Direct-current power supply circuit and intelligent glass control system

Abstract

The invention belongs to the technical field of direct-current power supplies, and particularly discloses a direct-current power supply circuit and an intelligent glass control system, and the direct-current power supply circuit comprises a direct-current-direct-current converter, a low-dropout voltage stabilizer, a digital-to-analog converter and a following voltage regulation circuit; the low dropout regulator is used for outputting a first voltage when the system runs and transmitting the first voltage to the following voltage regulation circuit; the digital-to-analog converter is used for receiving externally input preset digital voltage and converting the preset digital voltage into corresponding analog voltage so as to provide reference voltage for the low-dropout voltage stabilizer; the following voltage regulation circuit is used for regulating the output voltage of the direct current-direct current converter according to the first voltage and the built-in fixed output voltage of the direct current-direct current converter; the low dropout regulator is used for outputting a target voltage based on a reference voltage and an output voltage of the DC-DC converter. According to the invention, the output voltage precision of the system can be effectively improved, and the output stability and reliability of the direct-current power supply are improved.

Description

Technical Field

[0001] The present application belongs to the field of direct current power supply technology, and more specifically, relates to a direct current power supply circuit and an intelligent glass control system. Background Art

[0002] Currently, DC power supply circuits are widely used in many areas of the electronic information industry and are an essential component for the proper operation of electrical equipment. However, in existing DC power supply circuits, the power level generated is typically adjusted using a potentiometer. Due to the inherent precision limitations of the potentiometer, the actual output voltage accuracy of the system is not high.

[0003] Therefore, how to effectively improve the accuracy of the output voltage of a DC power supply circuit has become a technical problem that needs to be urgently solved in the industry. Summary of the Invention

[0004] In response to the defects of the existing technology, the purpose of this application is to improve the accuracy of the output voltage of the DC power supply circuit, aiming to solve the problem in the existing DC power supply circuit that the actual output voltage accuracy of the system is not high due to the limitation of the accuracy of the potentiometer itself.

[0005] To achieve the above objectives, the present application provides a DC power supply circuit, comprising: DC-DC converter, low voltage dropout regulator, digital-to-analog converter and follower voltage regulator circuit The output end of the digital-to-analog converter is connected to the first input end of the low-voltage dropout regulator, and the first output end of the DC-DC converter is connected to the second input end of the low-voltage dropout regulator; the first input end of the follower voltage regulator circuit is connected to the second output end of the DC-DC converter, the second input end is connected to the output end of the low-voltage dropout regulator, and the output end is connected to the first output end of the DC-DC converter; The low voltage dropout regulator is used to output a first voltage when the system is running, and transmit the first voltage to the follower voltage regulation circuit; The digital-to-analog converter is used to receive a preset digital voltage input from an external source and convert the preset digital voltage into a corresponding analog voltage to provide a reference voltage for the low-dropout regulator; The follower voltage regulator circuit is used to adjust the output voltage of the DC-DC converter according to the first voltage and the fixed output voltage built into the DC-DC converter; The low voltage dropout regulator is configured to output a target voltage based on the reference voltage and the output voltage of the DC-DC converter.

[0006] Optionally, the follower voltage regulation circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first transistor and a first capacitor; One end of the second resistor serves as the output end of the follower voltage regulation circuit and is connected to one end of the first resistor; The other end of the first resistor is connected to the emitter of the first transistor, and the other end of the second resistor, the base of the first transistor, and one end of the third resistor are connected in common; the other end of the third resistor is connected to one end of the first capacitor, one end of the first capacitor serves as the second input end of the follower voltage regulator circuit, and the other end of the first capacitor is grounded; The collector of the first transistor serves as the first input terminal of the follower voltage regulation circuit and is connected to one end of the fourth resistor, and the other end of the fourth resistor is grounded.

[0007] Optionally, a feedback control unit is further included; the input end of the feedback control unit is connected to the output end of the low-dropout voltage regulator, and the first output end is connected to the input end of the digital-to-analog converter; the output end of the low-dropout voltage regulator is connected to the second input end of the follower voltage regulator circuit through the second output end of the feedback control unit; The feedback control unit is used to detect the first voltage output by the low-dropout regulator, and based on the first voltage and the target voltage, output the preset digital voltage to control the digital-to-analog converter to output the corresponding analog voltage, providing a reference voltage for the low-dropout regulator; and is used to transmit the first voltage to the follower voltage regulation circuit so that the follower voltage regulation circuit can regulate the output voltage of the DC-DC converter.

