A control circuit and method for waking up a power supply by differential signals on a can bus

Abstract

The application relates to the technical field of circuit wake-up circuit, and specifically provides a control circuit and method for waking up a power supply through a differential signal on a CAN bus, which comprises the following steps: when a differential signal is generated between a high-level signal end and a low-level signal end of the CAN bus, a first optocoupler transmits a first voltage to an input end and an output end of a positive electrode of the power supply; the output end of the positive electrode of the power supply receives the first voltage and transmits a second voltage after voltage reduction to a microcontroller unit; the microcontroller unit receives the second voltage, transmits the second voltage to a negative electrode of the power supply through a second light-emitting device, transmits the voltage to the input end and the output end of the positive electrode of the power supply through a second optocoupler, and turns on the power supply to wake up the power supply. The control circuit and method for waking up the power supply through the differential signal on the CAN bus can avoid the problem that an LDO in a power conversion circuit is in a standby state and additional LDO power consumption is generated, and standby zero power consumption of the power wake-up circuit is realized.

Description

Technical Field

[0001] This invention relates to the field of circuit wake-up circuit technology, and in particular to a control circuit and method for waking up a power supply via differential signals on a CAN bus. Background Technology

[0002] In existing technologies, there are generally two solutions for achieving low power consumption of the entire device by waking up the power supply through differential signals on the CAN bus:

[0003] One approach is to configure the microcontroller to sleep mode. Sleep mode reduces the microcontroller's power consumption, but it still requires keeping both the microcontroller and the LDO (Low Dropout Regulator) power supply circuit on. When the microcontroller's CAN bus signal is interrupted, the microcontroller wakes up the LDO power supply circuit. This method offers a faster response time and can process data on the bus promptly, but the microcontroller and LDO power supply circuit still consume a relatively high amount of power.

[0004] Secondly, the microcontroller is configured into deep sleep mode. In deep sleep mode, the microcontroller's power consumption is reduced. However, an external I / O port level transition is required to exit deep sleep mode and wake the power supply, meaning the microcontroller and LDO power supply circuits still need to remain on, inevitably leading to higher power consumption from the LDO power supply circuit.

[0005] Therefore, no effective solution has yet been proposed to address the problem of high power consumption caused by the inability to avoid LDO power supply circuits in existing technologies. Summary of the Invention

[0006] The present invention provides a control circuit and method for waking up the power supply via a differential signal on a CAN bus, which at least solves the problem of high power consumption caused by the inability to avoid LDO power supply circuits in related technologies.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a control method for waking up a power supply via a differential signal on a CAN bus, comprising: when a differential signal is generated between the high-level signal terminal and the low-level signal terminal of the CAN bus, a first light-emitting device is turned on and emits light, and a first voltage is transmitted to the input terminal and output terminal of the positive terminal of the power supply through a first optocoupler; the output terminal of the positive terminal of the power supply receives the first voltage, and after being stepped down by a power conversion circuit, transmits a stepped-down second voltage to a microcontroller unit; the microcontroller unit receives the second voltage, transmits the second voltage to the negative terminal of the power supply through a second light-emitting device, causing the second light-emitting device to turn on and emit light, and transmits the second voltage to the input terminal and output terminal of the positive terminal of the power supply through a second optocoupler, thereby forming a loop between the positive and negative terminals of the power supply to turn on the power supply and wake up the power supply; when the microcontroller unit detects that it has not received the stepped-down second voltage from the power conversion circuit within a set time period, neither the input terminal nor the output terminal of the positive terminal of the power supply receives the first voltage or the second voltage, thereby cutting off the power supply.

[0009] Preferably, after the microcontroller unit receives the voltage, the control method includes: the microcontroller unit controlling the transistor to engage, thereby connecting the output terminal of the power supply positive terminal to the power supply negative terminal and energizing the coil; the energized coil generates electromagnetic force to engage the first switch, thereby connecting the input terminal of the power supply positive terminal to the power supply negative terminal and transmitting a third voltage to the motor drive circuit; the magnitude of the third voltage is between the first voltage and the second voltage; the motor drive circuit receives the third voltage and starts, receives a pulse width modulation signal from the microcontroller unit, and controls the operation of the motor.

[0010] Preferably, the output terminal of the power supply receives the first voltage, and after being stepped down by a power conversion circuit, transmits the stepped-down second voltage to the microcontroller unit, including: receiving the first voltage at the output terminal of the power supply, stepping down the first voltage through a first LDO power conversion circuit and a second LDO power conversion circuit to obtain the stepped-down second voltage, and transmitting the second voltage to the microcontroller unit.

