Real-time clock circuit and electronic equipment

Abstract

The utility model provides a real-time clock circuit and electronic equipment. The real-time clock circuit comprises a first one-way circulation module, an energy storage module, a second one-way circulation module, a third one-way circulation module and a real-time clock, the first end of the first one-way circulation module and the first end of the third one-way circulation module are used for being connected with a first power supply, and the second end of the first one-way circulation module is connected with the first end of the second one-way circulation module and the energy storage module. The second end of the second one-way circulation module and the second end of the third one-way circulation module are connected with the power supply end of the real-time clock. In the real-time clock circuit, the energy storage module is used as the standby power supply of the real-time clock, and power can be supplied to the real-time clock when the first power supply is powered off, so that normal work of the real-time clock is maintained, and the working reliability of the electronic equipment is improved.

Description

Technical Field

[0001] The embodiments of the present utility model relate to the technical field of electronic circuits, and particularly to a real-time clock circuit and an electronic device. Background Art

[0002] In various electronic devices, a Real Time Clock (RTC) function is usually set to record the time information of data generation. Particularly, in some occasions with high requirements for time information, an RTC clock circuit needs to be set. However, when the power supply of the RTC clock circuit is cut off, the RTC clock circuit cannot continue to work, and the time of the real-time clock will be abnormal, affecting the correctness of data recording. When the power is restored, the RTC clock must be reset, resulting in extremely inconvenient use and poor reliability. Summary of the Utility Model

[0003] The embodiments of the present utility model provide a real-time clock circuit and an electronic device, which can use an energy storage module to supply power to the real-time clock when the first power supply is cut off, maintain the normal operation of the real-time clock, and improve the reliability of the circuit operation.

[0004] In a first aspect, the embodiments of the present utility model provide a real-time clock circuit, which includes: a first unidirectional flow module, an energy storage module, a second unidirectional flow module, a third unidirectional flow module, and a real-time clock. The first ends of the first unidirectional flow module and the third unidirectional flow module are both used to connect to a first power supply. The second end of the first unidirectional flow module is respectively connected to the first end of the second unidirectional flow module and the energy storage module. The second ends of the second unidirectional flow module and the third unidirectional flow module are both connected to the power supply end of the real-time clock. Among them, the first unidirectional flow module is configured to conduct when the first power supply is supplying power, so that the first power supply charges the energy storage module; the third unidirectional flow module is configured to conduct when the first power supply is supplying power, so that the first power supply supplies power to the real-time clock; the second unidirectional flow module is configured to conduct when the first power supply is cut off, so that the energy storage module supplies power to the real-time clock.

[0005] In some embodiments, the first unidirectional flow module includes a diode D1 and a resistor unit. The anode of the diode D1 is used to connect to the first power supply, the cathode of the diode D1 is connected to the first end of the resistor unit, and the second end of the resistor unit is respectively connected to the first end of the second unidirectional flow module and the energy storage module.

[0006] In some embodiments, the resistance unit includes at least one resistor. The first end of the resistor is connected to the cathode of the diode D1, and the second end of the resistor is respectively connected to the first end of the second unidirectional current module and the energy storage module.

[0007] In some embodiments, the second unidirectional current module includes a diode D2; the anode of the diode D2 is respectively connected to the second end of the first unidirectional current module and the energy storage module, and the cathode of the diode D2 is connected to the power supply terminal of the real-time clock.

[0008] In some embodiments, the third unidirectional current module includes a diode D3; the anode of the diode D3 is used to connect to the first power supply, and the cathode of the diode D3 is connected to the power supply terminal of the real-time clock.

[0009] In some embodiments, the real-time clock circuit further includes a first level adjustment module and a second level adjustment module; the first end of the first level adjustment module is used to connect to a second power supply, the second end of the first level adjustment module is connected to the first signal terminal of the real-time clock, the third end of the first level adjustment module is used to connect to the first signal pin of the central processor, and the first level adjustment module is configured to provide a first voltage to the first signal terminal and the first signal pin based on the second power supply; the first end of the second level adjustment module is used to connect to the second power supply, the second end of the second level adjustment module is connected to the second signal terminal of the real-time clock, the third end of the second level adjustment module is connected to the second signal pin of the central processor, and the second level adjustment module is configured to provide the first voltage to the second signal terminal and the second signal pin based on the second power supply.

