Clock circuit and electronic equipment

Abstract

The present invention discloses a clock circuit and electronic device, wherein the clock circuit includes an RTC chip, a first power supply, a second power supply, and a first power supply activation module. The RTC chip includes a first end, the first end being used to output an interrupt signal; the first power supply is connected to the first power input end of the RTC chip; the second power supply is connected to the second power input end of the RTC chip; the first end of the first power supply activation module is connected to the first end of the RTC chip, and the second end of the first power supply activation module is connected to the first power supply, for activating the first power supply according to the interrupt signal. In this way, when the electronic device is in an inoperative state, not only can the RTC be powered by the second power supply so that the RTC can operate normally, but the first power supply can also be activated by the first power supply activation module based on the interrupt signal sent by the RTC chip. When the first power supply is activated, the built-in clock of the electronic device can be updated as the RTC is updated.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and in particular to a clock circuit and electronic equipment. Background Art

[0002] Real-time clocks (RTCs) are widely used in various electronic products as system synchronization or time markers. Their basic function is to keep track of information such as the time and date. However, to ensure battery life and range, new energy electric vehicles must keep the battery disconnected when not in use. If the battery is the only power source for the RTC, the on-board time display will be interrupted, which in turn interrupts the CPU clock function. This is because the CPU clock function only runs at startup, or when power is applied, and stops when the power is removed. If the clock cannot continuously track time, the time must be set manually. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a clock circuit and an electronic device to solve the problem that a clock in a vehicle cannot continuously track time when the vehicle power is turned off.

[0004] According to a first aspect, an embodiment of the present invention provides a clock circuit, comprising: an RTC chip, a first power supply, a second power supply and a first power supply activation module, wherein the RTC chip comprises a first end, the first end being used to output an interrupt signal; the first power supply is connected to the first power supply input end of the RTC chip; the second power supply is connected to the second power supply input end of the RTC chip; the first end of the first power supply activation module is connected to the first end of the RTC chip, and the second end of the first power supply activation module is connected to the first power supply, for activating the first power supply according to the interrupt signal.

[0005] In combination with the first aspect, in the first embodiment of the first aspect, the first power activation module includes a wake-up signal amplifying circuit and a power activation circuit; the input end of the wake-up signal amplifying circuit is connected to the first end of the RTC chip, and the output end of the wake-up signal amplifying circuit is connected to the power activation circuit; the input end of the power activation circuit is connected to the output end of the wake-up signal amplifying circuit, and the output end of the power activation circuit is connected to the first power supply.

[0006] In combination with the first embodiment of the first aspect, in the second embodiment of the first aspect, the first power activation module also includes a conversion circuit, the input end of the conversion circuit is connected to the power activation circuit, and the output end of the conversion circuit is connected to the first power supply.

[0007] In combination with the first embodiment of the first aspect, in the third embodiment of the first aspect, the wake-up signal amplifying circuit includes an optocoupler isolation, the first input end of the optocoupler isolation is connected to the first end of the RTC chip, the second input end of the optocoupler isolation is connected to the second power supply, and the output end of the optocoupler isolation is the output end of the wake-up signal amplifying circuit.

[0008] In combination with the first embodiment of the first aspect, in the fourth embodiment of the first aspect, the power activation circuit includes a first switching device and a second switching device; the first control end of the first switching device is connected to the output end of the wake-up signal amplification circuit, the second end of the first switching device is connected to the second control end of the second switching device, and the third end of the first switching device is grounded; the second end of the second switching device is connected to the power-on end, and the third end of the second switching device is the output end of the power activation circuit.

[0009] In combination with the fourth embodiment of the first aspect, in the fifth embodiment of the first aspect, the power supply activation circuit also includes a transient diode and a Zener diode; the transient diode is connected between the first control terminal of the first switching device and the third terminal of the first switching device; the Zener diode is connected between the second control terminal of the second switching device and the second terminal of the second switching device.

[0010] In combination with the first aspect, in the sixth embodiment of the first aspect, the clock circuit also includes a first switch and a second switch, the first end of the first switch is connected to the first power supply, and the second end of the first switch is connected to the first power supply input terminal; the first end of the second switch is connected to the second power supply, and the second end of the second switch is connected to the first power supply input terminal; the first power supply has a voltage greater than that of the second power supply.

[0011] In combination with the first aspect, in a seventh implementation of the first aspect, the clock circuit further includes a crystal oscillator circuit, and the crystal oscillator circuit is connected to the second end of the RTC chip.

[0012] In combination with the first aspect, in the eighth embodiment of the first aspect, the clock circuit also includes a serial data line and a serial clock line, the serial data line is connected to the third end of the RTC chip and the first power supply, and the serial clock line is connected to the fourth end of the RTC chip and the first power supply.