[0011] Preferably, after receiving the first voltage at the output terminal of the power supply positive terminal, the control method includes: reducing the first voltage to a third voltage through a first LDO power conversion circuit, and transmitting the third voltage to the input terminal of the motor drive circuit and a second LDO power conversion circuit; reducing the third voltage to a second voltage through the second LDO power conversion circuit, and transmitting the second voltage to the microcontroller unit.

[0012] Preferably, the microcontroller unit receives the second voltage and transmits the second voltage to the negative terminal of the power supply through the second light-emitting device, including: the microcontroller unit receives the stepped-down voltage and detects whether the variable of the external interface is normal through the peripheral interface module; when the variable of the external interface is abnormal, the microcontroller unit sends an alarm signal; when the variable of the external interface is normal, the microcontroller unit transmits the second voltage to the negative terminal of the power supply through the second light-emitting device and activates the transistor.

[0013] Secondly, the present invention provides a control circuit for waking up a power supply via differential signals on a CAN bus, and a control method for waking up a power supply via differential signals on a CAN bus. The control circuit includes: a CAN bus interface circuit, including a CAN bus, wherein the high-level signal terminal and the low-level signal terminal of the CAN bus are connected through a first light-emitting device, and the first light-emitting device is connected to the input terminal and the output terminal of the positive power supply through a first optocoupler; a microcontroller circuit, including a microcontroller unit, wherein the power supply terminal of the microcontroller unit is connected to the output terminal of the positive power supply through a power conversion circuit; and one output terminal of the microcontroller unit is connected to the negative power supply through a second light-emitting device, which is connected to the input terminal and the output terminal of the positive power supply through a second optocoupler, for forming a loop between the positive and negative power supplies to conduct the power supply and wake it up.

[0014] Preferably, the CAN bus interface circuit further includes: a first capacitor disposed on the connection line between the high-level signal terminal and the low-level signal terminal, used to filter out interference signals; a third light-emitting device disposed on the connection line between the high-level signal terminal and the first capacitor, used to connect the high-level signal terminal and the low-level signal terminal when a voltage difference is generated between the high-level signal terminal and the low-level signal terminal, so as to turn on the first light-emitting device; and a first resistor disposed on the connection line between the third light-emitting device and the first light-emitting device, used for current limiting.

[0015] Preferably, the control circuit further includes: a motor drive circuit, connected to the input terminal of the positive power supply via a first switch, the first switch being closed when the coil is conducting; the coil is connected between the microcontroller unit and the transistor; the control terminal of the transistor is connected to the microcontroller unit, and is closed when the control terminal receives voltage, connecting the coil to the negative power supply and making the coil conduct; the input terminal of the motor drive circuit is connected to the microcontroller unit, the output terminal of the motor drive circuit is connected to the motor, and the motor drive circuit is used to receive pulse width modulation signals from the microcontroller circuit to control the operation of the motor.

[0016] Preferably, the power conversion circuit includes: a first LDO power conversion circuit and a second LDO power conversion circuit; wherein, the first LDO power conversion circuit is connected to the output terminal of the positive power supply and the motor drive circuit, and is used to receive a first voltage from the positive power supply, reduce the first voltage to a third voltage, and transmit the third voltage to the motor drive circuit; the second LDO power conversion circuit is connected to the first LED power conversion circuit and the microcontroller unit, and is used to receive the third voltage from the first LED power conversion circuit, reduce the third voltage to a second voltage, and transmit the second voltage to the power supply terminal of the microcontroller unit.

[0017] Preferably, the microcontroller unit is connected to a peripheral interface module and an alarm module; wherein, the peripheral interface module is used to detect whether the variables of the external interface are normal and send normal or abnormal signals to the microcontroller unit; when the microcontroller unit receives an abnormal signal, it sends an alarm signal to the alarm module.

[0018] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0019] This invention provides a control circuit and method for waking up a power supply via differential signals on a CAN bus. The differential signals on the CAN bus connect the positive input and output terminals of the power supply. The output terminal of the positive power supply is then connected to a power conversion circuit to activate a microcontroller unit. Based on the microcontroller unit's control functions, the negative terminal of the power supply is connected to the input and output terminals of the positive terminal, creating a loop and waking up the power supply. This invention's control circuit does not require the microcontroller unit to process CAN bus data and I / O level transition signals in real time. Therefore, it does not need to keep the microcontroller unit and power conversion circuit constantly active. The power conversion circuit and microcontroller unit can be activated only after the positive output terminal of the power supply is connected, thus avoiding the problem of the LDO in the power conversion circuit being in standby mode and generating additional LDO power consumption. This achieves the technical effect of zero standby power consumption in the power wake-up circuit. Furthermore, the circuit control principle of this invention is simple, the control method is easy to implement, and signal transmission is achieved through the cooperation of light-emitting devices and optocouplers, resulting in strong anti-interference capabilities and ensuring effective signal transmission, thereby improving the reliability of the power supply wake-up circuit. Attached Figure Description