[0010] In some embodiments, the first level adjustment module includes a switching transistor Q1, a resistor R6, and a resistor R9; the first signal terminal is connected to the first end of the switching transistor Q1, the second end of the switching transistor Q1 is respectively connected to the first end of the resistor R9 and the first signal pin, the third end of the switching transistor Q1 is connected to the first end of the resistor R6, and the second ends of the resistor R6 and the resistor R9 are both connected to the second power supply.

[0011] In some embodiments, the second level adjustment module includes a switching transistor Q2, a resistor R7, and a resistor R10; the second signal terminal is connected to the first end of the switching transistor Q2, the second end of the switching transistor Q2 is respectively connected to the first end of the resistor R10 and the second signal pin, the third end of the switching transistor Q2 is connected to the first end of the resistor R7, and the second ends of the resistor R7 and the resistor R10 are both connected to the second power supply.

[0012] In some embodiments, the energy storage module includes a capacitor; one end of the capacitor is respectively connected to the second end of the first unidirectional flow module and the first end of the second unidirectional flow module, and the other end of the capacitor is grounded.

[0013] In a second aspect, an embodiment of the present invention provides an electronic device, which includes a first power supply and the real-time clock circuit as described in the first aspect; the first power supply is connected to the first end of the first unidirectional flow module and the first end of the third unidirectional flow module.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: Different from the prior art, an embodiment of the present invention provides a real-time clock circuit and an electronic device, including a first unidirectional flow module, an energy storage module, a second unidirectional flow module, a third unidirectional flow module and a real-time clock; the first end of the first unidirectional flow module and the first end of the third unidirectional flow module are both used to connect to a first power supply, the second end of the first unidirectional flow module is respectively connected to the first end of the second unidirectional flow module and the energy storage module, and the second end of the second unidirectional flow module and the second end of the third unidirectional flow module are both connected to the power supply terminal of the real-time clock; wherein, the first unidirectional flow module is configured to conduct when the first power supply supplies power, so that the first power supply charges the energy storage module; the third unidirectional flow module is configured to conduct when the first power supply supplies power, so that the first power supply supplies power to the real-time clock; the second unidirectional flow module is configured to conduct when the first power supply is powered off, so that the energy storage module supplies power to the real-time clock. In this real-time clock circuit, by using the energy storage module as a backup power supply, it can supply power to the real-time clock when the first power supply is powered off, so as to maintain the normal operation of the real-time clock and improve the reliability of the circuit operation. Description of the Drawings

[0015] In one or more embodiments, exemplary illustrations are provided through the pictures in the corresponding drawings. These exemplary illustrations do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise stated, the drawings in the figures do not constitute a scale limitation.

[0016] Figure 1 is a structural block diagram of a real-time clock circuit provided by an embodiment of the present invention;

[0017] Figure 2 is a structural schematic diagram of a real-time clock circuit provided by an embodiment of the present invention. Detailed Embodiments

[0018] The present utility model will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present utility model, but do not limit the present utility model in any form. It should be noted that those of ordinary skill in the art can make several modifications and improvements without departing from the concept of the present utility model. These all fall within the protection scope of the present utility model.

[0019] To facilitate the understanding of this application, the following will provide a more detailed description of this application in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not used to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0020] It should be noted that if there is no conflict, the various features in the embodiments of the present utility model can be combined with each other, and all are within the protection scope of this application. In addition, although the functional modules are divided in the device schematic diagram, in some cases, it can be different from the module division in the device. In addition, the terms "first", "second", etc. used herein do not limit the data and execution order, but only distinguish the same items or similar items with basically the same function and role.