[0008] Optionally, the feedback control unit includes a detection circuit and a micro control unit; the first output terminal of the detection circuit is connected to the input terminal of the micro control unit; The input end of the detection circuit serves as the input end of the feedback control unit; the output end of the micro control unit serves as the first output end of the feedback control unit; the second output end of the detection circuit serves as the second output end of the feedback control unit; The detection circuit is used to detect the first voltage output by the low-dropout voltage regulator when the system is running, and transmit the first voltage to the micro control unit and the follower voltage regulation circuit respectively; The micro control unit is used to compare the first voltage with the target voltage, and output the preset digital voltage if it is determined that the first voltage does not match the target voltage. Optionally, the digital-to-analog converter and the micro control unit communicate data using an IIC serial communication protocol.

[0009] Optionally, the detection circuit includes a filter circuit, a power detection module, and an eighth resistor; the input end of the filter circuit serves as the input end of the detection circuit; the output end of the power detection module serves as the first output end of the detection circuit, and one end of the eighth resistor serves as the second output end of the detection circuit; The first output end of the filter circuit is connected to one end of the eighth resistor, the second output end is connected to the first input end of the power detection module, and the third output end is connected to the second input end of the power detection module; the other end of the eighth resistor is connected to the third input end of the power detection module; The filtering circuit is used to filter the output voltage of the low-dropout voltage regulator; The power detection module is used to detect the output voltage of the filter circuit.

[0010] Optionally, the filtering circuit includes a fifth resistor, a sixth resistor, a seventh resistor and a second capacitor; One end of the fifth resistor is connected to one end of the sixth resistor, and one end of the sixth resistor serves as the input end of the filter circuit; the other end of the fifth resistor is connected to one end of the seventh resistor, and one end of the seventh resistor serves as the first output end of the filter circuit; the other end of the sixth resistor is connected to one end of the second capacitor, and the other end of the sixth resistor serves as the second output end of the filter circuit; the other end of the seventh resistor is connected to the other end of the second capacitor, and the other end of the seventh resistor serves as the third output end of the filter circuit.

[0011] Optionally, the power detection module further includes an alarm signal terminal, wherein the alarm signal terminal is connected to the enable control terminal of the DC-DC converter; The power supply detection module is configured to output an alarm signal to the DC-DC converter via the alarm signal terminal when detecting that the first voltage is greater than a target threshold, so as to shut down the DC-DC converter.

[0012] Optionally, the power detection module and the micro control unit use an IIC serial communication protocol for data communication.

[0013] In a second aspect, the present application provides an intelligent glass control system, wherein the power supply circuit of the system is any one of the aforementioned DC power supply circuits.

[0014] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies: The present application provides a DC power supply circuit and intelligent glass control system. A DC power supply circuit is constructed by introducing a DC-DC converter, a low-voltage difference regulator, a digital-to-analog converter and a following voltage regulation circuit. A digital-to-analog converter with higher output accuracy is used to control the output voltage, thereby avoiding the problem that the traditional power supply system is limited by the accuracy of the potentiometer itself. By introducing a following voltage regulation circuit and designing a method in which the DC-DC converter automatically follows the low-voltage difference regulator for voltage regulation, the stability and reliability of the DC power supply output can be improved while effectively improving the system output voltage accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is one of the structural diagrams of the DC power supply circuit provided in the embodiment of the present application; Figure 2 Schematic diagram of the structure of the follower voltage regulator circuit provided in an embodiment of the present application; Figure 3 This is the second structural diagram of the DC power supply circuit provided in the embodiment of the present application; Figure 4 This is the third structural diagram of the DC power supply circuit provided in the embodiment of the present application; Figure 5 It is a structural schematic diagram of the detection circuit in the DC power supply circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0017] The terms "first" and "second" in the specification and claims of this application are used to distinguish different objects, rather than to describe a specific order of objects. For example, the terms "first input terminal" and "second input terminal" are used to distinguish input terminals with different functions, rather than to describe a specific order of the input terminals.

