Vehicle-mounted RTC wake-up circuit, power management system and electric vehicle

Abstract

The utility model discloses a vehicle-mounted RTC wake-up circuit, a power management system and an electric vehicle, and relates to the technical field of wake-up circuits. The system specifically comprises a wake-up circuit which is provided with an RTC chip and can send a wake-up instruction to a BMS; the power supply circuit is used for reducing the voltage of a constant power supply to the working voltage of the wake-up circuit, and the power supply circuit comprises a power supply KL30, a step-down circuit, a voltage-regulator tube Z1 and a switch element T2; wherein the power supply KL30 is connected to the input end of the step-down circuit, the output end of the step-down circuit is connected to the cathode of the voltage-regulator tube Z1, the anode of the voltage-regulator tube Z1 is grounded, the grid electrode of the switch element T2 is connected to the cathode of the voltage-regulator tube Z1, the drain electrode of the switch element T2 is connected to the power supply KL30, and the source electrode of the switch element T2 is connected to the interrupt pin of the RTC chip. The objective of the utility model is to provide stable power supply for an RTC chip and ensure the reliability of an RTC wake-up function.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of wake -up circuit, especially in kind of vehicle RTC wake -up circuit, power management system and electric automobile. BACKGROUND

[0002] With the wide application of battery management system (BMS) in various battery driven devices, BMS as a key control and management unit plays a vital role. The control board of BMS generally has two working states, namely sleep state and normal state. In the sleep state, in order to prolong the service life of the battery, BMS will reduce the power consumption and stop most functions, only some key modules (such as real-time clock (RTC)) continue to work. When BMS transits from sleep state to normal working state, an external wake-up signal is usually needed to activate the system to enter normal mode.

[0003] In the BMS system, RTC (Real-Time Clock) chip as a very important time reference element, its main role is to provide stable clock signal, ensure that the system can accurately record time, control sleep wake-up cycle and other functions. RTC chip usually works in low power consumption mode, so it often needs separate power supply, and the always-on power supply (i.e. the power supply that can continue to provide power when BMS enters sleep mode) is the main power supply for RTC work.

[0004] At present, the always-on power supply widely used in the market is mostly designed through low power consumption circuit, so as to provide power for RTC chip with extremely low power consumption when BMS system is in sleep state. These power supply schemes adopt battery direct current output or low voltage linear regulator to supply power for RTC chip. However, the traditional voltage stabilizing power supply design cannot maintain stable output under low load, resulting in voltage fluctuation, which cannot provide sufficient and stable working voltage for RTC chip. More seriously, such voltage instability may cause RTC chip to fail to operate correctly, or even fail to provide accurate clock signal, thereby affecting the sleep wake-up function of BMS, and finally may cause the system to fail to respond in time when it needs to wake up, or even malfunction.

[0005] Therefore, how to provide stable power supply for RTC chip and ensure the reliability of RTC wake-up function has become a technical problem to be solved. UTILITY MODEL CONTENTS

[0006] The main purpose of the utility model is to provide a kind of vehicle RTC wake -up circuit, power management system and electric automobile, it aims at providing stable power supply for RTC chip and ensuring the reliability of RTC wake-up function.

[0007] In order to achieve the above object, the utility model provides a vehicle-mounted RTC wake -up circuit, include:

[0008] Wake -up circuit has RTC chip, and can send wake -up instruction to BMS;

[0009] Power supply circuit is used for reducing the voltage of the constant power supply to the operating voltage of the wake -up circuit, and the power supply circuit includes: power supply KL30, voltage reducing circuit, voltage stabilizing tube Z1, switching element T2;Among them, the power supply KL30 is connected to the input end of the voltage reducing circuit, the output end of the voltage reducing circuit is connected to the cathode of the voltage stabilizing tube Z1, the anode of the voltage stabilizing tube Z1 is grounded, the gate of the switching element T2 is connected to the cathode of the voltage stabilizing tube Z1, the drain of the switching element T2 is connected to the power supply KL30, and the source of the switching element T2 is connected to the interrupt pin of the RTC chip.Through accurate voltage regulation and control, the vehicle-mounted RTC wake -up circuit can wake up at the appropriate time and work with the BMS system, and has stable working principle and efficient power management ability.