[0020] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other embodiments based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating a control method for waking up the power supply via differential signals on a CAN bus, according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the CAN bus interface circuit in a control circuit that wakes up the power supply via a differential signal on the CAN bus, according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a power conversion circuit in a control circuit that wakes up the power supply via a differential signal on a CAN bus, according to an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of a motor drive circuit in a control circuit that wakes up the power supply via a differential signal on a CAN bus, according to an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of a microcontroller circuit in a control circuit that wakes up the power supply via a differential signal on a CAN bus, according to an embodiment of the present invention. Detailed Implementation

[0026] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0027] In related technologies, power-on wake-up circuits use CAN interrupts or I / O port level transitions to wake up the microcontroller from sleep or deep sleep mode. Such circuits typically require rapid response to external events and timely data processing; therefore, the LDO power supply circuit needs to be kept on to ensure the microcontroller can quickly resume operation.

[0028] However, since the LDO power supply circuit is always on, it inevitably generates additional power consumption, resulting in high power consumption of the wake-up circuit, which consumes current in the order of mA.

[0029] Among them, LDO power supply circuit generally refers to power conversion circuit that uses LDO. Since the rated operating voltage of the microcontroller unit (usually a single-chip microcomputer) and the motor drive circuit is usually lower than the actual output voltage of the power supply, and a continuous and stable voltage is required, an LDO power supply circuit is usually set between the power supply and the microcontroller unit to convert the output voltage of the power supply and generate a stable output voltage.

[0030] like Figure 1 As shown, to avoid the problem of high power consumption generated by the LDO power supply circuit, one embodiment of the present invention provides a control method for waking up the power supply via differential signals on the CAN bus, including:

[0031] Step S101: When a differential signal is generated between the high-level signal terminal and the low-level signal terminal of the CAN bus, the first light-emitting device is turned on and emits light, transmitting the first voltage to the input terminal +B and the output terminal +B_OUT of the power supply through the first optocoupler.

[0032] In step S102, the output terminal of the power supply receives the first voltage, and after being stepped down by the power conversion circuit, the stepped-down second voltage is transmitted to the microcontroller unit.

[0033] In step S103, the microcontroller unit receives the second voltage and transmits the second voltage to the negative terminal of the power supply through the second light-emitting device, so that the second light-emitting device is turned on and emits light. The second voltage is transmitted to the input and output terminals of the positive terminal of the power supply through the second optocoupler, so that a circuit is formed between the positive and negative terminals of the power supply to turn on the power supply and wake up the power supply.

[0034] Step S104: When the microcontroller unit detects that it has not received the second voltage from the power conversion circuit within a set time period, the input and output terminals of the power supply positive terminal do not receive the first voltage and the second voltage, and the power supply is cut off.

[0035] It is worth noting that steps S101, S102, and S103 are power-on wake-up steps, while step S104 is power-off step. The order of steps S101, S102, and S103 is usually fixed, but the order of steps S101 and S104 is not. It's possible that step S104 is executed first to cut off the power, followed by step S101 to wake up the power, or vice versa.

[0036] In this embodiment of the invention, when the CAN bus transmits and receives data, a differential signal is generated between the high-level signal terminal CAN_H and the low-level signal terminal CAN_L. During normal operation of the CAN bus, the voltage of the high-level signal terminal CAN_H is higher than that of the low-level signal terminal CAN_L. The voltage difference between CAN_H and CAN_L represents the bus level state. For example, at a dominant level (logic 0), the voltage difference between CAN_H and CAN_L is approximately 2V; at a recessive level (logic 1), the voltage difference between CAN_H and CAN_L is close to 0V.

[0037] In this embodiment of the invention, the high-level signal terminal CAN_H and the low-level signal terminal CAN_L of the CAN bus are respectively connected to the two ends of the first light-emitting device. When the CAN bus receives data, a voltage difference is generated between the high-level signal terminal CAN_H and the low-level signal terminal CAN_L, which causes the two ends of the first light-emitting device to be forward biased, thereby turning on the first light-emitting device and making it emit light.