[0018] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0019] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0020] Figure 1 This is one of the structural diagrams of the DC power supply circuit provided in the embodiment of the present application, such as Figure 1 As shown, the system includes: Direct current-to-direct current (DC-DC) converter 1, low dropout regulator (LDO) 2, digital-to-analog converter (DAC) 3, and follower voltage regulation circuit 4; The output end of DAC 3 is connected to the first input end of LDO 2, and the first output end of DC-DC converter 1 is connected to the second input end of LDO 2; the first input end of follower voltage regulator circuit 4 is connected to the second output end of DC-DC converter 1, the second input end is connected to the output end of LDO 2, and the output end is connected to the first output end of DC-DC converter 1; The LDO 2 is used to output a first voltage when the system is running, and transmit the first voltage to the follower voltage regulation circuit 4; DAC 3 is used to receive a preset digital voltage input from an external source and convert the preset digital voltage into a corresponding analog voltage to provide a reference voltage for LDO 2; The follower voltage regulating circuit 4 is used to adjust the output voltage of the DC-DC converter 1 according to the first voltage and the fixed output voltage built into the DC-DC converter 1; The LDO 2 is used to output a target voltage based on a reference voltage and the output voltage of the DC-DC converter 1 .

[0021] Specifically, the first voltage described in the embodiments of the present application refers to the voltage output by the LDO before adjusting the output voltage of the entire system.

[0022] The target voltage described in the embodiment of the present application refers to a pre-set DC voltage that the system needs to ultimately output.

[0023] The preset digital voltage described in the embodiments of the present application is used to convert into a corresponding analog signal to provide a reference voltage for the LDO so that the LDO outputs a target voltage. The preset digital voltage can be input through a manual front-end digital signal instrument or automatically input by introducing a corresponding control circuit. The specific value can be set according to actual needs.

[0024] In an embodiment of the present application, the output of a DAC is connected to the first input of an LDO. This allows the LDO's first output voltage to be detected through voltage measurement during system operation. If the first voltage is determined not to be the target voltage, a preset digital voltage can be sent to the DAC through manual front-end operation or external control circuitry. Upon receiving the externally input preset digital voltage, the DAC converts it into a corresponding analog voltage and transmits the analog voltage signal to the LDO's SET pin, thereby providing a reference voltage for the LDO's output that matches the target voltage.

[0025] In the prior art, the output voltage is generally obtained by multiplying the current by the resistance of the potentiometer. An 8-bit potentiometer is usually selected for adjustment. For example, under a 3.3V reference voltage, the corresponding minimum output scale is 3.3V / 256≈12.9mV. In the embodiment of the present application, a DAC is used to control the output voltage. Specifically, a 12-bit DAC can be used. Under the same conditions, its minimum output scale is 3.3V / 4095≈0.8mV, and the output accuracy can be greatly improved.

[0026] It should be noted that in the embodiments of this application, the design of the follower voltage regulator circuit is based on the selection of a DC-DC to follow the LDO voltage regulation method, maintaining a fixed voltage difference between the DC-DC and LDO, thereby ensuring that the LDO stably outputs the required voltage. For example, the fixed voltage difference between the DC-DC and LDO is fixed at 1V through the follower voltage regulator circuit. When the DAC is used to adjust the LDO output to 3V, the DC-DC output will automatically be adjusted to 4V and provided as input power to the LDO.

[0027] It should also be noted that DC-DC converters offer high efficiency and a wide voltage range, but using a DC-DC converter alone may not meet stringent requirements for power supply noise, while using an LDO alone may be unsuitable due to its limited input voltage range or low efficiency. In this case, connecting a DC-DC converter with an LDO can form an efficient, stable, and low-noise power supply system, thereby improving the overall performance of the circuit.

[0028] In power supply systems, LDOs can also protect loads. When the input voltage fluctuates significantly or the load changes suddenly, the LDO can quickly adjust the output voltage to maintain stability, thereby protecting the load from voltage fluctuations.

[0029] Furthermore, in an embodiment of the present application, the first output terminal of the DC-DC converter is connected to the second input terminal of the LDO; the first input terminal of the follower voltage regulator circuit is connected to the second output terminal of the DC-DC converter, the second input terminal of the follower voltage regulator circuit is connected to the output terminal of the LDO, and the output terminal of the follower voltage regulator circuit is connected to the first output terminal of the DC-DC converter. In this way, the follower voltage regulator circuit can receive the first voltage output by the LDO and, in combination with the fixed voltage difference designed by the circuit itself, use the first voltage and the fixed output voltage built into the DC-DC converter to adjust the output voltage of the DC-DC converter, thereby changing the input voltage of the LDO so that the LDO can output a target voltage based on the aforementioned reference voltage and the output voltage of the DC-DC converter, thereby achieving the output of the target DC voltage source, thereby providing the required low-noise, stable DC power supply to the external device.