[0013] According to a second aspect, an embodiment of the present invention further provides an electronic device, comprising the clock circuit described in the first aspect or any embodiment of the first aspect.

[0014] The clock circuit and electronic device provided by the embodiments of the present invention can, when the electronic device (such as a new energy vehicle) is in an inoperative state, not only supply power to the RTC chip through the second power supply so that the RTC chip can operate normally, but can also activate the first power supply through the first power activation module based on the interrupt signal sent by the RTC chip. When the first power supply is activated, the built-in clock of the electronic device can be updated as the RTC is updated. That is, the built-in clock of the electronic device can continuously track time even when the electronic device is in an inoperative state. Therefore, when the electronic device changes from an inoperative state to an operational state, there is no need to manually set the time, which can ensure the real-time time displayed by the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0016] Figure 1 It is the structural block diagram of the clock circuit;

[0017] Figure 2 is a schematic diagram of a clock circuit;

[0018] Figure 3 This is a schematic diagram of a wake-up signal amplification circuit;

[0019] Figure 4 Schematic diagram of the power activation circuit. DETAILED DESCRIPTION

[0020] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] Example 1

[0022] Embodiment 1 of the present invention provides a clock circuit. Figure 1 and Figure 2As shown, the clock circuit includes an RTC chip, a first power supply (VCC3), a second power supply (BAT) and a first power supply activation module, the RTC chip includes a first end, the first end is used to output an interrupt signal; the first power supply (VCC3) is connected to the first power supply (VCC3) input end of the RTC chip; the second power supply (BAT) is connected to the second power supply (BAT) input end of the RTC chip; the first end of the first power supply activation module is connected to the first end of the RTC chip, and the second end of the first power supply activation module is connected to the first power supply (VCC3), for activating the first power supply (VCC3) according to the interrupt signal.

[0023] Specifically, such as Figure 2 As shown, the first power supply (VCC3) input terminal and the second power supply (BAT) input terminal are both power supply terminals of the RTC chip, namely, VDD terminals.

[0024] Specifically, the first power supply (VCC3) is the power supply of an electronic device (such as a new energy vehicle); the second power supply (BAT) is a backup power supply, such as a button battery BAT.

[0025] Specifically, the first end of the RTC chip is the / INT pin.

[0026] Therefore, when the electronic device is in an inoperative state, not only can the second power supply (BAT) be used to supply power to the RTC chip so that the RTC chip can operate normally, but the first power supply (VCC3) can also be activated through the first power supply activation module based on the interrupt signal sent by the RTC chip. When the first power supply (VCC3) is activated, the built-in clock of the electronic device can be updated as the RTC is updated. That is to say, the built-in clock of the electronic device can continuously track time even when the electronic device is in an inoperative state. Therefore, when the electronic device changes from an inoperative state to an operational state, there is no need to manually set the time, which can ensure the real-time nature of the time displayed by the electronic device.

[0027] exist Figures 1 to 4 In the figure, R represents a resistor, C represents a capacitor, and D represents a diode. D8 is a TVS diode, and D9 is a Zener diode. Y1 represents a crystal oscillator, U1 is an RTC chip, BAT is a fixed backup battery, U2 is an NMOS transistor, and U3 is a PMOS transistor.

[0028] Specifically, the clock circuit further includes a crystal oscillator circuit, and the crystal oscillator circuit is connected to the second end of the RTC chip. Figure 2 As shown, C1, C2, and Y1 constitute a crystal oscillator circuit.

[0029] Specifically, the clock circuit further includes a serial data line and a serial clock line, wherein the serial data line is connected to the third terminal of the RTC chip and the first power supply (VCC3), and the serial clock line is connected to the fourth terminal of the RTC chip and the first power supply (VCC3). Figure 2 As shown, the serial data line (SDA) and the serial clock line (SCL) are connected to the first power supply (VCC3) through a pull-up resistor and transmit data with the built-in clock of the electronic device (such as a new energy vehicle).