[0038] By setting the first light-emitting device, it can automatically turn on and emit light when there is a differential signal on the CAN bus, without the need to detect the data on the CAN bus using the detection circuit of the microcontroller unit. This eliminates the need for the microcontroller unit to respond quickly to external events, thus eliminating the need to keep the power conversion circuit and the microcontroller unit in the on state.

[0039] After the first light-emitting device emits light, the first optocoupler receives the optical signal from the first light-emitting device, converts the optical signal into an electrical signal, and transmits the electrical signal to the input and output terminals of the positive power supply. This enables the CAN signal to be powered on in a timely manner when it is transmitting data.

[0040] After being powered on at the output terminal of the positive power supply, the first voltage is processed by the power conversion circuit and then a stepped-down second voltage is transmitted to the microcontroller unit, which powers the microcontroller unit. The microcontroller unit then transmits the second voltage to the second light-emitting device. One end of the second light-emitting device is connected to the negative power supply. When the other end of the second light-emitting device receives the second voltage from the microcontroller unit, a forward bias is generated, which powers the second light-emitting device and makes it emit light.

[0041] After the second light-emitting device emits light, the second optocoupler receives the light signal from the second light-emitting device, converts the light signal into an electrical signal, and transmits the electrical signal to the input and output terminals of the positive terminal of the power supply. This allows the second voltage of the negative terminal of the power supply to be transmitted to the input and output terminals of the positive terminal of the power supply, enabling the power generation circuit to conduct the power supply and thus waking up the power supply.

[0042] The control method of this invention does not require the microcontroller unit to process CAN bus data and IO level transition signals in a timely manner. Therefore, it does not require the microcontroller unit and power conversion circuit to be kept on at all times. The power conversion circuit and microcontroller unit can be turned on after the output terminal of the power supply is connected. This avoids the problem of the LDO in the power conversion circuit being in standby mode and generating additional LDO power consumption, thus achieving the technical effect of zero standby power consumption of the power wake-up circuit.

[0043] The microcontroller unit provided in this embodiment can be understood as a single-chip microcomputer (MCU), or it can be a control device with control and signal processing functions such as a digital signal processor (DSP), a field-programmable gate array (FPGA), and a microprocessor (MPU).

[0044] In the power-on wake-up circuit, the microcontroller unit receives and activates a second voltage from the output terminal of the power supply after being stepped down. It then transmits the second voltage to the second light-emitting device, causing the second light-emitting device to turn on and emit light. Through signal transmission between the second light-emitting device and the second optocoupler, the voltage at the negative terminal of the power supply can flow back to the positive terminal, thereby waking up the power supply.

[0045] Meanwhile, the circuit control principle of this invention is simple, the control method is easy to implement, and the signal transmission is achieved through the cooperation of light-emitting devices and optocouplers. It has strong anti-interference ability and can ensure effective signal transmission, thereby improving the reliability of the wake-up power supply circuit.

[0046] like Figure 2 As shown, before step S101, the control method includes: connecting the two ends of the first light-emitting device to the high-level signal terminal CAN_H and the low-level signal terminal CAN_L of the CAN bus respectively, and connecting the two ends of the first optocoupler to the input terminal +B and the output terminal +B_OUT of the positive power supply respectively.

[0047] In a preferred but non-limiting embodiment of the present invention, the first light-emitting device is generally a first light-emitting diode (LED). The input terminal of the first LED is connected to the high-level signal terminal CAN_H of the CAN bus, and the output terminal of the second LED is connected to the low-level signal terminal CAN_L of the CAN bus.

[0048] The first light-emitting diode can be combined with the first optocoupler to form the first solid-state relay U1, or it can work independently.

[0049] like Figure 3 As shown, step S102 further includes:

[0050] The output terminal +B_OUT of the power supply receives the first voltage, and through the first LDO power conversion circuit and the second LDO power conversion circuit, the first voltage is reduced to the second voltage and transmitted to the microcontroller unit MCU.

[0051] Before step S103, the control method includes: connecting the low-power control terminal MCU_LP and the negative power supply terminal of the microcontroller unit MCU to the two ends of the second light-emitting device respectively; and connecting the two ends of the second optocoupler to the high-level signal terminal CAN_H and the low-level signal terminal CAN_L of the CAN bus respectively.

[0052] Furthermore, the second light-emitting device is generally a second light-emitting diode. The input terminal of the second light-emitting diode is connected to the high-level signal terminal CAN_H of the CAN bus, and the output terminal of the second light-emitting diode is connected to the low-level signal terminal CAN_L of the CAN bus.

[0053] The second light-emitting diode can be combined with the second optocoupler to form the second solid-state relay U2, or it can work independently.