[0021] Currently, the power supply method of the existing real-time clock circuit generally uses a button battery for power supply, and the button battery is generally arranged on the control circuit board. When the button battery fails or runs out of power, the abnormal time will affect the correctness of data recording. After replacing the button battery, the real-time clock circuit must be reset, resulting in extremely inconvenient use and maintenance. In addition, the button battery is easily affected by the working temperature fluctuation and affects its normal operation. The typical working temperature range of the button battery is -20 to +40 °C, but it is prone to thermal runaway, which reduces the efficiency and may even pose a great safety hazard.

[0022] In order to solve the problems that occur when the button battery is used as a backup power supply, the embodiments of the present utility model provide a real-time clock circuit that uses an energy storage module as a backup power supply. When the first power supply is in operation, the first power supply supplies power to the real-time clock, and the first power supply charges the energy storage module. When the first power supply is powered off, the energy storage module can supply power to the real-time clock to ensure the normal operation of the real-time clock and avoid the problems that occur when the button battery is used as a backup power supply.

[0023] In a first aspect, the embodiments of the present utility model provide a real-time clock circuit, which includes: a first unidirectional flow module 10, a second unidirectional flow module 20, a third unidirectional flow module 30, an energy storage module 40, and a real-time clock 50.

[0024] The first ends of the first unidirectional circulation module 10 and the third unidirectional circulation module 30 are both used to connect to the first power supply DVCC1. The second end of the first unidirectional circulation module 10 is respectively connected to the first end of the second unidirectional circulation module 20 and the energy storage module 40. The second ends of the second unidirectional circulation module 20 and the third unidirectional circulation module 30 are both connected to the power supply terminal of the real-time clock 50. Among them, the first unidirectional circulation module 10 is configured to conduct when the first power supply DVCC1 supplies power, so that the first power supply DVCC1 charges the energy storage module 40. The third unidirectional circulation module 30 is configured to conduct when the first power supply DVCC1 supplies power, so that the first power supply DVCC1 supplies power to the real-time clock 50. The second unidirectional circulation module 20 is configured to conduct when the first power supply DVCC1 is powered off, so that the energy storage module 40 supplies power to the real-time clock 50.

[0025] The real-time clock 50 refers to an element that can be used to provide a clock signal, which may include elements such as a crystal oscillator, a frequency divider, a counter, a memory, and a clock display circuit. The specific circuit structure can refer to the prior art and is not limited here. For example, refer to Figure 2 , the real-time clock may include a clock chip U1. The clock chip U1 can adopt the chip PCF8563T. This chip has a built-in 32.768KHz crystal oscillator unit, and the operating voltage range at room temperature is 1.0 - 5.5V, and the standby current is 250nA. The power supply terminal of the real-time clock 50 can be the power input pin VDD of the clock chip U1. In practical applications, the actual model of the clock chip U1 can be set according to actual needs and is not limited here.

[0026] The first power supply DVCC1 is a DC power supply, which can be provided by a power supply module in an electronic device. The power supply module can be a boost circuit or a buck circuit. The specific structure can refer to the prior art and is not limited here. The first power supplies DVCC1 can be connected to each other by a bus, and the voltage magnitude of the first power supply DVCC1 can be set according to actual needs and is not limited here. For example, it can be 5V.

[0027] The energy storage module 40 is a device that can store and release energy. The unidirectional current flow module refers to a device used to make the current flow unidirectionally, including devices such as diodes. After the first unidirectional current flow module 10 and the third unidirectional current flow module 30 are both connected to the first power supply DVCC1, when the first power supply DVCC1 is normally powered, the first unidirectional current flow module 10 and the third unidirectional current flow module 30 are turned on, and the second unidirectional current flow module 20 is turned off, so that the first power supply DVCC1 charges the energy storage module 40 through the first unidirectional current flow module 10, and the first power supply DVCC1 supplies power to the real-time clock 50 through the third unidirectional current flow module 30. When the first power supply DVCC1 is powered off, the electric energy of the energy storage module 40 will make the second unidirectional current flow module 10 turn on, and at this time, the first unidirectional current flow module 10 and the third unidirectional current flow module 30 are in the off state, and the energy storage module 40 will supply power to the real-time clock 50 through the second unidirectional current flow module 10.