[0030] The DC power supply circuit of the embodiment of the present application constructs a DC power supply circuit by introducing a DC-DC converter, a low-voltage difference regulator, a digital-to-analog converter and a following voltage regulation circuit, and uses a digital-to-analog converter with higher output accuracy to control the output voltage, thereby avoiding the problem that the traditional power supply system is limited by the accuracy of the potentiometer itself. By introducing a following voltage regulation circuit and designing a DC-DC converter to automatically follow the low-voltage difference regulator for voltage regulation, the stability and reliability of the DC power supply output can be improved while effectively improving the system output voltage accuracy.

[0031] Figure 2 Schematic diagram of the structure of the follower voltage regulator circuit provided in the embodiment of the present application. Figure 2 As shown, in the embodiment of the present application, the follower voltage regulation circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first transistor T1 and a first capacitor C1; One end of the second resistor R2 serves as the output end of the follower voltage regulator circuit 4 and is connected to one end of the first resistor R1; The other end of the first resistor R1 is connected to the emitter of the first transistor T1, the other end of the second resistor R2, the base of the first transistor T1, and one end of the third resistor R3 are connected in common; the other end of the third resistor R3 is connected to one end of the first capacitor C1, one end of the first capacitor C1 serves as the second input end of the follower voltage regulator circuit 4, and the other end of the first capacitor C1 is grounded; The collector of the first transistor T1 serves as the first input terminal of the follower voltage regulator circuit 4 and is connected to one end of the fourth resistor R4 , and the other end of the fourth resistor R4 is grounded.

[0032] Specifically, in the embodiment of the present application, a resistor network and a transistor structure are used to implement a follower voltage regulation method between the DC-DC converter and the LDO.

[0033] More specifically, the follower voltage regulation circuit includes resistors R1 , R2 , R3 and R4 , a first transistor T1 and a first capacitor C1 .

[0034] In the embodiment of the present application, when the follower voltage regulator circuit is in operation, the first input terminal of the follower voltage regulator circuit is connected to the second output terminal (FB pin) of the DC-DC converter, and the FB pin outputs a fixed output voltage to the collector of the first transistor T1. As a result, the voltage on the collector (c) side of the first transistor T1 is fixed. Here, according to the characteristics of the transistor, the current on the c side of the first transistor T1 is approximately equal to the current on the emitter (e) side, that is, , thus, the resistor R4 can be To fix.

[0035] Assume that the output voltage of the detection circuit is , the output voltage of the DC-DC converter is , according to the circuit analysis, we can get: ; Therefore, resistors R2 and R3 can be set according to this relationship.

[0036] make ,in, is a preset fixed pressure difference, then: ; From this we can see that when When changes, It will also vary in magnitude.

[0037] At the same time, it can be seen from the characteristics of the transistor that ,in, The value is usually 0.6 to 0.7V. When R1 is fixed, When changes, It will also vary in magnitude.

[0038] Therefore, through the follower voltage regulation circuit designed in this application, when the parameters After the resistance values of R1, R2, R3 and R4 are set, A fixed pressure difference can be achieved between By changing the voltage with equal amplitude, a fixed voltage difference can be maintained between the DC-DC and LDO, so that the DC-DC converter can automatically follow the LDO to adjust the voltage.

[0039] The DC power supply circuit of the embodiment of the present application uses a resistor network and a transistor structure to design a follower voltage regulation circuit, which can effectively realize the DC-DC converter automatically following the LDO to regulate the voltage, thereby improving the stability and reliability of the LDO output voltage.

[0040] Figure 3 This is the second structural diagram of the DC power supply circuit provided in the embodiment of the present application, such as Figure 3 As shown, the system further includes a feedback control unit 5; the input end of the feedback control unit 5 is connected to the output end of the LDO 2, and the first output end is connected to the input end of the DAC 3; the output end of the LDO 2 is connected to the second input end of the follower voltage regulator circuit 4 through the second output end of the feedback control unit 5; The feedback control unit 5 is used to detect the first voltage output by the LDO 2 and, based on the first voltage and the target voltage, output a preset digital voltage to control the DAC 3 to output a corresponding analog voltage, thereby providing a reference voltage for the LDO 2; and is used to transmit the first voltage to the follower voltage regulator circuit 4 so that the follower voltage regulator circuit 4 can adjust the output voltage of the DC-DC converter 1.

[0041] Specifically, in the embodiments of the present application, a feedback control unit may be introduced to implement feedback control of the LDO output voltage.

