A low-power distribution method with wide current range

Abstract

The application provides a low-power power distribution method with a wide current range. The low-power power distribution method with a wide current range comprises a low-power power distribution general circuit, wherein the low-power power distribution general circuit comprises a voltage conversion circuit, a control circuit, a mode switching circuit and a VN9D5D20F chip U7; the voltage conversion circuit is used for converting a power supply voltage into a working voltage, so that normal communication power supply can be guaranteed; the control circuit is used for controlling the operation of the whole system; and the mode switching circuit is used for switching the working mode to avoid abnormal power-off of an ECU. The low-power power distribution method with a wide current range provided by the application can supply power to multiple ECUs in a normal working mode, can supply power to multiple ECUs in a low-power mode, and can be seamlessly switched when being converted from the low-power mode to the normal working mode, so that the abnormal power-off of the ECU can be avoided, and the problem of battery feeding can be solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of circuits, and particularly relates to a low-power distribution method with a wide current range. BACKGROUND

[0002] The current distribution box in an automobile is generally an intelligent distribution box, which adopts a large number of semiconductor devices and is mainly responsible for dividing the main power supply into multiple paths to supply power to other ECUs. When the vehicle is in a dormant state, the power supply of the vehicle is generally provided by a storage battery, and the ECU still needs the distribution box to provide a certain load current to maintain its normal operation. At this time, the distribution box needs to maintain normal output. Due to the limited battery capacity, in order to avoid rapid depletion of the battery capacity, the power consumption of the distribution box itself needs to be reduced as much as possible, so that the distribution box can maintain power supply to the outside in a low-power mode. When the ECU exits the low-power mode, the distribution box needs to be seamlessly switched to the normal working mode to avoid abnormal power-off of the ECU.

[0003] However, at present, when the vehicle is in a dormant state, the method for maintaining the output of the distribution box is to control the distribution box to continuously output by an MCU, and to turn off unnecessary loads, so as to reduce the overall power consumption of the distribution box. However, this method requires the MCU to continuously work, and thus a large amount of current is consumed, which is easy to cause battery feeding.

[0004] Therefore, it is necessary to provide a new low-power distribution method with a wide current range to solve the above technical problems. SUMMARY

[0005] The technical problem solved by the application is to provide a low-power distribution method with a wide current range, which can supply power to multiple ECUs in a normal working mode, can supply power to multiple ECUs in a low-power mode, and can seamlessly switch when converting from the low-power mode to the normal working mode, so as to avoid abnormal power-off of the ECU and solve the problem of battery feeding.

[0006] To solve the above technical problems, the low-power distribution method with a wide current range provided by the application comprises a low-power distribution total circuit, which comprises a voltage conversion circuit, a control circuit, a mode switching circuit and a VN9D5D20F chip U7.

[0007] The voltage conversion circuit is used to convert the power supply voltage into a working voltage, so as to ensure normal communication power supply.

[0008] The control circuit is used to control the operation of the entire system.

[0009] The mode switching circuit is used to switch the working mode to avoid abnormal power-off of the ECU.

[0010] The working mode of the VN9D5D20F chip U7 is as follows:

[0011] (1). When the system is in normal working mode, the MCU initializes and configures the VN9D5D20F through SPI communication, and controls the 4-channel external output to drive the corresponding ECU load (ECU1, ECU2, ECU3, ECU4);

[0012] (2). When the system is in low-power mode, the MCU configures the VN9D5D20F through SPI communication, so that the VN9D5D20F stops external output and is in standby mode to reduce chip power consumption.