[0028] It can be seen that in the real-time clock circuit provided by the present utility model, after the first power supply DVCC1 is powered off, the energy storage module 40 can be used as a backup power supply to supply power to the real-time clock 50 to ensure the normal operation of the real-time clock 50. And the energy storage module 40 is charged when the first power supply DVCC1 is normally powered, without the need to frequently replace the battery as when using a button battery as a backup power supply, improving the user experience.

[0029] In some of the embodiments, refer to Figure 2 , the first unidirectional current flow module 10 includes a diode D1 and a resistor unit 11. The anode of the diode D1 is used to connect to the first power supply DVCC1, the cathode of the diode D1 is connected to the first end of the resistor unit 11, and the second end of the resistor unit 11 is respectively connected to the first end of the second unidirectional current flow module 20 and the energy storage module 40.

[0030] The diode D1 can be a common diode. The voltage drop of the diode D1 in the on state is 0.9V, and when the diode D1 is in reverse bias, the reverse leakage current is 3pA. By setting the diode D1, when the voltage at the anode end is lower than the voltage at the cathode end, the diode D2 is in the off state, which can prevent current backflow, protect the devices in the circuit from damage, and improve the reliability of the circuit operation. In addition, the resistor unit 11 can be used to divide the voltage and limit the current, and it can be composed of multiple resistors in parallel and / or in series to achieve the purpose.

[0031] In some of the embodiments, the resistor unit 11 includes at least one resistor. The first end of the resistor is connected to the cathode of the diode D1, and the second end of the resistor is respectively connected to the first end of the second unidirectional current flow module 20 and the energy storage module 40.

[0032] Specifically, refer to Figure 2, the resistor unit 11 includes three resistors, namely resistor R1, resistor R2, and resistor R3. The first ends of resistor R1, resistor R2, and resistor R3 are all connected to the cathode of diode D1, and the second ends of resistor R1, resistor R2, and resistor R3 are respectively connected to the first end of the second unidirectional current flow module 20 and the energy storage module 40. By connecting the three resistors in parallel, the voltage and current in the circuit can be effectively adjusted to meet the circuit requirements and ensure the normal operation of the circuit.

[0033] In some embodiments, refer to Figure 2 , the second unidirectional current flow module 20 includes diode D2. The anode of diode D2 is respectively connected to the second end of the first unidirectional current flow module 10 and the energy storage module 40, and the cathode of diode D2 is connected to the power supply terminal of the real-time clock 50. Specifically, the anode of diode D2 is respectively connected to the energy storage module 40, the second end of resistor R1, the second end of resistor R2, and the second end of resistor R3.

[0034] Diode D2 can be a Schottky diode. The voltage drop of diode D2 in the conduction state is 0.8V. In this embodiment, by setting diode D2, when the voltage at the anode end is lower than the voltage at the cathode end, diode D2 is in the cut-off state, which can prevent current backflow, protect the devices in the circuit from damage, and improve the reliability of the circuit operation.

[0035] In some embodiments, refer to Figure 2 , the third unidirectional current flow module 30 includes diode D3. The anode of diode D3 is used to connect to the first power supply DVCC1, and the cathode of diode D3 is connected to the power supply terminal of the real-time clock 50.

[0036] Diode D2 can be a general diode. The voltage drop of diode D2 in the conduction state is 0.9V. When diode D2 is in reverse bias, the reverse leakage current is 3pA. In this implementation, by setting diode D2, when the voltage at the anode end is lower than the voltage at the cathode end, diode D2 is in the cut-off state, which can prevent current backflow, protect the devices in the circuit from damage, and improve the reliability of the circuit operation.

[0037] In some embodiments, refer to Figure 2 , the energy storage module 40 includes capacitor TC1; one end of capacitor TC1 is respectively connected to the second end of the first unidirectional current flow module 10 and the first end of the second unidirectional current flow module 20, and the other end of capacitor TC1 is grounded to DGND.

