Control circuit compatible with USB slow charging and USB PD fast charging

Abstract

The utility model relates to a control circuit compatible with USB slow charging and USB PD fast charging, which comprises a power supply module, a main control module, a switch module, a step-down / step-up module and a battery module, the main control module is used for identifying whether the power supply module supports a USB PD protocol, adjusting the output voltage of the power supply module supporting the USB PD protocol, and controlling the switch module or the step-down / step-up module to quickly charge or slowly charge the battery module; the switch module is controlled by the main control module to be switched on, so that the voltage of the power supply module is transmitted to the battery module through the switch module for quick charging; and the step-down / step-up module is controlled by the main control module to work and is used for step-down or step-up the voltage of the power supply module so as to slowly charge the battery module. According to the utility model, USB PD protocol communication, fast charging management and slow charging management are completed through the master control module, the integration level is high, the use of chips and peripheral elements can be saved, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of USB charging control, in particular to a control circuit compatible with USB slow charging and USB PD fast charging. Background Art

[0002] The traditional PD (Power Delivery) fast charging circuit is generally composed of USB PD protocol chip, fast charging control chip and circuit, slow charging control chip and circuit, main control chip, etc. The USB PD protocol chip is used to communicate with USB power supply devices that support the USB PD protocol and apply for the specified power supply voltage. The fast charging control chip is used to achieve high-current fast charging management of the battery. The slow charging control chip is used to be compatible with USB power supply devices that do not support the USB PD protocol. As an auxiliary charging chip of the fast charging control chip, it completes functions such as battery activation and constant voltage charging at the end of charging. The main control chip is responsible for coordinating the work of all circuits.

[0003] However, the traditional PD fast charging circuit has a complex overall circuit, with many chips and peripheral components, making it difficult to implement and resulting in high costs. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a control circuit that is compatible with USB slow charging and USB PD fast charging.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A control circuit compatible with USB slow charging and USB PD fast charging, comprising: a power supply module, a main control module, a switch module, a buck / boost module and a battery module;

[0007] The power supply module is a USB power supply device that outputs a fixed voltage or a USB power supply device that supports the USB PD fast charging protocol;

[0008] The main control module is used to identify whether the power supply module supports the USB PD protocol; if it does, the output voltage of the power supply module is set according to the USB PD protocol, and is used to determine whether to turn on the switch module or control the buck / boost module to fast charge or slow charge the battery module according to the status of the power supply module and the battery module;

[0009] The switch module is used to control the switch module to be turned on when the main control module identifies that the power supply module and the battery module meet the fast charging conditions, so that the voltage of the power supply module is transmitted to the battery module through the switch module, so as to fast charge the battery module;

[0010] The buck / boost module is used when the power supply module or the battery module does not meet the fast charging conditions. The main control module controls the buck / boost module to operate and buck or boost the voltage of the power supply module to slowly charge the battery module.

[0011] In a specific embodiment, the main control module includes a main chip U1, pins 1 and 2 of the main chip U1 are connected to the power supply module, pins 21 and 22 of the main chip U1 are connected to the buck / boost module, pin 24 of the main chip U1 is connected to the switch module, and pin 13 of the main chip U1 is connected to the battery module.

[0012] In a specific embodiment, the power supply module also includes a USB socket J1, the USB socket J1 is connected to the USB power supply device, the A5 pin and the B5 pin of the USB socket J1 are respectively connected to the 1 pin and the 2 pin of the main chip U1, and the buck / boost module and the switch module are connected to the USB socket J1.

[0013] In a specific embodiment, the buck / boost module includes a resistor R1, a field effect transistor Q3, a triode Q4, a field effect transistor Q5, an inductor L1, a diode D1 and a diode D2, pin 1 of the triode Q4 is connected to pin 22 of the main chip U1, pin 3 of the triode Q4 is connected to pin 1 of the field effect transistor Q3 and one end of the resistor R1, pin 2 of the field effect transistor Q3 is connected to the USB socket J1 and the other end of the resistor R1, pin 3 of the field effect transistor Q3 is connected to one end of the inductor L1 and one end of the diode D2, the other end of the inductor L1 is connected to pin 3 of the field effect transistor Q5 and one end of the diode D1, the other end of the diode D1 is connected to the battery module, and pin 1 of the field effect transistor Q5 is connected to pin 21 of the main chip U1.