[0013] As a further scheme of the application, the voltage conversion circuit is connected with a 12V power supply, and the voltage conversion circuit comprises U15, which is an SBC chip, the model of the SBC chip is UJA1076A, the SBC chip can convert the input 12V voltage into 5V voltage to supply power to the MCU, and the MCU initializes and configures the SBC chip through SPI communication, and the connection mode of the SBC chip is as follows:

[0014] (1). The U15 is connected with the 12V power supply, and the U15 and the 12V power supply are connected with power supply filtering capacitors C138, C139 and C140;

[0015] (2). The 6th pin of the U15 is connected with the 97th pin reset of the MCU, which can reset the chip;

[0016] (3). The 9th, 10th, 11th and 12th pins of the U15 are connected with the 28th, 47th, 48th and 54th pins of the MCU through resistors R267, R268, R269 and R270 respectively, which can realize the SPI communication function of the SBC chip and the MCU chip;

[0017] (4). The 16th pin of the U15 is grounded through resistor R278, which is used for configuring the working mode of the SBC itself.

[0018] As a further scheme of the application, the mode switching circuit comprises U6, which is a pre-drive chip, the model of the pre-drive chip is VNF1048 chip, the pre-drive chip can not only drive the external MOS device (MOS_0), but also detect the current flowing through the external MOS device (MOS_0), the VNF1048 internally integrates PMOS, and the working mode of the VNF1048 is as follows:

[0019] (1). When the VNF 1048 is in low power mode, the PMOS inside the VNF 1048 is turned on and outputs 12V voltage externally, at this time, the 4-way PMOS device (MOS_1, MOS_2, MOS_3, MOS_4) is also turned on, thereby realizing low power supply for the ECU load (ECU1, ECU2, ECU3, ECU4);

[0020] (2). When the ECU load (ECU1, ECU2, ECU3, ECU4) exits the low power mode, thereby the load current increases rapidly, the source-drain voltage of the internal PMOS will increase rapidly, the VNF 1048 can detect the voltage and compare it with the threshold voltage, if it exceeds the threshold voltage, the VNF 1048 will automatically turn off the internal PMOS output, and synchronously turn on the external MOS device (MOS_0), thereby avoiding the ECU from being powered off temporarily due to MOS switching when switching from low power mode to normal mode, and further avoiding ECU abnormal reset, this process does not require the participation of MCU, thereby avoiding the problem that the time required for the MCU to switch from low power mode to normal mode is not synchronized with the time required for the load ECU to switch from low power mode to normal mode.

[0021] As a further scheme of the application, the PMOS is composed of Q26, Q60, Q61, Q62 and Q78, the mode switching circuit further comprises diode D27, diode D28, diode D29, diode D30, diode D31, diode D32, diode D33, diode D34, diode D35, diode D36, diode D37, diode D38, diode D39, diode D41, capacitor C34, capacitor C35, capacitor C36, capacitor C37, capacitor C38, capacitor C39, capacitor C40, capacitor C41, capacitor C42, capacitor C43, capacitor C44, capacitor C45, resistor R92, resistor R93, resistor R94, resistor R95, resistor R102, resistor R103, resistor R104 and resistor R109, the 23th pin of U6 is connected with the 1th, 2th and 3th pins of Q26, the 24th pin of U6 is connected with the 4th pin of Q26 through resistor R87, thereby driving the conduction or cut-off of Q26, the diode D29 is connected with the 23th and 24th pins of U6, to protect the gate-source of Q26, the 12V power supply and the drain of Q26 are connected through resistor R84, the resistor R84 is connected with the 21th and 20th pins of U6, for sampling the load current flowing through Q26.

[0022] As a further scheme of the present application, the capacitor C34 and C36 are connected to the 25th pin of U6 for filtering and decoupling the power voltage, the capacitor C37 is connected to the 28th and 29th pin of U6, the capacitor C38 is connected to the 30th and 31st pin of U6, the capacitor C37 and C38 are flying capacitors of the charge pump function of U6 for voltage boosting, the capacitor C39 is connected to the 1st pin of U6 for decoupling the VSPI power supply of U6, the capacitor C40 is connected to the 12th pin of U6 for decoupling the V3V3 power supply of U6, the 1st pin of U6 is connected to the 6th pin of U6 through the resistor R89 for pulling up the voltage of the 6th pin, the 1st pin of U6 is connected to the 16th pin of U7 through the resistor R105 for supplying power to U7 chip, and the diode D38 is connected to the 16th pin of U7 for protecting the 16th pin of U7 from overvoltage.