[0042] More specifically, in an embodiment of the present application, the input end of the feedback control unit is connected to the output end of the LDO, and the first output end is connected to the input end of the DAC; the output end of the LDO is connected to the second input end of the follower voltage regulation circuit through the second output end of the feedback control unit. In this way, when the system operates the LDO output voltage, the feedback control unit can detect the first voltage output by the LDO in real time, and when the system needs to adjust to the target voltage, if it determines that the first voltage does not match the target voltage, it outputs a preset digital voltage for prompting the LDO to output the target voltage. The preset digital voltage is input into the DAC, causing the DAC to output a corresponding analog voltage, thereby providing a reference voltage for the LDO.

[0043] Furthermore, the feedback control unit will also transmit the detected first voltage to the follower voltage regulation circuit 4, so that the follower voltage regulation circuit can adjust the output voltage of the DC-DC converter according to the set fixed voltage difference between the DC-DC and the LDO, ensuring that the LDO stably outputs the target voltage under the control of the input voltage and the reference voltage.

[0044] The system of the embodiment of the present application introduces a feedback control unit to automatically detect the voltage output by the LDO, determine whether the first voltage is the target voltage to be adjusted, output the output of the preset digital voltage adjustment DAC, and adjust the output of the DC-DC converter, thereby forming feedback control of the LDO output and realizing automatic control of the output of the DC power supply circuit, which can improve the efficiency and reliability of the system's adaptive output. Figure 4 This is the third structural diagram of the DC power supply circuit provided in the embodiment of the present application, such as Figure 4 As shown, the feedback control unit 5 includes a detection circuit 51 and a micro control unit (MCU) 52; the first output terminal of the detection circuit 51 is connected to the input terminal of the MCU 52; The input end of the detection circuit 51 serves as the input end of the feedback control unit 5; the output end of the MCU 52 serves as the first output end of the feedback control unit 5; the second output end of the detection circuit 51 serves as the second output end of the feedback control unit 5; The detection circuit 51 is used to detect the first voltage output by the LDO 2 when the system is running, and transmit the first voltage to the MCU 52 and the follower voltage regulation circuit 4 respectively; The MCU 52 is configured to compare the first voltage with the target voltage, and output a preset digital voltage if it is determined that the first voltage does not match the target voltage. Specifically, in the embodiments of the present application, the feedback control unit can be constructed using a detection circuit and an MCU. The input end of the detection circuit serves as the input end of the feedback control unit and is connected to the output end of the LDO; the output end of the MCU serves as the first output end of the feedback control unit and is connected to the input end of the DAC; the second output end of the detection circuit 51 serves as the second output end of the feedback control unit 5 and is connected to the second input end of the follower voltage regulator circuit 4. In this way, when the system is operating the LDO output voltage, the detection circuit can detect the first voltage output by the LDO in real time.

[0045] At the same time, the detection circuit can transmit the first voltage to the MCU on the one hand, so that when the system needs to be adjusted to the target voltage, the MCU can determine whether the first voltage matches the target voltage. If it is determined that the two do not match, the MCU can output a preset digital voltage to the DAC, so that the DAC outputs the corresponding analog voltage to provide a reference voltage for the LDO.

[0046] Optionally, in an embodiment of the present application, data communication between the DAC and the MCU is performed using an IIC serial communication protocol.

[0047] It should be noted that the IIC (Inter-Integrated Circuit) serial communication protocol, also known as the I2C (Inter-IC) bus protocol, only requires two signal lines, the serial clock line (SCL) and the serial data line (SDA), to achieve communication between multiple devices.

[0048] In an embodiment of the present application, the MCU can efficiently send the required controlled voltage data to the input end (SDA pin) of the DAC through IIC communication for the DAC to receive, and convert it into a corresponding analog voltage and output it to the SET pin of the LDO to provide a reference voltage for the LDO.

[0049] The system of the embodiment of the present application adopts the IIC serial communication protocol. The IIC bus consists of only two lines (SDA and SCL), which can greatly simplify the complexity of hardware design. At the same time, IIC communication supports high-speed data transmission and has bidirectional communication capabilities and a response mechanism. It can enable the MCU to efficiently transmit data with the DAC, realize real-time data exchange and control, and improve the reliability and stability of data transmission between the MCU and the DAC.

[0050] On the other hand, the detection circuit synchronously transmits the first voltage to the following voltage regulation circuit, prompting the following voltage regulation circuit to adjust the output voltage of the DC-DC converter according to the set fixed voltage difference between the DC-DC and the LDO, and ultimately make the LDO stably output the target voltage under the control of the DC-DC converter output voltage and the reference voltage.

[0051] The system of the embodiment of the present application, by adopting a detection circuit and an MCU to construct a feedback control unit, can achieve high precision, high stability and fast dynamic response of the system output voltage, and improve the reliability and flexibility of the intelligent regulation and output of the power supply system.