[0014] In a specific embodiment, the switch module includes a field effect transistor Q1, a field effect transistor Q2, a transistor Q6 and a resistor R2, pin 1 of the transistor Q6 is connected to pin 24 of the main chip U1, pin 3 of the transistor Q6 is connected to the resistor R2, the field effect transistor Q1 and the gate of the field effect transistor Q2, the resistor R2 is also connected to the source of the field effect transistor Q1 and the field effect transistor Q2, the drain of the field effect transistor Q1 is connected to the USB socket J1, and the drain of the field effect transistor Q2 is connected to the battery module.

[0015] In a specific embodiment, the battery module includes a rechargeable battery BT1, a temperature sensor NTC, a resistor R8 and a capacitor C10, the temperature sensor NTC is connected to the rechargeable battery BT1, the temperature sensor NTC, the resistor R8 and the capacitor C10 are connected to pin 13 of the main chip U1, the resistor R8 is also connected to pin 8 of the main chip U1, and the positive electrode of the rechargeable battery BT1 is connected to the diode D1 and the drain of the field effect transistor Q2.

[0016] In a specific embodiment, the control circuit compatible with USB slow charging and USB PD fast charging also includes a current acquisition circuit, which includes a resistor R3, a capacitor C5, a resistor R4 and a resistor R5. The resistor R3, the capacitor C5 and the resistor R4 are connected to pin 17 of the main chip U1, and the resistor R3 is also connected to pin 8 of the main chip U1. The resistor R4 and the resistor R5 are also connected to the negative electrode of the rechargeable battery BT1.

[0017] In a specific embodiment, the control circuit compatible with USB slow charging and USB PD fast charging also includes a chip power supply circuit, which includes a power supply chip U2, a capacitor C6 and a capacitor C7. Pin 2 of the power supply chip U2 and the capacitor C6 are connected to the USB socket J1, and pin 3 of the power supply chip U2 and the capacitor C7 are connected to pin 8 of the main chip U1.

[0018] In a specific embodiment, the control circuit compatible with USB slow charging and USB PD fast charging also includes a power supply voltage detection circuit, and the power supply voltage detection circuit includes a resistor R6, a resistor R9 and a capacitor C8. The resistor R6, the resistor R9 and the capacitor C8 are connected to pin 14 of the main chip U1, and the resistor R6 is also connected to the USB socket J1.

[0019] In a specific embodiment, the control circuit compatible with USB slow charging and USB PD fast charging also includes a battery voltage detection circuit, and the battery voltage detection circuit includes a resistor R7, a resistor R10 and a capacitor C9, and the resistor R7, the resistor R10 and the capacitor C9 are connected to pin 15 of the main chip U1, and the resistor R7 is also connected to the positive electrode of the rechargeable battery BT1.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: the main control module is used to identify whether the power supply module supports the USB PD protocol. If it does, the output voltage of the power supply module is set through the USB PD protocol, and is used to decide whether to turn on the switch module for fast charging according to the status of the power supply module and the battery module. When the power supply module or the battery module does not meet the fast charging conditions, the main control module controls the buck / boost module to step down or boost the voltage of the power supply module to slow charge the battery module, that is, USB PD protocol communication, fast charging management and slow charging management are completed through the main control module, with high integration, which can save the use of chips and peripheral components and reduce costs.