[0023] As a further scheme of the present application, the 2nd, 3rd, 4th and 5th pins of U6 are connected to the 7th, 39th, 40th and 45th pins of MCU through the resistors R85, R88, R91 and R100 respectively, so as to realize the SPI communication between U6 and MCU, the diodes D28, D30, D35, D36 and D37 are used for protecting the corresponding SPI communication ports from being damaged by overvoltage, the 6th pin of U6 is connected to the 20th pin of MCU through the resistor R83, when U6 abnormally exits from the low-power mode, the 6th pin of U6 outputs a low level to wake up MCU, the D27 is connected to the 6th pin of U6 for protecting the pin from being damaged by overvoltage, the U7 chip is a power chip integrated with 4 high-side output and with SPI communication interface, the VCC pin of U7 is connected to a 12V power supply and a capacitor C41, the capacitor C41 is used for filtering and decoupling the power voltage, the 5th, 6th, 7th and 8th pins of U7 are connected to the 12V power voltage to avoid being suspended, the 12th, 13th and 14th pins of U7 are connected to the 83rd, 45th and 39th pins of MCU through the resistors R111, R112 and R113 respectively, and the 15th pin of U7 is connected to the 40th pin of MCU through the resistors R115 and R114, so as to realize the SPI communication between U7 and MCU.

[0024] As a further scheme of the present application, the diode D41 is used for protecting the SPI communication port from overvoltage or reverse polarity damage, the diode D39 and the resistor R117 are connected to the 17th pin of U7 to prevent damage when U7 is reversely connected, the resistor R102 and the capacitor C42 are connected to the 1st, 2nd, 3rd and 4th pins of the OUT0 output channel of U7 for protecting the output port, the resistor R109 and the capacitor C45 are connected to the 21st, 22nd, 23rd and 24th pins of the OUT1 output channel of U7 for protecting the output port, the resistor R104 and the capacitor C44 are connected to the 27th and 28th pins of the OUT2 output channel of U7 for protecting the output port, and the resistor R103 and the capacitor C43 are connected to the 29th and 30th pins of the OUT3 output channel of U7 for protecting the output port.

[0025] As a further scheme of the present application, the gates of the PMOS Q78, Q62, Q61 and Q60 are connected to the 4th pins of the resistors R96, R97, R98 and R99 respectively, and the sources are all connected to the 23rd pin of U6, so that when the 23rd pin of U6 outputs 12V voltage, Q78, Q62, Q61 and Q60 are turned on, the resistor R92 and the diode D31 are used for protecting the stable operation of Q78, the resistor R93 and the diode D32 are used for protecting the stable operation of Q62, the resistor R94 and the diode D33 are used for protecting the stable operation of Q61, and the resistor R95 and the diode D34 are used for protecting the stable operation of Q60.

[0026] As a further scheme of the present application, the control circuit comprises U18, which is a master control chip, and is used for controlling U15 UJA1076A chip, U6 VNF1048F chip and U7 VN9D5D20F chip, and controlling the operation of the whole system.

[0027] The control circuit further comprises capacitors C174, C168, C169, C175, C170, C171, C172, C176, C173, C177, C178, C179, C180, resistors R327 and R328, the capacitors C174, C168, C169, C175, C170, C171, C172, C176, C173 and C177 are decoupling capacitors of the power supply pins of the MCU, the resistor R327 and the capacitor C178 form a reset circuit for power-on reset of the MCU, and the resistor R328, the capacitor C179 and the capacitor C180 form a crystal oscillator circuit for providing a clock source for the MCU.