[0010] In an embodiment of the present application, the wake -up circuit includes:

[0011] Voltage reducing circuit is arranged between the constant power supply and the gate of the switching element T2, and is used for reducing the operating voltage of the gate of the switching element T2.The above technical scheme is adopted, the voltage reducing circuit reduces the high voltage of the constant power supply KL30 to the low voltage suitable for the operation of the gate of the switching element T2 by resistance voltage division.The gate voltage of the switching element T2 is too high to cause the damage or failure of the MOS tube, and is too low to trigger the normal conduction thereof.The voltage reducing circuit ensures that the switching element T2 always operates in the appropriate voltage range, and guarantees the reliability of the circuit.

[0012] In an embodiment of the present application, the voltage reducing circuit includes: resistance R1 and resistance R2, the first end of the resistance R1 is connected to the power supply KL30, the second end of the resistance R1 is connected to the first end of the resistance R2, and the second end of the resistance R2 is connected to the cathode of the voltage stabilizing tube Z1.The resistance voltage division mode is used to realize the accurate regulation of the voltage, ensure that the circuit can normally work at the appropriate voltage, effectively protect the key elements in the system, and improve the stability and reliability of the circuit.

[0013] In an embodiment of the present application, the wake -up circuit includes:

[0014] Triode T1, switching element T3, resistance R3, voltage stabilizing tube D1, power supply VCC;

[0015] The collector of the triode T1 is connected to the BMS system, the emitter of the triode T1 is connected to the power supply KL30; the base of the triode T1 is connected to the drain of the switching element T3, the source of the switching element T3 is connected to the interrupt pin of the RTC chip; the first end of the resistor R3 is connected to the source of the switching element T2, the second end of the resistor R3 is connected to the interrupt pin of the RTC chip, and the gate of the switching element T3 is connected between the first end of the resistor R3 and the source of the switching element T2; the power supply pin of the RTC chip is connected between the first end of the resistor R3 and the source of the switching element T2; the cathode of the voltage stabilizing tube D1 is connected to the power supply pin of the RTC chip, and the anode of the voltage stabilizing tube D1 is connected to the power supply VCC; the data pin of the RTC chip and the clock pin of the RTC chip are connected to the MCU control chip respectively; and the data pin of the RTC chip and the clock pin of the RTC chip are connected to the power supply VCC respectively. Through the cooperative work of multiple elements, the stable power supply and wake-up control of the RTC chip are ensured, and the wake-up instruction can be accurately sent to the BMS system. The combination of the triode T1 and the switching element T3 realizes accurate control of the interrupt pin of the RTC chip, and through reasonable configuration of the resistors R3, R4 and R5, the stability of the signal and the reasonable distribution of the current are ensured. The voltage stabilizing tube D1 plays a role in protecting the circuit, avoids reverse flow of the power supply current, and enhances the reliability of the circuit.

[0016] In an embodiment of the present application, the wake-up circuit further comprises:

[0017] The resistor R4 and the resistor R5; the first end of the resistor R4 is connected to VCC, and the second end of the resistor R4 is connected to the data pin of the RTC chip; the first end of the resistor R5 is connected to VCC, and the second end of the resistor R5 is connected to the clock pin of the RTC chip. The resistor R4 and the resistor R5 are connected to the power supply VCC and the data pin and the clock pin of the RTC chip respectively. When the RTC chip communicates with the vehicle-mounted micro control unit, the resistors R3 and R4 play a role in pulling up, ensuring stable transmission of signals on the communication bus. In this way, the MCU can perform timing control and data interaction on the RTC chip.

