Control circuit and method for awakening power supply through differential signal on CAN bus

Abstract

The invention relates to the technical field of circuit awakening circuits, and particularly provides a control circuit and method for awakening a power supply through a differential signal on a CAN bus, and the method comprises the 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 optical coupler transmits a first voltage to the input end and the output end of the positive electrode of the power supply; the output end of the positive electrode of the power supply receives a first voltage and transmits a second voltage after voltage reduction to the microcontroller unit; and the microcontroller unit receives the second voltage, transmits the second voltage to the negative electrode of the power supply through the second light-emitting device, and transmits voltage to the input end and the output end of the positive electrode of the power supply through the second optical coupler to conduct the power supply so as to wake up the power supply. According to the control circuit and method for waking up the power supply through the differential signal on the CAN bus, the problem that extra LDO power consumption is generated due to the fact that the LDO in the power conversion circuit is in the standby state can be avoided, and zero standby power consumption of the power supply waking-up circuit is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit wake-up circuits, and in particular to a control circuit and method for waking up a power supply via a differential signal on a CAN bus. Background Art

[0002] In the prior art, 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] First, place the MCU in sleep mode. While this mode reduces MCU power consumption, it still requires the MCU and LDO (low dropout regulator) power circuit to remain powered on. If the MCU's CAN bus signal is interrupted, the LDO power circuit is awakened by the MCU. This method offers faster response and allows for timely processing of bus data, but it still consumes more power than the MCU and LDO power circuit.

[0004] Second, configure the MCU in deep sleep mode. Deep sleep mode reduces MCU power consumption. However, exiting deep sleep mode requires a level change on an external IO port to wake up the power supply, which means the MCU and LDO power supply circuit still need to remain powered on, leading to higher power consumption in the LDO power supply circuit.

[0005] Therefore, with respect to the problem in the prior art that the LDO power supply circuit generates high power consumption and cannot be avoided, no effective solution has been proposed yet. Summary of the Invention

[0006] The present invention provides a control circuit and method for waking up a power supply through a differential signal on a CAN bus, which at least solves the problem in the related art that the LDO power supply circuit cannot generate high power consumption.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In the first aspect, the present invention provides a control method for waking up a power supply through a differential signal on a CAN bus, comprising: when a differential signal is generated between the high-level signal end and the low-level signal end of the CAN bus, a first light-emitting device is turned on and emits light, and a first voltage is transmitted to the input and output ends of the positive pole of the power supply through a first optical coupler; the output end of the positive pole of the power supply receives the first voltage, and after voltage reduction processing by a power conversion circuit, the stepped-down second voltage is transmitted to a microcontroller unit; the microcontroller unit receives the second voltage, and transmits the second voltage to the negative pole of the power supply through a second light-emitting device, so that the second light-emitting device is turned on and emits light, and the second voltage is transmitted to the input and output ends of the positive pole of the power supply through a second optical coupler, so that a loop is formed between the positive pole of the power supply and the negative pole of the power supply to turn on the power supply and wake up the power supply; when the microcontroller unit detects that the stepped-down second voltage from the power conversion circuit is not received within a set time period, the input and output ends of the positive pole of the power supply do not receive the first voltage and the second voltage, and the power supply is cut off.

[0009] Preferably, after the microcontroller unit receives the voltage, the control method includes: the microcontroller unit controls the transistor to be attracted, and through the transistor being attracted, the line between the output end of the positive pole of the power supply and the negative pole of the power supply is connected, and the coil is energized; after the coil is energized, an electromagnetic force is generated to attract the first switch, and the input end of the positive pole of the power supply is connected to the negative pole of the power supply through the first switch, and a third voltage is transmitted 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 the pulse width modulation signal sent by the microcontroller unit, and controls the operation of the motor.

[0010] Preferably, the output end of the positive pole 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 end of the positive pole of the power supply receives the first voltage, and steps down the first voltage by the first LDO power conversion circuit and the second LDO power conversion circuit to obtain the stepped-down second voltage, and transmits the second voltage to the microcontroller unit.

[0011] Preferably, after receiving the first voltage at the output end of the positive pole of the power supply, 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 end of the motor drive circuit and the second LDO power conversion circuit; reducing the third voltage to a second voltage through a 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 pole of the power supply through the second light-emitting device, including: the microcontroller unit receives the stepped-down 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 pole of the power supply through the second light-emitting device and closes the transistor.