[0028] Compared with the related art, the low-power distribution method with a wide current range provided by the present application has the following beneficial effects:

[0029] 1、 The application can supply power for multiple ECUs in normal working mode, can supply power for multiple ECUs in low-power mode, and can seamlessly switch from low-power mode to normal working mode, can avoid abnormal power-off of ECU, and can solve the problem of battery feeding. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to facilitate the understanding of those skilled in the art, the application will be further described below in combination with the drawings.

[0031] Figure 1 The flowchart of the application is shown in the figure.

[0032] Figure 2 The connection diagram of the voltage conversion circuit in the application is shown in the figure.

[0033] Figure 3 The connection diagram of the control circuit in the application is shown in the figure.

[0034] Figure 4 The connection diagram of the mode switching circuit in the application is shown in the figure. DETAILED DESCRIPTION

[0035] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , wherein, Figure 1 The flowchart of the application is shown in the figure. Figure 2 The connection diagram of the voltage conversion circuit in the application is shown in the figure. Figure 3 The connection diagram of the control circuit in the application is shown in the figure. Figure 4 The connection diagram of the mode switching circuit in the application is shown in the figure. The low-power power distribution method with wide current range comprises a low-power power distribution total circuit, the low-power power distribution total circuit comprising a voltage conversion circuit, a control circuit, a mode switching circuit and a VN9D5D20F chip U7.

[0036] The voltage conversion circuit is used for converting the power supply voltage into working voltage, so as to guarantee normal communication power supply.

[0037] The control circuit is used for controlling the operation of the whole system.

[0038] The mode switching circuit is used for switching the working mode to avoid abnormal power-off of ECU.

[0039] The working mode of the VN9D5D20F chip U7 is as follows:

[0040] (1) When the system is in normal mode, the MCU initializes and configures the VN9D5D20F through SPI communication and controls the 4-channel output to drive the corresponding ECU load (ECU1, ECU2, ECU3, ECU4);

[0041] (2) When the system is in low-power mode, the MCU configures the VN9D5D20F through SPI communication to stop the output and enter standby mode, so as to reduce the power consumption of the chip.

[0042] As shown in Figure 2 , the voltage conversion circuit is connected with the 12V power supply, the voltage conversion circuit includes U15, the U15 is an SBC chip, the model of the SBC chip is UJA1076A, the SBC chip can convert the input 12V voltage into 5V voltage, thereby supplying power for the MCU, and the MCU initializes and configures the SBC chip through SPI communication, and the connection mode of the SBC chip is as follows:

[0043] (1) The U15 is connected with the 12V power supply, and the U15 and the 12V power supply are connected with power supply filtering capacitors C138, C139 and C140;

[0044] (2) The 6th pin of the U15 is connected with the 97th pin reset of the MCU, and the chip can be reset;

[0045] (3) The 9th, 10th, 11th and 12th pins of the U15 are connected with the 28th, 47th, 48th and 54th pins of the MCU through resistors R267, R268, R269 and R270 respectively, so as to realize the SPI communication function of the SBC chip and the MCU chip;

[0046] (4) The 16th pin of the U15 is grounded through the resistor R278, which is used for configuring the working mode of the SBC itself.

[0047] As shown in Figure 4 , the mode switching circuit includes U6, the U6 is a pre-driver chip, the model of the pre-driver chip is VNF1048 chip, the pre-driver chip can not only drive the external MOS device (MOS_0), but also detect the current flowing through the external MOS device (MOS_0), the VNF1048 internally integrates a PMOS, and the working mode of the VNF1048 is as follows:

[0048] (1). When the VNF 1048 is in low power mode, the PMOS inside the VNF 1048 is turned on and outputs 12V voltage externally, at this time, the 4-way PMOS device (MOS_1, MOS_2, MOS_3, MOS_4) is also turned on, thereby realizing low power supply for the ECU load (ECU1, ECU2, ECU3, ECU4);

[0049] (2). When the ECU load (ECU1, ECU2, ECU3, ECU4) exits the low power mode, thereby the load current increases rapidly, the voltage between the source and the drain of the internal PMOS will increase rapidly, the VNF 1048 can detect the voltage and compare it with the threshold voltage, if it exceeds the threshold voltage, the VNF 1048 will automatically turn off the internal PMOS output, and synchronously turn on the external MOS device (MOS_0), thereby avoiding the ECU from being powered off temporarily due to MOS switching when switching from low power mode to normal mode, and further avoiding ECU abnormal reset, this process does not require the participation of MCU, thereby avoiding the problem that the time required for the MCU to switch from low power mode to normal mode is not synchronized with the time required for the load ECU to switch from low power mode to normal mode.