[0052] Figure 5 Schematic diagram of the structure of the detection circuit in the DC power supply circuit provided in the embodiment of the present application. Figure 5 As shown, in the embodiment of the present application, the detection circuit 6 includes a filter circuit 61, a power detection module 62 and an eighth resistor R8; The input end of the filter circuit 61 serves as the input end of the detection circuit 6; the output end of the power detection module 62 serves as the first output end of the detection circuit 6, and one end of the eighth resistor R8 serves as the second output end of the detection circuit; The first output terminal of the filter circuit 61 is connected to one end of the eighth resistor R8, the second output terminal is connected to the first input terminal of the power detection module 62, and the third output terminal is connected to the second input terminal of the power detection module 62; the other end of the eighth resistor R8 is connected to the third input terminal of the power detection module 62; The filter circuit 61 is used to filter the output voltage of the LDO; The power detection module 62 is used to detect the output voltage of the filter circuit 61 .

[0053] Specifically, in the embodiments of the present application, a filter circuit, a power detection module, and a resistor R8 can be used to construct a detection circuit. The input end of the filter circuit serves as the input end of the detection circuit and is connected to the output end of the LDO; the output end of the power detection module serves as the first output end of the detection circuit and is connected to the input end of the MCU; and one end of the eighth resistor R8 serves as the second output end of the detection circuit and is connected to the second input end of the follower voltage regulator circuit.

[0054] It should be noted that, in the embodiment of the present application, the power detection module may specifically adopt a power management chip with current and voltage detection functions. In the embodiments of the present application, by considering the obvious advantages of the INA233AIDGSR power chip in its high precision, low power consumption, multi-interface compatibility, wide operating temperature range and compact packaging design, as well as its power monitoring and management, the power detection module can specifically adopt a power chip of model INA233AIDGSR, which can effectively improve the performance of the entire DC power supply circuit.

[0055] Furthermore, the first output end of the filter circuit is connected to one end of the eighth resistor R8, the second output end is connected to the first input end of the power detection module, and the third output end is connected to the second input end of the power detection module; the other end of the eighth resistor R8 is connected to the third input end of the power detection module. In this way, when the output voltage of the LDO is output to the detection circuit for detection, it is first filtered by the filter circuit and then input as an input voltage source to the power detection module through the first input end (VIN+ pin) and the second input end (VIN- pin) of the power detection module, so that the power detection module operates normally. Finally, the power detection module detects the voltage output by the filter circuit, thereby completing the detection of the first voltage output by the LDO.

[0056] In the embodiment of the present application, one end of resistor R8 serves as the second output terminal of the detection circuit, while the other end is connected to the third input terminal (VBUS pin) of the power detection module. This third input terminal of the power detection module enables detection and monitoring of the output voltage Vout at the second output terminal of the detection circuit. Furthermore, the output terminal of the power detection module serves as the first output terminal of the detection circuit, transmitting the detected first voltage to the MCU for evaluation and outputting a preset digital voltage to the DAC. The DAC then outputs an analog voltage corresponding to the voltage provided as a reference voltage for the LDO.

[0057] Based on the content of the above embodiment, as an optional embodiment, the power detection module and the MCU use the IIC serial communication protocol for data communication.

[0058] In an embodiment of the present application, through IIC communication, the output end (SDA pin) of the power detection module can feed back the detected first voltage data to the MCU in real time, so as to facilitate the subsequent execution of voltage regulation control by the MCU.

[0059] In an embodiment of the present application, the MCU and the power detection module communicate data by adopting the IIC serial communication protocol. Based on the advantages of IIC communication, the MCU can efficiently transmit data with the power detection module, realize real-time data exchange and control, and improve the reliability and stability of data transmission between the MCU and the power detection module.

[0060] The system of the embodiment of the present application constructs a detection circuit through a filtering circuit, a power detection module and a fixed resistor, so that the detection circuit has the functions of voltage filtering and real-time monitoring and detection. It can improve the stability of voltage signal transmission and the accuracy of voltage detection, which is conducive to further improving the stability and reliability of the output of the entire DC power supply circuit.

[0061] Continue to refer to Figure 5As an optional embodiment, the filter circuit 61 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a second capacitor C2; One end of the fifth resistor R5 is connected to one end of the sixth resistor R6, and one end of the sixth resistor R6 serves as the input end of the filter circuit; the other end of the fifth resistor R5 is connected to one end of the seventh resistor R7, and one end of the seventh resistor R7 serves as the first output end of the filter circuit; the other end of the sixth resistor R6 is connected to one end of the second capacitor C2, and the other end of the sixth resistor R6 serves as the second output end of the filter circuit; the other end of the seventh resistor R7 is connected to the other end of the second capacitor C2, and the other end of the seventh resistor R7 serves as the third output end of the filter circuit.