[0038] The capacitor TC1 can be a supercapacitor TC1, and its rated operating voltage can be 5.5V. A supercapacitor is a capacitor that can store and release a large amount of charge, and has characteristics such as relatively high energy density and relatively high power density. A supercapacitor can be recycled almost infinitely, and has advantages such as extremely low internal resistance, long service life, and high safety. The high-capacity and high-current output characteristics of the supercapacitor enable it to store enough charge and can also quickly release the charge for use by the real-time clock when discharging electrical energy.

[0039] In some embodiments, the real-time clock 50 further includes a crystal oscillator X1, a resistor R8, a capacitor C4, and a capacitor C5. One end of the crystal oscillator X1 is respectively connected to one end of the capacitor C4, one end of the resistor R8, and the OSC I pin of the clock chip U1. The other end of the crystal oscillator X1 is respectively connected to one end of the capacitor C5, the other end of the resistor R8, and the OSCO pin of the clock chip U1. The other ends of the capacitor C4 and the capacitor C5 are both grounded to DGND. Among them, the crystal oscillator X1 can be a 27.12MHz passive crystal oscillator. Through the above circuit, a crystal oscillator oscillation circuit can be formed to provide a real-time clock signal to the clock chip U1.

[0040] The following uses Figure 2 the illustrated embodiment to elaborate in detail the specific working process of the real-time clock circuit provided by the embodiment of the present invention.

[0041] In Figure 2In the illustrated embodiment, the voltage value of the first power supply DVCC1 is 5V, the voltage value of the second power supply DVCC2 is 3.3V, the resistance values of the resistor R1, the resistor R2 and the resistor R3 are all 470Ω, and the voltage division across the resistor unit 11 is 25mV. When the first power supply DVCC1 is normally powered, the first diode D1 and the third diode D3 are both conducting, and the cathode voltage of the diode D3 is 5V - VD3, where VD3 is the forward conduction voltage drop of the diode D1 and is 0.9V, that is, the cathode voltage of the diode D3 is 5V - 0.9V = 4.1V. In addition, the first power supply DVCC1 charges the capacitor TC1 through the first unidirectional current flow module 10, and the voltage at the first end of the capacitor TC1 is 5V - VD1 - VR, where VD1 is the forward conduction voltage drop of the diode D1 and is 0.9V, VR is the voltage division across the resistor unit 11 and is 25mV. Then, the voltage at the first end of the capacitor TC1 is 5V - 0.9V - 0.025V = 4.075V. That is, the anode voltage of the diode D2 is 4.075V and the cathode voltage is 4.1V, and the diode D2 is cut off. At this time, the first power supply DVCC1 supplies power to the clock chip U1 through the diode D3, and the supply voltage DVCC_RTC is 4.1V. When the first power supply DVCC1 is powered off, the diode D2 conducts, and the capacitor TC1 supplies power to the clock chip U1 through the diode D2, and the supply voltage is 4.075V - VD2, where VD2 is the forward conduction voltage drop of the diode D2 and is 0.8V. Then, the supply voltage DVCC_RTC is 4.075V - 0.8V = 3.275V.

[0042] It can be seen that the real-time clock circuit has a simple structure and the cost of the electronic devices used is relatively low. When the first power supply DVCC1 is powered off, the capacitor TC1 can be used as a backup power supply to supply power to the clock chip U1 to maintain the normal operation of the clock chip U1. Moreover, due to the unidirectional conductivity of the diode and the extremely low leakage current, it will not cause additional discharge of the capacitor TC1. The capacitor TC1 can maintain the working time of the clock chip U1 as T = C * V1 / I, where C is the capacitance value of the capacitor TC1 and can be 1.0F, V1 is the difference between the voltage of the clock chip U1 when the capacitor TC1 starts to discharge and the minimum normal working voltage of the clock chip U1, such as V1 = 3.275V - 1.0V = 2.275V, I is the minimum working current of the clock chip U1, such as 250nA. After substituting and calculating, it can be obtained that the working time T of the capacitor TC1 to maintain the clock chip U1 is about 2531 hours, and this time is sufficient to meet the self-maintenance function of the clock chip U1. And, this real-time clock circuit does not need to replace the battery at regular intervals as in the way of using a button battery as a backup power supply, which greatly improves the user experience.