[0018] In an embodiment of the present application, the wake-up circuit further comprises:

[0019] The capacitor C1, the first end of the capacitor C1 is connected to the power supply pin of the RTC chip, and the second end of the capacitor C1 is grounded. The capacitor C1 is connected between the power supply pin of the RTC chip and the ground, plays a role in effective power filtering, reduces the interference of power supply noise and voltage fluctuation, and improves the stability and precision of the RTC chip.

[0020] In an embodiment of the present application, the wake-up circuit further comprises:

[0021] A crystal oscillator Y1, a first end of the crystal oscillator Y1 is connected to a first oscillator pin of the RTC chip, and a second end of the crystal oscillator Y1 is connected to a second oscillator pin of the RTC chip, for waking up the RTC chip. The crystal oscillator Y1 provides a stable and accurate clock signal for the RTC chip, ensuring the time accuracy and stability of the RTC chip during operation. Through the action of the crystal oscillator Y1, the wake-up circuit can trigger the wake-up action based on the accurate time control mechanism, thereby improving the reliability and accuracy of the system in waking up at a specific time point.

[0022] In an embodiment of the present application, the switch element T2 and the switch element T3 are both N-type MOS tubes.

[0023] The present application also discloses a power management system comprising the vehicle-mounted RTC wake-up circuit as described above.

[0024] The present application also discloses an electric vehicle comprising the power management system as described above.

[0025] The above technical scheme adopts precise voltage regulation and control, so that the vehicle-mounted RTC wake-up circuit can wake up at the appropriate time and work cooperatively with the BMS system, and has stable working principle and efficient power management capability. BRIEF DESCRIPTION OF DRAWINGS

[0026] The present application will be described in detail below with specific embodiments and drawings, in which:

[0027] Figure 1 The first embodiment of the present application is a structural schematic diagram. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be described in detail below with drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present application, and do not limit the present application.

[0029] As Figure 1 shown, in order to achieve the above-mentioned purpose, the present application proposes a vehicle-mounted RTC wake-up circuit, comprising:

[0030] The wake-up circuit has an RTC chip and can send a wake-up instruction to the BMS.

[0031] The power supply circuit is used for converting the voltage of the normal power supply into the working voltage of the wake-up circuit.

[0032] Specifically, the wake-up circuit comprises an RTC chip, which functions to control the wake-up circuit through time and send a wake-up instruction to the BMS.

[0033] The power supply circuit is used for converting the voltage of the normal power supply into the working voltage of the wake-up circuit.

[0034] The power supply KL30 is a normal power supply, which serves as the input end of the power supply circuit. The power supply KL30 is connected with the voltage reduction circuit. The voltage reduction circuit converts the normal power supply voltage provided by the power supply KL30 into a low voltage suitable for the working of the wake-up circuit. The function of the voltage stabilizing tube Z1 in the circuit is one-way conduction, which prevents the reverse flow of current and protects other elements in the circuit from damage. The anode of the voltage stabilizing tube Z1 is grounded, and the cathode is connected with the output end of the voltage reduction circuit.

[0035] The function of the switch element T2 in the circuit is to serve as a switch element, which determines the current path between the source and the drain through the control of the gate. The gate of the switch element T2 is connected with the cathode of the voltage stabilizing tube Z1, the drain is connected with the power supply KL30, and the source is connected with the interrupt pin of the RTC chip, thereby controlling the working state of the RTC chip at a specific time.

[0036] By using the above technical scheme, the vehicle-mounted RTC wake-up circuit can be woken up at an appropriate time and work cooperatively with the BMS system through accurate voltage regulation and control, and has a stable working principle and efficient power management capability.

[0037] In an embodiment of the present application, the wake-up circuit comprises:

[0038] The voltage reduction circuit is arranged between the normal power supply and the gate of the switch element T2, and is used for reducing the working voltage of the gate of the switch element T2.