[0050] As shown in Figure 4 , the PMOS is composed of Q26, Q60, Q61, Q62 and Q78, the mode switching circuit further comprises diode D27, diode D28, diode D29, diode D30, diode D31, diode D32, diode D33, diode D34, diode D35, diode D36, diode D37, diode D38, diode D39, diode D41, capacitor C34, capacitor C35, capacitor C36, capacitor C37, capacitor C38, capacitor C39, capacitor C40, capacitor C41, capacitor C42, capacitor C43, capacitor C44, capacitor C45, resistor R92, resistor R93, resistor R94, resistor R95, resistor R102, resistor R103, resistor R104 and resistor R109, the 23th pin of U6 is connected with the 1st, 2nd and 3rd pins of Q26, the 24th pin of U6 is connected with the 4th pin of Q26 through resistor R87, thereby driving the conduction or cut-off of Q26, the diode D29 is connected with the 23th and 24th pins of U6, to protect the gate-source of Q26, the 12V power supply and the drain of Q26 are connected through resistor R84, the resistor R84 is connected with the 21st and 20th pins of U6, for sampling the load current flowing through Q26.

[0051] As shown in Figure 4As shown, the capacitor C34 and C36 are connected to the 25 pin of U6 for filtering and decoupling the power voltage, the capacitor C37 is connected to the 28 and 29 pin of U6, the capacitor C38 is connected to the 30 and 31 pin of U6, the capacitor C37 and C38 are flying capacitors of the charge pump function of U6 for voltage boosting, the capacitor C39 is connected to the 1 pin of U6 for decoupling the VSPI power of U6, the capacitor C40 is connected to the 12 pin of U6 for decoupling the V3V3 power of U6, the 1 pin of U6 is connected to the 6 pin of U6 through the resistor R89 for pulling up the voltage of the 6 pin, the 1 pin of U6 is connected to the 16 pin of U7 through the resistor R105 for supplying power to U7 chip, the diode D38 is connected to the 16 pin of U7 for protecting the 16 pin of U7 from overvoltage.

[0052] As shown, Figure 4 the 2, 3, 4, 5 pin of U6 are connected to the 7, 39, 40, 45 pin of MCU through the resistor R85, R88, R91, R100 respectively, so as to realize the SPI communication between U6 and MCU, the diode D28, D30, D35, D36, D37 are used for protecting the corresponding SPI communication port from being damaged by overvoltage, the 6 pin of U6 is connected to the 20 pin of MCU through the resistor R83, when U6 abnormally exits from the low power consumption mode, the 6 pin of U6 will output low level to wake up MCU, the D27 is connected to the 6 pin of U6 for protecting the pin from being damaged by overvoltage, the U7 chip is a power chip integrated with 4 high-side output and with SPI communication interface, the VCC pin of U7 is connected to 12V power supply and the capacitor C41, the capacitor C41 is used for filtering and decoupling the power voltage, the 5, 6, 7, 8 pin of U7 are connected to 12V power voltage to avoid being suspended, the 12, 13, 14 pin of U7 are connected to the 83, 45, 39 pin of MCU through the resistor R111, R112, R113 respectively, the 15 pin of U7 is connected to the 40 pin of MCU through the resistor R115, R114, so as to realize the SPI communication between U7 and MCU.