[0013] In the second aspect, the present invention provides a control circuit for waking up a power supply through a differential signal on a CAN bus, and a control method for waking up a power supply through a differential signal on a CAN bus before use. The control circuit includes: a CAN bus interface circuit, including a CAN bus, the high-level signal end and the low-level signal end of the CAN bus are connected through a first light-emitting device, and the first light-emitting device is connected to the input and output ends of the positive pole of the power supply through a first optical coupler; a micro-control circuit, including a micro-controller unit, the power end of the micro-controller unit is connected to the output end of the positive pole of the power supply through a power conversion circuit; an output end of the micro-controller unit and the negative pole of the power supply are connected through a second light-emitting device, and the second light-emitting device is connected to the input and output ends of the positive pole of the power supply through a second optical coupler, and is used to form a loop between the positive pole of the power supply and the negative pole of the power supply to turn on the power supply and wake up the power supply.

[0014] Preferably, the CAN bus interface circuit also includes: a first capacitor, arranged on the connecting line between the high-level signal end and the low-level signal end, for filtering out interference signals; a third light-emitting device, arranged on the connecting line between the high-level signal end and the first capacitor, for connecting the high-level signal end and the low-level signal end when a voltage difference is generated between the high-level signal end and the low-level signal, so as to turn on the first light-emitting device; a first resistor, arranged on the connecting line between the third light-emitting device and the first light-emitting device, for current limiting.

[0015] Preferably, the control circuit also includes: a motor drive circuit, which is connected to the input end of the positive pole of the power supply through a first switch, and the first switch is used to close when the coil is turned on; the coil is connected between the microcontroller unit and the transistor; the control end of the transistor is connected to the microcontroller unit, and is used to close when the control end receives a voltage, connecting the coil to the negative pole of the power supply to turn on the coil; the input end of the motor drive circuit is connected to the microcontroller unit, and the output end of the motor drive circuit is connected to the motor, and the motor drive circuit is used to receive a pulse width modulation signal 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 end of the positive electrode of the power supply and the motor drive circuit, and is used to receive a first voltage from the positive electrode of the power supply, and 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, and reduce the third voltage to a second voltage, and transmit the second voltage to the power supply end 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 a normal signal or an abnormal signal to the microcontroller unit; when the microcontroller unit receives an abnormal signal, it sends an alarm signal to the alarm module.

[0018] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0019] The present invention provides a control circuit and method for waking up a power supply through a differential signal on a CAN bus. The differential signal of the CAN bus is used to connect the input and output ends of the positive electrode of the power supply, and then the power conversion circuit is connected to start the microcontroller unit through the output end of the positive electrode of the power supply. Then, based on the control function of the microcontroller unit, the negative electrode of the power supply is connected to the input and output ends of the positive electrode of the power supply to generate a loop, thereby waking up the power supply. The control circuit of the present invention does not need to process the CAN bus data and the IO level jump signal in a timely manner through the microcontroller unit, so there is no need to keep the microcontroller unit and the power conversion circuit turned on all the time. After the output end of the positive electrode of the power supply is connected, the power conversion circuit and the microcontroller unit can be turned on, thereby avoiding the problem of the LDO in the power conversion circuit being in standby state and generating additional LDO power consumption, and achieving the technical effect of zero standby power consumption of the power wake-up circuit. At the same time, the circuit control principle of the present invention is simple, the control method is easy to implement, and the signal transmission is achieved by cooperating with the light-emitting device and the optical coupler, with strong anti-interference ability, which can ensure the effective transmission of the signal, thereby improving the reliability of the wake-up power circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without inventive effort.

[0021] Figure 1 This is a flow chart of a control method for waking up a power supply through a differential signal on a CAN bus according to an embodiment of the present invention;

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

[0023] Figure 3 1 is a schematic diagram of a power conversion circuit in a control circuit for waking up a power supply through a differential signal on a CAN bus according to an embodiment of the present invention;

[0024] Figure 4 1 is a schematic diagram of a motor drive circuit in a control circuit for waking up a power supply through a differential signal on a CAN bus according to an embodiment of the present invention;

[0025] Figure 5 The present invention is a schematic diagram of a microcontroller circuit in a control circuit for waking up a power supply via a differential signal on a CAN bus according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following describes embodiments of the present invention in more detail with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying 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 described 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] Related art power 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 need to quickly respond to external events and process data in a timely manner. Therefore, they need to keep the LDO power supply circuit enabled to quickly resume operation.