[0039] By adopting the technical scheme, the voltage reducing circuit reduces the high voltage of the normal power supply KL30 to a low voltage suitable for the gate of the switching element T2 through resistance voltage division. If the gate voltage of the switching element T2 is too high, the MOS tube will be damaged or fail, and if the gate voltage is too low, the switching element T2 cannot be triggered to normally conduct. The voltage reducing circuit ensures that the switching element T2 always works in a suitable voltage range, thereby ensuring the reliability of the circuit.

[0040] In an embodiment of the present application, the voltage reducing circuit comprises a resistor R1 and a resistor R2, a first end of the resistor R1 is connected to the power supply KL30, a second end of the resistor R1 is connected to a first end of the resistor R2, and a second end of the resistor R2 is connected to a cathode of a voltage stabilizing tube Z1.

[0041] Specifically, the voltage reducing circuit comprises the resistor R1 and the resistor R2, which are responsible for reducing the power supply voltage through resistance voltage division. The resistor R1 and the resistor R2 together constitute a resistor voltage divider, which reduces the power supply voltage to a voltage suitable for use in the subsequent circuit.

[0042] A first end of the resistor R1 is connected to the power supply KL30 and is responsible for receiving the power supply voltage. The resistor R1 and the resistor R2 are connected in series to form a voltage division circuit. A second end of the resistor R2 is connected to a cathode of the voltage stabilizing tube Z1, which finally provides a suitable voltage for the diode to work normally. The voltage stabilizing tube Z1 prevents reverse current flow and thus protects other elements in the circuit.

[0043] By adopting the technical scheme, the voltage is precisely adjusted through resistance voltage division, which ensures that the circuit can work normally at an appropriate voltage, effectively protects key elements in the system, and improves the stability and reliability of the circuit.

[0044] In an embodiment of the present application, the wake-up circuit comprises:

[0045] a triode T1, a switching element T3, a resistor R3, a voltage stabilizing tube D1, and a power supply VCC;

[0046] The collector of the triode T1 is connected to the BMS system, and the emitter of the triode T1 is connected to the power supply KL30; the base of the triode T1 is connected to the drain of the switching element T3, and the source of the switching element T3 is connected to the interrupt pin of the RTC chip; the first end of the resistor R3 is connected to the source of the switching element T2, the second end of the resistor R3 is connected to the interrupt pin of the RTC chip, and the gate of the switching element T3 is connected between the first end of the resistor R3 and the source of the switching element T2; the power supply pin of the RTC chip is connected between the first end of the resistor R3 and the source of the switching element T2; the cathode of the voltage stabilizing tube D1 is connected to the power supply pin of the RTC chip, and the anode of the voltage stabilizing tube D1 is connected to the power supply VCC; the data pin of the RTC chip and the clock pin of the RTC chip are connected to the MCU control chip respectively; the data pin of the RTC chip and the clock pin of the RTC chip are connected to the power supply VCC respectively, wherein the clock pin of the RTC chip unidirectionally receives data from the MCU control chip, and the data pin of the RTC chip bidirectionally interacts with the MCU control chip.

[0047] Specifically, the triode T1 serves as a switching element, the collector of which is connected to the BMS system, the emitter of which is connected to the power supply KL30, and the base of which is connected to the drain of the switching element T3. The triode T1 controls the connection state of the BMS system, controls the communication and wake-up signal of the BMS based on the switching state of the switching element T3.

[0048] The switching element T3 cooperates with the triode T1. The source thereof is connected to the interrupt pin of the RTC chip, and the gate thereof is connected between the first end of the resistor R3 and the source of the switching element T2. The gate of the switching element T3 controls the switching state thereof, and when the interrupt pin of the RTC chip is open-drain, i.e. is at a low level, the resistor R3 pulls down the pin, so that the switching element T2 is turned on, and the triode T1 is turned on, at this time, the MCU of the BMS and the RTC chip are turned on, and receive the on / off instruction.