[0062] Specifically, in an embodiment of the present application, an RC filter circuit is formed by resistors R5, R6, and R7, and a second capacitor C2. One end of the fifth resistor R5 is connected to one end of the sixth resistor R6, which serves as the input of the filter circuit and is connected to the output of the LDO. The other end of the sixth resistor R6 serves as the second output of the filter circuit and is connected to the first input (VIN+ pin) of the power detection module. The other end of the fifth resistor R5 is connected to one end of the seventh resistor R7, which serves as the first output of the filter circuit and is connected to one end of the eighth resistor R8. The other end of the seventh resistor R7 is connected to the other end of the second capacitor C2, which serves as the third output of the filter circuit and is connected to the second input (VIN- pin) of the power detection module.

[0063] The system of the embodiment of the present application constructs a filtering circuit by using resistors R5, R6, R7 and capacitor C2 to form a multi-stage RC network. The structure is simple and good filtering effect can be achieved, which is conducive to further improving the accuracy and reliability of voltage detection in the detection circuit.

[0064] Based on the content of the above embodiment, as an optional embodiment, the power detection module further includes an alarm signal terminal, which is connected to the enable control terminal of the DC-DC converter; The power supply detection module is used to output an alarm signal through the alarm signal terminal when detecting that the first voltage is greater than the target threshold, so as to shut down the DC-DC converter.

[0065] Specifically, the target threshold value described in the embodiment of the present application refers to the protection value of voltage and current set by the power detection module, which is used to trigger the alarm function of the power detection module.

[0066] In an embodiment of the present application, the power detection module may also have an alarm function. For example, the power detection module may pre-set an ALERT pin for outputting an alarm signal, and connect the ALERT pin to the enable control terminal (EN pin) of the DC-DC converter as an alarm signal terminal.

[0067] In a specific implementation, the protection values of voltage and current can be pre-set. If the voltage and current values detected by the power detection module are greater than the set protection values, the power detection module will issue an alarm signal, that is, the Alert signal output by the ALERT pin is low, and the protection will be triggered at this time. The Alert signal is input to the enable control terminal of the DC-DC converter, so that the DC-DC converter is turned off, thereby avoiding any output causing damage to subsequent equipment.

[0068] The system of the embodiment of the present application can monitor the status of the power supply system in real time, improve the reliability and safety of the system, and better realize the monitoring and management of the power supply system by introducing a power supply detection module with an alarm function into the detection circuit.

[0069] On the other hand, in an embodiment of the present application, a smart glass control system is further provided, and the power supply circuit of the system can be any of the aforementioned DC power supply circuits.

[0070] Specifically, in an embodiment of the present application, the system may include a DC power supply circuit and a positive and negative voltage complementary output circuit connected in sequence, wherein the positive and negative voltage complementary output circuit is used to convert the output voltage of the DC power supply circuit into corresponding positive and negative voltages for output to control externally connected smart glass, such as electrochromic glass, to color and fade.

[0071] The system of the embodiment of the present application adopts any of the aforementioned DC power supply circuits as the power supply circuit of the smart glass control system, introduces a DC-DC converter that automatically follows the LDO for voltage regulation, and automatically controls the generation of high-precision DC power supply. This can provide high-precision power input for the smart glass control system, which is beneficial to improving the color control accuracy and color control effect of the smart glass control system.

[0072] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0073] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0074] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A DC power supply circuit, characterized in that: include: DC-DC converter, low voltage dropout regulator, digital-to-analog converter and follower voltage regulator circuit; The output end of the digital-to-analog converter is connected to the first input end of the low-voltage dropout regulator, and the first output end of the DC-DC converter is connected to the second input end of the low-voltage dropout regulator; the first input end of the follower voltage regulator circuit is connected to the second output end of the DC-DC converter, the second input end is connected to the output end of the low-voltage dropout regulator, and the output end is connected to the first output end of the DC-DC converter; The low voltage dropout regulator is used to output a first voltage when the system is running, and transmit the first voltage to the follower voltage regulation circuit; The digital-to-analog converter is used to receive a preset digital voltage input from an external source and convert the preset digital voltage into a corresponding analog voltage to provide a reference voltage for the low-dropout regulator; The follower voltage regulator circuit is used to adjust the output voltage of the DC-DC converter according to the first voltage and the fixed output voltage built into the DC-DC converter; The low voltage dropout regulator is configured to output a target voltage based on the reference voltage and the output voltage of the DC-DC converter.