[0043] In some of these embodiments, the real-time clock 50 further includes a resistor R4 and a resistor R5. The signal pin SCL of the clock chip U1 is connected to the supply voltage DVCC_RTC of the clock chip U1 through the resistor R4, and the signal pin SDA is connected to the supply voltage DVCC_RTC of the clock chip U1 through the resistor R5. This supply voltage DVCC_RTC is the voltage of the power input pin VDD of the clock chip U1. By setting the resistors R4 and R5, it can be ensured that the clock chip U1 can transmit data normally when communicating using the I2C bus.

[0044] It can be understood that for the central processing unit, the maximum allowable voltage of its pin voltage is usually 3.6V. As can be seen from the foregoing, the supply voltage DVCC_RTC can reach 3.725V or 4.1V, exceeding the allowable voltage of the central processing unit's pins. To protect the central processing unit, in some of these embodiments, refer to Figure 2 , the real-time clock circuit further includes a first level adjustment module 61 and a second level adjustment module 62. The first end of the first level adjustment module 61 is used to connect to the second power supply DVCC2, the second end of the first level adjustment module 61 is connected to the first signal end of the real-time clock 50, and the third end of the first level adjustment module 61 is used to connect to the first signal pin I2C2_SCL of the central processing unit. The first level adjustment module 61 is configured to provide a first voltage to the first signal end and the first signal pin I2C2_SCL based on the second power supply DVCC2. The first end of the second level adjustment module 62 is used to connect to the second power supply DVCC2, the second end of the second level adjustment module 62 is connected to the second signal end of the real-time clock 50, and the third end of the second level adjustment module 62 is connected to the second signal pin I2C2_SDA of the central processing unit. The second level adjustment module 62 is configured to provide a first voltage to the second signal end and the second signal pin I2C2_SDA based on the second power supply DVCC2.

[0045] The second power supply DVCC2 is a DC power supply, which can be provided by the power supply module in the electronic device. The second power supplies DVCC2 can be interconnected with each other using a bus, and the voltage magnitude of the second power supply DVCC2 can be set according to actual needs and is not limited herein. For example, it can be 3.3V. The first power supply DVCC1 and the second power supply DVCC2 can be provided by the same power supply after passing through different voltage conversion circuits.

[0046] The central processing unit can be an integrated control chip in the electronic device, which is the computing core of the electronic device and can be responsible for executing instructions, processing data, and controlling various operations. Its specific structure can refer to the prior art and is not limited herein.

[0047] The first signal terminal of the real-time clock 50 can be the signal pin SCL of the clock chip U1, and the second signal terminal of the real-time clock 50 can be the signal pin SDA of the clock chip U1. The signal pin SCL and the signal pin SDA of the clock chip U1 are respectively connected to the first signal pin I2C2_SCL and the second signal pin I2C2_SDA of the central processor. In this way, the two can implement I2C communication or other protocol communications, enabling data transmission between the real-time clock 50 and the central processor, and enabling the central processor to obtain information such as time and date.

[0048] In this real-time clock circuit, when the second power supply DVCC2 is normally powered, the first level adjustment module 61 will output a first voltage to the signal pin SCL of the clock chip U1 and the first signal pin I2C2_SCL according to the second power supply DVCC2, making the signal pin SCL of the clock chip U1 and the second signal pin I2C2_SDA at the first voltage. Similarly, the second level adjustment module 62 will output a first voltage to the signal pin SDA of the clock chip U1 and the second signal pin I2C2_SDA according to the second power supply DVCC2, making the signal pin SDA of the clock chip U1 and the second signal pin I2C2_SDA at the first voltage. Among them, the first voltage can be 3.3V. In this way, during the communication process between the real-time clock 50 and the central processor, the signal pin SCL, the first signal pin I2C2_SCL, the signal pin SDA, and the second signal pin I2C2_SDA are at the first voltage through the first level adjustment module 61 and the second level adjustment module 62, preventing high voltage from being input to the central processor and damaging the central processor, and improving the reliability of the circuit operation.