[0054] Furthermore, a second resistor R2 is provided on the connection line between the low-power control terminal MCU_LP of the microcontroller unit MCU and the second light-emitting device. The second resistor R2 has a current limiting protection function and can ensure that the MCU_LP pin has a definite high level state, avoiding interference or uncertainty in the pin level, and ensuring the stability and reliability of the MCU receiving signals.

[0055] This invention uses a light-emitting device and an optocoupler to achieve signal transmission between the CAN bus and the positive terminal of the power supply, as well as between the microcontroller unit, the negative terminal of the power supply, and the positive terminal of the power supply, through electro-optical-electro-electrical signal conversion. This achieves electrical isolation and improves the anti-interference capability of signal transmission.

[0056] In step S104, when no data is received on the CAN bus, no voltage difference will be generated between the high-level signal terminal CAN_H and the low-level signal terminal CAN_L of the CAN bus. At this time, the first light-emitting device will not emit light, the input and output terminals of the positive power supply will not be energized, the power conversion circuit will not be energized, and the microcontroller unit will not receive the second voltage from the output terminal of the positive power supply and the voltage reduction processing.

[0057] When the microcontroller unit does not receive the second voltage within a set time period, the second light-emitting device is de-energized, the second optocoupler no longer receives optical signals, and it does not transmit the voltage from the negative terminal of the power supply to the input and output terminals of the positive terminal. At this time, the power supply is cut off, achieving power-down. Simultaneously, the power conversion circuit is also disconnected, the LDO is in a disconnected state, and no additional LDO power consumption is generated.

[0058] The preferred time period is 1 second, but it is not limited to that.

[0059] Another preferred embodiment of the present invention provides a control method for waking up a power supply via a differential signal on a CAN bus. Based on the previous embodiment, after the microcontroller unit receives the second voltage in step S103, the control method further includes:

[0060] In step S1031, the microcontroller unit (MCU) controls the transistor Q1 to engage. By engaging the transistor Q1, the output terminal of the positive power supply is connected to the negative power supply, and the coil is energized.

[0061] In step S1032, after the coil is energized, it generates an electromagnetic force to attract the first switch. The first switch connects the input terminal of the positive power supply to the negative power supply and transmits the third voltage to the motor drive circuit. The third voltage is between the first voltage and the second voltage.

[0062] In step S1033, the motor drive circuit starts after receiving the third voltage and receives the pulse width modulation signal from the microcontroller unit to control the operation of the motor.

[0063] Among them, such as Figure 4 As shown, the transistor in step S1031 is preferably, but not limited to, a metal-oxide-semiconductor field-effect transistor. Its source and drain are connected to the coil and the negative terminal of the power supply, respectively, and its gate is connected to the bus power supply control terminal DR_MOS of the microcontroller unit MCU. By receiving the level signal of DR_MOS, the switching of transistor Q1 is controlled.

[0064] Furthermore, a third resistor R3 is provided on the connection line between the control terminal of transistor Q1 and the bus power supply control terminal DR_MOS of the microcontroller unit. The third resistor has a current limiting protection function and can ensure that transistor Q1 is reliably cut off when there is no signal input and can quickly turn on when there is a signal input.

[0065] In a preferred but non-limiting embodiment of the present invention, the first switch is an armature with conductive properties. When the coil is energized, it generates an electromagnetic force that can attract the armature to close, thereby connecting the contacts of the first switch and connecting the coil to the negative terminal of the motor.

[0066] Furthermore, the first switch can be combined with the coil to form a power relay U7, or it can operate independently.

[0067] The input terminal of the motor drive circuit is connected to six PWM pulse width modulation signals from the microcontroller unit, namely PWM_UH, PWM_UL, PWM_VH, PWM_VL, PWM_WH, and PWM_WL. The output terminal of the motor drive circuit is connected to the U, V, and W phases of the motor M.

[0068] When the first switch is closed, the motor drive circuit is connected to the positive input terminal +B of the power supply, which powers the motor drive circuit and enables it to work. It receives pulse width modulation signals from the microcontroller unit and controls the rotation of the motor M by controlling the three phases of the motor.

[0069] This invention provides a motor drive step after the control circuit wakes up the power supply. The microcontroller unit (MCU) activates the transistor Q1, which connects the motor drive circuit to the +B input of the power supply positive terminal, thus turning on the motor drive circuit. This ensures that the motor drive circuit is completely disconnected when the power supply and the microcontroller unit are not working. By introducing a transistor, the microcontroller unit can control the level of the bus power supply control terminal DR_MOS to turn the motor drive circuit on and off.