[0028] However, the LDO power supply circuit is always kept on, which inevitably generates additional power consumption, resulting in higher power consumption of the wake-up circuit and consumption of MA level current.

[0029] Among them, the LDO power supply circuit generally refers to a 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 requires a continuous and stable voltage, an LDO power supply circuit is usually set between the power supply and the microcontroller unit to convert the power supply output voltage and generate a stable output voltage.

[0030] like Figure 1 As shown, in order to avoid the problem of high power consumption of the LDO power supply circuit, an embodiment of the present invention provides a control method for waking up the power supply through a differential signal on a 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 a first voltage to the input terminal +B and the output terminal +B_OUT of the positive electrode of the power supply through the first optical coupler;

[0032] Step S102: The output terminal of the positive electrode of the power supply receives a first voltage, and after the voltage is reduced by the power conversion circuit, transmits the reduced voltage to the microcontroller unit.

[0033] In step S103, the microcontroller unit receives the second voltage, transmits the second voltage to the negative electrode of the power supply through the second light-emitting device, causing the second light-emitting device to turn on and emit light, and transmits the second voltage to the input and output terminals of the positive electrode of the power supply through the second optical coupler, so that a loop is formed between the positive and negative electrodes of the power supply to turn on the power supply, thereby waking up the power supply.

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

[0035] It's worth noting that steps S101, S102, and S103 are the power-awakening steps, i.e., the power-on steps, while step S104 is the power-off step, i.e., the power-off step. Generally, the order of steps S101, S102, and S103 is fixed, but the order of steps S101 and S104 is not fixed. Step S104 may be executed first to shut down the power, followed by step S101 to wake up the power, or step S101 may be executed first to wake up the power, followed by step S104 to shut down the power.

[0036] When the CAN bus of the present invention 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. When the CAN bus is operating normally, the voltage at the high-level signal terminal CAN_H is higher than that at the low-level signal terminal CAN_L. The voltage difference between CAN_H and CAN_L indicates the bus level. 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 an embodiment of the present 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, so that the two ends of the first light-emitting device are forward biased, thereby turning on the first light-emitting device and causing it to emit light.

[0038] By setting up a first light-emitting device, it can automatically turn on and emit light when the CAN bus has a differential signal, without the need to detect the data of the CAN bus with the help of the detection circuit of the microcontroller unit, so that the microcontroller unit does not need to respond quickly to external events, and thus there is no need to keep the power conversion circuit and the microcontroller unit in the turned-on state.

[0039] After the first light-emitting device emits light, the first optocoupler receives the light signal from the first light-emitting device, converts the light signal into an electrical signal, and transmits the electrical signal to the input and output ends of the positive electrode of the power supply, so that when the CAN signal has data transmission, the input and output of the positive electrode of the power supply can be powered in time.

[0040] After the output end of the positive pole of the power supply is energized, the first voltage will be voltage-processed by the power conversion circuit, and the stepped-down second voltage will be transmitted to the microcontroller unit, so that the microcontroller unit is energized, and the second voltage is transmitted to the second light-emitting device through the microcontroller unit. One end of the second light-emitting device is connected to the negative pole of the power supply. When the other end of the second light-emitting device receives the second voltage from the microcontroller unit, a forward bias will be generated so that the second light-emitting device is energized and emits 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 ends of the positive pole of the power supply, so that the second voltage of the negative pole of the power supply can be transmitted to the input and output ends of the positive pole of the power supply, so that the power supply generation circuit turns on the power supply, thereby realizing the awakening of the power supply.

[0042] The control method of the embodiment of the present invention does not need to promptly process CAN bus data and IO level jump signals through the microcontroller unit, and thus does not need to always keep the microcontroller unit and the power conversion circuit turned on. The power conversion circuit and the microcontroller unit can be turned on after the output end of the positive pole of the power supply is connected, thereby avoiding the problem of the LDO in the power conversion circuit being in a standby state and generating additional LDO power consumption, and 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 a control device with control functions 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 wake-up circuit, the microcontroller unit receives a second voltage from the output end of the positive pole of the power supply that has been stepped down and started, transmits the second voltage to the second light-emitting device, so that the second light-emitting device is turned on and emits light. Through signal transmission between the second light-emitting device and the second optocoupler, the voltage at the negative pole of the power supply can flow back to the positive pole of the power supply, thereby realizing power wake-up.