[0049] In some embodiments, refer to Figure 2 , the first level adjustment module 61 includes a switching transistor Q1, a resistor R6, and a resistor R9. The first signal terminal SCL is connected to the first end of the switching transistor Q1. The second end of the switching transistor Q1 is respectively connected to the first end of the resistor R9 and the first signal pin I2C2_SCL. The third end of the switching transistor Q1 is connected to the first end of the resistor R6. The second ends of the resistor R6 and the resistor R9 are both connected to the second power supply DVCC2.

[0050] In this real-time clock circuit, the switching transistor Q1 can be an NMOS transistor, a triode, or any other suitable switching device. When the second power supply DVCC2 is powered, the switching transistor Q1 will conduct, and the second power supply DVCC2 will maintain the first signal terminal SCL and the first signal pin I2C2_SCL at the first voltage through the resistor R9, realizing the level adjustment of the first signal terminal SCL and the first signal pin I2C2_SCL.

[0051] In some embodiments, refer to Figure 2, the second level adjustment module 62 includes a switching transistor Q2, a resistor R7, and a resistor R10; the second signal terminal SDA is connected to the first end of the switching transistor Q2, the second end of the switching transistor Q2 is respectively connected to the first end of the resistor R10 and the second signal pin I2C2_SDA, the third end of the switching transistor Q2 is connected to the first end of the resistor R7, and the second ends of the resistor R7 and the resistor R10 are both connected to the second power supply DVCC2.

[0052] In this real-time clock circuit, the switching transistor Q2 can be an NMOS transistor, a triode, or any other suitable switching device. When the second power supply DVCC2 supplies power, the switching transistor Q2 will conduct, and the second power supply DVCC2 will maintain the second signal terminal SDA and the second signal pin I2C2_SDA at the first voltage through the resistor R10, realizing the level adjustment of the second signal terminal SDA and the second signal pin I2C2_SDA.

[0053] It can be seen that in Figure 2 the shown real-time clock circuit, when the second power supply DVCC2 supplies power, both the switching transistor Q1 and the switching transistor Q2 are conducting. The pin SCL of the clock chip U1 and the first signal pin I2C2_SCL of the central processor are pulled down to the amplitude value of the second power supply DVCC2, such as 3.3V, through the resistor R9. Similarly, the pin SDA of the clock chip U1 and the second signal pin I2C2_SDA of the central processor are pulled down to the amplitude value of the second power supply DVCC2, such as 3.3V, through the resistor R10. In this way, when the clock chip U1 and the central processor communicate, it can prevent high voltage from damaging the central processor and improve the reliability of the circuit operation.

[0054] In a second aspect, an embodiment of the present invention provides an electronic device, which includes a first power supply and the real-time clock circuit as in the first aspect. The first power supply is connected to the first end of the first unidirectional flow module and the first end of the third unidirectional flow module.

[0055] In this embodiment, the real-time clock circuit has the same structure and function as the real-time clock circuit described in the first aspect, and will not be elaborated here. The electronic device can be a charging pile, a computer, etc. Among them, the charging pile can include a charging pile telematics control unit (TCU), and the TCU can be used to communicate with the vehicle networking platform and the charging control unit to implement service functions such as authentication, metering and billing, platform communication, and human-computer interaction.

[0056] In this embodiment, by using the energy storage module as the backup power supply of the real-time clock, it can supply power to the real-time clock when the first power supply is powered off to maintain the normal operation of the real-time clock and improve the reliability of the electronic device operation.