[0070] Furthermore, in this embodiment of the invention, after the output terminal of the positive power supply receives the first voltage in step S102, the control method includes:

[0071] The first voltage is stepped down by the first LDO power conversion circuit to a third voltage level, and the third voltage is transmitted to the input terminal of the motor drive circuit and the second LDO power conversion circuit.

[0072] The third voltage is reduced to the second voltage by the second LDO power conversion circuit, and the second voltage is transmitted to the microcontroller unit.

[0073] Furthermore, the second voltage is adapted to the rated voltage of the motor drive circuit, preferably 12V, while the third voltage is adapted to the rated voltage of the microcontroller unit, preferably 3.3V. This invention, by using two LDO power conversion circuits, can meet the operating voltage requirements of both the motor drive circuit and the microcontroller unit.

[0074] like Figure 5 As shown, another embodiment of the present invention provides a control method for waking up a power supply via a differential signal on a CAN bus. Based on the previous embodiment, in step S103, the microcontroller unit receives a second voltage and transmits the stepped-down second voltage to the negative terminal of the power supply through a second light-emitting device, including:

[0075] The microcontroller unit receives the second voltage and uses the peripheral interface module to detect whether the variables of the external interface are normal.

[0076] When the variables of the external interface are abnormal, the microcontroller unit sends an alarm signal;

[0077] When the external interface variables are normal, the microcontroller unit transmits a stepped-down second voltage to the negative terminal of the power supply through the second light-emitting device and activates the transistor.

[0078] The peripheral devices connected to the peripheral interface module typically include switches and accelerator pedals. The variables detected by the peripheral interface module are generally the digital and analog quantities of the peripheral devices.

[0079] This invention detects variables on the external interface through a peripheral interface module, ensuring that the microcontroller unit operates normally when the variables on the external interface are normal, and issuing an alarm signal when abnormal, which can promptly remind maintenance personnel.

[0080] like Figures 2-5 As shown, another embodiment of the present invention provides a control circuit for waking up a power supply via a differential signal on a CAN bus, using the control method for waking up a power supply via a differential signal on a CAN bus as described in any of the foregoing embodiments. The control circuit includes a CAN bus interface circuit and a microcontroller circuit.

[0081] The CAN bus interface circuit includes a CAN bus. The high-level signal terminal CAN_H and the low-level signal terminal CAN_L of the CAN bus are connected through a first light-emitting device. The first light-emitting device is connected to the input terminal +B and the output terminal +B_OUT of the positive power supply through a first optocoupler.

[0082] The microcontroller circuit includes a microcontroller unit (MCU). The power supply terminal of the MCU is connected to the output terminal +B_OUT of the positive power supply through a power conversion circuit.

[0083] One output terminal of the microcontroller unit (MCU), MCU_LP, is connected to the negative terminal of the power supply via a second light-emitting device. The second light-emitting device is connected to the input terminal +B and the output terminal +B_OUT of the positive terminal of the power supply via a second optocoupler. This is used to form a circuit between the positive and negative terminals of the power supply to turn on the power supply and wake it up.

[0084] In a preferred but non-limiting embodiment of the present invention, the CAN bus interface circuit further includes: a first capacitor C1, a third light-emitting device D1, and a first resistor R1.

[0085] The first capacitor C1 is placed on the connection line between the high-level signal terminal CAN_H and the low-level signal terminal CAN_L to filter out interference signals.

[0086] The third light-emitting device D1 is located on the connection line between the high-level signal terminal CAN_H and the first capacitor C1. When a voltage difference is generated between the high-level signal terminal and the low-level signal terminal, it connects the high-level signal terminal and the low-level signal terminal to turn on the first light-emitting device. This prevents a loop from being formed between the two ends of the first capacitor C1 and the high-level signal terminal CAN_H and the low-level signal terminal CAN_L, prevents the voltage of the first capacitor C1 from interfering with the CAN bus, and turns on the first light-emitting device.

[0087] The first resistor R1 is placed on the connection line between the third light-emitting device and the first light-emitting device to limit current.

[0088] Furthermore, the control circuit also includes a motor drive circuit.

[0089] like Figure 4 As shown, the motor drive circuit is connected to the positive input terminal +B of the power supply via a first switch. The first switch is used to close when the coil is conducting. The coil is connected between the microcontroller unit and the transistor.

[0090] The control terminal of transistor Q1 is connected to the bus power supply control terminal DR_MOS of the microcontroller unit. It closes when the control terminal receives voltage, connecting the coil to the negative terminal of the power supply and thus turning on the coil. Preferably, but not limited to, the gate of a metal-oxide-semiconductor field-effect transistor (MOSFET) is the control terminal of transistor Q1.