[0045] At the same time, the circuit control principle of the present invention is simple, the control method is easy to implement, and signal transmission is achieved by cooperating with the light-emitting device and the optical coupler, which has strong anti-interference ability and can ensure the effective transmission of the signal, 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 optical coupler to the input terminal +B and the output terminal +B_OUT of the positive pole of the 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, the input end of the first light emitting diode is connected to the high level signal end CAN_H of the CAN bus, and the output end of the second light emitting diode is connected to the low level signal end CAN_L of the CAN bus.

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

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

[0050] The output terminal +B_OUT of the positive pole of the power supply receives a first voltage, reduces the first voltage to a second voltage through the first LDO power conversion circuit and the second LDO power conversion circuit, and transmits the second voltage to the microcontroller unit MCU.

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

[0053] The second light emitting diode can be combined with the second optical coupler to form a second solid-state relay U2, or 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 certain high-level state, avoid the pin level from being interfered with or in an uncertain state, and ensure the stability and reliability of the MCU receiving signal.

[0055] The present invention realizes signal transmission between the CAN bus and the positive electrode of the power supply, and signal transmission between the microcontroller unit, the negative electrode of the power supply and the positive electrode of the power supply through the cooperation of the light-emitting device and the optical coupler, and through electrical-optical-electrical signal conversion, thereby achieving electrical isolation and improving the anti-interference ability of signal transmission.

[0056] In step S104, when no data is received on the CAN bus, no voltage difference is 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 pole of the power supply will not be powered, and the power conversion circuit will not be powered, and the microcontroller unit will not receive the second voltage from the positive pole output terminal of the power supply and after the voltage reduction processing.

[0057] If the microcontroller unit does not receive the second voltage within a set period of time, the second light-emitting device will not be powered, the second optocoupler will no longer receive light signals, and will not transmit the voltage of the negative power supply to the input and output terminals of the positive power supply. At this time, the power supply is cut off, achieving power-off. At this time, the power conversion circuit is also cut off, and the LDO is in a cut-off state, so no additional LDO power consumption is generated.

[0058] The set time period is preferably but not limited to 1 second.

[0059] Another preferred embodiment of the present invention provides a control method for waking up a power supply through 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] Step S1031: The microcontroller unit MCU controls the transistor Q1 to be closed, thereby connecting the positive output terminal of the power supply to the negative output terminal of the power supply and energizing the coil.

[0061] Step S1032: After the coil is energized, an electromagnetic force is generated to close the first switch, thereby connecting the positive input terminal of the power supply to the negative input terminal of the power supply through the first switch, and transmitting a third voltage to the motor drive circuit; wherein the third voltage is between the first voltage and the second voltage;

[0062] In step S1033 , the motor driving circuit starts up after receiving the third voltage, receives the pulse width modulation signal from the microcontroller unit, and controls 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, whose source and drain are respectively connected to the coil and the negative electrode of the power supply, and the 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 switch of the transistor Q1 is controlled.

[0064] Furthermore, a third resistor R3 is provided on the connection line between the control end of the transistor Q1 and the bus power supply control end DR_MOS of the microcontroller unit. The third resistor has a current limiting protection function and can ensure that the transistor Q1 is reliably cut off when there is no signal input and can be quickly turned 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, an electromagnetic force is generated, which can attract the armature to close, so that the contacts of the first switch are connected, thereby connecting the coil to the negative pole of the motor.

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

[0067] The input end of the motor drive circuit is connected to the 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 end 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 input terminal +B of the positive pole of the power supply, so that the motor drive circuit is powered and works, receives the pulse width modulation signal from the microcontroller unit, and controls the rotation of the motor by controlling the three phases of the motor M.

[0069] An embodiment of the present invention provides a motor driving step for the control circuit after the power supply is awakened. The microcontroller unit MCU is started to close the transistor Q1, and then the motor drive circuit is connected to the +B input of the positive electrode of the power supply, and the motor drive circuit is turned on. When the power supply and the microcontroller unit are not working, the motor drive circuit is completely cut off. By introducing a transistor, the microcontroller unit can realize the opening and closing of the motor drive circuit by controlling the level of the bus power supply control terminal DR_MOS.