[0021] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 A schematic block diagram of a control circuit compatible with USB slow charging and USB PD fast charging provided by the utility model;

[0024] Figure 2 A circuit diagram of the main control module provided by the utility model;

[0025] Figure 3 A circuit diagram of the power supply module provided by the utility model;

[0026] Figure 4 A circuit diagram of the buck / boost module provided by the utility model;

[0027] Figure 5 A circuit diagram of a switch module, a battery module and a current collection circuit provided by the utility model;

[0028] Figure 6 A circuit diagram of a chip power supply circuit provided by the utility model;

[0029] Figure 7 A circuit diagram of a power supply voltage detection circuit provided by the utility model;

[0030] Figure 8 This is a circuit diagram of a battery voltage detection circuit provided by the utility model. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0038] See also Figure 1 , Figure 1 A schematic block diagram of a control circuit compatible with USB slow charging and USB PD fast charging provided by an embodiment of the utility model includes: a power supply module 10, a main control module 20, a switch module 30, a buck / boost module 40 and a battery module 50;

[0039] The power supply module 10 is a USB power supply device that outputs a fixed voltage or a USB power supply device that supports the USB PD fast charging protocol;

[0040] The main control module 20 is used to identify whether the power supply module 10 supports the USB PD protocol; if supported, the output voltage of the power supply module 10 is set according to the USB PD protocol, and is used to determine whether to turn on the switch module 30 or control the buck / boost module 40 to fast charge or slow charge the battery module 50 according to the status of the power supply module 10 and the battery module 50;

[0041] The switch module 30 is used to control the switch module 30 to be turned on when the main control module 20 identifies that the power supply module 10 and the battery module 50 meet the fast charging conditions, so that the voltage of the power supply module 10 is transmitted to the battery module 50 through the switch module 30, so as to fast charge the battery module 50;

[0042] The buck / boost module 40 is used when the power supply module 10 or the battery module 50 does not meet the fast charging conditions. The main control module 20 controls the buck / boost module 40 to operate and buck or boost the voltage of the power supply module 10 to perform slow charging on the battery module 50.

[0043] Among them, the control circuit is mainly used in the field of USB charging control, that is, USB PD protocol communication, fast charging management and slow charging management are completed through the main control module 20. It has high integration, can save the use of chips and peripheral components, and reduce costs.

[0044] Specifically, the control circuit can intelligently identify whether the device connected is a USB power supply device that only supports standard USB charging (slow charging) (for example, a power bank or a USB power adapter) or a USB power supply device that supports the USB PD fast charging protocol (using the existing public fast charging protocol technology). This automatic identification function ensures that the device can fully utilize the performance of the USB power supply device, whether it is a low-cost ordinary charger or a high-performance fast charging device; in addition, when it is detected that the device connected is a USB power supply device that supports the USB PD fast charging protocol and the battery module 50 also has the fast charging conditions, the main control module 20 will connect the USB PD power supply device to the battery module 50 through the USB PD fast charging protocol. The PD protocol adjusts the voltage output by the USB power supply device to a voltage range suitable for battery charging, and by controlling the conduction of the switch module 30, the voltage is efficiently and safely transmitted to the battery module 50 for fast charging. This process greatly shortens the charging time and improves the user experience. In addition, when the power supply module 10 or the battery module 50 does not meet the fast charging conditions, it can automatically switch to the slow charging mode, and by controlling the buck / boost module 40 to work, the voltage output by the USB power supply device is adjusted to a voltage range suitable for battery charging, ensuring that the battery can be charged safely and stably, avoiding damage that may be caused by voltage mismatch. In addition, a single chip can be used to implement the functions of USB PD protocol communication, fast charging management and slow charging management, greatly improving the integration of the circuit. This design not only simplifies the circuit design and reduces the number of components, but also significantly reduces the production cost, making this technology more suitable for large-scale commercial applications.