[0091] Furthermore, a third resistor R3 is provided on the connection line between the control terminal of transistor Q1 and the bus power supply control terminal DR_MOS of the microcontroller unit. The third resistor has a current limiting protection function and can ensure that transistor Q1 is reliably cut off when there is no signal input and can quickly turn on when there is a signal input.

[0092] The input terminal of the motor drive circuit is connected to the microcontroller unit (MCU), and the output terminal of the motor drive circuit is connected to the three phases of the motor M. The motor drive circuit is used to receive pulse width modulation signals from the microcontroller circuit to control the operation of the motor.

[0093] like Figure 3 As shown, in a preferred but non-limiting embodiment of the present invention, the power conversion circuit includes: a first LDO power conversion circuit and a second LDO power conversion circuit.

[0094] The first LDO power conversion circuit is connected to the output terminal of the positive power supply and the motor drive circuit. It is used to receive the first voltage from the positive power supply, step down the first voltage to the third voltage, and transmit the third voltage to the motor drive circuit.

[0095] The second LDO power conversion circuit is connected to the first LED power conversion circuit and the microcontroller unit. It is used to receive the third voltage from the first LED power conversion circuit, reduce the third voltage to the second voltage, and transmit the second voltage to the power supply terminal of the microcontroller unit.

[0096] In a preferred but non-limiting embodiment of the present invention, the microcontroller unit is connected to the peripheral interface module and the alarm module.

[0097] The peripheral interface module is used to detect whether the variables of the external interface are normal and send normal or abnormal signals to the microcontroller unit; when the microcontroller unit receives an abnormal signal, it sends an alarm signal to the alarm module.

[0098] This invention provides a control circuit for waking up the power supply via differential signals on the CAN bus. It provides a specific control circuit for achieving zero standby power consumption via differential signals on the CAN bus, which can completely cut off the power supply when there is no data input on the CAN bus, avoiding the additional LDO power consumption caused by the power conversion circuit always being on.

[0099] It should be noted that the term "comprising" and its variations used in the embodiments of this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "a plurality" mentioned in the embodiments of this invention are illustrative and not restrictive, and those skilled in the art should understand that unless explicitly indicated otherwise in the context, they should be understood as "one or more".

[0100] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of this invention are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0101] The steps described in the method embodiments provided by the present invention can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0102] The term "embodiment" in this specification refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily imply the same embodiment, nor does it imply independence or alternativeity from other embodiments. The various embodiments in this specification are described in a related manner, with reference to each other for similar or identical parts. In particular, for apparatus, device, and system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, and relevant details are referred to in the description of the method embodiments.

[0103] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A control method for waking up a power supply via differential signals on a CAN bus, characterized in that, include: When a differential signal is generated between the high-level signal terminal and the low-level signal terminal of the CAN bus, the first light-emitting device is turned on and emits light, transmitting the first voltage to the input and output terminals of the power supply through the first optocoupler; The output terminal of the positive power supply receives the first voltage, and after being stepped down by the power conversion circuit, it transmits the stepped-down second voltage to the microcontroller unit. The microcontroller unit receives the second voltage and transmits the second voltage to the negative terminal of the power supply through the second light-emitting device, so that the second light-emitting device is turned on and emits light. The second voltage is transmitted to the input and output terminals of the positive terminal of the power supply through the second optocoupler, so that a circuit is formed between the positive and negative terminals of the power supply to turn on the power supply and wake up the power supply. When the microcontroller unit detects that it has not received the second voltage from the power conversion circuit within a set time period, the input and output terminals of the power supply positive terminal will not receive the first and second voltages, and the power supply will be cut off.

2. The control method for waking up the power supply via differential signals on the CAN bus according to claim 1, characterized in that, After the microcontroller unit receives the voltage, the control method includes: The microcontroller unit controls the transistor to engage. By engaging the transistor, the line between the positive output terminal of the power supply and the negative terminal of the power supply is connected, and the coil is energized. After the coil is energized, it generates an electromagnetic force that attracts the first switch. The first switch connects the input terminal of the positive power supply to the negative power supply and transmits a third voltage to the motor drive circuit. The magnitude of the third voltage is between the first voltage and the second voltage. The motor drive circuit receives the third voltage and starts, and receives the pulse width modulation signal from the microcontroller unit to control the operation of the motor.