[0053] As shown, Figure 4As shown, diode D41 is used to protect the SPI communication port from overvoltage or reverse polarity damage. Diode D39 and resistor R117 are connected to pin 17 of U7 to prevent damage when U7 is reversed. Resistor R102 and capacitor C42 are connected to pins 1, 2, 3, and 4 of the OUT0 output channel of U7 to protect the output port. Resistor R109 and capacitor C45 are connected to pins 21, 22, 23, and 24 of the OUT1 output channel of U7 to protect the output port. Resistor R104 and capacitor C44 are connected to pins 27 and 28 of the OUT2 output channel of U7 to protect the output port. Resistor R103 and capacitor C43 are connected to pins 29 and 30 of the OUT3 output channel of U7 to protect the output port.

[0054] like Figure 4 As shown, the gate pins 4 of PMOS transistors Q78, Q62, Q61, and Q60 are connected to GND via resistors R96, R97, R98, and R99, respectively. Their sources are all connected to pin 23 of the U6 chip. When pin 23 of U6 outputs 12V, Q78, Q62, Q61, and Q60 will conduct. Resistor R92 and diode D31 are used to protect Q78 for stable operation; resistor R93 and diode D32 are used to protect Q62 for stable operation; resistor R94 and diode D33 are used to protect Q61 for stable operation; and resistor R95 and diode D34 are used to protect Q60 for stable operation.

[0055] like Figure 3 As shown, the control circuit includes U18, which is the main control chip. U18 is used to control the U15UJA1076A chip, the U6 VNF1048F chip, and the U7 VN9D5D20F chip, and to control the operation of the entire system.

[0056] The control circuit also includes capacitors C174, C168, C169, C175, C170, C171, C172, C176, C173, C177, C178, C179, C180, and resistors R327 and R328. Capacitors C174, C168, C169, C175, C170, C171, C172, C176, C173, and C177 are decoupling capacitors for the MCU power supply pins. Resistor R327 and capacitor C178 form a reset circuit for MCU power-on reset. Resistor R328, capacitors C179, and C180 form a crystal oscillator circuit for providing a clock source to the MCU.

[0057] The low-power distribution circuit uses VNF1048 and VN9D5D20F to achieve multi-channel low-power output power supply.

[0058] The application can supply power for multiple ECUs in a normal working mode, can supply power for multiple ECUs in a low-power mode, and can seamlessly switch from the low-power mode to the normal working mode, so that the abnormal power-off of the ECU can be avoided, and the problem of battery feeding can be solved.