[0045] In one embodiment, the battery module 50 is a single string or multiple strings of lithium batteries or other rechargeable batteries. The power supply module 10 can be a USB power supply device such as a power adapter or a mobile power supply with a traditional fixed 5V voltage output, or a USB power supply device such as a power adapter or a mobile power supply that supports the USB PD fast charging protocol, to provide voltage for the battery module 50; the switch module 30 can be a switch circuit such as MOSFET, IGBT or relay. When the main control module 20 recognizes that the USB power supply device and the battery module 50 have fast charging conditions, the main control module 20 controls its conduction to allow the voltage of the USB power supply device to be transmitted to the battery module 50 through the switch circuit. In this charging state, there is only loss in the switch circuit, and the switch circuit has an extremely low internal resistance. Therefore, the charging loss in this charging state is extremely low, which can adapt to large current charging and realize the fast charging function; the buck / boost module 40 can be a synchronous / asynchronous buck / boost circuit composed of MOSFET and diodes. When the USB power supply device or the battery module 50 does not have fast charging conditions (for example, the USB power supply device does not support USB PD fast charging protocol or low battery voltage, etc.), the main control module 20 controls its operation, steps down or steps up the voltage of the USB power supply device to a suitable voltage and outputs it to the battery module 50 to realize the slow charging function; the main control module 20 can be a single-chip microcomputer or a specially customized charging chip, which is used to identify whether the USB power supply device supports the USB PD protocol. If it does, it performs protocol communication, sets the output voltage of the USB power supply device through the USB PD protocol, and decides whether to turn on the switch circuit or control the buck / boost module 40 to fast charge or slow charge the battery according to the status of the USB power supply device and the battery module 50, and at the same time completes the control of charging current, voltage, etc., and detects the battery temperature to realize charging temperature protection and other functions.

[0046] See also Figure 2 As shown, the main control module 20 includes a main chip U1, pins 1 and 2 of the main chip U1 are connected to the power supply module 10, pins 21 and 22 of the main chip U1 are connected to the buck / boost module 40, pin 24 of the main chip U1 is connected to the switch module 30, and pin 13 of the main chip U1 is connected to the battery module 50.

[0047] Specifically, when the connected USB power supply device does not support the USB PD protocol, its output voltage is generally fixed at 5V. The main chip U1 controls the buck / boost module 40 to buck or boost the fixed voltage of the USB power supply device to a suitable charging voltage according to the battery voltage, and the battery is slowly charged. The switch module 30 is in a disconnected state and does not participate in the work. In addition, when the connected USB power supply device supports the USB PD protocol and the battery voltage is within the voltage range supported by the USB power supply device, the main chip U1 adjusts the output voltage of the USB power supply device according to the battery voltage and charging current through the USB PD protocol (adjusting the voltage according to the USB PD protocol is an existing public technology and will not be elaborated on here), and controls the switch module 30 to conduct, and the battery is quickly charged. At this time, the buck / boost module 40 is in a disconnected state and does not participate in the work. In addition, when the connected USB power supply device supports the USB PD protocol, but the battery voltage exceeds the voltage range supported by the USB power supply device, refer to the previous slow / fast charging process, first charge the battery slowly, and then switch to fast charging when the battery voltage is within the voltage range supported by the USB power supply device. In addition, during the slow / fast charging process, the main chip U1 will also detect the USB power supply device voltage, battery voltage and temperature, charging current and other conditions in real time, and adjust and protect the charging status in real time.

[0048] See also Figure 3 As shown, the power supply module 10 also includes a USB socket J1, which is connected to the USB power supply device. The A5 pin and the B5 pin of the USB socket J1 are respectively connected to the 1 pin and the 2 pin of the main chip U1, and the buck / boost module 40 and the switch module 30 are connected to the USB socket J1.

[0049] Specifically, the main chip U1 communicates with the USB power supply device inserted into the USB socket J1 through the signals of the A5 and B5 pins of the USB socket, determines whether the USB power supply device supports the USB PD protocol, and sets the output voltage of the USB power supply device according to the current charging needs (this voltage conversion is based on the USB PD protocol and is an existing public technology).

[0050] See also Figure 4As shown, the buck / boost module includes a resistor R1, a field effect transistor Q3, a triode Q4, a field effect transistor Q5, an inductor L1, a diode D1 and a diode D2. Pin 1 of the triode Q4 is connected to pin 22 of the main chip U1, pin 3 of the triode Q4 is connected to pin 1 of the field effect transistor Q3 and one end of the resistor R1, pin 2 of the field effect transistor Q3 is connected to the USB socket J1 and the other end of the resistor R1, pin 3 of the field effect transistor Q3 is connected to one end of the inductor L1 and one end of the diode D2, the other end of the inductor L1 is connected to pin 3 of the field effect transistor Q5 and one end of the diode D1, the other end of the diode D1 is connected to the battery module, and pin 1 of the field effect transistor Q5 is connected to pin 21 of the main chip U1.