[0070] In addition, in an embodiment of the present invention, after the output terminal of the positive electrode of the 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 reduce the first voltage to a third voltage, and the third voltage is transmitted to the input end of the motor drive circuit and the second LDO power conversion circuit;

[0072] The third voltage is reduced to a 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 12 V, and the third voltage is adapted to the rated voltage of the microcontroller unit, preferably 3.3 V. The present invention can meet the operating voltage requirements of the motor drive circuit and the microcontroller unit by using two LDO power conversion circuits.

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

[0075] The microcontroller unit receives the second voltage and detects whether the variables of the external interface are normal through the peripheral interface module;

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

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

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

[0079] The present invention detects variables of the external interface through the peripheral interface module, can ensure that the microcontroller unit works when the variables of the peripheral interface are normal, and can send out an alarm signal when they are abnormal, so as to promptly remind maintenance personnel.

[0080] like Figure 2-Figure 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 described in any of the aforementioned embodiments. The control circuit includes a CAN bus interface circuit and a microcontroller circuit.

[0081] Among them, 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, and the first light-emitting device is connected to the input terminal +B and the output terminal +B_OUT of the positive pole of the power supply through a first optical coupler.

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

[0083] An output terminal MCU_LP of the microcontroller unit MCU is connected to the negative pole of the power supply through 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 pole of the power supply through a second optical coupler, so as to form a loop between the positive pole and the negative pole of the power supply to turn on the power supply and wake up the power supply.

[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 provided on the connection line between the high-level signal terminal CAN_H and the low-level signal terminal CAN_L, and is used for filtering out interference signals.

[0086] The third light-emitting device D1 is arranged on the connection line between the high-level signal terminal CAN_H and the first capacitor C1, 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, so as to turn on the first light-emitting device, avoid the generation of a loop 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, prevent the voltage of the first capacitor C1 from interfering with the CAN bus, and turn on the first light-emitting device.

[0087] The first resistor R1 is provided on the connection line between the third light emitting device and the first light emitting device, and is used for current limiting.

[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 input terminal +B of the positive electrode of the power supply through the first switch, and the first switch is used to close when the coil is turned on; 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 and is configured to close when the control terminal receives a voltage, connecting the coil to the negative terminal of the power supply, thereby turning on the coil. The control terminal of transistor Q1 is preferably, but not limited to, the gate of a metal-oxide-semiconductor field-effect transistor.

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

[0092] The input end of the motor drive circuit is connected to the microcontroller unit MCU, and the output end of the motor drive circuit is connected to the three phases of the motor M. The motor drive circuit is used to receive a pulse width modulation signal 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 end of the positive electrode of the power supply and the motor drive circuit, and is used to receive a first voltage from the positive electrode of the power supply, step down the first voltage to a 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, and 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 end 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] Among them, the peripheral interface module is used to detect whether the variables of the external interface are normal, and send a normal signal or an abnormal signal to the microcontroller unit; when the microcontroller unit receives an abnormal signal, it sends an alarm signal to the alarm module.

[0098] The present invention provides a control circuit for waking up a power supply through a differential signal on a CAN bus, and provides a specific control circuit for achieving zero standby power consumption through the differential signal of the CAN bus. When there is no data input on the CAN bus, the power supply can be completely cut off, thereby avoiding the additional LDO power consumption generated by the power conversion circuit being always on.

[0099] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "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 other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that unless the context clearly indicates otherwise, 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 the present invention are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and corresponding operation entrances shall be provided for users to choose to authorize or refuse.

[0101] The various steps described in the method implementation methods provided by the embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method implementation methods 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 specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments are referenced to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0103] The above-described embodiments merely represent several implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A control method for waking up a power supply via a differential signal 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 a first voltage to the input terminal and the output terminal of the positive electrode of the power supply through the first optical coupler; The output end of the positive electrode of the power supply receives the first voltage, and after the voltage is reduced by the power conversion circuit, transmits the reduced voltage to the microcontroller unit; The microcontroller unit receives the second voltage, transmits the second voltage to the negative electrode of the power supply through the 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 electrode of the power supply through the second optical coupler, so that a loop is formed between the positive electrode of the power supply and the negative electrode of the power supply to turn on the power supply, thereby waking up the power supply; When the microcontroller unit detects that it does not receive the second voltage from the power conversion circuit within a set time period, the input terminal and the output terminal of the positive pole of the power supply do not receive the first voltage and the second voltage, and the power is cut off.