[0059] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the present application within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A low power distribution method for a wide current range, characterized by, The application relates to a low-power distribution general circuit, which comprises a voltage conversion circuit, a control circuit, a mode switching circuit and a VN9D5D20F chip U7. The voltage conversion circuit is used for converting a power supply voltage into a working voltage, so that normal communication power supply can be guaranteed. The control circuit is used for controlling the operation of the whole system. The mode switching circuit is used for switching the working mode to avoid abnormal power-off of an ECU. The working mode of the VN9D5D20F chip U7 is as follows: (1) When the system is in a normal working mode, an MCU initializes and configures the VN9D5D20F through SPI communication, controls four-channel external output, and drives corresponding ECU loads (ECU1, ECU2, ECU3 and ECU4); (2) When the system is in a low-power mode, the MCU configures the VN9D5D20F through SPI communication, so that the VN9D5D20F stops external output and is in a standby mode, so as to reduce the chip power consumption. The voltage conversion circuit is connected with a 12V power supply, the voltage conversion circuit comprises an U15, the U15 is an SBC chip, the model of the SBC chip is UJA1076A, the SBC chip can convert the input 12V voltage into a 5V voltage, thereby supplying power for the MCU, and the MCU initializes and configures the SBC chip through SPI communication, and the connection mode of the SBC chip is as follows: (1) The U15 is connected with the 12V power supply, and input power supply filter capacitors C138, C139 and C140 are arranged between the U15 and the 12V power supply; (2) The 6th pin of the U15 is connected with the 97th pin reset of the MCU, so that the chip can be reset; (3) The 9th, 10th, 11th and 12th pins of the U15 are connected with the 28th, 47th, 48th and 54th pins of the MCU through resistors R267, R268, R269 and R270 respectively, so that the SPI communication function of the SBC chip and the MCU chip can be realized; (4) The 16th pin of the U15 is grounded through a resistor R278 and is used for configuring the working mode of the SBC itself; The mode switching circuit comprises an U6, the U6 is a pre-driver chip, the model of the pre-driver chip is a VNF1048 chip, the pre-driver chip can not only drive an external MOS device (MOS_0), but also detect the current flowing through the external MOS device (MOS_0), the VNF1048 internally integrates a PMOS, and the working mode of the VNF1048 is as follows: (1) When the VNF1048 is in a low-power mode, the PMOS in the VNF1048 is turned on and outputs a 12V voltage, at the moment, four PMOS devices (MOS_1, MOS_2, MOS_3 and MOS_4) are also turned on, so that low-power power supply for the ECU loads (ECU1, ECU2, ECU3 and ECU4) is realized. ​ (2). When the ECU load (ECU1, ECU2, ECU3, ECU4) exits the low-power mode, thereby the load current increases rapidly, the voltage between the source and the drain of the internal PMOS increases rapidly, VNF1048 can detect the voltage and compare it with the threshold voltage, if the threshold voltage is exceeded, VNF1048 will automatically turn off the internal PMOS output and synchronously turn on the external MOS device (MOS_0), thereby avoiding the ECU from being powered off temporarily due to MOS switching when switching from low-power mode to normal mode, and further avoiding ECU abnormal reset, this process does not require the participation of MCU, thereby avoiding the problem that the time required for the MCU to switch from low-power mode to normal mode is not synchronized with the time required for the load ECU to switch from low-power mode to normal mode.

2. The low power distribution method for wide current range as claimed in claim 1 wherein: The PMOS is composed of Q26, Q60, Q61, Q62 and Q78, and the mode switching circuit further comprises diode D27, diode D28, diode D29, diode D30, diode D31, diode D32, diode D33, diode D34, diode D35, diode D36, diode D37, diode D38, diode D39, diode D41, capacitor C34, capacitor C35, capacitor C36, capacitor C37, capacitor C38, capacitor C39, capacitor C40, capacitor C41, capacitor C42, capacitor C43, capacitor C44, capacitor C45, resistor R92, resistor R93, resistor R94, resistor R95, resistor R102, resistor R103, resistor R104 and resistor R109, the 23th pin of U6 is connected with the 1st, 2nd and 3rd pins of Q26, the 24th pin of U6 is connected with the 4th pin of Q26 through resistor R87, thereby driving the conduction or cut-off of Q26, the diode D29 is connected with the 23th and 24th pins of U6, for protecting the gate-source of Q26, the 12V power supply is connected with the drain of Q26 through resistor R84, and the resistor R84 is connected with the 21st and 20th pins of U6, for sampling the load current flowing through Q26.

3. The low power distribution method for wide current range as claimed in claim 2 wherein: The capacitor C34 and C36 are connected with the 25th pin of U6, for filtering and decoupling the power voltage, the capacitor C34 and C36 are connected with the 25th pin of U6, for filtering and decoupling the power voltage, the capacitor C37 is connected with the 28th and 29th pins of U6, the capacitor C38 is connected with the 30th and 31st pins of U6, the capacitor C37 and C38 are flying capacitors of the charge pump function of U6, for voltage boosting, the capacitor C39 is connected with the 1st pin of U6, for decoupling the VSPI power supply of U6, the capacitor C40 is connected with the 12th pin of U6, for decoupling the V3V3 power supply of U6, the 1st pin of U6 is connected with the 6th pin of U6 through resistor R89, for up pulling the voltage of the 6th pin, the 1st pin of U6 is connected with the 16th pin of U7 through resistor R105, thereby supplying power for U7 chip, and the diode D38 is connected with the 16th pin of U7, for protecting the 16th pin of U7 from overvoltage.