[0051] Specifically, the main chip U1 controls the buck / boost module 40 through the signals of pins 21 and 22. The main chip U1 controls the conduction and cutoff of the triode Q4 through the signal (PWM signal) of pin 22, thereby controlling the conduction and cutoff of the field effect tube Q3, forming a switch-type buck circuit with the inductor L1 and the diode D2, and adjusting the duty cycle of pin 22 to adjust the output voltage, which can reduce the input voltage; the main chip U1 controls the conduction and cutoff of the field effect tube Q5 through the signal (PWM signal) of pin 21, and forms a switch-type boost circuit with the inductor L1 and the diode D1, and adjusting the duty cycle of pin 21 to adjust the output voltage, which can increase the input voltage. Therefore, the main chip U1 can control the buck / boost module 40 to convert the voltage input by the USB power supply device into any voltage output to the battery to meet the voltage requirements of the battery in all states.

[0052] See also Figure 5 As shown, the switch module includes a field effect transistor Q1, a field effect transistor Q2, a transistor Q6 and a resistor R2, wherein pin 1 of the transistor Q6 is connected to pin 24 of the main chip U1, pin 3 of the transistor Q6 is connected to the resistor R2, the field effect transistor Q1 and the gate (pin 4) of the field effect transistor Q2, the resistor R2 is also connected to the source (pins 1, 2 and 3) of the field effect transistor Q1 and the field effect transistor Q2, the drain (pin 5) of the field effect transistor Q1 is connected to the USB socket J1, and the drain (pin 5) of the field effect transistor Q2 is connected to the battery module.

[0053] Specifically, the main chip U1 controls the conduction and cutoff of the transistor Q6 through the signal of pin 24, thereby controlling the conduction and cutoff of the field effect transistor Q1 and the field effect transistor Q2. When the fast charging conditions are met, the main chip U1 controls the switch module 30 to turn on, and the voltage of the USB power supply device is directly output to the battery for fast charging.

[0054] See also Figure 5As shown, the battery module 50 includes a rechargeable battery BT1, a temperature sensor NTC, a resistor R8 and a capacitor C10. The temperature sensor NTC is connected to the rechargeable battery BT1. The temperature sensor NTC, the resistor R8 and the capacitor C10 are connected to pin 13 of the main chip U1. The resistor R8 is also connected to pin 8 of the main chip U1. The positive electrode of the rechargeable battery BT1 is connected to the diode D1 and the drain (pin 5) of the field effect transistor Q2.

[0055] Specifically, the rechargeable battery BT1 is used as an energy storage unit; the temperature sensor NTC is connected to the rechargeable battery BT1 to monitor the temperature of the battery in real time. The NTC thermistor has a negative temperature coefficient characteristic, that is, the higher the temperature, the lower the resistance value, so the temperature change can be accurately sensed by measuring the change in resistance value. Among them, the resistor R8 and the capacitor C10 are connected to the 13th pin of the main chip U1 together with the temperature sensor NTC to form a temperature signal acquisition and filtering circuit. The resistor R8 is used for current limiting, and the capacitor C10 is used to filter out the high-frequency noise in the signal to ensure the accuracy and stability of the temperature signal.

[0056] See also Figure 5 As shown, the control circuit compatible with USB slow charging and USB PD fast charging also includes a current acquisition circuit, and the current acquisition circuit includes a resistor R3, a capacitor C5, a resistor R4 and a resistor R5. The resistor R3, the capacitor C5 and the resistor R4 are connected to pin 17 of the main chip U1, and the resistor R3 is also connected to pin 8 of the main chip U1. The resistor R4 and the resistor R5 are also connected to the negative electrode of the rechargeable battery BT1.