[0049] The cathode of the voltage stabilizing tube D1 is connected to the power supply pin of the RTC chip, and the anode thereof is connected to the power supply VCC. The voltage stabilizing tube D1 serves as a current unidirectional conduction function, prevents the current from flowing in the opposite direction, protects the power supply system of the RTC chip, and ensures the stability of the power supply.

[0050] The circuit, through the power supply circuit composed of the switching element T2, the resistor R1, the resistor R2 and the voltage stabilizing tube Z1, reduces the voltage of the constant power supply KL30 to a suitable working voltage of the RTC chip, so as to ensure that the RTC chip can operate stably. In the process of circuit operation, when the interrupt pin of the RTC chip is in an open-drain state, i.e. is at a low level, the resistor R3 pulls down the pin, so that the switching element T2 is turned on, and the triode T1 is turned on in turn, thereby completing the turn-on of the MCU of the BMS and the RTC chip.

[0051] By the cooperative work of the plurality of elements, stable power supply and wake-up control of the RTC chip are ensured, and the wake-up instruction can be accurately sent to the BMS system. The combination of the triode T1 and the switching element T3 realizes accurate control of the interrupt pin of the RTC chip, and the stability of the signal and the reasonable distribution of the current are ensured by the reasonable configuration of the resistors R3, R4 and R5. The voltage stabilizing tube D1 plays a role of protecting the circuit, avoids reverse flow of the power supply current, and enhances the reliability of the circuit.

[0052] In an embodiment of the present application, the wake-up circuit further comprises:

[0053] The resistor R4 has a first end connected to VCC and a second end connected to a data pin of the RTC chip, and the resistor R5 has a first end connected to VCC and a second end connected to a clock pin of the RTC chip.

[0054] Specifically, the resistors R4 and R5 are connected to the power supply VCC and the data pin and the clock pin of the RTC chip, respectively. When the RTC chip communicates with the vehicle-mounted micro control unit, the resistors R3 and R4 play a role of pull-up, ensuring stable transmission of the signal on the communication bus. In this way, the MCU can perform timing control and data interaction on the RTC chip.

[0055] In an embodiment of the present application, the wake-up circuit further comprises:

[0056] The capacitor C1 has a first end connected to a power supply pin of the RTC chip and a second end grounded.

[0057] Specifically, the capacitor C1 provides stable power supply for the RTC chip, suppresses voltage fluctuation on the power supply pin, reduces the influence of power supply noise, and ensures stable work of the RTC chip.

[0058] By the above technical solution, the capacitor C1 is connected between the power supply pin of the RTC chip and the ground, plays an effective power supply filtering role, reduces the interference of power supply noise and voltage fluctuation, and improves the stability and precision of the RTC chip.

[0059] In an embodiment of the present application, the wake-up circuit further comprises:

[0060] The crystal oscillator Y1 has a first end connected to a first oscillator pin of the RTC chip and a second end connected to a second oscillator pin of the RTC chip, and is used for waking up the RTC chip.

[0061] The crystal oscillator Y1 provides a stable clock signal for the RTC chip, ensuring that the RTC chip can work according to an accurate time reference, thereby ensuring the timing control of the wake-up circuit.

[0062] The crystal oscillator Y1 provides a stable clock signal for the RTC chip, ensuring that the RTC chip can work according to an accurate time reference, thereby ensuring the timing control of the wake-up circuit.

[0063] In an embodiment of the present application, the switch element T2 and the switch element T3 are both N-type MOS tubes.

[0064] The present application also discloses a power management system comprising the vehicle-mounted RTC wake-up circuit as described above.

[0065] The present application also discloses an electric vehicle comprising the power management system as described above.

[0066] The above technical solution provides accurate voltage regulation and control, so that the vehicle-mounted RTC wake-up circuit can wake up at the appropriate time and work cooperatively with the BMS system, and has a stable working principle and efficient power management capability.

[0067] The above only describes preferred embodiments of the present application, and does not limit the patent range of the present application, and any equivalent structural transformation or direct / indirect application in other related technical fields within the scope of the present application is included in the patent protection range of the present application.