4. The low power distribution method for wide current range as claimed in claim 3 wherein: The 2, 3, 4, 5 pins of the U6 are connected with the 7, 39, 40, 45 pins of the MCU through the resistors R85, R88, R91, R100 respectively, so as to realize the SPI communication between the U6 and the MCU, the diodes D28, D30, D35, D36 and D37 are used for protecting the corresponding SPI communication port from being damaged by overvoltage, the 6 pin of the U6 is connected with the 20 pin of the MCU through the resistor R83, when the U6 abnormally exits from the low-power mode, the 6 pin of the U6 outputs low level to wake up the MCU, the D27 is connected with the 6 pin of the U6, and is used for protecting the pin from being damaged by overvoltage, the U7 chip is a power chip integrated with four high-side output and with an SPI communication interface, the VCC pin of the U7 is connected with the 12V power supply and the capacitor C41, the capacitor C41 is used for power voltage filtering and decoupling, the 5, 6, 7, 8 pins of the U7 are connected with the 12V power voltage, so as to avoid being suspended, the 12, 13, 14 pins of the U7 are connected with the 83, 45, 39 pins of the MCU through the resistors R111, R112, R113 respectively, the 15 pin of the U7 is connected with the 40 pin of the MCU through the resistors R115, R114, so as to realize the SPI communication between the U7 and the MCU.

5. The low power distribution method for wide current range as claimed in claim 4 wherein: The diode D41 is used for protecting the SPI communication port from being damaged by overvoltage or reverse polarity, the diode D39 and the resistor R117 are connected with the 17 pin of the U7, so as to prevent the U7 from being damaged when being reversely connected, the resistor R102 and the capacitor C42 are connected with the 1, 2, 3, 4 pins of the OUT0 output channel of the U7, so as to protect the output port, the resistor R109 and the capacitor C45 are connected with the 21, 22, 23, 24 pins of the OUT1 output channel of the U7, so as to protect the output port, the resistor R104 and the capacitor C44 are connected with the 27, 28 pins of the OUT2 output channel of the U7, so as to protect the output port, and the resistor R103 and the capacitor C43 are connected with the 29, 30 pins of the OUT3 output channel of the U7, so as to protect the output port.

6. The low power distribution method for wide current range as claimed in claim 5 wherein: The gates 4 pins of the Q78, Q62, Q61 and Q60 of the PMOS are connected with the GND through the resistors R96, R97, R98 and R99 respectively, and the sources are all connected with the 23 pin of the U6 chip, when the 23 pin of the U6 outputs 12V voltage, the Q78, Q62, Q61 and Q60 will be turned on, the resistor R92 and the diode D31 are used for protecting the stable work of the Q78, the resistor R93 and the diode D32 are used for protecting the stable work of the Q62, the resistor R94 and the diode D33 are used for protecting the stable work of the Q61, and the resistor R95 and the diode D34 are used for protecting the stable work of the Q60.

7. The low power distribution method for wide current range as claimed in claim 6 wherein: The control circuit comprises the U18, the U18 is a main control chip, and the U18 is used for controlling the U15 UJA1076A chip, the U6 VNF1048F chip and the U7 VN9D5D20F chip, and controlling the operation of the whole system.

8. The low power distribution method for wide current range as claimed in claim 1 wherein: The control circuit further comprises capacitors C174, C168, C169, C175, C170, C171, C172, C176, C173, C177, C178, C179, C180, resistors R327 and R328, wherein the capacitors C174, C168, C169, C175, C170, C171, C172, C176, C173 and C177 are decoupling capacitors of MCU power supply pins, the resistor R327 and the capacitor C178 form a reset circuit for power-on reset of the MCU, and the resistor R328, the capacitor C179 and the capacitor C180 form a crystal oscillator circuit for providing a clock source for the MCU.

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