[0057] Specifically, the current in the circuit is converted into a voltage signal through the resistor R5. When the current flows through the resistor R5, a voltage drop will be generated at both ends. This voltage drop is proportional to the current. Therefore, the current in the circuit can be indirectly measured by measuring this voltage drop. The capacitor C5 and the resistor R4 are connected to form a simple RC filter circuit. The function of this filter circuit is to filter out high-frequency noise and interference in the current signal to ensure that the collected current signal is more stable and accurate. The resistor R3 provides a bias voltage for the current voltage signal. In addition, the resistor R3, the capacitor C5 and the resistor R4 are connected to the 17th pin of the main chip U1, and the collected current signal is input to the main chip U1. The main chip U1 will contain an analog-to-digital converter (ADC) or other signal processing circuits to convert the analog current signal into a digital signal for further processing and analysis.

[0058] See also Figure 6As shown, the control circuit compatible with USB slow charging and USB PD fast charging also includes a chip power supply circuit, which includes a power supply chip U2, a capacitor C6 and a capacitor C7. Pin 2 of the power supply chip U2 and the capacitor C6 are connected to the USB socket J1, and pin 3 of the power supply chip U2 and the capacitor C7 are connected to pin 8 of the main chip U1.

[0059] Specifically, the main function of the power supply chip U2 is to convert the voltage received from the USB socket J1 into a voltage suitable for the main chip U1 and other required circuit elements to work. This conversion is necessary because different circuit elements may have different requirements for the power supply voltage. Through the voltage stabilization mechanism of the power supply chip U2, it can be ensured that the voltage output to the main chip U1 is stable and meets its working requirements, which helps to prevent voltage fluctuations from damaging the main chip U1 and ensure that it can work normally. In addition, capacitors C6 and C7 play a role in filtering and denoising in the circuit. They can filter out high-frequency noise and interference in the power supply voltage, ensuring that the voltage supplied to the main chip U1 is clean and stable, which is crucial to improving the stability and reliability of the circuit. In addition, pin 2 of the power supply chip U2 and capacitor C6 are connected to the USB socket J1, which means that the power supply chip U2 obtains power from the USB interface. In addition, pin 3 of the power supply chip U2 and capacitor C7 are connected to pin 8 of the main chip U1 to provide the required power supply voltage for the main chip U1. The main chip U1 is the core of the entire control circuit and is responsible for processing various charging protocols, monitoring battery status, controlling the charging process and other tasks. Therefore, a stable and reliable power supply is crucial to it.

[0060] See also Figure 7 As shown, the control circuit compatible with USB slow charging and USB PD fast charging also includes a power supply voltage detection circuit, and the power supply voltage detection circuit includes a resistor R6, a resistor R9 and a capacitor C8. The resistor R6, the resistor R9 and the capacitor C8 are connected to pin 14 of the main chip U1, and the resistor R6 is also connected to the USB socket J1.

[0061] Specifically, resistor R6 and resistor R9 are used as voltage divider resistors, connected to the USB socket J1, and are used to collect the voltage signal input from the USB power supply device. When the USB power supply device is connected to the USB socket J1, the voltage output by the device will be divided by resistor R6 and resistor R9 to obtain a voltage signal suitable for processing by the main chip U1. Capacitor C8 is connected to resistor R6 and resistor R9 to form a simple RC filter circuit. The function of this filter circuit is to filter out high-frequency noise and interference in the voltage signal to ensure that the collected voltage signal is more stable and accurate. In addition, resistor R6, resistor R9 and capacitor C8 are connected to pin 14 of the main chip U1, and the collected and filtered voltage signal is input to the main chip U1. The main chip U1 will contain an analog-to-digital converter (ADC) or other signal processing circuits to convert the analog voltage signal into a digital signal for further processing and analysis; the main chip U1 will adjust the charging strategy by detecting the power supply voltage, which helps to ensure the safety of the battery and circuit while ensuring the charging speed.