2. The control method for waking up a power supply through a differential signal on a 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 close, and through the closing of the transistor, the line between the output terminal of the positive electrode of the power supply and the negative electrode of the power supply is connected, so that the coil is energized; When the coil is energized, an electromagnetic force is generated to close the first switch, thereby connecting the positive input terminal of the power supply to the negative input terminal of the power supply through the first switch, and transmitting a third voltage to the motor drive circuit; the third voltage is between the first voltage and the second voltage; The motor driving circuit receives the third voltage and starts, receives the pulse width modulation signal sent by the microcontroller unit, and controls the operation of the motor.

3. The control method for waking up a power supply through a differential signal on a CAN bus according to claim 2, characterized in that: The output end of the positive electrode of the power supply receives the first voltage, and after the voltage is reduced by the power conversion circuit, transmits the reduced voltage to the microcontroller unit, including: The output end of the positive pole of the power supply receives the first voltage, and steps down the first voltage through the first LDO power conversion circuit and the second LDO power conversion circuit to obtain a stepped-down second voltage, and transmits the second voltage to the microcontroller unit.

4. The control method for waking up a power supply through a differential signal on a CAN bus according to claim 3, characterized in that: After the output terminal of the positive electrode of the power supply receives the first voltage, 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 an input terminal of a motor drive circuit and a second LDO power conversion circuit; The third voltage is reduced to a second voltage by a second LDO power conversion circuit, and the second voltage is transmitted to the microcontroller unit.

5. The control method for waking up a power supply through a differential signal on a CAN bus according to claim 2, characterized in that: The microcontroller unit receives the second voltage and transmits the second voltage to the negative electrode 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 electrode of the power supply through the second light-emitting device and closes 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 according to any one of claims 1 to 5, characterized in that: The control circuit comprises: A CAN bus interface circuit includes a CAN bus, wherein a high-level signal terminal and a low-level signal terminal of the CAN bus are connected via a first light-emitting device, and the first light-emitting device is connected to an input terminal and an output terminal of a positive electrode of a power supply via a first optical coupler; 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 electrode of the power supply through the power conversion circuit; An output end of the microcontroller unit and the negative pole of the power supply are connected through a second light-emitting device, and the second light-emitting device is connected to the input end and output end of the positive pole of the power supply through a second optical coupler, so as to form a loop between the positive pole and the negative pole of the power supply to turn on the power supply and wake up the power supply.

7. The control circuit for waking up a power supply through a differential signal on a CAN bus according to claim 6, characterized in that: The CAN bus interface circuit also includes: A first capacitor is provided on the connection line between the high-level signal terminal and the low-level signal terminal, and is used to filter out interference signals; a third light-emitting device, provided on the connection line between the high-level signal terminal and the first capacitor, for connecting the high-level signal terminal and the low-level signal terminal to turn on the first light-emitting device when a voltage difference is generated between the high-level signal terminal and the low-level signal terminal; The first resistor is provided 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 a power supply through a differential signal on a CAN bus according to claim 6, characterized in that: The control circuit further includes: A motor drive circuit is connected to the positive input terminal of the power supply via a first switch, wherein the first switch is configured to be closed when the coil is turned on; the coil is connected between the microcontroller unit and the transistor; The control end of the transistor is connected to the microcontroller unit and is used to close when the control end receives a voltage, connecting the coil to the negative pole of the power supply, so that the coil is turned on; The input end of the motor driving circuit is connected to the microcontroller unit, and the output end of the motor driving circuit is connected to the motor. The motor driving circuit is used to receive a pulse width modulation signal from the microcontroller circuit to control the operation of the motor.

9. The control circuit for waking up a power supply via a differential signal on a 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 end of the positive electrode of the power supply and the motor drive circuit, and is used to receive a first voltage from the positive electrode of the 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 end of the microcontroller unit.

10. The control circuit for waking up a power supply via a differential signal on a 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 a normal signal or an abnormal signal to the microcontroller unit; When the microcontroller unit receives an abnormal signal, it sends an alarm signal to the alarm module.

Images