[0057] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0058] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A real-time clock circuit, characterized in that: include: A first one-way circulation module, an energy storage module, a second one-way circulation module, a third one-way circulation module and a real-time clock; The first end of the first one-way circulation module and the first end of the third one-way circulation module are both used to connect to a first power source, the second end of the first one-way circulation module is respectively connected to the first end of the second one-way circulation module and the energy storage module, and the second end of the second one-way circulation module and the second end of the third one-way circulation module are both connected to the power supply end of the real-time clock; The first one-way circulation module is configured to be turned on when the first power source supplies power, so that the first power source charges the energy storage module; The third one-way flow module is configured to be turned on when the first power supply is powered, so that the first power supply supplies power to the real-time clock; The second one-way flow module is configured to be turned on when the first power source is powered off, so that the energy storage module can supply power to the real-time clock.

2. The real-time clock circuit according to claim 1, wherein: The first unidirectional flow module includes a diode D1 and a resistor unit; The anode of the diode D1 is used to connect to the first power source, the cathode of the diode D1 is connected to the first end of the resistance unit, and the second end of the resistance unit is respectively connected to the first end of the second unidirectional flow module and the energy storage module.

3. The real-time clock circuit according to claim 2, wherein: The resistance unit includes at least one resistor; The first end of the resistor is connected to the cathode of the diode D1 , and the second end of the resistor is connected to the first end of the second unidirectional flow module and the energy storage module respectively.

4. The real-time clock circuit according to any one of claims 1 to 3, characterized in that: The second unidirectional flow module includes a diode D2; The anode of the diode D2 is connected to the second end of the first unidirectional flow module and the energy storage module respectively, and the cathode of the diode D2 is connected to the power supply end of the real-time clock.

5. The real-time clock circuit according to any one of claims 1 to 3, characterized in that: The third one-way flow module includes a diode D3; The anode of the diode D3 is used to connect to the first power supply, and the cathode of the diode D3 is connected to the power supply end of the real-time clock.

6. The real-time clock circuit according to any one of claims 1 to 3, characterized in that: The real-time clock circuit further includes a first level adjustment module and a second level adjustment module; The first end of the first level adjustment module is used to connect to the second power supply, the second end of the first level adjustment module is connected to the first signal end of the real-time clock, and the third end of the first level adjustment module is used to connect to the first signal pin of the central processing unit. The first level adjustment module is configured to provide a first voltage to the first signal end and the first signal pin based on the second power supply; The first end of the second level adjustment module is used to connect to the second power supply, the second end of the second level adjustment module is connected to the second signal end of the real-time clock, and the third end of the second level adjustment module is connected to the second signal pin of the central processing unit. The second level adjustment module is configured to provide the first voltage to the second signal end and the second signal pin based on the second power supply.

7. The real-time clock circuit according to claim 6, characterized in that: The first level adjustment module includes a switch tube Q1, a resistor R6 and a resistor R9; The first signal end is connected to the first end of the switch tube Q1, the second end of the switch tube Q1 is respectively connected to the first end of the resistor R9 and the first signal pin, the third end of the switch tube Q1 is connected to the first end of the resistor R6, and the second end of the resistor R6 and the second end of the resistor R9 are both connected to the second power supply.

8. The real-time clock circuit according to claim 6, characterized in that: The second level adjustment module includes a switch tube Q2, a resistor R7 and a resistor R10; The second signal end is connected to the first end of the switch tube Q2, the second end of the switch tube Q2 is respectively connected to the first end of the resistor R10 and the second signal pin, the third end of the switch tube Q2 is connected to the first end of the resistor R7, and the second end of the resistor R7 and the second end of the resistor R10 are both connected to the second power supply.

9. The real-time clock circuit according to any one of claims 1 to 3, characterized in that: The energy storage module includes a capacitor; One end of the capacitor is connected to the second end of the first unidirectional flow module and the first end of the second unidirectional flow module respectively, and the other end of the capacitor is grounded.

10. An electronic device, characterized in that: comprising a first power supply and a real-time clock circuit according to any one of claims 1 to 9; The first power source is connected to a first end of the first unidirectional flow module and a first end of the third unidirectional flow module.

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