2. The DC power supply circuit according to claim 1, wherein: The follower voltage regulation circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first transistor and a first capacitor; One end of the second resistor serves as the output end of the follower voltage regulation circuit and is connected to one end of the first resistor; The other end of the first resistor is connected to the emitter of the first transistor, and the other end of the second resistor, the base of the first transistor, and one end of the third resistor are connected in common; the other end of the third resistor is connected to one end of the first capacitor, one end of the first capacitor serves as the second input end of the follower voltage regulator circuit, and the other end of the first capacitor is grounded; The collector of the first transistor serves as the first input terminal of the follower voltage regulation circuit and is connected to one end of the fourth resistor, and the other end of the fourth resistor is grounded.

3. The DC power supply circuit according to claim 1, wherein: It also includes a feedback control unit; the input end of the feedback control unit is connected to the output end of the low-dropout voltage regulator, and the first output end is connected to the input end of the digital-to-analog converter; the output end of the low-dropout voltage regulator is connected to the second input end of the follower voltage regulator circuit through the second output end of the feedback control unit; The feedback control unit is used to detect the first voltage output by the low-dropout regulator, and based on the first voltage and the target voltage, output the preset digital voltage to control the digital-to-analog converter to output the corresponding analog voltage, providing a reference voltage for the low-dropout regulator; and is used to transmit the first voltage to the follower voltage regulation circuit so that the follower voltage regulation circuit can regulate the output voltage of the DC-DC converter.

4. The DC power supply circuit according to claim 3, wherein: The feedback control unit includes a detection circuit and a micro control unit; the first output terminal of the detection circuit is connected to the input terminal of the micro control unit; The input end of the detection circuit serves as the input end of the feedback control unit; the output end of the micro control unit serves as the first output end of the feedback control unit; the second output end of the detection circuit serves as the second output end of the feedback control unit; The detection circuit is used to detect the first voltage output by the low-dropout voltage regulator when the system is running, and transmit the first voltage to the micro control unit and the follower voltage regulation circuit respectively; The micro control unit is used to compare the first voltage with the target voltage, and output the preset digital voltage if it is determined that the first voltage does not match the target voltage.

5. The DC power supply circuit according to claim 4, characterized in that: The digital-to-analog converter and the microcontroller unit use an IIC serial communication protocol for data communication.

6. The DC power supply circuit according to claim 4, characterized in that: The detection circuit includes a filter circuit, a power detection module and an eighth resistor; the input end of the filter circuit serves as the input end of the detection circuit; the output end of the power detection module serves as the first output end of the detection circuit, and one end of the eighth resistor serves as the second output end of the detection circuit; The first output end of the filter circuit is connected to one end of the eighth resistor, the second output end is connected to the first input end of the power detection module, and the third output end is connected to the second input end of the power detection module; the other end of the eighth resistor is connected to the third input end of the power detection module; The filtering circuit is used to filter the output voltage of the low-dropout voltage regulator; The power detection module is used to detect the output voltage of the filter circuit.

7. The DC power supply circuit according to claim 6, wherein: The filtering circuit includes a fifth resistor, a sixth resistor, a seventh resistor and a second capacitor; One end of the fifth resistor is connected to one end of the sixth resistor, and one end of the sixth resistor serves as the input end of the filter circuit; the other end of the fifth resistor is connected to one end of the seventh resistor, and one end of the seventh resistor serves as the first output end of the filter circuit; the other end of the sixth resistor is connected to one end of the second capacitor, and the other end of the sixth resistor serves as the second output end of the filter circuit; the other end of the seventh resistor is connected to the other end of the second capacitor, and the other end of the seventh resistor serves as the third output end of the filter circuit.

8. The DC power supply circuit according to claim 6, wherein: The power detection module further includes an alarm signal terminal connected to the enable control terminal of the DC-DC converter; The power supply detection module is configured to output an alarm signal to the DC-DC converter via the alarm signal terminal when detecting that the first voltage is greater than a target threshold, so as to shut down the DC-DC converter.

9. The DC power supply circuit according to any one of claims 6 to 8, characterized in that: The power detection module and the micro control unit use the IIC serial communication protocol for data communication.

10. An intelligent glass control system, characterized in that: The power supply circuit of the system is the DC power supply circuit according to any one of claims 1 to 9.

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