Claims

1. An on-board RTC wake-up circuit, characterized by, The application relates to a vehicle-mounted RTC wake-up circuit. The wake-up circuit comprises an RTC chip and can send a wake-up instruction to a BMS. The power supply circuit is used for reducing the voltage of a constant power supply to the working voltage of the wake-up circuit, and comprises a power supply KL30, a voltage reduction circuit, a stabilizing tube Z1 and a switching element T2; the power supply KL30 is connected to the input end of the voltage reduction circuit; the output end of the voltage reduction circuit is connected to the cathode of the stabilizing tube Z1; the anode of the stabilizing tube Z1 is grounded; the gate of the switching element T2 is connected to the cathode of the stabilizing tube Z1; the drain of the switching element T2 is connected to the power supply KL30; and the source of the switching element T2 is connected to the interrupt pin of the RTC chip.

2. The vehicle-mounted RTC wake-up circuit of claim 1, wherein, The wake-up circuit comprises: The voltage reduction circuit is arranged between the constant power supply and the gate of the switching element T2 and is used for reducing the working voltage of the gate of the switching element T2.

3. The vehicle-mounted RTC wake-up circuit of claim 2, wherein, The voltage reduction circuit comprises a resistor R1 and a resistor R2; the first end of the resistor R1 is connected to the power supply KL30; the second end of the resistor R1 is connected to the first end of the resistor R2; and the second end of the resistor R2 is connected to the cathode of the stabilizing tube Z1.

4. The vehicle-mounted RTC wake-up circuit according to any one of claims 1 to 3, wherein The wake-up circuit comprises: The wake-up circuit comprises a triode T1, a switching element T3, a resistor R3, a stabilizing tube D1 and a power supply VCC. The collector of the triode T1 is connected to the BMS system; the emitter of the triode T1 is connected to the power supply KL30; the base of the triode T1 is connected to the drain of the switching element T3; the source of the switching element T3 is connected to the interrupt pin of the RTC chip; the first end of the resistor R3 is connected to the source of the switching element T2; the second end of the resistor R3 is connected to the interrupt pin of the RTC chip; the gate of the switching element T3 is connected between the first end of the resistor R3 and the source of the switching element T2; the power supply pin of the RTC chip is connected between the first end of the resistor R3 and the source of the switching element T2; the cathode of the stabilizing tube D1 is connected to the power supply pin of the RTC chip; the anode of the stabilizing tube D1 is connected to the power supply VCC; the data pin of the RTC chip and the clock pin of the RTC chip are respectively connected to an MCU control chip; and the data pin of the RTC chip and the clock pin of the RTC chip are respectively connected to the power supply VCC.

5. The vehicle-mounted RTC wake-up circuit of claim 4, wherein, The wake-up circuit further comprises: The first end of the resistor R4 is connected to VCC; the second end of the resistor R4 is connected to the data pin of the RTC chip; the first end of the resistor R5 is connected to VCC; and the second end of the resistor R5 is connected to the clock pin of the RTC chip.

6. The vehicle-mounted RTC wake-up circuit of claim 5, wherein, The wake-up circuit further comprises: The first end of the capacitor C1 is connected to the power supply pin of the RTC chip; and the second end of the capacitor C1 is grounded.

7. The vehicle-mounted RTC wake-up circuit of claim 4, wherein, The wake-up circuit further comprises: The first end of the crystal oscillator Y1 is connected to the first oscillator pin of the RTC chip; and the second end of the crystal oscillator Y1 is connected to the second oscillator pin of the RTC chip, which is used for waking up the RTC chip.

8. The vehicle-mounted RTC wake-up circuit of claim 4, wherein, The switching element T2 and the switching element T3 are both N-type MOS tubes.

9. A power management system, characterized by, The application further relates to a vehicle-mounted RTC wake-up circuit.

10. An electric vehicle, characterized by The application further relates to a power supply management system.

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