[0030] For new energy vehicles, when the new energy vehicle is in an inoperative state, the first power supply (VCC3) is in an open circuit. At this time, the RTC can only be powered by BAT, so that its RTC crystal oscillator is still in an operational state, and after a period of time, the / INT pin sends a low level to activate the first power supply (VCC3) through the first power activation module, so that the first power supply (VCC3) is in an operational state. When the first power supply (VCC3) is in an operational state, the built-in clock of the new energy vehicle can read the current time from the RTC and can display it based on the read current time under its own mechanism; that is, using the clock circuit of embodiment 1 of the present invention, when the new energy vehicle is in an inoperative state, the first power supply (VCC3) is in an operational state. When the car is in an inoperative state, not only can the RTC be powered by the second power supply (BAT) so that the RTC can operate normally, but the first power supply (VCC3) can also be activated by the first power supply activation module based on the interrupt signal sent by the RTC chip. When the first power supply (VCC3) is activated, the built-in clock of the new energy vehicle can be updated as the RTC is updated. In other words, the built-in clock of the new energy vehicle can continuously track time even when the new energy vehicle is in an inoperative state. Therefore, when the new energy vehicle changes from an inoperative state to an operational state, there is no need to manually set the time, which can ensure the real-time nature of the time displayed by the new energy vehicle.

[0031] Specifically, such as Figure 1 As shown, the first power activation module includes a wake-up signal amplifying circuit and a power activation circuit; the input end of the wake-up signal amplifying circuit is connected to the first end of the RTC chip, and the output end of the wake-up signal amplifying circuit is connected to the power activation circuit; the input end of the power activation circuit is connected to the output end of the wake-up signal amplifying circuit, and the output end of the power activation circuit is connected to the first power supply (VCC3).

[0032] Further, such as Figure 1 As shown, the first power activation module further includes a conversion circuit, the input end of the conversion circuit is connected to the power activation circuit, and the output end of the conversion circuit is connected to the first power supply (VCC3).

[0033] More specifically, Figure 3As shown, the wake-up signal amplifying circuit includes an optocoupler isolation, the first input end of the optocoupler isolation is connected to the first end of the RTC chip, the second input end of the optocoupler isolation is connected to the second power supply (BAT), and the output end of the optocoupler isolation is the output end of the wake-up signal amplifying circuit. Therefore, the wake-up amplifying circuit only needs one optocoupler isolation to complete, and the circuit is simple. BAT is normally high, and when / INT is low, RTC_WAKE outputs a high level as Figure 4 activation signal.

[0034] More specifically, Figure 4 As shown, the power activation circuit includes a first switch device (U2) and a second switch device (U3); a first control end of the first switch device (U2) is connected to the output end of the wake-up signal amplifying circuit, a second end of the first switch device (U2) is connected to the second control end of the second switch device (U3), and a third end of the first switch device (U2) is grounded; a second end of the second switch device (U3) is connected to VCC1, and a third end of the second switch device (U3) is connected to VCC2.

[0035] Furthermore, the power activation circuit further includes a transient diode (D8) and a voltage regulator diode (D9); the transient diode (D8) is connected between the first control terminal of the first switching device (U2) and the third terminal of the first switching device (U2); and the voltage regulator diode (D9) is connected between the second control terminal of the second switching device (U3) and the second terminal of the second switching device (U3).

[0036] Specifically, such as Figure 4 As shown, D3-D7 act as anti-reverse diodes. When an activation signal is applied to any of D3-D7, U2 conducts, and then U3, bringing its VCC2 voltage to a high level, thus powering the controller. D8 effectively protects U2 from surges caused by the activation signal. D9 limits Vgd voltage to a limited range, preventing damage to U3.

[0037] For example, Figure 1 As shown, the real-time clock includes an RTC circuit, a wake-up signal amplifier circuit (i.e. Figure 1 The circuit comprises the RTC output activation control circuit, the power activation circuit, the conversion circuit, the low-voltage application circuit, and the MCU circuit. Its operating principle is as follows: the interrupt signal from the RTC serves as the primary wake-up activation signal, which is amplified by the wake-up signal amplifier circuit. This in turn controls the power activation circuit to complete power activation, or power-up. After power-up, the power conversion circuit outputs the required low-voltage DC power to power the low-voltage application circuit, the MCU, and the RTC circuit.

[0038] More specifically, Figure 2 As shown, the clock circuit further includes a first switch (D1) and a second switch (D2), wherein a first end of the first switch (D1) is connected to the first power supply (VCC3), and a second end of the first switch (D1) is connected to an input end of the first power supply (VCC3); a first end of the second switch (D2) is connected to the second power supply (BAT), and a second end of the second switch (D2) is connected to an input end of the first power supply (VCC3); and the voltage of the first power supply (VCC3) is greater than that of the second power supply (BAT).

[0039] By using the first switch (D1) and the second switch (D2), the backup power supply can be disconnected when the new energy vehicle is powered on, thereby extending its service life.

[0040] Specifically, the power supply for new energy vehicles is not the same as the first power supply (VCC3) activated by the interrupt signal. VCC3 is converted by the power module after the vehicle is powered on. The vehicle's power supply may be 24V, while VCC3 is only 3.3V. In the circuit, the power supply for new energy vehicles refers to VCC1.