3. The control method for waking up the power supply via differential signals on the CAN bus according to claim 2, characterized in that, The output terminal of the power supply receives the first voltage, and after being stepped down by the power conversion circuit, transmits the stepped-down second voltage to the microcontroller unit, including: The output terminal of the power supply receives the first voltage, and the first voltage is stepped down by the first LDO power conversion circuit and the second LDO power conversion circuit to obtain the stepped-down second voltage, which is then transmitted to the microcontroller unit.

4. The control method for waking up the power supply via differential signals on the CAN bus according to claim 3, characterized in that, After receiving the first voltage at the output terminal of the positive power supply, the control method includes: The first voltage is reduced to the third voltage by the first LDO power conversion circuit, and the third voltage is transmitted to the input terminal of the motor drive circuit and the second LDO power conversion circuit. The third voltage is reduced to the second voltage by the second LDO power conversion circuit, and the second voltage is transmitted to the microcontroller unit.

5. The control method for waking up the power supply via differential signals on the CAN bus according to claim 2, characterized in that, The microcontroller unit receives the second voltage and transmits the second voltage to the negative terminal of the power supply through the second light-emitting device, including: The microcontroller unit receives the second voltage and detects whether the variables of the external interface are normal through the peripheral interface module; When the variables of the external interface are abnormal, the microcontroller unit sends an alarm signal; When the variables of the external interface are normal, the microcontroller unit transmits the second voltage to the negative terminal of the power supply through the second light-emitting device and activates the transistor.

6. A control circuit for waking up a power supply via a differential signal on a CAN bus, using the control method for waking up a power supply via a differential signal on a CAN bus as described in any one of claims 1-5, characterized in that... The control circuit includes: A CAN bus interface circuit includes a CAN bus, wherein the high-level signal terminal and the low-level signal terminal of the CAN bus are connected through a first light-emitting device, and the first light-emitting device is connected to the input terminal and the output terminal of the positive power supply through a first optocoupler. The microcontroller circuit includes a microcontroller unit, wherein the power supply terminal of the microcontroller unit is connected to the output terminal of the positive power supply through a power conversion circuit; One output terminal of the microcontroller unit is connected to the negative terminal of the power supply via a second light-emitting device. The second light-emitting device is connected to the input and output terminals of the positive terminal of the power supply via a second optocoupler, which is used to form a circuit between the positive and negative terminals of the power supply to conduct the power supply and wake up the power supply.

7. The control circuit for waking up the power supply via differential signals on the CAN bus according to claim 6, characterized in that, The CAN bus interface circuit also includes: The first capacitor is disposed on the connection line between the high-level signal terminal and the low-level signal terminal, and is used to filter out interference signals. The third light-emitting device is disposed on the connection line between the high-level signal terminal and the first capacitor, and is used to connect the high-level signal terminal and the low-level signal terminal when a voltage difference is generated between the high-level signal terminal and the low-level signal terminal, so as to turn on the first light-emitting device. The first resistor is disposed on the connection line between the third light-emitting device and the first light-emitting device, and is used for current limiting.

8. The control circuit for waking up the power supply via differential signals on the CAN bus according to claim 6, characterized in that, The control circuit also includes: The motor drive circuit is connected to the positive input terminal of the power supply via a first switch, which is used to close when the coil is conducting; the coil is connected between the microcontroller unit and the transistor. The control terminal of the transistor is connected to the microcontroller unit and is used to close when the control terminal receives voltage, thereby connecting the coil to the negative terminal of the power supply and making the coil conduct. The input terminal of the motor drive circuit is connected to the microcontroller unit, and the output terminal of the motor drive circuit is connected to the motor. The motor drive circuit is used to receive pulse width modulation signals from the microcontroller circuit to control the operation of the motor.

9. The control circuit for waking up the power supply via differential signals on the CAN bus according to claim 8, characterized in that: The power conversion circuit includes: a first LDO power conversion circuit and a second LDO power conversion circuit; The first LDO power conversion circuit is connected to the output terminal of the positive power supply and the motor drive circuit. It is used to receive the first voltage from the positive power supply, reduce the first voltage to the third voltage, and transmit the third voltage to the motor drive circuit. The second LDO power conversion circuit is connected to the first LED power conversion circuit and the microcontroller unit. It is used to receive the third voltage from the first LED power conversion circuit, reduce the third voltage to the second voltage, and transmit the second voltage to the power supply terminal of the microcontroller unit.

10. The control circuit for waking up the power supply via differential signals on the CAN bus according to claim 6, characterized in that: The microcontroller unit is connected to the peripheral interface module and the alarm module; The peripheral interface module is used to detect whether the variables of the external interface are normal and send normal or abnormal signals to the microcontroller unit. When the microcontroller unit receives an abnormal signal, it sends an alarm signal to the alarm module.

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