[0062] See also Figure 8 As shown, the control circuit compatible with USB slow charging and USB PD fast charging also includes a battery voltage detection circuit, and the battery voltage detection circuit includes a resistor R7, a resistor R10 and a capacitor C9. The resistor R7, the resistor R10 and the capacitor C9 are connected to pin 15 of the main chip U1, and the resistor R7 is also connected to the positive electrode of the rechargeable battery BT1.

[0063] Specifically, the battery voltage detection circuit is connected to the positive electrode of the rechargeable battery BT1 through the resistor R7, and the voltage signal of the battery is collected in real time, which is the basis for understanding the current state of the battery (such as power, charging progress, etc.). The resistor R7 and the resistor R10 form a voltage divider circuit to reduce the high voltage of the battery to a range suitable for the main chip U1 to process, and at the same time play a certain protective role to prevent the high voltage from directly damaging the main chip U1. In addition, the capacitor C9 is connected to the resistor R7 and the resistor R10 to form an RC filter circuit. The main function of this circuit is to filter out the high-frequency noise and interference in the battery voltage signal, ensuring that the collected voltage signal is more stable and accurate, thereby improving the accuracy of voltage detection. In addition, the resistor R7, the resistor R10 and the capacitor C9 are connected to the 15th pin of the main chip U1, and the collected and filtered battery voltage signal is input to the main chip U1. The main chip U1 contains an analog-to-digital converter (ADC) or other signal processing circuit inside, which is used to convert the analog battery voltage signal into a digital signal, and further process and analyze it. In addition, the main chip U1 can determine the battery charging status (such as whether it is full, whether the charging current needs to be adjusted, etc.) based on the battery voltage signal, and adjust the charging strategy accordingly, which helps to achieve precise charging control and protect the battery from damage due to overcharging or over-discharging.

[0064] See also Figures 2 to 8 As shown, the main chip U1 is powered by the input voltage VBUS after being stepped down by the chip power supply circuit, and is connected to the power supply voltage detection circuit through the signal of pin 14 to detect the voltage of the USB power supply device, and then connected to the battery voltage detection circuit through the signal of pin 15 to detect the battery voltage, and then the battery temperature is detected through the signal of pin 13, and then the charging current is detected by the current acquisition circuit through the signal of pin 17. Finally, the main chip U1 adjusts the charging state according to all the detected signals through the internal charging algorithm of the main chip U1 (using the existing public standard lithium battery charging algorithm, which will not be elaborated here) to complete the entire charging process.

[0065] In summary, the control circuit consists of a main chip plus some low-cost peripheral components, realizing a charging solution that traditional architectures require several times the cost to complete. In addition to the huge cost advantage, the control circuit also has the ability to adapt to various USB power supply devices and can simply adjust software parameters to adapt to the capabilities of various rechargeable batteries.

[0066] In this utility model, the components and their models and connection relationships not shown are Figures 2 to 8 The specific circuit diagram has been marked and will not be repeated here.

[0067] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present technical solution is within the protection scope of the present invention.

Claims

1. A control circuit compatible with USB slow charging and USB PD fast charging, characterized in that: include: Power supply module, main control module, switch module, buck / boost module and battery module; The power supply module is a USB power supply device that outputs a fixed voltage or a USB power supply device that supports the USB PD fast charging protocol; The main control module is used to identify whether the power supply module supports the USB PD protocol; if supported, the output voltage of the power supply module is set according to the USB PD protocol, and is used to determine whether to turn on the switch module or control the buck / boost module to fast charge or slow charge the battery module according to the status of the power supply module and the battery module; The switch module is used to control the switch module to be turned on when the main control module identifies that the power supply module and the battery module meet the fast charging conditions, so that the voltage of the power supply module is transmitted to the battery module through the switch module, so as to fast charge the battery module; The buck / boost module is used to control the buck / boost module to operate when the main control module identifies that the power supply module or the battery module does not meet the fast charging conditions, and to buck or boost the voltage of the power supply module to slowly charge the battery module.

2. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 1, characterized in that: The main control module includes a main chip U1, pins 1 and 2 of the main chip U1 are connected to the power supply module, pins 21 and 22 of the main chip U1 are connected to the buck / boost module, pin 24 of the main chip U1 is connected to the switch module, and pin 13 of the main chip U1 is connected to the battery module.

3. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 2, characterized in that: The power supply module also includes a USB socket J1, which is connected to the USB power supply device. The A5 pin and the B5 pin of the USB socket J1 are respectively connected to the 1 pin and the 2 pin of the main chip U1. The buck / boost module and the switch module are connected to the USB socket J1.

4. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 3, characterized in that: The buck / boost module includes a resistor R1, a field effect transistor Q3, a triode Q4, a field effect transistor Q5, an inductor L1, a diode D1 and a diode D2. Pin 1 of the triode Q4 is connected to pin 22 of the main chip U1, pin 3 of the triode Q4 is connected to pin 1 of the field effect transistor Q3 and one end of the resistor R1, pin 2 of the field effect transistor Q3 is connected to the USB socket J1 and the other end of the resistor R1, pin 3 of the field effect transistor Q3 is connected to one end of the inductor L1 and one end of the diode D2, the other end of the inductor L1 is connected to pin 3 of the field effect transistor Q5 and one end of the diode D1, the other end of the diode D1 is connected to the battery module, and pin 1 of the field effect transistor Q5 is connected to pin 21 of the main chip U1.

5. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 4, characterized in that: The switch module includes a field effect transistor Q1, a field effect transistor Q2, a transistor Q6 and a resistor R2, wherein pin 1 of the transistor Q6 is connected to pin 24 of the main chip U1, pin 3 of the transistor Q6 is connected to the resistor R2, the field effect transistor Q1 and the gate of the field effect transistor Q2, the resistor R2 is also connected to the source of the field effect transistor Q1 and the field effect transistor Q2, the drain of the field effect transistor Q1 is connected to the USB socket J1, and the drain of the field effect transistor Q2 is connected to the battery module.

6. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 5, characterized in that: The battery module includes a rechargeable battery BT1, a temperature sensor NTC, a resistor R8 and a capacitor C10. The temperature sensor NTC is connected to the rechargeable battery BT1. The temperature sensor NTC, the resistor R8 and the capacitor C10 are connected to pin 13 of the main chip U1. The resistor R8 is also connected to pin 8 of the main chip U1. The positive electrode of the rechargeable battery BT1 is connected to the diode D1 and the drain of the field effect transistor Q2.

7. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 6, characterized in that: The control circuit compatible with USB slow charging and USB PD fast charging also includes a current acquisition circuit, which includes a resistor R3, a capacitor C5, a resistor R4 and a resistor R5. The resistor R3, the capacitor C5 and the resistor R4 are connected to pin 17 of the main chip U1, and the resistor R3 is also connected to pin 8 of the main chip U1. The resistor R4 and the resistor R5 are also connected to the negative electrode of the rechargeable battery BT1.

8. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 6, characterized in that: The control circuit compatible with USB slow charging and USB PD fast charging also includes a chip power supply circuit, which includes a power supply chip U2, a capacitor C6 and a capacitor C7. Pin 2 of the power supply chip U2 and the capacitor C6 are connected to the USB socket J1, and pin 3 of the power supply chip U2 and the capacitor C7 are connected to pin 8 of the main chip U1.

9. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 6, characterized in that: The control circuit compatible with USB slow charging and USB PD fast charging also includes a power supply voltage detection circuit, which includes a resistor R6, a resistor R9 and a capacitor C8. The resistor R6, the resistor R9 and the capacitor C8 are connected to pin 14 of the main chip U1, and the resistor R6 is also connected to the USB socket J1.

10. The control circuit compatible with USB slow charging and USB PD fast charging according to claim 6, characterized in that: The control circuit compatible with USB slow charging and USB PD fast charging also includes a battery voltage detection circuit, which includes a resistor R7, a resistor R10 and a capacitor C9. The resistor R7, the resistor R10 and the capacitor C9 are connected to pin 15 of the main chip U1, and the resistor R7 is also connected to the positive electrode of the rechargeable battery BT1.

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