[0041] Specifically, the first switch (D1) and the second switch (D2) are diodes, the first end of the first switch (D1) and the first end of the second switch (D2) are the anodes of the diodes, and the second end of the first switch (D1) and the second end of the second switch (D2) are the cathodes of the diodes.

[0042] For example, Figure 2 The real-time clock chip is powered by a dual power supply. One is VCC3, which is the main system power supply and is converted into a power supply suitable for the RTC circuit; the other is a fixed backup power supply such as a button battery. The voltage of VCC3 is higher than the voltage of BAT. The two voltages are prevented from shorting by a diode in series. When the car is running, the controller generates power VCC3 to power the RTC chip. Since VCC3 is higher than the BAT voltage, diode D2 is cut off, and only VCC3 is used for power supply.

[0043] In summary, the clock circuit provided in Embodiment 1 of the present invention has the following beneficial effects:

[0044] (1) The dual power supply mode ensures that the time and date displayed by the electronic equipment can be kept real-time by adding a backup power supply, and the backup power supply can be disconnected when the power is turned on to extend its service life.

[0045] (2) The interrupt signal wake-up amplifier circuit only needs an optocoupler isolation to complete, and the circuit is simple.

[0046] (3) The wake-up signal amplification circuit and power activation circuit with TVS diode and Zener diode can effectively prevent device damage caused by surge and overvoltage.

[0047] Example 2

[0048] On the basis of the embodiment 1 of the present invention, the embodiment 2 of the present invention further provides an electronic device, including the real-time circuit of the embodiment 1 of the present invention.

[0049] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A clock circuit, characterized in that: include: An RTC chip, the RTC chip comprising a first terminal, the first terminal being used to output an interrupt signal; A first power supply connected to a first power input terminal of the RTC chip; a second power supply connected to a second power input terminal of the RTC chip; A first power activation module, wherein the first end of the first power activation module is connected to the first end of the RTC chip, and the second end of the first power activation module is connected to the first power supply, and is used to activate the first power supply according to the interrupt signal.

2. The clock circuit according to claim 1, wherein: The first power activation module includes a wake-up signal amplification circuit and a power activation circuit; The input end of the wake-up signal amplifying circuit is connected to the first end of the RTC chip, and the output end of the wake-up signal amplifying circuit is connected to the power activation circuit; The input end of the power activation circuit is connected to the output end of the wake-up signal amplifying circuit, and the output end of the power activation circuit is connected to the first power supply.

3. The clock circuit according to claim 2, wherein: The first power activation module further includes a conversion circuit, an input end of the conversion circuit is connected to the power activation circuit, and an output end of the conversion circuit is connected to the first power supply.

4. The clock circuit according to claim 2, wherein: The wake-up signal amplifying circuit includes an optocoupler isolation, a first input end of the optocoupler isolation is connected to the first end of the RTC chip, a second input end of the optocoupler isolation is connected to the second power supply, and an output end of the optocoupler isolation is the output end of the wake-up signal amplifying circuit.

5. The clock circuit according to claim 2, wherein: The power activation circuit includes a first switching device and a second switching device; the first control end of the first switching device is connected to the output end of the wake-up signal amplification circuit, the second end of the first switching device is connected to the second control end of the second switching device, and the third end of the first switching device is grounded; the second end of the second switching device is connected to the power-on end, and the third end of the second switching device is the output end of the power activation circuit.

6. The clock circuit according to claim 5, wherein: The power activation circuit also includes a transient diode and a Zener diode; the transient diode is connected between the first control terminal of the first switching device and the third terminal of the first switching device; the Zener diode is connected between the second control terminal of the second switching device and the second terminal of the second switching device.

7. The clock circuit according to claim 1, wherein: Also includes: a first switch, wherein a first end of the first switch is connected to the first power supply, and a second end of the first switch is connected to the first power supply input terminal; a second switch, wherein a first end of the second switch is connected to the second power supply, and a second end of the second switch is connected to the first power supply input end; The voltage of the first power supply is greater than that of the second power supply.

8. The clock circuit according to claim 1, wherein: It also includes a crystal oscillator circuit, which is connected to the second end of the RTC chip.

9. The clock circuit according to claim 1, wherein: It also includes a serial data line and a serial clock line, wherein the serial data line is connected to the third end of the RTC chip and the first power supply, and the serial clock line is connected to the fourth end of the RTC chip and the first power supply.

10. An electronic device, characterized in that: The clock circuit comprises the clock circuit according to any one of claims 1 to 9.

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