switch control circuit includes a third resistor, a fourth resistor, and a first field-effect transistor. The first end of the third resistor is connected to the power input terminal, the second end of the third resistor is connected to the input terminal of the first field-effect transistor, the output terminal of the first field-effect transistor is connected to the first end of the fourth resistor, the second end of the fourth resistor is grounded, the controlled terminal of the first field-effect transistor is also connected to the output terminal of the feedback indicator circuit, and the second end of the third resistor is also connected to the controlled terminals of the constant current circuit and the constant voltage charging circuit, respectively.

7. The charging control circuit as described in claim 1, characterized in that, The charging control circuit also includes: A voltage conversion circuit is provided, wherein the input terminal of the voltage conversion circuit is connected to the power input terminal, and the output terminal of the voltage conversion circuit is connected to the input terminal of the constant current charging circuit. The voltage conversion circuit is used to convert the power supply into a charging power supply and then output it.

8. The charging control circuit as described in claim 1, characterized in that, The constant voltage charging circuit is an LDO voltage regulator circuit.

9. An electronic device, characterized in that, It includes a battery module and a charging control circuit as described in any one of claims 1-8.

Images